ON CALL NEURO

ON CALL NEURO aims to provide residents with a quick “guide” to handling neurological cases and consults while on service or on call.This guide is not a replacement for understanding concepts in neurology in depth. However, it does provide a quick summary of pertinent clinical information and a reference for management algorithms and treatment options.This website's intended audience is for medical providers for educational purposes only. It is not meant to be used as medical advice for the general public. Please see the disclaimer for further information.If you have any feedback for the website, please fill out the survey here.

Approach to...

COMING SOON

Approach to... is a new section that will provide approaches to various undifferentiated cases (e.g. weakness, dizziness, and diplopia) Check back soon for when this section launches.

Headache

Important to rule out secondary headache causes from primary headache disorders using SNOOP4

Clinical FeaturesDifferential Diagnosis
SSystemic symptoms (e.g. weight loss, fevers)Malignancy, infections, GCA
NNeurological symptoms (e.g. focal neurological symptoms, confusion vision loss)Structural lesions, strokes, encephalitis
OOlder age (Over 50)Mass lesions, GCA
OOnset ("Thunderclap" like, maximal intensity in less than a minute)Vascular causes (e.g. SAH, RCVS, hemorrhagic stroke)
PPapilledemaRaised ICP (IIH)
PPregnancyPre-eclampsia, CVST, RCVS
PPositional (e.g. worse with Valsalva or worse from supine to sitting)SIH, CVST, mass lesions
PPattern change (change in headache pattern or quality)Assess other secondary causes

Migraines & Tension Headaches

By Dr. Andrea Kuczynski and Dr. Caz Zhu
Reviewed by Dr. Will Kingston

Migraines

Pathophysiology and Epidemiology

  • Activation of trigeminal vascular system and cortical spreading depression

  • Affects people in their peak productive years. Second most disabling condition, second only to low back pain

  • More common in females, strong family history present

Clinical Features

  • 5 or more attacks

  • Lasting 4hrs to 3 days

  • With 2 of the following: unilateral, pulsating/throbbing quality, moderate to severe intensity, worse with activity

  • With 1 of: photo/phonophobia or nausea/vomiting

  • Aura lasting 5 to 60min before headache onset, accompanied or followed by headache within 60min. Symptoms of aura are fully reversible and can present as sensory (e.g. numbness/parasthesias), visual, speech and/or language, motor, or brainstem (rare) features

⊙ CLINICAL PEARL
Three best clinical clues to diagnosis migraines: PIN the diagnosis - Photophobia, impairing, and nausea

Investigations

Neuroimaging is needed if red flags are present

  • Unusual, prolonged, or persistent aura

  • Increasing frequency, severity, or change in migraine clinical features unless change in pattern (i.e. medication overuse headache)

  • First or worst migraine

  • Migraine with brainstem aura

  • Confusional migraine

  • Hemiplegic migraine

  • Late-life migrainous accompaniments - acephalgic migraine

  • Migraine aura without headache

  • Side-locked migraine

  • Post-traumatic migraine

Treatment

  • Abortive therapy: NSAIDs (e.g. Ibuprofen, Naproxen 250-500mg p.o. with PPI, Cambia 1 sachet p.o.), Tylenol, triptans, Mg can be taken with aura to try and reduce its duration and severity, Ubrogepant (CGRP antagonist) - 50-100 mg daily is a new approved medication for an abortive agent (side effects: nausea, drowsiness)

  • Acute therapy in the ED: normal saline 2-3L IV bolus (ensure no CHF), metoclopramide 10mg IV (check QTc interval), Mg 1g IV, Ketorolac 15-30mg IV, DHE 0.5mg IV with metoclopramide and if tolerated can receive 1mg as next dose (contraindicated if triptan use within 24 hours; check QTc interval)

  • Preventative therapy: started when >4 headache days/month and/or no response to acute therapy, and the choice depends on comorbidities and symptoms

  • CGRP antagonists can be considered in outpatient follow-up as a preventative therapy

  • Lidocaine nerve block (+/- methylprednisone) acts as both acute and preventative therapies

  • Nutraceuticals: Mg 300-600mg qhs, vitamin D 1000-2000IU, riboflavin 400mg, coenzyme Q10 300mg daily

  • Non-pharmacological therapy: reduce lifestyle triggers, relaxation/meditation, massage, exercise, reduce caffeine intake, increase hydration, protein-rich diet (especially breakfast), Cephaly device, mindfulness

  • Medication overuse headache (>15 days/month of NSAID/Tylenol use and/or >10 days/month of triptan use) therapy: discontinue NSAIDs/Tylenol, attempt to break the headache cycle with a longer acting NSAID (e.g. Anaprox 550mg BID or Naproxen 250-500mg BID) x1-2 weeks

Note: Lidocaine nerve block (+/- methylprednisone) and Botox injections act as both acute and preventative therapies

TRIPTANS

TriptanMedication DoseUsesSide-effects
Almotriptan12.5mg p.oGood for patients with significant side effects from previous triptansLowest side-effect profile; Mild stiffness
Sumatriptan25-50mg p.o, 5-10mg intra-nasal, 4-6mg SCNasal options are best for patients with rapid onset/wake-up headaches; Only triptan with an injectable optionBad taste, burning sensation (intra-nasal and SC), tingling, injection site reaction, nausea/vomiting
Rizatriptan5-10mg p.o./MLTMLT option is useful for patients with strong components of nauseaLowest risk of medication overuse headaches;; Dizziness, somnolence, dry mouth, asthenia
Zolmitriptan2.5-10mg p.o./MLT, 5mg intra-nasalMLT option is useful for patients with strong components of nausea; Nasal options are best for patients with rapid onset/wake-up headachesNausea/vomiting, paraesthesias, somnolence, nasal discomfort
Frovatriptan2.5mg p.o.Menstrually-related migraine (used on day -2 or -3 of menses)GI upset, nausea/vomiting
Naratriptan2.5mg p.o.Menstrually-related migraine (used on day -2 or -3 of menses)GI upset, nausea/vomiting
Eletriptan40mg p.o.-Lowest risk of Medication overuse headaches; Dizziness, somnolence, dry mouth, asthenia

Contraindications of triptans:

  • MAO inhibitor within 2 weeks

  • CAD, vasculopathy, PVD

  • Cardiac arrhythmia

  • Recent stroke

  • Uncontrolled HTN

  • Renal disease

  • Anaphylaxis to triptans previously

  • Hemiplegic migraine

  • Migraine with brainstem aura

  • Intake of ergots or triptans within 24 hours

PREVENTIVE MEDICATIONS FOR MIGRAINES

MedicationDoseConsiderationsSide-effects
Candesartan2mg p.o. daily with up-titration by 2mg weekly (maximum 16mg/day)Comorbid HTN; Contraindicated in pregnancyHypotension, dizziness
Propranolol40-80mg p.o daily and uptitrate up to 240mg/dayAvoid in patients with asthma or heart block; Comorbid anxietyHypotension, dizziness
Gabapentin300mg p.o. daily/TID with up-titration by 300mg weekly targeting 1200-1500mg/day divided TID (max 1800mg/day)Avoid in renal failure; Sleep disturbances, mood, neuropathyDrowsiness, dizziness
Topiramate15-25mg p.o. daily with up-titration by 15-25mg q1-2weeks targeting 100mg qhs or 50mg BID (max 200mg/day)Comorbid mood disturbances; Contraindicated in pregnancyNephrolithiasis, acute closure glaucoma, dizziness, tremor, cognitive slowing, weight loss
Nortriptyline10mg p.o. Qhs with up-titration of 10mg q1-2weeks targeting 20-40mg daily (maximum 150 mg/day)Sleep disturbances, moodWeight gain, drowsiness, increased seizure threshold
Amitriptyline10mg p.o. Qhs with up-titration of 10mg q1-2weeks targeting 20-40mg daily (maximum 150 mg/day)Comorbid anxiety/depressionWeight gain, drowsiness, increased seizure threshold
Atojepant5mg/kg p.o. daily-Constipation, nausea
  • CGRP antagonists (erenumab, fremanezumab, galcanezumab) are options for treating migraines as well - although currently, indicated for patients who have headaches ≥ 8 headache days/months and have failed or are intolerant to ≥ 2 preventative agents. Side effects of CGRP antagonists include constipation, injection site reaction, and hypertension (erenumab).

Patient Education

  • Encourage patients to keep track of the frequency and intensity of their migraines (Migraine Tracker app)

  • Patients should be taking abortive therapies EARLY (as soon as they feel like they are getting their migraine) to prevent central sensitization

  • If their migraines continue to persist - they can take another NSAID or triptan in another 2 hours

  • Not all triptans are effective for everyone; just because one triptan is not effective does not mean another will not be for the patient

  • If a patient still experiences high intensity of migraine after taking a triptan, a second dose can be taken 2 hours after the first dose (maximum 2 doses in 24 hours)

  • Preventative therapy can take 2-3 months to see benefits and often can be up-titrated as tolerated

  • Treatment of comorbid conditions (e.g. depression) is important

Tension Type Headaches

Important to note that many people diagnosed with tension type headaches are mis-diagnosed migraines

Clinical Features

  • Can last hours to days

  • With 2 of the following: bilateral, pressing/tightening (non-pulsatile), mild or moderate intensity, not worse with activity

  • No more than 1 of photophobia, phonophobia, or mild nausea

  • Considered a chronic tension type headache if it occurs < 15 days a month or > 3 months

  • If a patient presents to the physician/hospital with TTH, re-think the diagnosis

Investigations & Treatment

See above section for migraines

Idiopathic intracranial hypertension

By Dr. Kia Gilani
Reviewed by Dr. Jonathan Micieli and Dr. Will Kingston

Pathophysiology and Epidemiology

  • Raised ICP without the presence of a space-occupying lesion

  • Thought to be related to reduced CSF absorption

  • More common in females of child-bearing age

Clinical Features

  • Headache

  • Transient visual obscurations - unilateral or bilateral greying of vision or dark spots that are worse when bending over or Valsalva

  • Blurry vision

  • Horizontal diplopia - CN6 palsy

  • Reduced visual acuity in some (less common)

  • Pulsatile tinnitus

  • Back and/or neck pain

  • Radicular pain

  • Cognitive disturbance

ICHD criteria for Headache attributed to IIH

  • New headache or significant worsening of pre-existing headache

  • Both of: IIH diagnosis, and CSF opening pressure >25 cmH2O

  • Either of: headache developed or significantly worsened in relation to IIH or led to its diagnosis; headache accompanied by either or both of pulsatile tinnitus, papilledema

  • Not better accounted for by other ICHD-3 criteria

Click image to enlarge

Must rule out secondary causes of increased ICP

  • CVST

  • Medications: antibiotics (tetracyclines, fluoroquinolones), vitamin A derivatives, lithium, thyroxine in children, corticosteroids

  • SVC obstruction (very rare)

Associations with IIH:

  • Endocrine: PCOS, Cushing’s, Addison’s, hypoparathyroidism, hypothyroidism

  • Polycythemia, anemia

  • Uremia and/or renal failure

  • OSA

  • SLE

  • Down’s syndrome, Turner’s syndrome

Investigations

  • CBC

  • MRI/MRV brain or acutely CT/CTV brain if MRI unavailable

  • Consult/refer to Ophthalmology

  • Lumbar puncture with opening pressure in supine position

  • Blood pressure

Common neuroimaging findings in IIH

  • Optic nerve tortuosity

  • Enlarged optic nerve sheath

  • Flattened posterior globe

  • Intraocular protrusion of optic nerve head

  • Empty sella

  • Bilateral transverse sinus stenosis

  • Slit-like ventricles

  • Acquired tonsillar ectopia

Treatment

  • Weight loss; consider referral to bariatric clinic

  • Low sodium diet

  • Acetazolamide 500mg p.o. BID (up to 4000mg/day) - titrated by Ophthalmology based on degree of papilledema and visual function

  • Topiramate

  • Discontinue offending agent if present; treat underlying cause if present

  • Management of comorbidities (i.e. OSA)

  • Surgery in fulminant cases: VP shunting, optic nerve sheath fenestration, sinus stenting

Patient Education

  • Treatment is aimed at visual sparing and persistence of headache should not be considered treatment failure

  • Patients should be counseled on the importance of weight loss, as it is the most common risk factor and the only disease modifying treatment available

  • The importance of adequate follow up should be emphasized, as untreated IIH can cause permanent vision loss

  • Up to 40% of patients may have recurrence

Spontaneous Intracranial Hypotension

By Dr. Caz Zhu
Reviewed by Dr. Will Kingston

Pathophysiology and Epidemiology

  • Caused by CSF leakage, diagnosis requires presence of low CSF pressure and/or evidence of CSF leak on imaging

  • Female predominance (2:1) and in patients in their 30-50's

Clinical Features

  • Orthostatic headaches (develops when upright and improves with lying supine) - orthostatic features may disappear if SIH has been longstanding

  • Other symptoms include: nausea/vomiting, hypoacusis, neck stiffness/pain, tinnitus, other neurological symptoms if due to downward displacement of the brain (e.g. diplopia, gait changes)

  • Can also be seen in unexplained coma

ICHD criteria for Headache attributed to SIH

  • Headache fulfilling criteria for 7.2 Headache attributed to low cerebrospinal fluid (CSF) pressure (see below)

  • Absence of a procedure or trauma known to be able to cause CSF leakage (Cannot be diagnosed within 30 days of a spinal tap)

  • Headache has developed in temporal relation to occurrence of low CSF pressure or CSF leakage, or has led to its discovery

  • Not better accounted for by another ICHD-3 diagnosis

Headache attributed to low CSF pressure

  • Either or both of the following:

  • Low CSF pressure (<60 mm CSF)

  • Evidence of CSF leakage on imaging

Investigations

  • MRI/MRV brain and spine

  • Consider CT Myelogram or Digital Subtraction Myelography - helpful to localize CSF leak

  • Lumbar puncture with opening pressure in supine position (may not be necessary if enough clinical suspicion)

Common neuroimaging findings in SIH

  • Subdural collections

  • Enhancement of pachymeninges

  • Engorgement of venous structure

  • Pituitary enlargement

  • Sagging of brain (can ask radiology to look specifically for mammilopontine distance)

  • Subdural collection and hematomas

Treatment

  • Conservative: Bed rest, hydration, NSAIDs, caffeine

  • Epidural blood patch or fibrin glue patch (intrathecal infusion of 20 - 130 cc of blood) - will need to consult anesthesiology - however only 1/3 patients respond to first patch

  • Surgical referral if three failed blood patches

Trigeminal autonomic cephalalgias

By Dr. Caz Zhu
Reviewed by Dr. Will Kingston

Pathophysiology and Epidemiology

  • Male to female predominance (3:1) only in cluster headaches

  • Unclear pathophysiology - thought to be related to trigeminal autonomic reflex (trigeminovascular system, occipital nerves, thalamus and hypothalamus)

  • Most causes are primary but important to rule out secondary causes of cluster headaches including vascular & masses (carotid artery dissections, cavernous meningioma, pituitary adenomas)

  • More pituitary lesions seen in people with cluster headaches

Clinical Features

  • Often side-locked headaches with unilateral autonomic symptoms (lacrimation, red eye, ptosis/eye edema, nasal congestion, sweating/flushing)

  • Associated with restlessness/agitation (banging head on wall, rocking), not able to sit still during an attack

  • Four common TACS:

TACSCluster HeadachesShort-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing (SUNCT)
Clinical characteristicsUnilateral side-locked headaches, “suicide headaches”, often “wake-up” headaches and occur seasonallyProminent autonomic symptoms, +++ frequent and short-lived
ICHD-3At least 5 attacks that are severe, unilateral orbital/supraorbital, temporal pain lasting 15-180 minutes; unilateral autonomic symptoms and/or restless or agitation; occurring every other day - 8 attacks/dayAt least 20 attacks that are moderate - severe pain in orbital, supraorbital, temporal, trigeminal distribution lasting 1 - 600 seconds as stabbing/saw-tooth pattern; unilateral autonomic symptoms; occurring once a day up to half the time
TACSParoxysmal HemicraniaHemicrania Continua
Clinical characteristicsSimilar to cluster headaches but shorter and less restlessness. Responds to indomethacinConstant, side locked headache, occasional migrainous features due to constant nature. Responds to indomethacin
ICHD-3At least 20 attacks that are severe, unilateral, orbital, supraorbital, temporal pain lasting 2 - 30 minutes; unilateral autonomic symptoms; occurring 5 attacks/day or more than half the time; attacks prevented by indomethacinUnilateral headache that is present for more than 3 months with exacerbations of moderate/great intensity, can be remitting (pain remission for 1 day) or unremitting (no pain remission for 1 day for at least 1 year), attacks prevented by indomethacin

Investigations

  • MRI brain with sella views +/- vascular imaging (MRA)

  • Hormonal testing - testosterone

  • Sleep study

Treatment

  • Cluster Headache treatment classified as abortive, transitional, and preventative treatment

Abortive TherapyTransitional TherapyPreventative Therapy
High flow oxygen (12-15 L/NRB), Intranasal Zolmitriptan 5-10 mg, Intranasal Sumatriptan 20 mg, Intranasal lidocaineSuboccipital steroid injection, Corticosteroids (prednisone/dexamethasone), Naratriptan, possibly IV corticosteroids for refractory casesGalcazemuab, Level C evidence but verapamil, lithium, warfarin, melatonin, and gabapentin (high dose, non-invasive vagal nerve stimulation
  • Paroxysmal Hemicrania and Hemicrania Continua: Indomethacin (up to 75 mg TID) and/or Melatonin

  • Indomethacin trial: Start with 25 mg TID for 1 week, then increase by 25 mg TID per week until final dose of 75 mg TID. If headaches are eliminated, then slowly remove one tablet per week until you reach the lowest effective dose for headache improvement. PPI is also recommended.

  • SUNCT: Lamotrigine is 1st line, then topiramate, gabapentin/pregabalin, verapamil, methylprednisolone

  • Secondary causes of cluster headaches: Medical or surgical treatment of lesion can improve headaches

Trigeminal Neuralgia

By Dr. Andrea Kuczynski
Reviewed by Dr. Will Kingston

Pathophysiology and Epidemiology

  • Must rule out post-herpetic neuralgia

  • Usually middle age, females affected more

  • May be secondary to MS lesions (especially if bilteral)

Clinical Features

  • Greater than or equal to 3 attacks

  • Recurrent sudden onset paroxysmal attacks lasting <2min that are severe, described as electrical shocks, shooting, sharp pain

  • Affecting the greater than or equal to 1 trigeminal nerve distribution unilaterally (V2 and V3 are more common than V1)

  • Pain with innocuous stimuli (eating, brushing teeth, shaving, wind blowing on face)

  • Refractory period: period of time where repetitive innocuous stimuli do not aggravate the attack; not a feature in TACs

Investigations

  • Can consider MRI brain with trigeminal nerve protocol to visualize is there is any vascular compression of the nerve

Treatment

  • Acute treatment in the ED: Phenytoin 15 mg/kg IV over 30 minutes or Lacosamide 100 mg IV

  • Carbamazepine 200-1200 mg/day

  • Gabapentin or Pregabalin

  • Gamma knife radiosurgery (if refractory to medical treatment)

  • Surgical decompression of nerve if evident pathology

Demyelinating disease

Multiple Sclerosis

By Dr. Jane Liao
Reviewed by Dr. Alex Muccilli

Pathophysiology and Epidemiology

  • Chronic inflammatory disease of the CNS with evidence of demyelination and axonal damage

  • Mean age of onset 30 years (40 years with PPMS), affecting female : male 3:1

Risk Factors

  • Latitude - further from equator, greater risk; when a patient immigrates from their country of origin after 15 years old, they maintain the MS risk from the country of origin.

  • Low vitamin D levels and sunlight exposure

  • Genetics - HLA DRB1

  • Smoking

  • Adolescent obesity

  • Vitral triggers - EBV

For Poor Prognosis Factors for MS, see Figure 1 in this article: Reaching an evidence-based prognosis for personalized treatment of multiple sclerosis

Diagnosis of MS requires evidence of dissemination in time and dissemination in space (McDonald Criteria) through a combination of clinical and radiographic criteria

Criteria are meant to be applied to a patient presenting with symptoms consistent with CNS inflammatory demyelinating disease

  • NOT meant for patient with incidental MRI findings

  • Imperative that alternative diagnoses are considered and excluded (particularly NMO/MOG in the right contexts)

  • An attack/relapse/exacerbation: symptoms or signs typical of an acute inflammatory demyelinating event (current or historical) with duration at least 24 hours, in absence of fever or infection

Radiologically speaking:

  • Dissemination in Space (DIS): 1 or more T2 lesions in at least 2 of 4 areas (periventricular, juxtacortical, infratentorial, spinal cord)

  • Dissemination in Time (DIT): A new T2 and/or gadolinium enhancing lesion on follow up MRI (at least 30 days after presentation) OR simultaneous presence of asymptomatic gadolinium-enhancing and non-enhancing lesions at any time

The diagnosis can be made with:

  • History of 2 or more attacks and objective clinical evidence of 2 or more lesions (or objective clinical evidence of 1 lesion with reasonable historical evidence of a prior attack)

  • 2 or more attacks but only objective clinical evidence of 1 lesion: demonstrate DIS as above or await further attack involving a different CNS site

  • 1 attack and objective clinical evidence of 2 or more lesions: demonstrate DIT as above or await second clinical attack

  • 1 attack and objective clinical evidence of 1 lesion (CIS): must demonstrate DIS and DIT as above or await second attack

  • CSF studies positive for OCBs can be used as a surrogate for DIT if the DIS criteria are met to make a diagnosis

Subtypes of MS

  • Clinically isolated syndrome (CIS): one clinical attack with corresponding MRI finding, but does not fit dissemination in time or space criteria

  • Relapsing remitting MS (RRMS): most common (80%); discrete clinical relapses with resolution of symptoms back to baseline in-between attacks

  • Primary progressive MS (PPMS): progression of disease from onset with variable degree of recovery; stable between episodes of PPMS

  • Secondary progressive MS (SPMS): initially beginning as RRMS, patients continue to have clinical attacks with less and less baseline recovery in-between attacks

Clinical features

Symptoms of MS can vary but common presentations of MS include:

  • Optic neuritis - reduced visual and color acuity, blurry vision, and pain with extraocular eye movements

  • Internuclear ophthalmoplegia - inability to adduct one eye due to lesion in MLF but with compensatory abduction Video Example

  • Transverse myelitis - defined sensory level loss, weakness in upper or lower extremities, autonomic dysfunction (e.g. bladder/bowel or respiratory)

  • Brainstem syndrome presenting with ataxia, vertigo, or dysarthria

  • Upper cervical cord lesions can have L'hermitte's sign (electric-like shock radiating down the back with flexion of the neck)

  • MS relapse usually lasts for a minimum of 24 hours without an alternative explanation. However, patients with MS can also have fluctuations in their symptoms due to concurrent infection (e.g. UTI), fevers, or heat which represent pseudo-relapses and need additional work-up

Common MS Mimics

InflammatoryInfectiousNeoplasticVascularMetabolic/ToxicGenetic
MOG ADEM-LymphomaVasculitisOsmotic myelinolysisCADASIL
NeurosarcoidSyphilisBrain metastasesSusac’s syndromeCarbon monoxide leukoencephalopathyAdrenoleukodyrstrophy
Behcet’sLymeVirchow-Robins spacesVitamin B12 deficiencyMELAS
Sjogren’sHIVCADASILPRESFabry’s disease
SLEPMLHeroin inhalationFamilial hyperlipidemia
Tumefactive MSTBMarchiafava-Bignami diseasePhenylketonuria
Balo concentric rings

Algorithm

Click image to enlarge

Investigations

Work-up for diagnosis

An MS diagnosis is based on clinical history and MRI. Additional investigations do NOT always need to be performed

  • MRI brain and spine with GAD - (important to include GAD to look for enhancing, active lesions)

  • Lumbar puncture - send for oligoclonobands (CSF and serum)

  • Bloodwork - Consider serum NMO/MOG in appropriate context

Consideration of immunotherapy

  • CBC, lytes, extended lytes, Cr, LFTs, TSH

  • Hep B core antibody, Hep C

  • TB skin test prior to certain immunotherapies

  • Strongyloides testing if from endemic region

Relapse vs pseudo-relapse

  • Chest x-ray, urinalysis and urine culture, blood cultures x2

Treatment

The treatment section will focus specifically on treating patients who are admitted to hospital for an exacerbation of their MS symptoms.

Glucocorticosteroids (1st line)

  • Indications: Acute disabling MS relapse

  • Dosage & Duration: IV methylprednisolone 1g OR PO prednisone 1250mg for 3-5 days

  • Contraindication: Sepsis or severe infection

  • Precautions: Administer in AM to minimize nighttime insomnia

Adverse Effects of Glucocorticosteroids

  • Short-term: GI upset, psychiatric symptoms (insomnia, depression, mania, hallucinations), hyperglycemia, susceptibility to infections

  • Long-term: Hypertension, weight gain, osteoporosis and avascular necrosis of the hip (rare)

Plasma Exchange (2nd line)

  • No clear evidence for PLEX in people with MS, though sometimes used in an off-label fashion if severe relapse with poor recovery

  • Indications: Acute, severe MS relapses poorly responsive to glucocorticosteroids

  • Dosage & Duration: 1 PV exchange x7 over 14 days

  • Contraindications: Prior anaphylactic reaction

  • Precautions: Central line insertion may be required

Adverse Effects of Plasma Exchange

  • Mild: Citrate toxicity, hypotension, fever/chills/rigor, urticaria, pruritis

  • Severe: Arrythmia, thromboembolism, pulmonary edema, seizures, coagulopathy, angioedema, bronchospasm, anaphylaxis

  • Indications: Acute, severe MS relapses poorly responsive to glucocorticosteroids or PLEX; MS relapses in pregnancy

  • Dosage & Duration: 2 g/kg over 2-5 days

  • Contraindication: Prior anaphylactic reaction

Neuromyelitis Optica Spectrum Disease (NMOSD)

By Dr. Andrea Kuczynski
Reviewed by Dr. Alex Muccilli

Pathophysiology and Epidemiology

  • NMOSD is an inflammatory disease of CNS characterized by episodes of optic neuritis, transverse myelitis, and other focal neurological symptoms

  • AQP4 (Aquaporin-4) IgG is the most common antibody found in patients with NMOSD (80% of cases)

  • Consider MOG (myelin oligodendrocyte glycoprotein) IgG in seronegative patients

  • Less common in predominantly Caucasian countries

Diagnostic Criteria of NMO with (+) AQP4 IgG:

  • One core clinical feature: optic neuritis, acute myelitis, area postrema syndrome, other brainstem syndrome, symptomatic narcolepsy or acute diencephalic syndrome with with MRI lesion(s), symptomatic cerebral syndrome with MRI lesion(s)

  • No better explanation

Diagnostic Criteria of NMO without AQP4 IgG:

  • 2+ core clinical features including 1 of optic neuritis, acute myelitis, or area postrema syndrome

  • Meets MRI requirements for clinical features (see below)

  • Dissemination in space met with two or more different core clinical characteristics

  • No better explanation for the clinical syndrome

  • Negative testing for AQP4 IgG (ideally with cell-based testing)

MRI criteria for seronegative NMOSD

  • Optic neuritis with either normal MRI or optic nerve lesion (T2/FLAIR or T1-GAD) involving more than half of the optic nerve or chiasm

  • Acute myelitis with MRI cord lesions extending over 3 + continuous segments (or atrophy in patients with remote history of myelitis)

  • Acute area postrema syndrome: Dorsal medulla lesion

  • Acute brainstem syndrome: Periependymal brainstem lesions

MSNMOMOG
Optic neuritisVariable severity (rarely severe) with 2/3 affecting posterior optic nerve, good recoveryCan present as bilateral simultaneous optic neuritis; posterior nerve involvement and may involve optic chiasm; uncommon to have disc edema; more severe with poor prognosis for visual recovery (; can have recurrent attacksCan present as bilateral simultaneous or unilateral optic neuritis; longitudinal, anterior optic neuritis; disc edema and perineural gadolinium enhancement; better visual outcome than NMO
Transverse myelitisPreference for posterior and lateral cord; lesions will be less than 3 vertebral bodies in lengthLesion extends 3+ vertebral segments; preference for central cord but can expand; more than ⅔ of the axial cord will be involved swollen cord; enhancement; often poor prognosis with permanent gait instabilityLinear or expansile lesions, preference for conus

Investigations

  • (See #7 in requisitions for serum NMOSD panel)

  • Serum anti-aquaporin-4 IgG - greater specificity than in CSF and with cell based assays

  • Serum MOG antibodies - greater specificity than in CSF

  • Do not test MOG in all patients with MS; only send off antibodies in appropriate clinical scenarios

  • MRI brain +/- spine (depending on symptomatology)

  • Lumbar puncture if indicated to rule out other causes of optic neuritis/transverse myelitis as indicated

Treatment

  • Acute therapy: pulse steroids, early PLEX if disabling symptoms (see MS section)

  • Maintenance: MMF, Rituximab, Azathioprine

  • New agents that can be used: Eculizumab, Satralizumab, Inebilizumab for AQP4+ NMOSD

  • MOG+ disease may require longterm immunosuppression with agents such as MMF, Azathioprine, Rituximab, or monthly IVIG

Patient Education

  • Pediatric patients with ADEM have a 10-15% risk of developing or initially presenting with MOG

  • Many cases of MOG are monophasic

  • AQP4+ NMO can be paraneoplastic so consider screening for malignancy in elderly individuals

  • MOG and MS have typically better functional recovery than NMO

Transverse Myelitis

By Dr. Andrea Kuczynski

Definitions

  • Transverse myelitis: heterogeneous group of disorders with acute to subacute inflammatory spinal cord syndrome

  • “Complete” cord lesion: relatively symmetric moderate or severe sensory-motor loss. Suggestive of a monophasic disorder (i.e., infectious) or relapsing NMO

  • “Partial” cord lesion: incomplete or patchy involvement of at least one spinal segment with mild to moderate weakness and asymmetric or dissociated sensory symptoms. More likely secondary to MS with high risk for relapses in the future

Diagnostic Criteria of Transverse Myelitis

  • Development of sensory, motor, or autonomic dysfunction due to spinal cord etiology

  • Clearly defined sensory level

  • MRI-confirmed exclusion of extra-axial compressive etiology

  • Inflammation within the spinal cord - CSF pleocytosis, elevated IgG index, or gadolinium enhancement

  • Progression to nadir between 4 hours and 21 days following symptom onset

Differential Diagnosis

DemyelinatingInfectiousInflammatoryNeoplasticMetabolicVascular
MSVDRLSarcoidosisCNS lymphomaVitamin B12Dural AV fistula
NMOViral (WNV, Polio, HSV2, EBV, CMV)SLEEpendymomaVitamin E-
MOGADTBSjogren’sAstrocytomaCopper-
ADEMLymeSclerodermaParaneoplastic syndrome (anti-Hu, anti-CRMP-5)--
-HIVBehcet’sPrimary intramedullary tumor--
-HTLV-1----

Clinical Features

  • Bowel/bladder dysfunction - constipation, urinary retention, urinary/fecal incontinence

  • Weakness - upper and/or lower limb involvement depending on spinal level

  • Hypotonia in affected limbs

  • Numbness, paraesthesias - upper and/or lower limb involvement depending on spinal level

  • Pain or tightness - often occurring around stomach or chest

  • +/- Lhermitte sign

  • Paroxysmal tonic spasms

Investigations

  • CT lumbar spine if bowel/bladder symptoms - first rule out cauda equina and indication for surgery!

  • MRI spine with contrast (level depends on limb involvement)

  • Serum NMOSD antibodies (see NMOSD section)

  • LP including infectious work-up

  • Rheumatological work-up: ANA, anti-dsDNA, ENA, RF, ANCA, C3/C4, APLA

  • HIV, VDRL, Lyme serology

  • Vitamin B12, vitamin E

  • Serum copper

Treatment

  • Solumedrol 1g IV daily x5 days then maintenance Prednisone 1 mg/kg with slow taper

  • IVIG 2 g/kg IV over 2 days if no response to steroids

  • PLEX

  • Prophylaxis while on high dose steroids: calcium, vitamin D, PPI, PJP prophylaxis

  • Management of comorbid symptoms (i.e., neuropathic pain, bowel regimen, spasticity, spasms)

Seizure

Seizure

By Dr. Andrea Kuczynski
Reviewed by Dr. Jerry Chen and Dr. Matthew Burke

Definition

  • Seizure: A transient occurrence of signs and/or symptoms (e.g. sensory, motor, speech, consciousness) due to abnormal excessive or synchronous neuronal activity in the brain

  • Epilepsy: disorder of the brain with an enduring predisposition to generate epileptic seizures and by the neurobiological, cognitive, psychological, and social consequences of this condition; in a patient who has any of the following:

  • 1) at least 2 unprovoked seizures occurring >24 hours apart;

  • 2) one unprovoked (or reflex) seizure and a probability of further seizures (similar to the general recurrence risk after two unprovoked seizures (at least 60%) occurring over the next 10 years (e.g. abnormal imaging with a potential seizure focus or EEG with epileptiform activity);

  • 3) diagnosis of epilepsy syndrome (e.g. West, Dravet, Lennox-Gastaut)

  • Provoked seizure: occur with an identifiable proximate cause (metabolic, toxic, structural, infectious, inflammatory) and are not expected to recur in the absence of that particular cause/trigger (e.g., hypoglycemia, alcohol withdrawal, etc.)

  • Unprovoked seizure: occur without an identifiable cause or in the context of a remote symptomatic cause (i.e., pre-existing brain lesions, such as a remote stroke). Recurrent unprovoked seizures are more likely to be associated epilepsy

  • Focal onset (“partial”) seizure: abnormal synchronous neuronal activity originating from one location (within limited to one hemisphere) of the brain, more concerning to be associated with elevated future recurrence risk

  • Generalized onset seizure: abnormal synchronous neuronal activity arising within and rapidly engaging bilaterally distributed networks

Click image to enlarge

Source: ILAE operational classification of seizure types: Fisher et al. Instruction manual for the ILAE 2017 operational classification of seizure types. Epilepsia

Differential Diagnosis

  • Stroke/TIA

  • Syncope: cardiac arrhythmia, orthostatic syncope, vasovagal syncope

  • Migraine

  • Encephalopathy: drug-induced, metabolic disturbance

  • Psychiatric: anxiety/panic attack, PNES

TIASeizureMigraine Aura
EtiologyVascular risk factors (e.g. CAD, atherosclerosis)Trauma, brain lesions (e.g. previous strokes, tumors)Migraines
Cardiovascular manifestationsFrequentN/AN/A
Neurological manifestations*Negative symptoms (deficits - weakness, vision loss)Positive symptoms but can have negative symptoms post-ictal (Todd's Paresis)Positive symptoms (visual more common), headaches
Symptom onsetSuddenLess than 2 minutes with progressionMore than 10 minutes with progression
Duration5-10 minutesLess than 5 minutesMore than 20 minutes

Psychogenic Non-epileptiform seizures (PNES)

  • Involuntary events in response to internal or external triggers that have similar features to those seen in epileptic seizures, but without corresponding electrophysiological features (i.e., epileptiform discharges)

  • Patients with epilepsy can also have PNES

  • Associated with adverse events and trauma

  • Triggers for PNES may include positional change, physical exertion, emotional/stressful situations, dehydration, or heat

  • Treatment may involve education and support (see Functional Neurological Disorders section)

PNESEpileptic Seizure
Preceding auraCan be variable with shorter duration over time due to dissociationSensory, experiential (e.g., déjà vu, jamais vu), autonomic aura
Onset of myoclonusFollows loss of consciousness, occurs with situational associations and often has preserved awarenessImmediate
Eye deviationUpward, often with closed eyes and resistance to eyelid openingLateral, with eyes open
Myoclonus rhythmArrhythmic jerksRhythmic jerks
Myoclonus patternMultifocal jerks briefly involving bilateral proximal and distal muscles; may see pelvic jerkingUnilateral or asymmetric jerks, may exhibit neuroanatomic evolution or GTC behaviour
Post-ictal presentationFatigue but no confusion, with relatively rapid recovery to baselineConfusion, +/- Todd’s paresis (hemiparesis)

Risk factors

  • Traumatic brain injury

  • Abnormalities in childhood development and birth history

  • Febrile seizures

  • Meningitis and/or untreated meningitis

  • Intracranial structural lesion: (gliosis, encephalomalacia, mass lesion, developmental malformations, cavernomas)

  • Previous seizure/epilepsy history

  • Family history

  • Neurodegenerative disorders

Seizure triggers

  • Sleep deprivation

  • Substance use/withdrawal

  • Infection

  • Trauma

  • Menstruation and ovulation

  • Non-adherence to treatment

  • Metabolic abnormalities: hypoglycemia, hyponatremia >hypernatremia, hypocalcemia > hypercalcemia, hypomagnesium

Clinical Features

  • Preceding aura: somatosensory, experiential (i.e., deja vu, jamais vu, epigastric rising sensation), motor, speech/language, autonomic, olfactory/gustatory, and/or visual perceptual disturbance experienced prior to the seizure with positive phenomenology

  • Event: level of awareness, circumstances leading up to the event (i.e., sleeping, awake), duration, movements (i.e., facial movements, head deviation, eye movements and deviation, rhythmic vs. arrhythmic limb movements, tonic clonic, posturing), urinary/fecal incontinence, tongue biting

  • Post-ictal period: confusion, drowsiness/altered level of consciousness, Todd’s paresis (hemiparesis), duration to return to baseline; important to complete neurological examination following event and assess for lateralizing signs

Investigations

  • Stat CT head to rule out acute intracranial abnormality (i.e., hemorrhage, stroke, mass lesion)

  • CBC

  • Lytes, extended lytes (Mg, Ca, PO4), creatinine

  • Blood glucose

  • CK

  • Prolactin (When considering PNES, should be drawn within 10-20 minutes, should be ~2x versus baseline)

  • Liver enzymes

  • Toxicology screen if indicated

  • Blood, urine, CSF cultures if indicated

  • MRI brain with contrast (seizure protocol) when clinically stable: may see some T2/FLAIR hyperintensity, diffusion restriction (ADC drop >10% is associated with permanent damage)

  • EEG

  • AED levels if prescribed to patient

  • LP with cell count and differential, protein, glucose, bacterial/viral/fungal cultures, cytology/flow cytometry, autoimmune/paraneoplastic panels as indicated

  • Serum autoimmune/paraneoplastic panels if indicated

  • Autoimmune work-up: ANA, anti-dsDNA, ENA, RF, C3/C4, cryoglobulins as indicated

  • If there is suspicion for PNES - prolonged video EEG or EMU is helpful for the diagnosis

Treatment

  • ABCs (airway, breathing, circulation) and consultation of ICU if the patient may require intubation with prolonged seizure

  • First-line Benzodiazepines - Midazolam 10mg IM x1 (if patient is >40kg) or Lorazepam 2mg IV q2min (max 8mg)

  • AED load after acute management if indicated

  • Patients with a single provoked seizure do not typically require maintenance AED

  • Maintenance AED: predominantly used if unprovoked seizure with high risk of recurrence or multiple unprovoked seizures or abnormal EEG/MRI or nocturnal seizures

  • If suspicious of infectious cause, antimicrobials based on suspected organism/etiology should be initiated after the collection of cultures (if possible)

  • Correction of metabolic abnormalities

For Pocket Card Algorithm in Status Epilepticus, see Figure 1 in this article: The Efficacy and Use of a Pocket Card Algorithm in Status Epilepticus Treatment

AEDLoad Dose and RateMaintenance DoseClearanceSide-effects for Monitoring
Phenytoin20 mg/kg IV at a rate no faster than 50 mg/minStart at 300mg p.o. Daily (up to 400mg BID)HepaticCardiac side-effects (hypotension, QTc prolongation), avoid if possible in patients with hepatic dysfunction
Keppra40-60 mg/kg IV (max 4500mg) over 5-10 minStart at 500mg p.o. BID (up to 1500mg BID)RenalAvoid if possible in patients with anxiety/depression or renal dysfunction
VPA20-40 mg/kg IV (max 3000mg) over 20 minStart at 500mg p.o. BID (up to 750mg BID)HepaticMay affect platelet function even without thrombocytopenia, Avoid if possible in patients with hepatic dysfunction
Lacosamide200-400mg IVStart at 100mg IV/p.o. BID (up to 200mg BID)Renal more than hepaticCardiac side-effects (PR interval prolongation, heart block, bradycardia), Avoid in patients with type 2 or 3 heart block, sick sinus syndrome

Click image to enlarge

[Source: Dr. Arina Bingeliene's Emergency Lecture 2020]

In choosing a long-term AED, consider the following:

  • Seizure type (focal vs. generalized onset, specific seizure syndrome)

  • Comorbidities

  • Side effects and tolerance

  • Dosing frequency

  • Drug coverage/affordability

Teratogenic AEDs to avoid in pregnancy:

  • VPA

  • Carbamazepine

  • Topiramate

  • Phenytoin

  • Phenobarbital

OCP efficacy is reduced by:

  • High Topiramate levels

  • Enzyme inducers: Phenytoin, Carbamazepine

  • Phenobarbital, primidone, oxcarbazepine

Patient Education

  • Driving: reporting to MTO is a mandatory obligation in Ontario and instruct the patient not to drive until driving privileges are reinstated by the MTO

  • Precautions to counsel patients surrounding baths alone, swimming alone, heights/dangerous activities (e.g. climbing ladders)

Status Epilepticus

By Dr. Andrea Kuczynski
Reviewed by Dr. Alex Muccilli

Definition

  • A single seizure lasting more than 5 minutes or multiple seizures with incomplete recovery of level of consciousness to baseline between the seizures

  • May present as generalized tonic clonic (GTC) seizures or non-convulsive seizures

  • Defined by 2 time-points: T1 (time beyond which seizures will likely prolong >5 minutes GTC) and T2 (GTC 30 minutes with higher risk for long-term consequences)

  • Mortality is 20% - most important determinant of mortality is underlying cause

  • Evidence supporting early treatment of seizures stems from studies showing increasing pharmaco-resistance (especially to benzos) and neuronal injury with longer seizure durations

Causes of status epilepticus

  • Neuroleptic Malignant Syndrome

  • Serotonin Syndrome

  • Substance use/withdrawal

  • Autoimmune encephalitis - suspect if no response to AEDs

Clinical Features

  • GTC seizure with head and gaze deviation, +/- urinary/fecal incontinence

  • Non-convulsive seizure - nystagmus, sustained eye deviation, facial/periorbital twitching, abnormalities in vital signs

  • Post-ictal phenomenon - confusion/agitation, dysarthria/aphasia, altered level of consciousness, Todd’s paresis (unilateral hemiparesis)

Investigations

  • Stat CT head to rule out acute intracranial abnormality (i.e., hemorrhage, stroke, mass lesion)

  • CBC

  • Lytes, extended lytes (Mg, Ca, PO4), creatinine

  • Blood glucose

  • Liver enzymes

  • Toxicology screen if indicated

  • Blood, urine, CSF cultures if indicated

  • MRI brain with contrast (seizure protocol) when clinically stable: may see some T2/FLAIR hyperintensity, diffusion restriction (involving cortex, hippocampi/mesial temporal lobes, thalamus, and cerebellum)

  • EEG

  • AED levels if prescribed to patient

  • LP with cell count and differential, protein, glucose, bacterial/viral/fungal cultures, cytology/flow cytometry, oligoclonal bands/IgG index, autoimmune/paraneoplastic panels as indicated

  • Serum autoimmune/paraneoplastic panels if indicated (see requistions)

Treatment

  • ABCs (airway, breathing, circulation) and consultation of ICU as the patient may require intubation with prolonged seizure

  • First-line Benzodiazepines - Midazolam 10mg IM x1 (if patient is >40kg) or Lorazepam 2mg IV q2min (max 8mg)

  • AED load after acute management

AEDSDose and RateSide-effects for Monitoring
Phenytoin20 mg/kg IV at a rate no faster than 50 mg/minCardiac side-effects (hypotension, QTc prolongation), Purple Glove Syndrome (Extensive skin necrosis and limb ischemia), Avoid if possible in patients with hepatic dysfunction
Keppra40-60 mg/kg IV (max 4500mg) over 5-10 minAvoid if possible in patients with anxiety/depression or renal dysfunction or dose accordingly
VPA20-40 mg/kg IV (max 3000mg) over 20 minMay affect platelet function even without thrombocytopenia, hyperammonemia, pancreatitis, Avoid if possible in patients with hepatic dysfunction
Lacosamide200-400mg IV bolus then 100mg IV BIDCardiac side-effects (PR interval prolongation, heart block, bradycardia), Avoid in patients with type 2 or 3 heart block, sick sinus syndrome

* Max dose of Levetiracetam is 4.5 g for status epilepticus
** In an average-size (70 kg) individual, consider 1500 mg load of
phenytoin if unable to obtain weight quickly

Click image to enlarge

  • Consider giving thiamine 500 mg IV followed by 50 ml of D50

  • Intubated patients may require burst suppression (target 40-60%) and ICU monitoring with titration of sedatives including propofol and barbiturates

  • If suspicious of infectious cause, antimicrobials based on suspected organism/etiology should be initiated after the collection of cultures (if possible)

  • Correction of metabolic abnormalities

  • * Max dose of Levetiracetam is 4.5 g for status epilepticus

  • ** In an average-size (70 kg) individual, consider 1500 mg load of

  • phenytoin if unable to obtain weight quickly

Patient Education

  • For patients with known seizure disorders, compliance to AEDs is important to reduce risk of status epilepticus

Movement disorders

Parkinson's Disease (PD)

By Dr. Priti Gros
Reviewed by Dr. Emily Swinkin

Pathophysiology and Epidemiology

  • Second most common neurodegenerative disorder following Alzheimer's disease

  • Due to dopamine deficiency secondary to degradation of dopaminergic neurons in the substantia nigra

  • Can be genetic (10%) or idiopathic (90%)

  • Average age of onset in 60’s

  • Pathologically characterized as an alpha synuclein proteinopathy with presence of Lewy bodies

Clinical Features

  • Cardinal features of Parkinsonism are: 4-6 Hz Rest tremor, Rigidity, Akinesia/Bradykinesia, and Postural instability not due to visual, vestibular, or cerebellar or proprioceptive dysfunction (TRAP)

  • Non-motor features of PD: Rapid eye movement (REM) sleep disorders, anosmia, autonomic dysfunction (constipation, orthostatic hypotension), mood changes, cognitive changes

  • Constipation, REM sleep disorders, and anosmia can precede motor symptoms of PD by over a decade

  • At present there are no confirmatory diagnostic tests for PD, it is a clinical diagnosis

Many diseases have Parkinsonism features - important to distinguish from PD as they often do not respond to levodopa. Examples include the following:

  • Drug induced: Antipsychotic use (especially first generation like haloperidol) and dopamine antagonists (e.g. metoclopramide) - can often have tardive dyskinesia and akathsias

  • Toxins: Manganese, MPTP

  • Vascular parkinsonism: concomitant vascular risk factors, may be more symmetric and have lower body predominance

  • Parkinson’s Plus Syndromes (see below)

EtiologyPSPMSACBSDLB
Age of onset60’s50’s60’s50-80’s
FeaturesDifficulties with vertical gaze, falls, axial rigidityAutonomic dysfunction, cerebellar signs, upper motor neuron signsAlien limb, apraxia, myoclonus, cortical signs and cognitive impairmentCognitive changes progressing to dementia with visual hallucinations onset BEFORE or shortly after parkinsonism
NeuroimagingHumming bird and Mickey Mouse signHot cross bun signAsymmetrical parietal/basal ganglia atrophyN/A

Diagnosis

UK Parkinson’s Disease Society Brain Bank Criteria:

Step 1: Diagnosis of parkinsonism requires bradykinesia and one of the following features:

  • Rigidity

  • 4-6 Hz rest tremor

  • Postural instability “not caused by primary, visual, vestibular, cerebellar or proprioceptive dysfunction

Step 2: Exclusion of “red flags”. One or more could suggest another diagnosis (e.g. Parkinson’s Plus Syndromes)

  • History of repeated strokes with stepwise progression of parkinsonism

  • History of repeated injury

  • History of definitive encephalitis

  • Neuroleptic treatment at onset of symptoms

  • MPTP exposure

  • Negative response to large doses of levodopa

  • >1 relative affected (this criteria is usually no longer applied)

  • Sustained remission

  • Strictly unilateral features after 3 years

  • Early severe autonomic involvement

  • Early severe dementia with disturbances of memory, language and praxis

  • Oculogyric crises

  • Supranuclear gaze palsy

  • Babinski sign

  • Cerebellar signs

  • Presence of cerebral tumor or communicating hydrocephalus on CT or MRI

Step 3: Supportive features for PD. 3 or more are required for diagnosis of definite PD:

  • Unilateral onset

  • Rest tremor

  • Progressive disorder

  • Persistent asymmetry affecting the side of onset most

  • Excellent response (70-100%) to levodopa

  • Severe levodopa-induced chorea

  • Levodopa response for 5 years or more

  • Clinical course of 10 years or more

Physical Exam

Key exam maneuvers and features in Parkinson’s Disease or Parkinson’s Plus Syndromes

  • Inspection: Decreased facial expression (hypomimia), softer voice (hypophonia), decreased blink rate

  • Eye movements: Difficulties with extraocular eye movements (e.g. PSP - slowed or impaired vertical saccades), hypometric saccades (Can be tested with OKN strips, in PSP - decreased vertical saccades)

  • Tremor: Parkinson’s tremor typically occurs at rest and is asymmetrical, but can re-emerge with sustained posture, often described to have a “pill-rolling” quality and can worsen with distraction (“Count months of the years backwards”)

  • Bradykinesia: Finger tapping, hand open-close, supination-pronation, foot and heel tapping will demonstrate not just slowness but decrement in amplitude or freezing of movements

  • Tone: Testing for both appendicular rigidity (usually Parkinson’s Disease) and axial rigidity (often seen in PSP)

  • Gait: Slow, shuffling gait with often stooped posture. Arm swing can be diminished with emergence of tremor. Difficulty with turns, requiring multiple steps to move (en-bloc turning). Patients can walk slowly but then accelerate with small steps (festination). Advanced PD can demonstrate freezing of gait at times which are overcome by visual stimuli (e.g. stepping over a line)

  • Postural instability: Pull test to look for retropulsion (will require several >3 steps to regain balance)

  • Other signs: Micrographia or tremor in writing

Investigations

  • Atypical symptoms may benefit from MRI brain to rule out Parkinson’s Plus syndromes

Treatment

No disease-modifying therapy, only symptomatic management is available yet (see below):

Symptomatic management of motor PD symptoms

Class of medicationsLevodopaDopamine agonistsMonoamine oxidase type B inhibitors (MAO-B)COMT-inhibitorsAnticholinergic drugs
MedicationsLevodopa-Carbidopa (Sinemet)Pramipexole, Ropinirole, RotigotineSelegiline, Rasagiline, SafinamideEntacaponeTrihexylphenidyl
IndicationsUsually first line, start at Sinemet 100/25 1 tab TID, must be taken with food and protein can reduce efficacyLess well tolerated in elderly patients due to confusion but less incidence of fluctuations and dyskinesiaUsually add-on to improve efficacy of levodopaUsually add-on to improve efficacy of levodopaBest for tremor predominant but only for younger individuals
Side EffectsNausea, GI upset, daytime somnolence, orthostatic hypotension, oedema and can induce dyskinesia in long-termNausea, daytime somnolence, hallucinations, impulse control disorders (pathological gambling, hypersexuality, binge eating).Theoretical risk of serotonin syndrome if on an SSRI/SNRIConfusion, hallucination, urine discolorations, diarrhea, and dyskinesiasNOT FOR ELDERY, dry mouth, constipation, somnolence, memory changes

Treatment of non-motor Parkinson's Disease symptoms (non-exhaustive list)

  • Depression: Dopamine agonist (Pramipexole), Serotonin reuptake inhibitor (Citalopram, Fluoxetine), Serotonin and Norepinephrine Reuptake Inhibitor (Venlafaxine), Tricyclic antidepressant (Desipramine, Nortriptyline),

  • Psychosis: Atypical antipsychotic (Clozapine, Quetiapine), acetylcholinesterase inhibitor (Rivastigmine)

  • REM Sleep behaviour disorder: Hormone (Melatonin), Benzodiazepine (Clonazepam)

  • Constipation : Osmotic laxative (PEG)

  • Gastrointestinal motility : Peripheral dopamine antagonist (Domperidone)

  • Orthostatic hypotension: peripheral dopamine antagonist (Domperidone), Mineralocorticoid (Fludrocortisone), Vasopressor (Midodrine)

Essential Tremor

By Dr. Priti Gros
Reviewed by Dr. Emily Swinkin

Epidemiology

  • Common, can be both familial (about 50% will have a family history although no single causative gene yet identified) or idiopathic

  • Two peaks of onset at 20s and 60s

Clinical Features

  • Usually an isolated tremor syndrome of the bilateral upper limb presenting as a posture or kinetic tremor, with or without head tremor or tremor in other locations

  • Benign, but tremors can become progressively worse which may warrant symptomatic treatment

  • Tremors may improve with small amounts of alcohol

Diagnostic criteria: Essential Tremor

  • Isolated tremor syndrome of bilateral upper limb action tremor

  • At least 3 years’ duration

  • With or without tremor in other locations (e.g. head, voice or lower limbs)

  • Absence of other neurological signs, such as dystonia, ataxia, or parkinsonism

Exclusion criteria for ET

  • Isolated focal tremors (voice, head)

  • Orthostatic tremor with a frequency > 12 Hz

  • Task- and position-specific tremors

  • Sudden onset and step-wise deterioriation

Differential Diagnosis

  • Enhanced physiological tremor: common bilateral upper limb action tremor (8-12 hz), caused by anxiety, fatigue, hyperthyroidism, other drugs. It is often reversible if the cause of the tremor is removed

  • Parkinson’s disease and other forms of Parkinsonism: classic parkinsonian tremor is typically a 4-7 Hz rest tremor. It can involve the upper or lower extremities, jaw or tongue. See section on Parkinson’s disease. See section on Parkinson’s disease

  • Cervical dystonia: common cause of isolated head tremor.

  • Task- and position-specific tremors: focal tremor that typically occur during a specific task or posture

  • Primary orthostatic tremor: a generalized high frequency (13-18 hz) isolated tremor syndrome that occurs upon standing up. Often, confirmation of the tremor frequency is done using electromyography

  • Functional tremor: characterized by distractibility, frequency entrainment or antagonistic muscle coactivation

Investigations

  • Generally no investigations are needed unless there are atypical findings

Treatment

First line treatments

Propranolol

  • Initial dose: 60 - 80 mg/day (divided into two or three doses per day, e.g. 40 mg BID) and gradually titrate up to efficacy (may start at lower dose in elderly)

  • Maintenance dose : 120 to 320 mg/day (Lower dose is better for elderly individuals)

  • Side Effects: Lightheadedness, bradycardia, fatigue

  • Contraindications: Patients with heart block/heart failure, asthma, and type 1 diabetes

Primidone

  • Initial dose: 25 mg/day (at bedtime) and increase by 25 mg every 3-7 days

  • Maintenance dose : 250 mg - 500 mg/day

  • Side Effects: Sedation, drowsiness, fatigue, nausea and vomiting, ataxia

Second line treatments

  • Propranolol + Primidone

  • Gabapentin 100-300mg p.o. TID (max 1200mg daily)

  • Topiramate 25mg p.o. daily-BID (max 400mg daily)

Surgical treatments

  • MRI-guided focused ultrasound thalamotomy

  • Deep brain stimulation to thalamus

Patient Education

  • The clinical course of ET is typically slow, progressive over years

  • Younger age of onset usually correlates with slower progression

Myoclonus

By Dr. Caz Zhu
Reviewed by Dr. Emily Swinkin

Definition

  • Sudden, brief involuntary muscle jerks that occur occur at rest, movement, or provoked by stimuli (e.g. touch, sound)

  • Positive myoclonus: Caused by abrupt muscle contraction

  • Negative myoclonus: Caused by loss of tone (e.g. asterixis)

Clinical Features

  • Cortical myoclonus: Usually affecting the face and hands and with voluntary action. stimulus sensitive and triggered by action or touch, can also be seen in certain epilepsy syndromes

  • Subcortical/Brainstem myoclonus: Generalized jerks in axial and bilateral proximal extremities, stimulus sensitive to auditory triggers - startle response (e.g. loud clap)

  • Spinal myoclonus (Propriospinal myoclonus and segmental spinal myoclonus): Usually arrhythmic jerks in the arm/trunk but in propriospinal myoclonus, you can see abdominal myoclonus (torso flexion)

  • Secondary myoclonus is the most common form of myoclonus - due to an underlying neurological or non-neurological cause → important to differentiate whether onset of myoclonus is acute vs gradual

  • Diffuse myoclonus is often seen post-anoxic brain injury (associated with poor prognosis) - e.g. Lance-Adams Syndrome

Differential Diagnosis

*This is not an exhaustive list but some of the common causes of myoclonus to consider

ClassificationCommon causes
Toxic-MetabolicHepatic & renal failure, electrolyte abnormality, hyperthyroidism
Drug-inducedSSRIs, dopamine agonists, opioids, antibiotics (cephalosporins), benzodiazepine withdrawal
**Infectious **Herpes Simplex Encephalitis
TraumaLance-Adams Syndrome (action-induced myoclonus during recovery of anoxic brain injury) , spinal cord injury
Neurodegenerative DiseasesCJD, cortico-basal degeneration, other dementias
ParaneoplasticAnti-Ri antibodies (breast and lung cancer)
**Epileptic Myoclonus **Childhood myoclonic epilepsy (lennox-gastaut syndrome), Progressive myoclonus epilepsy (MERRF)
EssentialPurely isolated myoclonus
**Physiological **Hynagogic myoclonus (falling asleep), hiccups, physiological startle

Investigations

  • CBC, lytes, extended lytes, LFTs, TSH

  • MRI brain in appropriate clinic context to evaluate for anoxic injury, brainstem pathology, neurodegenerative conditions

  • EEG and EMG may be helpful but generally not required for diagnosis

Treatment

  • If reversible cause of myoclonus is found (e.g. due to metabolic cause or drug-induced) - need to treat

  • Symptomatic treatment for myoclonus:

CorticalSubcorticalSpinalFocal peripheral myoclonus (hemifacial spasm)
TherapiesValproic acid, Clonazepam, and LevetiracetamClonazepamClonazepamBotox injections

Stroke

Ischemic Stroke

By Dr. Andrea Kuczynski
Reviewed by Dr. Houman Khosravani

Definitions

  • Ischemic stroke: hypoperfusion of brain tissue due to thrombus/embolus within the intracranial vasculature

  • TIA*: transient episode of neurological dysfunction due to focal ischemia without infarction; should see resolution of symptoms without neuroimaging correlate if symptoms resolve within 24hrs and typically do not see neuroimaging correlate if symptoms resolve within 2hrs

  • High risk TIA: high risk for occurrence of an ischemic stroke within the first 48hrs in a patient with transient unilateral motor and/or speech/language symptoms lasting >5 minutes

  • Increasingly, there is recognition that TIA is not the best terminology and we expect the field to revolve to potentially remove this term; but for now it remains

Pathophysiology and Epidemiology

  • Cardioembolic - secondary to atrial fibrillation

  • Large vessel atherosclerosis

  • Small vessel/lacunar strokes - secondary to HTN

  • Other (more common in young patients <50) - PFO, carotid/vertebral dissections

  • Cryptogenic/unknown

Source: Dr. Houman Khosravani

Risk factors

  • HTN

  • Dyslipidemia

  • Diabetes

  • Smoking

  • Atrial fibrillation

  • Cardiac disease/PVD

  • Obesity/reduced physical activity

  • EtOH misuse

  • Pro-thrombotic/hypercoagulable state - OCP/hormone replacement use, SLE, APLA, Factor V Leiden, protein C and/or S deficiency, anti-thrombin III deficiency, malignancy

Click image to enlarge

Source: The Calgary Guide to Understanding Disease

⊙ CLINICAL PEARL
Patients may present with a variety of symptoms including headache, altered mentation, seizure, unilateral and/or brainstem deficits

Investigations

  • Stat CT/CTA/CTP - assess for ischemic changes, hemorrhage, arterial occlusion, perfusion mismatch

  • NIHSS clinical examination

  • Vital signs including heart rate and BP

  • ECG

  • CBC

  • Lytes, extended lytes (Mg, Ca, PO4), creatinine

  • Blood glucose

  • 24 hours after tPA and/or EVT: CT head

  • MRI brain when clinically stable

  • Lipid profile

  • HbA1c

  • Transthoracic +/- transesophageal echo with bubble study/definity contrast to look for vegetations, intracardiac thrombus, and/or PFO; TEE is for valves/PFO

  • In appropriate situations, consider cardiac CT for LAA clot

  • Blood and urine cultures - especially if patient is febrile and has risk factors for endocarditis (i.e., younger age, IVDU

  • Holter monitor

  • Stroke in the young work-up

CT early signs of ischemic stroke:

  • Hyperdense vessel

  • Loss of grey-white differentiation

  • Sulcal effacement

  • Loss of insular ribbon

  • Hypoattenuation of deep grey matter nuclei - highly specific for ischemia within 6hrs

  • Swelling/mass effect

For the ASPECTS score figure see ASPECTS (Alberta Stroke Program Early CT Score) Assessment of the Perfusion–Diffusion Mismatch

CT perfusion:

  • Assess the core and the penumbra (brain at risk)

  • Core features: increased MTT, markedly decreased CBF and CBV

  • Penumbra features: increased MTT, moderately reduced CBF, normal/increased CBV

  • More likely to have favourable outcome with mismatch ratio >/= 1.8, volume >/= 15mL

Click image to enlarge

[Source: Dr. Phavalan Rajendram Emergency Lecture 2020]

Treatment

  • Assess patient for stability and call for help from the emergency department/ICU as needed

  • Thrombolysis (TPA/TNK) and/or EVT (see below)

  • Thrombolysis-angioedema: Solumedrol 125mg IV or Hydrocortisone 200mg IV + Famotidine 20mg IV IV or Diphenhydramine 50mg IV

  • If clinically stable with stable CT head 24hrs post-intervention (tPA, EVT), can start single anti-platelet and DVT prophylaxis

  • If NIHSS </= 3 can start dual anti-platelets for 21 days, then monotherapy life-long thereafter (CHANCE, POINT trials)

  • Starting anti-coagulation post-ischemic stroke (i.e., for AFib): initiation on day 3 (small stroke), 6-7 (medium), or 12-14 (large stroke) but depends on staff and presence of any hemorrhage Reference: Secondary Stroke Prevention Guidelines 7.2

  • BP: target <140/90 or <130/80 (diabetic patients/small vessel disease)

  • Dyslipidemia: target LDL <1.8 for those with small vessel disease

  • Carotid endarterectomy versus stenting in patients with symptomatic large vessel atherosclerosis

  • Diabetes: target HbA1c <7% (some leniency in patients >80 based on Canadian Diabetes Association)

  • Must address driving based on residual function as an inpatient!

  • Lifestyle: cessation of smoking, physical activity, reduced salt intake/DASH diet/Mediterranean diet, reduced EtOH intake

Hemorrhagic Stroke

By Dr. Andrea Kuczynski
Reviewed by Dr. Keithan Sivakumar

Pathophysiology and Epidemiology

  • Etiology characterized based on location - lobar (CAA, ischemic stroke with hemorrhagic transformation), deep (HTN, tumor/metastasis), intraventricular (extension from HTN hemorrhage in basal ganglia, aneurysmal rupture, intraventricular AVM/tumor)

  • Less common stroke type (10-15%) - more common in individuals with hypertension and older adults (presence of CAA)

Risk factors

  • HTN

  • Age - > 65

  • Trauma & Head Injuries

  • Vascular anomalies - arterial dissection, CVST, AVM, aneurysmal rupture

  • Tumors/metastasis

  • Sympathomimetic drugs (e.g. cocaine, amphetamines)

  • Smoking

  • EtOH misuse

  • Family history

Click image to enlarge

Source: The Calgary Guide to Understanding Disease

Clinical Features

  • Headache - often described as sudden onset & worst headache (thunderclap)

  • Altered level of consciousness

  • Nausea/vomiting

  • Dizziness/vertigo

  • Focal neurological deficits

  • Seizure

Investigations

  • Stat CT/CTA/CTP - assess for ischemic changes, hemorrhage, arterial occlusion, perfusion mismatch

  • NIHSS clinical examination

  • ICH score

  • Vital signs including heart rate and BP

  • ECG

  • CBC

  • Lytes, extended lytes (Mg, Ca, PO4), creatinine

  • Blood glucose

  • Blood and urine cultures - especially if patient is febrile and has risk factors for endocarditis (i.e., younger age, IVDU) and subsequent mycotic aneurysms/emboli with hemorrhagic transformation

  • CT head 6-24 hours after initial presentation

  • MRI brain when clinically stable with SWI/GRE sequence

Common CT findings in hemorrhage:

  • Ventricular effacement

  • Midline shift

  • Hyperdense blood with surrounding hypodensity (edema)

  • Spot sign - active bleeding

Treatment

Acute treatment for all ICHs

  • Acute BP control: SBP <140 (if spot sign present indicating active bleeding) versus SBP <160 (if initial SBP >220 and/or renal dysfunction, absence of active bleeding)

  • Eventually target BP <140/90 or <130/80 (diabetics)

  • If patient uses Warfarin, can give Octaplex 1000IU (for patients 50-90kg with INR 1.5-4) and vitamin K 10mg IV push, TXA 1g IV push

  • Consult Neurosurgery - consideration of EVD and/or decompressive hemicraniectomy if indicated

  • Avoid secondary brain injury: treat Hb <70, avoid fever, correct coagulopathy

  • Patients do not require anti-platelets!

  • Risk factors for poor prognosis: ICH score - older age, initial GCS 3-4, intraventricular hemorrhage, hemorrhage volume >30mL

Stroke in the Young

By Dr. Andrea Kuczynski

Pathophysiology and Epidemiology

  • Typically considered a “stroke in the young” in an individual <50 years old

  • Systemic disease associated with prothrombotic state and infarct/hemorrhage: SLE, APLA, vasculitis, Behcet’s, Susac syndrome

Carotid DissectionVertebral DissectionCVSTEndocarditis
Risk FactorsHead/neck trauma, connective tissue disease (Marfan’s, Ehlers Danlos, fibromuscular dysplasia), neck manipulation (yoga, chiropractor)Head/neck trauma, connective tissue disease (Marfan’s, Ehlers Danlos, fibromuscular dysplasia), neck manipulation (yoga, chiropractor)Prothrombotic conditions, hematological disorders, systemic disease (SLE, IBD), incidental finding in trauma casesImmunocompromised host, IVDU, mechanical/prosthetic valve, atrial myxoma, intracardiac thrombus, marantic endocarditis
Clinical FeaturesHeadache, ipsilateral neck pain, possible ipsilateral Horner’s (rare), retinal/cerebral ischemia, pulsatile tinnitusHeadache, nausea/vomiting, vertigo/dizziness, unilateral pain/weaknessDiffuse, acute onset (thunderclap) headache, diplopia secondary to CN6 palsy, nausea/vomiting, altered level of consciousnessDepends on area of infarction; systemic signs including Osler’s nodes, splinter hemorrhages, etc.
InvestigationsCTA: crescent signCTA: crescent sign, double lumen signCT/CTV: delta sign/empty delta sign, subarachnoid hemorrhage, dense cord signCT/CTA: may see mycotic aneurysms
TreatmentSingle anti-platelet (CADISS trial)Single anti-platelet (CADISS trial)Anti-coagulationTreat underlying endocarditis

Clinical Features

Investigations

  • See ischemic stroke section for basic blood work, neuroimaging, and standard stroke investigations

  • Autoimmune work-up: ESR/CRP, ANA, anti-dsDNA, ENA, RF, C3/C4, cryoglobulins

  • Pro-thrombotic/hypercoagulable state work-up: APLA (anti-cardiolipin, B2-glycoprotein-1, lupus anticoagulant), Factor V Leiden, protein C and/or S deficiency, anti-thrombin III deficiency, testicular U/S in males, CT chest/abdo/pelvis for malignancy work-up

  • Infectious work-up: VDRL, HIV serology

Treatment

  • Depends on etiology (see table above for examples)

Cognitive Neurology

Normal Pressure Hydrocephalus (NPH)

By Dr. Calvin Santiago

Pathophysiology and Epidemiology

  • Caused by build-up of CSF

  • Idiopathic NPH (iNPH): Unknown etiology

  • Secondary NPH (sNPH): Due to conditions impairing CSF absorption (e.g. SAH, brain tumors)

Clinical Features

  • Insidious onset of changes starting with gait, then urinary and/or cognitive changes

  • Initially develops non-specific gait difficulties (slowing of gait, feeling imbalanced) before developing difficulties with initiating of gait (previously known as magnetic gait) or increased falls due to postural instability

  • May start with increased urinary frequency, than urgency, and finally incontinence

  • Cognitive impairment includes difficulties in executive dysfunction (e.g. multitasking, judgement)

Neuro-imaging Features

  • Ventriculomegaly present

  • DESH (disproprotionately enlarged subarachnoid hydrocephalus)

  • Crowding present

  • Transependymal flow present

  • Significant ischemic white matter changes present

  • Evans index >0.3

  • Callosal angle between 40º and 90º

Questions to consider

  • Are there secondary causes of NPH? (e.g. Head trauma, meningitis, SAH, ICH, tumors)

  • Does the patient have arthritis, spinal disease, pain/sensory symptoms, or other causes (e.g. poor vision, hearing, parkinsonism) that also explains gait difficulties?

  • Are there other confounders to diagnosis? (e.g. Sleep apnea, fecal incontinence, headaches, REM sleep disorders, orthostatic hypotension, anosmia)

  • Was gait difficulty before or after cognitive decline? - Gait onset before or at same time as cognitive changes has a good prognosis of shunting, not true if cognitive decline occurred prior to gait changes

  • How long have they had cognitive changes and do they have other comorbid cognitive dysfunction? - 2+ years of cognitive decline indicates poor prognosis with shunting

Investigations

  • UHN NPH protocol developed by Dr. Tang-Wai and Dr. Fasano - for use at UHN but can be used as a reference guide at other sites (i.e. but should not be printed and placed in patient's chart)

  • Physical exam to assess for orthostatic hypotension, extraocular eye movements, parkinsonism, UMN presence, and peripheral neuropathy

  • MRI Brain with sagittal FIESTA sequence

  • Need high clinical suspicion of NPH before proceeding with the NPH assessment

NPH assessment

  • Pre and post- MOCA with semantic fluency (e.g. animals), and naming (BNT-15)

  • Pre- video recording of gait (stand up from chair, walk towards camera for at least 10 meters, turn, walk back to chair, repeat)

  • Large volume lumbar puncture (30-40 cc)

  • 1 hour post-LP - Video record of walk

  • 3 hour post-LP - Video record of walk

  • ** Note: Gait is best performed at a Gait Lab to determine if gait is improved/changed

Treatment

  • If patient demonstrates improvement of gait post large-volume LP, they should be referred and assessed by Neurosurgery for possible shunt

Patient Education

  • Unfortunately, prognosis can still be poor without guarantee for improvement post-surgery and there can significant complications including infections and shunt malfunctions post-operatively

  • VP shunt’s main purpose is improvement in gait and urinary incontinence but NOT cognitive impairment

CREUTZFELD-JAKOB DISEASE

By Dr. Andrea Kuczynski

Pathophysiology and Epidemiology

  • Rapidly progressive dementia due to prion disease (conformational change of proteins)

  • Sporadic CJD: age 55-70 years, mean 64 years

  • Variant CJD: mean 26 years, longer duration of symptoms >6 months

  • Iatrogenic CJD: rare, due to dura mater transplantation

  • Heidenhain variant CJD: targeting of prions to occipital lobe

  • Fatal Familial Insomnia: 50's, progressive sleep and autonomic disturbances (hypertension, tachycardia, hyperhidrosis), ataxia

  • Gerstmann-Straussler-Scheniker: 40-50's, progressive cerebellar ataxia, dysarthria, nystagmus and then with cognitive and UMN symptoms

Clinical Features

  • Altered level of consciousness/mental status

  • Psychosis - delusions, hallucinations

  • Progressive cognitive impairment

  • Myoclonus

  • Seizures

  • Cortical visual disturbances (especially in Heidenhain variant CJD) - disturbed perception of colours or structures, optical distortions, hallucinations

  • Cerebellar ataxia

  • Extrapyramidal symptoms

Investigations

  • MRI brain - diffusion restriction in striatum and cortex (cortical ribboning), pulvinar sign, Hockey stick sign

  • LP - RT-QuIC assay with elevated 14-3-3 tau

  • EEG - periodic sharp wave complexes and triphasic components

Differential of cortical ribboning/striatal involvement:

  • Acute severe hepatic encephalopathy

  • Autoimmune encephalitis

  • Hypoglycemic brain injury

  • Hypoxic ischemic encephalopathy

  • Mitochondrial disease

  • Post-ictal state

  • Extrapontine osmotic demyelination

  • EBV encephalitis

Treatment

  • Supportive care

  • Management of comorbidities and symptoms (i.e., anti-epileptic medication)

  • Patient and family counseling

Patient Education

  • Average survival 6-7 months from diagnosis for most cases of CJD, although GSS can be longer (years)

  • Early involvement of the thalamus is a poor prognostic sign

Neuromuscular & Peripheral Neuropathies

Guillain-Barre Syndrome (GBS)

By Dr. Elliot Cohen
Reviewed by Dr. David Fam

Pathophysiology and Epidemiology

  • AIDP - Acute or subacute onset autoimmune demyelinating polyradiculoneuropathy - often thought to be preceded by respiratory or GI infection

Clinical Features

  • Numbness/paresthesias and weakness beginning in the legs, progressing proximally, commonly involving the face, eyes, and respiratory muscles (sensory symptoms are less pronounced than weakness)

  • Onset is over the course of days with rapid progression to possible quadriplegia in a few days, with maximum weakness achieved in 2-4 weeks

  • Hyporeflexia or areflexia

  • Neuropathic pain in lower back and thighs

  • Autonomic involvement, such as tachy/bradycardia, hyper/hypotension, gastric hypomotility, and urinary retention

  • 70% of cases are preceded by respiratory or gastrointestinal infection. Less common precipitants are pregnancy, vaccination (controversial), surgery, or cancer

⊙ CLINICAL PEARL
Often the reflexes in GBS are absent in the setting of initially mild or moderate weakness - if someone is already paralyzed, reduced reflexes may not offer much information since some strength in a muscle is necessary for a reflex. However, if someone has 4/4+ strength but absent reflexes, this suggests a demyelinating process

GBS Variants

  • Acute motor axonal neuropathy (AMAN)

  • Acute motor-sensory axonal neuropathy (AMSAN)

  • Miller-Fisher syndrome (Triad of ophthalmoparesis, ataxia, and hyporeflexia)

  • Paraplegic variant

  • Pharyngeal-cervical-brachial variant

Red flags for other causes (not GBS)

  • HIV

  • Rash

  • Severe pain

  • Pupillary involvement

Investigations

  • If concern for severe weakness, dyspnea, autonomic involvement - telemetry, VBG, consult RT, SLP, PT +/- ICU

  • ANA

  • SPEP with immunofixation and free light chains

  • HBA1c

  • ESR/CRP

  • Lumbar puncture (Cell count, Protein & Glucose, Cultures, Cytology & Flow Cytometry) - CSF analysis may show albuminocytologic dissociation (increased total protein without an increase in WBC)

  • MRI Spine with GAD (may see nerve root enhancement)

  • EMG/NCS (may show prolonged/absent F waves, temporal dispersion prolonged distal latencies, sural nerve sparing)

  • Consider: Lyme, HIV, CMV, ACE for other infectious/inflammatory causes

Treatment

Acute therapies

Usually IVIG is started instead of PLEX first

Intravenous Immunoglubulin (IVIg)

  • For severe exacerbation or prior to surgery if preo-operative bulbar/respiratory symptoms (Onset 3- 10 days, benefits weeks to months)

  • Dosing: 2g/kg IV over 2-5 days

  • Side effects: Infusion reactions, allergic reaction, aseptic meningitis, thromboembolic events, hemolytic transfusion reactions

Plasma Exchange (PLEX)

  • For severe exacerbation or prior to surgery if preo-operative bulbar/respiratory symptoms (Onset 1 - 5 days, benefits 1 - 3 months)

  • Dosing: 4-6 exchanges

  • Side effects: Hypocalcemia, hypotension, febrile/allergy, immunosuppression (if septic, give IVIg instead if indicated)

  • AVOID PLEX AFTER IVIg - otherwise you will be removing IVIg from patient’s system

Click image to enlarge

CIDP

By Dr. Caz Zhu

Pathophysiology and Epidemiology

  • Chronic inflammatory demyelinating polyradiculoneuropathy - similar to AIDP (e.g. GBS) except duration of symptoms can be over months or relapsing-remitting

  • Can initially present as GBS with severe weakness but progression is longer ( > 4 weeks)

  • Can be associated with HIV, paraprotein, inflammatory disease, malignancies

Clinical Features

  • Similar symptoms to that of AIDP/GBS with ascending sensory and motor symptoms (proximal and distal weakness) as well as areflexia Symptom progression beyond the 4 weeks seen in GBS (thus; important to change differential if GBS is persistent and worsening > 1 month)

  • Often have other features such as tremors, cranial nerve/bulbar findings, increased ICP

  • The differential for diseases like CIDP can also include the following:

DiseasesClinical featuresInvestigations
POEMS (Polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes)- Diffuse peripheral neuropathy; distal sensory symptoms with proximal & distal weakness with organomegaly, osteosclerotic bone lesions, castleman's disease, endocrine abnormalities (hypothyroid, diabetes), and skin changes (hyperpigmentation, telangiectasia, raynaud's)- SPEP and immunofixation, Skeletal survey, VEGF levels
CISP (Chronic immune sensory polyradiculopathy)- Prominent sensory ataxia- Similar to CIDP
MMN (Multifocal motor neuropathy)- PURE MOTOR - Asymmetric with multiple neuropathies; with cramps, and fasciculations WITHOUT UMN findings- Anti-GM1 antibodies
MADSAM (Multifocal acquired demyelinating sensory and motor neuropathy)- Insidious, asymmetrical, upper extremity symptoms & cranial nerve involvement (CN 2,3,5,7) 
DADS (Distal acquired demyelinating and symmetrical neuropathy)- Slowly progressive and indolent with sensory predominance; symmetrical distal > proximal symptoms favoring lower extremities; often with ataxia and tremors- anti-MAG antibodies

Investigations

  • If concern for severe weakness, dyspnea, autonomic involvement - telemetry, VBG, consult RT, SLP, PT +/- ICU

  • ANA

  • SPEP with immunofixation and free light chains *

  • HBA1c

  • ESR/CRP

  • Lumbar puncture (Cell count, Protein & Glucose, Cultures, Cytology & Flow Cytometry) - CSF analysis may show albuminocytologic dissociation (increased total protein without an increase in WBC)

  • MRI Spine with GAD (may see nerve root enhancement)

  • EMG/NCS (may show prolonged/absent F waves, temporal dispersion prolonged distal latencies, sural nerve sparing)

  • Consider: Lyme, HIV, CMV, ACE if concern for another process

  • CIDP panel - download requisition - Contactin-1, Neurofascin-155, CASPR1

  • ** If + for IgG or IGA lambda monoclonal gammopathy - consider skeletal survey and VEGF for possible POEMs*

Treatment

  • First line treatment include IVIG and PLEX (see GBS section)

  • Corticosteroids also considered depending on response to IVIG/PLEX - can consider steroid pulse x 5-7 days and then start prednisone 1mg/kg for 1-2 months before tapering

  • "Treatment resistant" - can consider cyclophosphamide but patients with antibodies to contactin-1 and neurofascin can benefit better from PLEX/B-cell depleting therapies (Rituximab)

  • POEMS - treatment is with targeted radiation (limited disease) or chemotherapy/stem cell transplant

Myasthenia Gravis

By Dr. Elliot Cohen
Reviewed by Dr. David Fam

Pathophysiology and Epidemiology

  • Autoimmune disease affecting post-synaptic proteins at neuromuscular junction - impairs binding of acetylcholine to receptor

  • Common Myasthenia Gravis antibodies include: Anti-ACHr (80-85%) and MuSK (8%)

  • More often seen in younger females and older males

  • Patients with MG may also have a thyoma

Clinical Features

  • Classic presentation is fatigable weakness of muscles - patients may endorse that symptoms worsen with activity (e.g. diplopia worse with reading, dysarthria if they talk for a long period of time)

  • Most common presenting symptoms:

WeaknessClinical presentation
Ocular weakness - most commonDiplopia, ptosis (may be asymmetric)
Facial weaknessEye closure weakness, “sad” facial appearance
Bulbar weaknessDysarthria (nasal speech), dysphonia, dysphagia, difficulty chewing over time
Limb WeaknessLoss of strength in different muscle groups (arms, legs, neck)
Respiratory weaknessOrthopnea
  • Patients may have ocular myasthenia gravis but this can “generalize” to affect elsewhere

  • Myasthenia Gravis can be exacerbated by: stress, illnesses, fever, hypothyroidism/hyperthyroidism, menstruation, drugs

Myasthenic Crisis

Life-threatening exacerbation of MG with worsening muscle weakness leading to respiratory failure

  • Clinical signs of an impending crisis include - prominent bulbar involvement, neck and deltoids weakness, changes in respiration

  • Need urgent evaluation and measurement of respiratory parameters (FVCs)

  • Indications for intubation include: FVC < 15 ml/Kg, PEmax < 20 cmH2O, Pmax less than -20 cmH2)

Physical Exam

Ptosis

  • Frontalis activation to compensate for ptosis

  • If asymmetric ptosis, lifting the obviously ptotic eyelid may bring out ptosis on the other side as the frontalis activation relaxes

  • Sustained upgaze for 1 minute with worsening of ptosis (diplopia will worsen at 15-30 seconds)

  • Ice-pack test: Hold ice against ptotic eye for 2-5 minutes. Improvement of ptosis is expected

Facial and neck weakness

  • Inability to bury the eyelashes upon eye closure with subsequent “peek sign” (sclera becomes visible as eye closure weakens)

  • Ability of examiner to open jaw against resistance (jaw closure is weaker than jaw opening)

  • Testing power for neck flexion and extension

Diplopia

  • Binocular diplopia with any combination of extraocular movement abnormalities (though downgaze typically spared)

Single breath count

  • Count to 20 at 2 Hz on one breath. If able to do so, respiratory weakness is unlikely. Also listen for nasal dysarthria

Limb power

  • Repeatedly test power in deltoids, triceps, or hip flexors, assessing for fatigability

Investigations

  • CBC, LFTs, HbA1c

  • Repetitive nerve stimulation and single-fiber EMG

  • CXR → CT Chest to rule out thyoma

  • AChR and MuSK antibody testing (Mitogen requisition forms or BC Neuro requisition forms)

  • If concern for respiratory weakness - VBG and consult RT +/- ICU , FVCS daily - TID (see above for indications for intubation for myasthenic crisis)

  • Refer for thymectomy if thymoma present (although can consider trhymectomy for non-thymomatous myasthenia gravis - see below in treatment)

Click image to enlarge

Treatment

Symptomatic management

Pyridostigmine (Mestinon): Acetylcholinesterase inhibitor

  • Temporary symptomatic improvement of symptoms (onset of action: 20-30 minutes)

  • Starting dose: 30 mg PO q4-6 hours (can increase by 30-60 mg every 1-2 weeks up to a maximum of 480 mg/day)

  • Side effects: Nausea, vomiting, diarrhea, secretions

  • May worsen symptoms in patients with anti-MuSK antibody-positive MG

  • Can increase secretions in patients in MG crisis - often held in the ICU setting

Myasthenic Crisis

Intravenous Immunoglubulin (IVIg)

  • For severe exacerbation or MG crisis (onset of action: 3-10 days, benefits last weeks to months)

  • Dosing: 2g/kg IV over 2-5 days

  • Side effects: Infusion reactions, allergic reaction, aseptic meningitis, thromboembolic events, hemolytic transfusion reactions

Plasma Exchange (PLEX)

  • For severe exacerbation or MG crisis (preferred to IVIg in anti-MuSK antibody-positive MG) (onset of action: 1-5 days, benefits last 1-3 months)

  • Dosing: 4-6 exchanges

  • Side effects: Hypocalcemia, hypotension, febrile/allergy, immunosuppression

  • AVOID PLEX AFTER IVIg - otherwise you will be removing IVIg from patient’s system

Click image to enlarge

Disease-modifying therapy

Prednisone

  • First line disease modifying therapy for intolerable symptoms or risk of deterioating respiratory/bulbar function

  • Starting dose for ocular - mild generalized MG: 10-20 mg PO daily

  • Starting dose for moderate-severe generalized MG: 0.5 - 0.75 mg/kg/day (start at 10 mg PO and increase by 10 mg every 3-5 days)

  • Starting dose for intubated patients: 100 mg PO daily

  • There can be a phenomenon of transient prednisone associated weakness that patients experience when first starting prednisone

  • Adverse effects: Sleep disturbance, mood changes, weight gain, GI irritation, avascular necrosis

  • Patient should also be on Vitamin D and Calcium

  • Patients may require PJP prophylaxis and should have TB, hepatitis B, and strongyloides testing prior to initiation of prednisone

Other disease modifying therapies (steroid-sparing) include:

  • Azathioprine

  • Mycophenolate mofetil

  • Cyclosporine

  • Tacrolimus

  • Rituximab

  • NEW TREATMENTS - Eculizumab, Ravulizumab, Efgartigimod

Thymectomy

  • Should be considered in patients who are found to have a thymoma and ACHr +

  • Can also be considered in patients < 55 who have moderate-severe generalized MG for < 2 years who may not be adequately controlled with symptomatic management

Patient Education

  • Counsel patients on medications to avoid that can exacerbate MG

Drugs that exacerbate MG

  • Absolutely contraindicated - Alpha-interferon, botulinum toxin, D-penicillamine, telithromycin

  • Relatively contraindicated:

Drug classSpecific drugs
AntibioticsMacrolides, fluoroquinolones, aminoglycosides
AntiepilepticsPhenytoin, gabapentin, barbiturates
Beta-blockersIncluding eye drops
Calcium-channel blockers-
Magnesium saltsMgSO4 , MgOH
Lithium-
Anti-arrhythmicsProcainamide, quinidine
Anti-malarialsQuinine, hydroxychloroquine
ParalyticsSuccinylcholine, rocuronium
StatinsAtorvastatin, Rosuvastatin - Can use at lowest possible dose with monitoring
Respiratory depressantsBenzos, Opiates - Monitor for respiratory depression

Lambert-Eaton Myasthenic Syndrome (LEMS)

By Dr. Elliot Cohen
Reviewed by Dr. David Fam

Pathophysiology and Epidemiology

  • Autoimmune disease affecting pre-synaptic voltage gated calcium channels (VGCC) - impairs release of acetylcholine into synaptic cleft

  • Can be either primary autoimmune or paraneoplastic (almost always associated with small cell lung cancer in adults)

  • Common antibodies: anti-VGCC found in 90% of patients

  • Age of onset - bimodal peak at ~35 and 60

Clinical Features

  • Prominent proximal weakness that progresses distally

  • Areflexia (but reflexes improve with sustained voluntary contraction)

  • Autonomic dysfunction: Dry mouth & eyes, constipation, erectile dysfunction, orthostatic hypotension, pupillary abnormalities

Investigations

  • anti-VGCC antibody testing (Mitogen requisition forms)

  • NCS and EMG

  • CT Chest to assess for SCLC

  • Refer to oncology for management of underlying SCLC if paraneoplastic

Treatment

Symptomatic management

3,4-Diaminopyridine (3,4 DAP)

  • Increases pre-synaptic release of Ach by blocking K+ channel, onset of action 30-90 minutes

  • If patient improves, no need for another treatment

  • Starting dose: 5-10 mg PO TID or QID (can increase to max 100 mg/day)

  • Side effects: Risk of seizures with > 100 mg/day, paraesthesia, nausea, palpitations

Disease-modifying therapy

  • Consider IVIG, PLEX, immunotherapy

  • ** For paraneoplastic LEMS - immunosuppression not recommended given risk of tumor progression **

Bell's Palsy

By Dr. Conrad Eng
Reviewed by Dr. David Fam

Pathophysiology and Epidemiology

  • Thought to be virally mediated by reactivation of HSV1 infection of the facial nerve

Clinical Features

  • Spontaneous, acute (can occur within hours), isolated unilateral facial palsy - since it’s lower motor neuron pattern of weakness, there should be weakness in BOTH upper and lower part of the face (e.g unlike a stroke where a facial droop is ‘forehead sparing’)

  • Patients may endorse a slight ear pain behind the ear during the onset

  • Patients may endorse difficulties closing eye, smiling, difficulty eating, decreased taste

  • Symptoms occur over 72 hours and gradually recover over months

  • As symptoms improve, synkinesis can occur due to aberrant regeneration of facial nerve (e.g. eye closing when smiling)

Red flags of atypical Bell’s Palsy

  • Gradual onset (slowly progressive over weeks and other cranial nerve involvement) - consider neoplastic cause

  • Vertigo, hearing loss, tinnitus - consider CPA angle mass/lesion

  • Bilateral facial nerve palsy - consider other infectious causes e.g. Lyme

  • Vesicles in external auditory canal, tympanic membrane, orophyrynx - Ramsay Hunt

  • Sensory symptoms - usually Bell's Palsy have more weakness than sensation difficulties

  • Extraocular eye movement abnormalities

Investigations

  • Usually a clinical diagnosis but if red flags are present, consider MRI brain +/- GAD

  • If suspicious for Lyme disease - can send for serological testing

Treatment

  • Eye care: given poor eyelid closure/tearing from facial palsy - consider artificial tears applied regularly, ointment, patches

  • Corticosteroids: given within 72 hours of symptom onset - 60-80 mg/day for 1 week

  • Adverse effects: Sleep disturbance, mood changes, weight gain, GI irritation, avascular necrosis

  • Patient should also be on Vitamin D and Calcium

  • Antiretrovirals: no clear evidence to be used with steroids but can consider: valcyclovir 1000 mg TID for 1 week - use with caution in patients with renal failure

Patient Education

  • Prognosis is good, 85% of patients recover within 3 weeks and if facial function does not return within 3-4 months, consider another diagnosis

  • Even after the disease is treated, there may still be asymmetry of the face and synkinesis with facial movements

Neuropathy

  • Can be divided into two categories - focal neuropathy (one nerve/root involvement) vs multifocal neuropathy (subdivided even further into three sections - see below)

Focal neuropathy

  • Can be focal mononeuropathy (affecting one nerve, e.g. carpal tunnel syndrome) or radiculopathy (affecting one nerve root e.g Disc herniation) or plexopathy (affecting plexus - e.g. Parsonage Turner)

  • Symptoms include numbness, paraesthesia, pain, and weakness that follows the distribution of the nerve or root

  • Usually due to a compressive or traumatic etiology

Note:
In Common Upper Extremity Mononeuropathies: Covers carpal tunnel, ulnar and radial neuropathy
In Common Lower Extremity Mononeuropathies: Covers lumbrosacral radiculopathy and foot drop (peroneal neuropathy)

Multifocal neuropathy

Polyneuropathy

  • Sensory symptoms (paraesthesia then numbness, usually vibration/proprioception affected first) with motor symptoms later in onset, length-dependent pattern (glove and stocking), reflexes diminish in ascending pattern

  • Often have autonomic dysfunction (e.g. decreased sweating in the feet, orthostatic hypotension, erectile dysfunction)

  • DDx: Toxic/metabolic causes (Diabetes, EtOH), Genetics (CMT)

Mononeuropathy multiplex

  • Presentation similar to multiple focal neuropathies

  • Often has a patchy pattern of sensory and motor symptoms, asymmetrical, nerves affected at different times, and subacute in onset

  • Unlike polyneuropathy, often have motor symptoms > sensory symptoms, asymmetrical reflexes, and occasionally cranial nerve involvement

  • DDx: Vasculitis (polyarteritis nodosa, eGPA, Sjogren's), Sarcoidosis

Generalized

  • ** Similar to polyneuropathy but more acute /subacute in onset with possible involvement of cranial nerves

  • DDx: GBS, CIDP

Common upper extremity mononeuropathies

By Dr. Conrad Eng and Dr. Caz Zhu

Upper extremity anatomy

  • Nerve roots supplying brachial plexus are C5-T1

NerveNerve rootsMuscle innervation
AxillaryC5-C6Deltoids
MusculocutaneousC5-C6Biceps
Median nerveC6-T1Pronator teres, flexor carpi radialis, LOAF (lumbricals 1+2, opponens pollicis, abductor pollicis brevis, flexor digitorum superficialis)
Anterior interosseous branch of median nerveC8-T1Flexor pollicis longus, flexor digitorum profundus 1 + 2
Ulnar nerveC8 - T1Flexor carpi ulnaris, flexor digitorum profundus 3+4, adductor pollicis, lumbricals 3+4, dorsal + palmar interossei, opponens digiti minimi, flexor digiti minimi, abductor digiti minimi
Radial nerveC5-C7Brachioradialis, triceps, extensor carpi radialis
Posterior interosseous branch of radial nerveC6-C8Supinator, extensor carpi ulnaris, extensor digitorum, extensor pollicis longus, extensor pollicis brevis, extensor indicis, extensor digiti minimi

Carpal Tunnel Syndrome

Pathophysiology and epidemiology

  • Common entrapment of the median nerve in the carpal tunnel of the wrist

  • Often affect women more than men

  • Can be idiopathic but other mechanisms include repetitive stress injury (wrist usage), edema, inflammation, or trauma to the wrist

  • Risk factors include obesity, pregnancy, aromatase inhibitors, acromegaly, and other medical conditions (e.g. diabetes, arthritis, hypothyroidism, infiltrative disorders, connective tissue disorders)

Clinical Features

  • Sensory symptoms: Can have pain, numbness, or paraesthesia of the hands (often noted in textbooks that it involves the distal thumb and 2nd + 3rd digits but spares the palmar aspect of the thumb since palmar sensory branch does not pass through carpal tunnel - however, patients may not always state that)

  • Some patients may endorse tingling radiates up to the shoulder at night when symptoms are severe

  • Motor symptoms: Difficulties holding objects if severe, thumb abduction weakness - if severe, will appreciate thenar atrophy

  • Key symptom is whether patients may complain of pain and paraesthesia waking them up at night or in the morning and improved with shaking/wringing of the hands

  • Provocative maneuvers for CTS: Phalen and Tinel

Physical exam

If suspicious for carpal tunnel syndrome:Motor findings:
Thumb abduction (APB) should be weak (Carpal tunnel - Median)
Thumb flexion (FPL) and pronation of forearm (Pronator Teres) should be normal (Proximal Median)
Elbow flexion (biceps) should be normal (C6)
Elbow extension should be normal (C7)
Sensory:
Digits 1-3 of hand that spares the thenar eminence
Positive Phalen's (forcefully flex wrists and hold for 30 seconds)
Positive Tinel's (can be a false positive at times)
Negative Spurling's (radiculopathy pain)
Reflexes:
Biceps, triceps, and brachioradialis reflex should be normal

Investigations

  • EMG/NCS

Treatment

  • Individualize treatment based on how severe nerve compression is as determined by electrodiagnostic findings

  • If mild-moderate - consider wrist splints at night and NSAID treatment for pain

  • If severe with significant motor deficits - carpal tunnel release surgery for those of whom nonsurgical therapies have failed

Ulnar neuropathy

Pathophysiology

  • Entrapment of the ulnar nerve at the elbow is second most common compressive neuropathy (compression at wrist (Guyon’s canal) is less common)

  • Usually due to compression or stretch at the groove of the elbow or cubital tunnel

  • Other etiologies include trauma and masses at the site (e.g. tumors, ganglias)

Clinical Features

  • Motor symptoms: Weak grip, dexterity, pinch strength and there may be atrophy of hypothenar and thenar (but thumb abduction will be spared)

  • Sensory symptoms: Pain, numbness and paraesthesia along the pinky and 4th digit of fingers

  • Provocative maneuvers: Tinel’s test on elbow

Physical exam

If suspicious for ulnar neuropathy:Motor findings:
Pinky flexion weakness (FDM), Finger abduction/adduction weakness (Dorsal/palmar interossei), and thumb adduction weakness (adductor pollicis) (Ulnar nerve)
Thumb abduction (APB) should be normal (Median nerve)
Thumb flexion (FPL) should be normal (Anterior Interosseous Nerve/C8)
Extension of index (EIP) should be normal (Radial nerve)
Sensory:
Digits 4+5 and ulnar border of hand affected
Positive Phalen's (forcefully flex wrists and hold for 30 seconds)
Positive Tinel's (can be a false positive at times)

Hand postures
1. Benediction posture: Clawing of ring and little finger (due to weakness of third and fourth lumbricals) and fingers and thumbs abducted (adductor pollicis weakness)
2. Wartenberg’s sign: Abducted little finger (weakness of interosseous muscle)
3. Froment’s sign: Difficulty pinching a piece of paper

Investigations

  • EMG/NCS

Treatment

  • Individualize treatment based on how severe nerve compression is as determined by electrodiagnostic findings

  • If mild-moderate - consider wrist splints at night and NSAID treatment for pain, avoid leaning on elbow

  • If severe with significant motor deficits - could consider surgery for cubital tunnel release

Radial neuropathy

Pathophysiology

  • Radial neuropathies are divided into three lesions: at the axilla, spiral groove, or below the elbow (posterior interosseous neuropathy)

  • Most common neuropathy is a lesion at the spiral groove due to compression or prolonged immobilization (e.g. Saturday night palsy)

  • Radial neuropathies at the axilla are due to prolonged compression (e.g. crutches)

  • Posterior interosseous neuropathy (PIN) may be due to entrapment

Clinical Features

  • Wrist drop is often the presenting chief concern

  • Radial neuropathy at spiral groove: wrist drop and finger drop, weakness in supination, sensory loss in lateral dorsum of hand and fingers

  • Radial neuropathy at the axilla: Motor weakness as above WITH arm extension weakness and sensory loss extending to posterior forearm and arm

  • Posterior interosseous neuropathy demonstrates reduction in wrist extension with radial deviation and NO SENSORY LOSS

  • If symptom onset of wrist drop is acute and if there are UMN findings, consider stroke/lesion in hand-knob region of the brain

⊙ CLINICAL PEARL
Weakness can seem more profound in the setting of mechanical disadvantage (e.g. if finger extension is weak, finger abduction may also seem weak since hand is in a "finger drop" position). If finger extensions are weak, place hand on flat surface to examine finger abduction.

Physical exam

Localizing wrist drop:

NerveSensory changesMotor weaknessReflexes affected
C7Digit 3Pronation of forearm (pronator teres)Triceps reflex
Radial nerve (axilla)Sensory loss to posterior arm and forearmElbow extension (triceps)Triceps reflex
Radial nerve (spiral groove)Sensory loss in lateral dorsum of handElbow flexion/supination (brachioradialis)Brachioradialis reflex
PINN/AFinger extension weakness: Extension of index finger (EIP), extension of thumb (EPL/EPB), extension of digits (EDC)N/A

Investigations

  • EMG/NCS

  • +/- CT Head/CTA to rule out stroke for acute wrist drop

Treatment

  • Symptoms generally resolve in weeks to months

  • Consider NSAIDs for pain management and wrist splinting to assist with hand function

Common lower extremity mononeuropathies

By Dr. Conrad Eng

Lower extremity anatomy

  • Nerve roots supplying lumbosacral plexus are L1 - S3

NerveNerve rootsMuscle innervation
FemoralL2-L4Iliopsoas, quadriceps
ObturatorL2-L4Thigh adductors
Superior GlutealL4-S1Gluteus medius/minimus
Inferior GlutealL5-S2Gluteus maximus
Sciatic NerveL5-S2Hamstrings
Peroneal NerveL4-S1Tibialis anterior, peroneus longus/brevis, extensor hallucis longus, extensor digitorum longus/brevis
Tibial NerveL5-S2Gastrocnemius, soleus, tibialis posterior, flexor digitorum longus, flexor hallucis longus

Lumbosacral Radiculopathy

Pathophysiology

  • Commonly due to nerve root compression from disc herniation/spondylosis (e.g. degenerative arthritis)

  • Less common can be due to inflammation, neoplasm, vascular disease

  • Most common nerve roots affected are L5 and S1

Clinical Features

  • Lower back pain that is radicular (sharp, burning, needle pain that radiates down leg) with sensory symptoms of numbness, tingling, burning, electric shock

  • Can also have associated weakness with walking up and down stairs

  • May have UMN signs

  • Common tests include straight leg raise (patient supine while examiner raises leg on the affected side with knee extended. Test is positive and suggestive of L5 or S1 nerve root compression if radicular symptoms are reproduced or worsened between 30-70 degrees)

Red flags to rule out for lower back pain

Symptoms, historyPossible diagnosis
Night painTumor
Fever, history of recent bacterial infection or IV drug use, severe back spasmDiskitis or epidural abscess
Leg painNerve root compression
Bilateral lower extremity weakness or numbness, bladder or bowel dysfunctionCauda equina or conus compression
Major traumaFracture, dislocation
Minor trauma with osteoporosisCompression Fracture
History of carcinomaMetastatic disease
Systemic symptomsMultiple myeloma
Back pain in childTumor, tethered cord
Worker’s compensation or legal claimSecondary gain

Investigations

  • MRI lumbar spine +/- GAD

  • NCS/EMG

Treatment

  • Improvement over months - a year

  • Symptomatic treatment with neuropathic pain medications (e.g. pregabalin, gabapentin)

  • If no improvement or significant pain component - consider referral to pain specialist for epidural injections

  • If symptoms are significant with motor deficits - referral to surgery

Peroneal Neuropathy

Pathophysiology

  • Most common lower extremity mononeuropathy

  • Commonly due to compression against fibular head (leg crossing, trauma, kneeling, surgery, weight loss)

Clinical Features

  • Motor symptoms include foot drop (due to tibialis anterior) and impairment in foot eversion

  • Sensory symptoms include numbness along lateral calf and dorsum of foot

Differentiating foot drop

NerveTibialis Anterior (Ankle Dorsiflexion)Peroneus longus (Ankle Eversion)Tibialis Posterior (Ankle Inversion)Gastrocnemius (Ankle Plantarflexion)Gluteus medius (Hip Abduction)
Deep peronealX----
Common peronealXX---
Sciatic nerveXXXX-
Lumbosacral plexusXXX* (if S1 involved)X
L5 RootXXX-X

Investigations

  • NCS/EMG

Treatment

  • Individualize treatment based on how severe nerve compression is as determined by electrodiagnostic findings

  • May require orthotics/foot brace to help provide support to the foot with dorsiflexion weakness

  • Physiotherapy/Occupational therapy to help retrain mobility

Polyneuropathies

By Dr. Caz Zhu

Definition

  • Affecting multiple nerves - can be classified into polyneuropathy, mononeuropathy multiplex, or generalized neuropathy

  • Any process affecting the peripheral nervous system that causes pain, paraesthesia, numbness, or weakness

  • Can affect the nerve roots to the peripheral nerves

**⊙ CLINICAL PEARL **
Unlikely to be a peripheral neuropathy if the patient presents with pure motor symptoms (i.e. absence of pain, numbness, etc)

Clinical Features

  • What modality is affected? Patients may have numbness, paraesthesia, pain, sensory ataxia, weakness, and autonomic symptoms (e.g. impaired sweating) which may point to one diagnosis more than another

  • How long has the patient had symptoms? A slower, chronic progression suggests a metabolic, toxic, or genetic (CMT) disease vs an acute onset may be more inflammatory

  • Length dependent or non-length dependent? Length-dependent patterns are typically axonal and non-length independent are often demyelinating (HOWEVER, demyelination can be associated with axonal loss)

  • Demyelinating neuropathies are special because acquired demyelinating neuropathies are often treatable

AxonalDemyelinating
Structure affectedAxonal dysfunctionMyelin affected
**Pattern **Length-dependent process, ascending from the feet up (glove and stocking)Proximal and distal involvement, can have hand and feet involvement at the same time
SymptomsParaesthesia, numbness, commonly vibration/proprioception involvement more than motor involvementMotor symptoms can be more predominant than sensory symptoms, early loss of reflexes
Common etiologiesMetabolic (diabetes, B12, hypothyroidism) , medications, chemotherapy, toxins (alcohol, heavy metals), infections, malignancy, vasculitisGBS/CIDP, MMN, POEMS, Toxins (amiodarone, chloroquine), Genetics

Investigations

  • CBC, ESR, CR, HbA1c, TSH, ANA, B12, SPEP

  • NCS/EMG

  • MRI of cauda equina MRI with contrast to assess for root enhancement

  • +/- LP to send for CSF if concerned for GBS or other immune/malignancy causes

Treatment

Symptomatic treatment for neuropathic pain

  • ** Gabapentin**(Starting dose: 300 mg BID/TID - can increase up to 1800 - 3600 mg max per day), Side effects: Drowsiness, ankle edema, weight gain, and caution in use with patients with renal failure

  • Pregabalin (Starting dose: 75 mg BID and increase up to 150 - 600 mg max daily) Side effects: Drowsiness

  • Amitriptyline (Starting dose: 10 mg QHS and increase up to 25 - 50 mg max daily) Side effects: Anticholinergic effects (Drowsiness, constipation, dizziness, dry mouth)

  • Duloxetine (Starting dose of 60 mg daily and increase to 60 mg BID) Side effects: Nausea, drowsiness, mental fogginess

Treatment of acquired demyelinating disorders

  • ** GBS/CIDP** - See GBS for further information

Patient Education

  • Importance of foot care, weight loss, management of metabolic and other conditions that is contributing to peripheral neuropathy

  • Counseling patients that for the majority of peripheral neuropathy (especially metabolic conditions like diabetes), symptoms may not improve or disappear completely even with treatment (success in treating neuropathic pain is 50% reduction in pain in 50% of patients)

  • Goal of treatment is to help patients live better and help maintain function & mobility (e.g. avoid falling, being able to walk)

Neuro-infectious Disorders

Viral Encephalitis

By Dr. Jeremy Zung
Reviewed by Dr. Alex Muccilli

Pathophysiology and Epidemiology

  • Diffuse or focal inflammation of the parenchyma due to infection (more commonly viral over bacterial, fungal, etc), autoimmune, and other processes

  • HSV1 accounts for up to 20% of identified viral encephalitis and has a mortality of 70% if untreated

  • More than 50% of presumed viral encephalitis remains undiagnosed

Risk factors

  • Travel (e.g., Zika virus, rabies in Africa)

  • Season (e.g., rabies, WNV, Powssan, Zika, EBV in the summer)

  • Immunocompromised host

  • Animal/insect/tick bites

  • Hiking, camping, fresh water exposures

Clinical Features

  • Lethargy

  • Altered mental status/level of consciousness

  • Headache

  • Seizures

  • Focal neurological deficits: aphasia, hemiparesis or flaccid paralysis, paraesthesias

  • Maculopapular pruritic rash (WNV) or Dermatoma rash (VZV)

Investigations

  • Stat CT head to rule out acute intracranial abnormality (i.e., hemorrhage, stroke, mass lesion)

  • CBC

  • Lytes, extended lytes (Mg, Ca, PO4), creatinine

  • Blood glucose

  • Liver enzymes

  • Toxicology screen if indicated

  • Blood and urine cultures

  • HIV serology

  • LP: cell count and differential, protein, glucose, bacterial/viral (HSV, VZV, WNV, CMV)/fungal cultures and Gram stain (HSV PCR sensitivity 96%, specificity 99%), cytology/flow cytometry - commonly find leukocytosis (lymphocytic), normal glucose, normal/elevated protein

  • Ask the Micro Lab to hold extra CSF for additional testing

  • MRI brain with contrast when clinically stable - HSV preferentially causes T2/FLAIR hyperintensities the medial temporal lobes or hemorrhagic necrosis; VZV may be associated with unilateral infarcts and vasculopathy; WNV preferentially causes T2/FLAIR hyperintensities in the basal ganglia/thalamus and leptomeningeal/periventricular enhancement

Treatment

  • Prudent to cover for bacterial meningitis until cultures are available: CTX 2g IV BID or Cefotaxime 2g IV q4-6h + Vancomycin 1-2g IV q12h + Dexamethasone 10mg IV q6h (for 4 days) administered before or with first dose of antibiotics

  • Consider adding Ampicillin 2g IV q4h if patient is less than 2, older than 50, immunosuppressed, or chronically ill for Listeria coverage

  • If AIDS and low CD4 (less than 100< consider gancyclovir for CMV (Check with Infectious Disease)

  • Acyclovir 10mg/kg IV q8h x14-21 days for encephalitis, x10-14 days for meningitis (HSV/VZV)

  • Supportive care for other viruses

  • IV hydration to avoid renal failure

Patient Monitoring

  • Viral encephalitis, unlike meningitis, is life-threatening and results in permanent neurologic damage

  • Often self-limiting, but the host inflammatory response contributes to neurologic damage

  • Post-infectious acute demyelinating encephalomyelitis (ADEM)

  • Up to 50% have permanent neurologic sequelae

  • 20% of patients with HSV encephalitis may go on to develop an autoimmune encephalitis, occurring 2-6 weeks after the viral encephalitis

Patient Education

  • Patients at risk should receive shingles vaccinations to reduce the risk of HSV/VZV encephalitis

Bacterial Meningitis

By Dr. Jeremy Zung
Reviewed by Dr. Alex Muccilli

Pathophysiology and Epidemiology

  • Inflammation of meninges - most commonly caused by infection (but can also be caused by chemical irritation, neoplastic causes)

  • Common pathogens: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Listeria monocytogenes (immunocompromised, EtOH misuse), Escheria coli

For common bacteria infections per age group, see Figure 1 in the article: Bacterial Meningitis in the United States, 1998–2007

Clinical Features

  • Fever

  • Headache

  • Neck stiffness - may be masked by analgesia or corticosteroids; Kernig and Brudzinski signs (limited sensitivity and specificity)

  • Altered mental status/level of consciousness

  • Cranial neuropathies (common with basiliar meningitis)

  • Seizures

  • Petechial rash (N. meningitidis)

  • Infants/children: nausea/vomiting, irritability, lethargy, anorexia, hypotonia, seizures (up to 34%), bulging anterior fontanelle, hydrocephalus

  • Immunocompromised hosts may not show classic signs!

Investigations

  • Stat CT head to rule out acute intracranial abnormality (i.e., hemorrhage, stroke, mass lesion) - consider CT with contrast to increase sensitivity for meningeal and parenchymal involvement

  • CBC

  • Lytes, extended lytes (Mg, Ca, PO4), creatinine

  • Blood glucose

  • Liver enzymes

  • Toxicology screen if indicated

  • Blood and urine cultures - bacteremia is common in up to 70% (always do cultures before starting antibiotics)

  • LP: cell count and differential, protein, glucose, bacterial/viral/fungal cultures and Gram stain, Cryptococcal, VDRL- commonly find leukocytosis (80-90% neutrophils), low glucose, elevated protein in bacteria meningitis

  • MRI brain with contrast when clinically stable

  • Consult ID to guide longterm management of antimicrobial agents

Differential for CSF findings

Neutrophilic pleocytosisLymphocytic pleocytosisHypoglycorrhachia (CSF: serum glucose less than 0.4)
Bacterial (not lyme or syphilis), epidural abscess, early viral, early TB/mycobacterial, fungal, cryptococcal, 1° amoebicViral (HSV, VZV, CMV), acute HIV, TB, bacterial (syphilis, lyme, leptospirosis,brucella, bartonella), fungal, cancer, partially-treated bacterial meningitisBacterial, fungal, carcinomatous, TB, sarcoid, SAH (present in 1%), lymphoma/carcinomatosis

Treatment

If there is a strong suspicion for meningitis and the patient is unwell (e.g. decreased level of consciousness) , do not wait to do a lumbar puncture to start empiric antibiotics (rapid start of antibiotics is crucial to decrease mortality)

  • Empiric treatment: CTX 2g IV BID or Cefotaxime 2g IV q4-6h + Vancomycin 1-2g IV q12h + Dexamethasone 10mg IV q6h (x 4 days) (administered before or with first dose of antibiotics + Acyclovir 10mg/kg IV q8h (as it is difficult to exclude viral encephalitis)

  • Consider adding Ampicillin 2g IV q4h if patient is less than 2, older than 50, immunosuppressed, or chronically ill for Listeria coverage

  • Steroids are associated with reduced risk of hearing loss in children, and reduced morbidity/mortality with S. pneumoniae

  • Antimicrobial therapy can be adjusted depending on cultures

OrganismAntimicrobialsDuration of Treatment (days)
S. pneumoniaeCTX 2g IV BID or Cefotaxime 2g IV q4-6h + Vancomycin 1-2g IV q12h + Dexamethasone 10mg IV q4-6h10-14
N. meningitidisCTX 2g IV BID or Cefotaxime 2g IV q4-6h7
H. influenzaeCTX 2g IV BID or Cefotaxime 2g IV q4-6h7-10
L. monocytogenesAmpicillin 2g IV q4h21
P. aeruginosaMeropenem 2g IV q8h or Ceftazadime 2g IV q8h + Vancomycin 1-2g IV q12h21

Patient Monitoring

  • There are increased risks of hearing loss, cognitive impairment, hemiparesis, epilepsy, vasospasm, ischemic and hemorrhagic stroke, and cerebral venous thrombosis

Patient Education

  • Patients at risk should receive Prevnar vaccinations to reduce the risk of bacterial meningitis due to S. pneumoniae

Neurosyphilis

By Dr. Jeremy Zung
Reviewed by Dr. Alex Muccilli

Clinical Features

Primary - mean 2-3 weeks post-exposure; spontaneous resolution within 3-6 weeks without treatment

  • Chancre: painless, non-pruritic, genital or oral

  • Lymphadenopathy

Secondary - mean 2-12 weeks post-exposure but can occur over weeks-years and resolve without treatment; early neurosyphilis

  • Rash: diffuse, symmetric, macular including palms/soles, condyloma lata in intertriginous regions and mucous patches

  • Neurological features: meningitis/encephalitis, meningovascular syphilis causing stroke (10%), cranial nerve palsies (especially II, III, VI, VII), uveitis/iritis with decreased visual acuity, otosyphilis with hearing loss and tinnitus, behavioural/cognitive changes

  • Other organ involvement: hepatitis, nephropathy, adenopathy, fever, sore throat, headache, generalized painless lymphadenopathy

Tertiary - years-decades post-exposure; late neurosyphilis

  • Cardiac involvement: aortitis, aortic aneurysms, saccular aneurysms

  • Gummatous lesions: affect long bones, upper respiratory tract

  • Neurological features: Symptoms of early neurosyphilis, PARESIS (see table below), and tabes dorsalis (33% - affects dorsal roots and dorsal columns of spinal cord)

PARESISFeatures
Personality disturbancesMania, Psychosis
Affect abnormalitiesDepression
Reflex hyperactivity 
Eye abnormalitiesUveitis/keratitis, Argyll Robertson pupils (constrict to accommodation but not to light, irregular pupil - Video)
Sensory changesSensory loss, impaired vibration and proprioception, lancinating pain, sensory ataxia
Intellectual impairmentFronto-temporal dementia
Slurred speech 

Latent - asymptomatic period

Investigations

Investigations  
Serum nontreponemal testsVenereal disease research laboratory (VDRL), Rapid plasma reagin (RPR). 
Serum treponemal testsFluorescent treponemal antibody absorption (FTA-ABS)., T. pallidum particle agglutination assay (TPPA)., T. pallidum enzyme immunoassay (TP-EIA) and chemiluminescence immunoassay (CIA)*NOTE: Public Health Ontario uses this chemiluminescent microparticle immunoassay as a first screen, then confirms with RPR or TPPA.
CSFLmphoytic pleocytosis, elevated protein, CSF VDRL 

If serum assays are positive:
If reactive and symptoms/signs are consistent with neurosyphilis, then perform lumbar puncture with CSF-VDRL. If positive, then treat for neurosyphilis.
Even with CSF-VDRL negative, treat for neurosyphilis if any abnormalities in CSF e.g. >5 WBC/microL or protein >0.45g/L and high clinical suspicion.

Treatment

  • Penicillin G 4 million units IV q4h x14 days.

  • Jarisch-Herxheimer reaction: result of release of endotoxin-like products within a few hours of the first dose of antibiotic; fever, chills, hypotension, hyperventilation, flushing.

  • If Penicillin allergy: Ceftriaxone 2g IV daily x14 days.

  • If severe Penicillin allergy: Doxycycline 200mg p.o. BID x28 days.

Patient Education

  • Pregnancy: screening (e.g. CIA) should be performed at the time pregnancy is confirmed.

  • Serologic and CSF titres of VDRL can be checked and fall with treatment of syphilis.

  • If untreated, syphilis can lead to tabes dorsalis or general paresis of the insane (frontotemporal dementia), which have declined in the antibiotic era.

Neuro-otology

Reviewed by Dr.Tess Fitzpatrick

The Head Impulse-Nystagmus-Test of Skew (HINTS) exam is a useful test to assess for central vs peripheral causes of vertigo/gait unsteadiness.

  • Head Impulse: Testing vestibulo-ocular reflex (VOR) by having the patient maintain focus on the examiner’s nose while the examiner quickly turns the patient’s head sharply to left or right (caution: avoid if patient has a cervical spine injury or vessel dissections) - abnormal head impulse is characterized by a re-fixation saccade (eyes will look away and then back at examiner's nose) and is suggestive of peripheral vertigo - Video demonstration of abnormal head impulse test

  • Nystagmus: Assessing if patient has nystagmus in primary gaze or looking in different directions, what kind of nystagmus it is (horizontal, vertical, torsional, direction-changing) - any nystagmus that is NOT unilateral or dominantly horizontal is concerning for a central lesion - Video demonstration of vertical nystagmus

  • Skew deviation: Misalignment of eyes - alternate-cover test while patient fixates on a distant target and see whether there is vertical movement of the eyes; presence of skew deviation suggests central lesion - Video demonstration of skew deviation

Central VertigoPeripheral Vertigo
Head ImpulseNormal, no corrective saccadesAbnormal with head turning, corrective saccades back to midline when head is turned
NystagmusVertical, Horizontal & direction-changing, TorsionalUnidirectional, dominantly horizontal (can have some mixed horizontal/torsional component)
Test of skewSkew deviation presentNo skew deviation

Benign paroxysmal positional vertigo (BPPV)

By Dr. Kia Gilani
Reviewed by Dr.Tess Fitzpatrick

Pathophysiology

  • Irritation of semicircular canals due to otoliths - usually induced by sudden change in head position (e.g. turning over in bed)

  • Most commonly affected semicircular canal is posterior (followed by anterior and horizontal)

Clinical Features

  • Acute onset vertigo (“the room is spinning”, “I’m on a rocking boat”) provoked by head movements and can be associated with nausea/vomiting

  • Can have multiple episodes that are short-lasting (< 1 minute) but due to periods of feeling unwell in between, patients often report that their symptoms are constant

Differential Diagnosis

Clinical featuresDistinctive from BPPV
Meniere’s DiseaseEpisodic attacks of vertigo with fluctuating hearing loss, aural fullness, and tinnitus in affected ear,triggered by head position changes, nausea/vomiting presentVertigo symptoms can last hours (instead of seconds-minutes like BPPV)
Vestibular neuritisAcute onset vertigo (often due to viral prodrome) - with vestibular labyrinthitis, can also have hearing loss/tinnitusVertigo is gradual onset (developing over hours), sustained, can occur at rest and can last days-weeks
Central cause (e.g. posterior circulation stroke, demyelination)Acute onset vertigo with other neurological symptoms (gaze palsies, ataxia, dysarthria, nystagmus)Vertigo symptoms are constant and sustained

Investigations

  • Diagnosis is made with a positive Dix-Hallpike test (DHT): Bring patient from upright to supine with head turned 45 degrees to one side and neck extended 20 degrees and look for vertigo and upbeating and torsional nystagmus. Repeat this with the head turned towards the opposite direction, if no nystagmus is elicited - Video demonstration of Dix-Hallpike

  • CAUTION: If downbeat nystagmus appears → consider central etiology

Treatment

  • Monitor - At least 30-50% of cases will resolve spontaneously without any treatment

  • Epley maneuver - Video demonstration of Epley

  • Vestibular rehab especially if there is a heightened risk of falls

  • Pharmacotherapy generally not effective but helpful for symptomatic management/prophylaxis prior to repositioning maneuvers but not for resolution of symptoms (e.g. antihistamines (diphenhydramine), betahistine, ondansetron)

Patient Education

  • Recurrence of symptoms is common (up to 30%) so important to counsel patients that symptoms may return/reoccur

  • Patients can access www.vestibular.org for resources

Neuro-ophthalmology

Anterior Ischemic Optic Neuropathy (AION)

Clinical Features: Two forms of AION- Non-arteritic AION (NAION) and Arteritic AION (AAION), which is typically caused by GCA.

Cranial Nerve III (oculomotor) Palsy

By Dr. Kia Gilani
Reviewed by Dr. Jonathan Micieli

**Anatomy **

  • The oculomotor (CN III) nuclear complex is in the midbrain at the level of the superior colliculus. It is ventral to the sylvian aqueduct, and dorsal to the medial longitudinal fasciculi

  • Innervates superior rectus, medial rectus, inferior rectus, and inferior oblique - Elevation, depression, and adduction of the eye

  • Innervates levator palpabrae - Eyelid elevation

  • Edinger-westphal nucleus is posterior to CN III - supplies parasympathetic fibers for pupil constriction

Click image to enlarge

Source: Radiopaedia

Clinical Features

  • Complete palsy: Ptosis, large unreactive and dilated pupil, paralysis of eye adduction, elevation, and depression

  • **Partial palsy: **Variably affect pupil, eyelid, and involves extraocular muscles

  • **Pupil-sparing CN III : **Pupillary fibers run on the medial exterior part of the nerve while the oculomotor fibers are inside the nerve. Thus, most compressive lesions will affect the pupillary fibers (causing impaired pupillary constriction) compared to ischemic lesions that affect the innermost fibers and often spares the pupil

  • Aberrant Regeneration: Indicative of chronic CN III palsy, with regeneration of axons that results in unintended ocular findings with attempted movement - may be suggestive of tumor, aneurysm, or trauma (can be seen by elevation of eyelid with downward gaze or adduction of the eye)

Left CN 3 Palsy (Click image to enlarge)

Source: Case-based neuro-ophthalmology

Differential Diagnosis

  • Majority of patients >50 with isolated CN III palsy have microvascular cause

  • BUT MUST RULE OUT aneurysmal etiology

MicrovascularAneurysmal
Most common cause, seen in patients over 50 years with vascular risk factorsNeurological emergency - associated commonly with PCOM aneurysm (but can also be basilar or cavernous sinus carotid aneurysm) - risk of subarachnoid hemorrhage
Acute or subacute, progressive over 2-4 weeks but should resolve by 3 months. If no recovery, than consider alternative diagnosis78% have pain/headaches
Patients may present with headache and eye painAlways has pupillary involvement (dilated, non-reactive pupils)

**Other etiologies **

  • Trauma - most common cause in young people and can occur post-neurosurgical procedure

  • Compression due to malignancy, sellar masses (e.g. pituitary apoplexy, pituitary adenoma)

  • GCA - may present as cranial neuropathy, do ESR/CRP

  • Neuromuscular (Myasthenia Gravis, Miller-Fisher)

  • Congenital

Physical Exam

  • Testing for extraocular movements, pupils, and convergence

  • Misalignment can be comitant (deviation similar to all position of gazes), or incomitant (deviation differs depending on gaze position).- childhood strabismus is comitant

Investigations

  • Blood pressure, glucose, HbA1c, ESR, CRP, platelets

  • CT/CTA (for all patients to rule out aneurysms)

  • If pupil is normal: Observe, no MRI in the beginning

  • If pupil is abnormal: URGENT MRI Brain with Orbits with GAD to rule out aneurysm or compressive lesion

Treatment

  • Aneurysm - Should be assessed by neurosurgery for consideration of endovascular coiling or surgical clipping (63% of patients with PCOM aneurysms operated on within 2 weeks of onset made complete recovery, compared to 30% 2-4 weeks, and 17% >1 month)

  • Ischemic/Microvascular cause - Usually conservative treatment including patching, prisms. Ocular surgery may be helpful to restore primary position alignment if CN III palsy persists

Click image to enlarge

Patient Education

  • Microvascular palsy: A vast majority of patients with microvascular third nerve palsy have complete recovery. Complete recovery is less common in post-neurosurgery (36%), aneurysmal (33%) and neoplastic (19%) compressive, and traumatic (22%).

  • Aneurysmal palsy: with successful aneurysm treatment a majority of patients have complete or partial recovery, which can take up to a year

Cranial Nerve IV (Trochlear) Palsy

By Dr. Kia Gilani
Reviewed by Dr. Jonathan Micieli

**Anatomy **

  • The trochlear nerve (CN IV nerve) is caudal to CN III, dorsal to MLF at the level of the inferior colliculus

  • The only nerve that runs dorsally from the brainstem

  • Innervates the superior oblique muscle - eye depression

Click image to enlarge

Source: Rardiopaedia

Clinical Features

  • CN IV Palsy causes hypertropia and excyclotorsion of the affected eye and patients may complain of vertical or horizontal diplopia

  • Hypotropia seen in the normal eye when the affected eye is fixating

  • Hypertropia is seen in the affected eye when the unaffected eye is fixating

  • Presence of excyclotropia

  • Patients may develop head tilt to compensate for hypertropia and cyclotropia (usually away from affected side)

The Three Step Test helps identify the CN IV palsy

  • Step 1: Identify hypertropic eye (the eye that looks higher up)

  • Step 2: Identify gaze direction which worsens hypertropia. Adduction of hypertropic eye should increase hypertropia if there is a CN IV palsy.

  • Step 3: Identify direction of head tilt that increases hypertropia

Example: For a LEFT CN IV palsy, the LEFT eye will be hypertrophic, looking RIGHT would worsen hypertropia, and tilting the head LEFT worsens hypertropia (Many patients will tilt their head on the opposite side of the CN IV palsy to compensate and improve their diplopia )

Left CN 4 Palsy (Click image to enlarge)

Source: Case-based neuro-ophthalmology

Differential Diagnosis

MicrovascularTraumaticCongenitalIntracranial lesions
Most common especially in patients older than 50 with diabetes/vasculopathic risk factors and often resolves without neuro-imaging. However, if progressive, associated with other neurological symptoms or not resolving within several months, may require imaging.Most common cause of isolated/bilateral CN IV lesions, imaging may help identify structural lesionAssess old photos for head tilt, have cyclotropia on exam but no torsional diplopiaRarely isolated CN IV, usually with other neurological symptoms

Investigations

  • Blood pressure, glucose, HbA1c, CBC

  • If > 50 - ESR/CRP

  • If other CN involvement and not congenital/traumatic - Consider MRI brain and orbits with contrast

Treatment

  • Non-pharmacological: Prisms and occasionally occluding one eye for symptomatic relief

  • Strabismus surgery: Indicated if lack of spontaneous improvement in 6 months

(Click image to enlarge)

Patient Education

  • Spontaneous improvement in 44% of patients from traumatic CN IV palsy (few days - months)

  • Majority of patients with microvascular CN IV palsy improves by 4-6 months

  • If no improvement after 6 months, consider corrective surgery

Cranial Nerve VI (Abducens) Palsy

By Dr. Kia Gilani
Reviewed by Dr. Jonathan Micieli

Anatomy

  • The abducens (CN VI) nucleus is located in the dorsal lower pons, separated from the floor of the 4th ventricle by the facial nerve fascicle (facial colliculus)

  • Innervates the lateral rectus - Abducts the eye

  • Coordinates horizontal eye movements (Looking to the right - right eye ABDUCTS and left eye ADDUCTS) - CN VI motor neurons are mixed with internuclear neurons through the medial longitudinal fasciculus (MLF), ascending through the pons and midbrain, terminating in the oculomotor (CN III) nucleus - Internuclear Opthalmoplegia (INO) can be a result if MLF is damaged

Click image to enlarge

Source: Rardiopaedia

Clinical Features

  • CN VI Palsy causes impaired abduction of the eye, horizontal diplopia and eso-deviation of the eye that is worse upon attempted abduction of the affected eye

Right CN 6 Palsy (Click image to enlarge)

Source: Case-based neuro-ophthalmology

Differential Diagnosis

EtiologyIschemicMasses//Raised ICPCongenital
DifferentialDiabetes, collagen vascular disease, giant-cell arteritis, parainfectious or post-infectious vasculitisSkull-based or sellar masses (e.g. pituitary adenoma, ICA aneurysm) , idiopathic intracranial hypertension, CVSTMobius syndrome
Associated Signs & SymptomsPain with eye abduction, headache, scalp tenderness, jaw claudicationVisual acuity loss, papilledema, headachesFacial diplegia and other cranial nerve abnormalities, bilateral ocular abduction weakness and conjugate horizontal gaze paresis
  • Other causes can include trauma, demyelination, inflammatory (neurosarcoid), or idiopathic

Investigations

  • If papilledema present - urgent MRI with contrast

  • Bloodwork: Blood pressure, glucose, HbA1c, ESR, CRP

  • Patients with isolated CN VI palsy that are >50 years of age, with microvascular risk factors (diabetes, hypertension) may not require neuroimaging

  • If patients do not improve in 3-4 months, consider MRI Brain with Orbits with GAD

Treatment

  • First 6 months: Patching and botulinium toxin injections may improve diplopia. Many CN VI palsies resolve within several months, and symptomatic management is warranted

  • >6 months: If CN VI palsy does not improve by 6 months, surgery is indicated

Patient Education

The importance of follow up must be discussed with patients that are not undergoing neuroimaging. Follow-up in 10-12 weeks after onset, lack of improvement may warrant imaging

  • Microvascular: 62% of patients recover over 6 months

  • Traumatic: Traumatic CN VI palsies recovery in almost all cases if partial, and in 1/3 of cases if complete

  • Idiopathic: A majority of patients with undetermined cause recover CN VI function

Optic neuritis

By Dr. Kia Gilani
Reviewed by Dr. Jonathan Micieli

Pathophysiology and Epidemiology

  • Typically in people in their 30’s, 77% female

  • Most commonly seen in demyelinating diseases - e.g. multiple sclerosis, NMOSD/MOG

Clinical Features

Features of Optic Neuritis include:

  • Must have RAPD (unless bilateral involvement)

  • Acute or subacute eye pain (or pain with eye movements)

  • Vision loss or blurry vision - typically peaks in 1-2 weeks

  • Dyschromatopsia and contrast sensitivity loss - abnormal color vision

  • Absent or mild disc edema

Red flags suggestive of a diagnosis outside of optic neuritis (additional testing may be required)

  • Age >50

  • Painless vision loss

  • Retinal abnormalities

  • Severe vision loss without early recovery

  • History of cancer

  • Worsening visual function after reducing or stopping steroids or immunosuppressants

FindingsTypical ONAtypical ON
CharacteristicsUnilateral, Pain with extraocular movements, RAPD, Gradual vision lossUnilateral and/or bilateral, Recurrent episodes, Gradual and/or acute visual loss, Typically younger than 12 and older than 55 year old patients
FundoscopyAbsent or mild disc edema, Absence of intraocular inflammation, Absence of optic disc hemorrhages, retinal hemorrhages, or retinal vasculitisOptic disc edema, Additional features including intraocular inflammation, hemorrhages, or retinal vasculitis
AssociationsMultiple sclerosisNMOSD, Lyme, TB, VDRL, HIV, sarcoidosis, vasculitis
PrognosisRecovery of vision without treatment,No recovery without treatment and/or progression of visual symptoms, Relapse after steroid withdrawal

Investigations

  • Patients should have a visual acuity measurement, retinal exam, clinical and formal visual field testing including red desaturation, pupil examination looking for RAPD.

  • Bloodwork: CBC, ESR/CRP, VDRL, ACE, ANA

  • NMO/MOG serum antibodies

  • MRI Brain and Orbits with GAD

  • Consider additional work-up including a lumbar puncture (CSF: Cytology, protein, glucose, oligoclonal bands)

Treatment

Acute treatment: IV Methylprednisolone or PO high-dose steroids

  • ONTT study found IV methylprednisolone accelerates visual recovery but no benefit in visual acuity at 2 years

  • Dose and Duration: Methylprednisolone 1000 mg IV or Prednisone 1250 mg PO for 5 days

  • For atypical cases that do not improve after initial treatment: consider prednisone 1 mg/kg pulse

  • Adverse effects: Sleep disturbance, mood changes, weight gain, GI irritation, avascular necrosis

  • Patient should also be on Vitamin D and Calcium

Other acute treatments: PLEX for steroid resistant severe optic neuritis

Long term management: If a diagnosis of a demyelinating disorder (e.g. MS) is suspected, patient should be referred to for consideration of disease modifying therapies

Click image to enlarge

Non-Anterior ischemic optic neuropathy (NAION)

By Dr. Andrea Kuczynski
Reviewed by Dr. Jonathan Micieli

Pathophysiology and Epidemiology

  • Idiopathic, vascular insult due to transient hypoperfusion of the optic nerve head

  • Does not involve embolic infarction

  • Common in middle aged individuals; more common in Caucasians due to smaller cup-to-disc ratios

Risk Factors

  • Vascular risk factors: HTN, dyslipidemia, type II diabetes, ischemic heart disease, OSA, tobacco use, nocturnal hypotension, coagulopathies

  • PDE5 inhibitors (e.g., Viagra, Tadalafil)

  • Renal failure on dialysis

  • Optic disc drusen

Clinical Features

  • Acute, painless, monocular vision loss

  • Ocular pain (present in 10%)

  • Disc-at-risk (unaffected optic disc is at risk of optic disc edema) - essential for the diagnosis

  • Fundoscopy: disc edema (may persist for 6-11 weeks), pallor, may see peripapillary wrinkles caused by displacement of the retina by the disc edema

  • Diagnosis is made when the disc edema resolves within the appropriate time course

Investigations

  • CBC

  • ESR/CRP

  • Monitor BP and avoid hypoperfusion which can exacerbate

  • Referral to Ophthalmology/Neuro-ophthalmology

Treatment

  • None - may have mild to no improvement in vision

  • Treatment of vascular risk factors in an attempt to preserve visual function in the other eye

Patient Education

  • Management of vascular risk factors (compliance with medications, CPAP if OSA present) is important to protect the unaffected eye

  • 15% of patients risk development of NAION in the other eye at 5 years

Neuroretinitis

By Dr. Andrea Kuczynski
Reviewed by Dr. Jonathan Micieli

Pathophysiology and Epidemiology

  • Inflammatory condition of the optic disc vasculature resulting in disc edema

Risk Factors and Causes

  • Infections: VDRL, TB, Lyme, WNV, Toxoplasmosis, Bartonella (most common; “cat scratch disease”)

  • Parainfectious: MMR, HSV/VZV, EBV, CMV, coxsackie B

  • Inflammatory: sarcoidosis, IBD, polyarteritis nodosa, tubulointerstitial nephritis and uveitis

Clinical Features

  • Acute, painless, monocular vision loss

  • RAPD if unilateral

  • Fundoscopy: disc edema, macular edema, macular exudates (“macular star”; late finding), subretinal fluid, loss of architecture under the fovea

Macular star pattern (Click image to enlarge)

Source: Case-based neuro-ophthalmology

Investigations

  • Referral to Ophthalmology/Neuro-ophthalmology

  • CBC

  • ESR/CRP

  • Infectious work-up: VDRL, Bartonella serology, Toxoplasmosis serology, and additional serology if indicated depending on clinical history

  • CXR

  • MRI brain with orbits (typically normal)

Treatment

  • None - most patients have gradual resolution without treatment

  • Antimicrobials depending on etiology (i.e., Azithromycin for cat scratch disease, Penicillin G for VDRL)

central retinal artery occlusion / Branch retinal artery occlusion (CRAO and BRAO)

By Dr. Andrea Kuczynski
Reviewed by Dr. Jonathan Micieli

Pathophysiology and Epidemiology

  • Vascular insult due to transient hypoperfusion of the optic nerve head typically due to vasculitic or embolic cause

  • CRAO is less common than BRAO

  • Common in middle aged individuals

Risk Factors

  • Vascular risk factors: carotid artery atherosclerosis, HTN, dyslipidemia, type II diabetes, ischemic heart disease, OSA, tobacco use, nocturnal hypotension, coagulopathies

  • Cardioembolic risk factors (more common in patients <40-years-old): infective endocarditis, IVDU, rheumatic heart disease, cardiac tumor

  • Other vascular disease: fibromuscular dysplasia, carotid artery dissection, Moyamoya disease, Fabry disease

  • Inflammatory disease: GCA, vasculitis, Susac syndrome, sarcoidosis

Clinical Features

  • Acute, painless, monocular vision loss

  • CRAO typically has more severe vision loss, rarely can count fingers but can identify hand motions

  • BRAO has less severe vision loss usually restricted to part of the visual field

  • Associated symptoms depending on etiology: headache, jaw claudication, unilateral sensory-motor loss, neck pain

  • Fundoscopy: ischemic retinal whitening, cherry red spot, retinal emboli (up to 40% of patients with CRAO)

  • Fluorescein angiography: slowed or absent filling of the central retinal artery with sparing of the choroid in the acute phase; if the choroid is also affected, consider GCA

Investigations

  • Can be seen as a Code Stroke - CONSULT OPHTHALMOLOGY STAT IF NOT ALREADY INVOLVED

  • CBC

  • ESR/CRP

  • Stroke work-up: HbA1c, Lipids, Echocardiogram, Holter monitor 48hrs, Referral to TIA/Rapid Stroke Clinic or ED (if patient seen in peripheral site/clinic)

  • Ophthalmology/Neuro-ophthalmology consultation/referral ASAP for fundoscopy and visual field testing

  • MRI/MRA brain and neck vasculature (or CT/CTA to obtain images quicker)

Treatment

  • Antiplatelet agent if no contraindications (i.e., already fully anticoagulated for another reason)

  • Treatment of vascular risk factors in an attempt to prevent recurrence and preserve visual function

  • Requires Ophthalmology to follow after the initial presentation to monitor for neovascular complications

Patient Education

  • Management of vascular risk factors (compliance with medications, CPAP if OSA present) is important to protect visual function

  • BRAO has a much better prognosis than CRAO, with up to 80% of patients recovering visual function; CRAO has a poor prognosis for spontaneous visual recovery

Arteritic Anterior ischemic optic neuropathy (AAION)

By Dr. Kia Gilani
Reviewed by Dr. Jonathan Micieli

Pathophysiology and Epidemiology

  • For those > 50, must consider Giant Cell Arteritis (GCA) in the differential diagnosis

  • Most common in females and Caucasians of Scandanavian descent

  • GCA can be associated with Polymyalgia Rheumatica (proximal muscle pain and stiffness that is worse in morning)

Differential Diagnosis

  • Giant Cell Arteritis

  • ANCA-associated vasculitis

  • Infection

  • Neoplastic

Clinical Features

  • Sudden, profound visual loss that can become bilateral in hours to days

  • Diplopia - Transient or persistent

  • Majority of patients have systemic symptoms: (Headache, scalp tenderness, jaw claudication, muscle aches/stiffness in the morning, malaise, fever)

  • Superficial temporal artery pulse: Cord-like feel with reduced pulses

  • Fundoscopy: optic disc may appear swollen, pale “chalky white” optic nerve head with nerve fiber layer hemorrhage and cotton wool spots

Fundoscopy of GCA (Click image to enlarge)

Source: Case-based neuro-ophthalmology

American College of Rheumatology Diagnostic Criteria for GCA

Minimum of 3 criteria from the following:

  • Age at onset ≥ 50 years

  • New headache

  • Temporal artery abnormality: tenderness or reduced pulsation

  • ESR ≥ 50 mm/hour

  • Abnormal artery biopsy demonstrating vasculitis, with mononuclear cell or granulomatous inflammation

Investigations

  • CBC

  • MUST DO ESR AND CRP

  • Referral to Ophthalmology/Neuro-ophthalmology and Rheumatology

  • MRI brain and orbits with GAD

  • If high pre-test probability of GCA: Consider temporal artery biopsy

Treatment

  • Confirmed GCA - Steroid pulse (do not delay for temporal artery biopsy because it can lead to permanent vision loss)

  • Methylprednisolone 1g IV pulse for 3-5 days with subsequent taper of with PO prednisone; in some cases of GCA, can treat with Prednisone 1 mg/kg dosing

  • Adverse effects: Sleep disturbance, mood changes, weight gain, GI irritation, avascular necrosis

  • Patients should also be on Vitamin D and Calcium

Patient Education

  • Vision loss at time of presentation may be irreversible but steroids can prevent further progression

Neurocritical care

TWH Level 2 ICU guide

By Dr. Andrea Kuczynski and Dr. Caz Zhu
Reviewed by Dr. Shaurya Taran, Dr. Leanne Casaubon, Tim Stewart, Dr. David Chan, and Dr. Jane Liao

How to use this guide

This guide was created to help residents feel more comfortable with managing the Level 2 during their neurology - stroke rotation at Toronto Western Hospital. This is meant to be a quick resource for different situations a resident may experience during the day or on call.You should always promptly go and assess a patient for whom you’ve been called for a change in clinical status. You should always document your assessment and plan before the end of the shift.

Consider calling CCRT if patients show acute changes in:

  • Airway - Threatened airway, stridor, excessive secretions (with vital sign changes)

  • Breathing - Respiratory rate > 30 or < 8, Oxygen saturations < 90% on 6L/min, or respiratory distress

  • Circulation - sBP < 90 mmHg or > 200 mmHg (if patient symptomatic) or changes of sBP > 60 mmHg

  • Disability - Altered Mental Status

  • You should ALWAYS call CCRT if you have concerns about a patient

  • Always call your staff if a patient becomes sick (e.g. status epilepticus, blown pupil)

  • or if you need to administer emergency medications

Change in Medical Status

Examples: Change in level of conciousness/behaviour, vital signs (e.g. fever) abnormalities, patient-specific concerns (e.g. chest pain)

  • Investigations: STAT CBC, lytes, extended

  • lytes, Cr, blood glucose, lactate, troponin,

  • VBG

  • +/- STAT blood cultures x 2 and urine

  • cultures

  • +/- STAT CXR and/or ECG

  • +/- STAT Imaging based on context

  • + Check for good IV access

  • Call CCRT and staff if concerned

Change in GCS or NIHSS

1. Assess the patient to confirm GCS/NIHSS change
2. Consider STAT CT Head if patient stable
3. Consider possible etiologies:

  • New stroke (re-infarction, new territory infarct,

  • hemorrhagic conversion)

  • Medications/drugs (check medication history for opioids, benzos)

  • Metabolic derangements (lytes, extended lytes, glucose, lactate)

  • Infection

  • Structural causes (hematoma expansion, edema, bleed)

  • Post-ictal

Symptomatic hemorrhagic conversion

Symptomatic hemorrhagic conversion
1. Investigations: STAT CBC, PTT/INR
2. Early blood pressure management (See Blood Pressure Targets section)
3. Hold DVT prophylaxis and antiplatelets/anticoagulants
4. Review case with staff MD
5. Repeat CT Head if patient clinically deterioates

Patient with acute onset fixed, dilated pupil
(“blown pupil”) and change in LOC

1. Call Code Blue +/- CCRT (if not protecting airway or GCS < 8)
2. Call RT for hyperventilation
3. Keep patient’s head of bed (HOB) > 30 degrees
4. Ensure you have IV access & avoid hypotension
5. Consider hyperosmolar solution and speak to ICU:

  • Hypertonic saline: 150-300 cc bolus over 15 - 30 min (Useful if patient needs volume expansion, Avoid if Na > 160)

  • 20% mannitol (1 – 1.5 g/kg BOLUS over 10-15 mins) * Rough calculation: patient wt in kg x 5 = amount of mannitol in mL to infuse (Useful if patient needs diuresis, Avoid mannitol in hypotension, poor renal function, or serum osmolality > 320 + Ensure patient has a foley in situ)

6. Call for STAT CT Head once patient stable and call
Neurosurgery if not already involved

Status Epilepticus

See Status Epilepticus section

Blood Pressure Targets

These targets can vary case by case! Please use the standardized order sets for post-tPA/EVT for blood pressure parameters

  • **Ischemic stroke not eligible for tPA/EVT ** – Permissive hypertension if sBP < 220 mmHg (If sBP > 220 mmHg or dBP > 120 mmHg, then reduce blood pressure by 15-25% over the first 24 hours

  • Ischemic stroke pre-tPA – BP < 180/105 mmHg (For stroke at UHN, otherwise 185/110)

  • **Ischemic stroke post-tPA ** – BP < 180/105 mmHg

  • Ischemic stroke post-EVT – sBP < 180/105 mmHg (Please check with stroke and INR staff for targets

  • Intracerebral hemorrhage – sBP < 140 -160 mmHg (Aim to reach sBP < 140 mmHg in 1-2 hours especially if spot sign positive, Factors that favor sBP <140 mmHg: LSN < 6 hours, initial sBP < 220 mmHg, anticoagulants, no renal dysfunction, spot sign positive on CTA)

Blood Pressure Management

Remember to repeat/cycle blood pressure regularly
when you’re giving medications!

Hypertension

1. Address underlying cause (e.g. pain, agitation, missed drugs, urinary retention, new stroke/hemorrhage)
2. Consider if patient requires immediate (IV) or gradual (PO/NG) treatment
* based on TORBSST +/- SLP assessment
Immediate: Acute ischemic stroke, acute ICH
Gradual: Non-emergent scenarios

Medications for Hypertension

1. Labetalol 10-20 mg IV push over 1- 2 mins (q10min PRN)
Max total dose 150 mg if received tPA
Max total dose 300 mg if no tPA
AVOID: HR < 50
2. Hydralazine 5-20 mg IV push over 1 - 2 mins (q15-20min PRN)
CAUTION: Unpredictable response, can cause sudden
drop in BP and can cause rebound HTN
Max dose: 40-50 mg q4hrs
3. Enalapril 1.25 mg IV x 1 over 5 mins

Hypotension

In acute stroke post-tPA, avoid pressor support as there is
increased risk of secondary ICH (Level A evidence)

1. Address underlying cause (medications, sepsis,
cardiac, PE)
2. +/- IV fluids and hold antihypertensives, opioids
3. Investigations dependent on likely cause: ECG, troponin, lactate, +/- blood cultures/imaging
if concerned about sepsis: Fluids and antibiotics
if concerned about cardiogenic/PE: Call CCRT or Cardiology

4. Give fluid bolus & hold anti-hypertensives
5. Consult ICU if pressor support required

Rhythm Abnormalities

Tachyarrhythmia (or atrial fib)

Unstable (ischemic chest pain, acute heart failure, sBP < 90, altered LOC):
1. CCRT - for cardioversion
2. Order STAT ECG, CXR, troponin, lytes, extended lytes

Stable: (failed TORBSST)
1. Order lytes, extended lytes
(target Mg > 1, K > 4), troponin, CXR, ECG
2. Give metoprolol 2.5 – 5 mg IV push over 1-2 minutes (q5min, can give up to 3 doses)
CAUTION: Hypotension, bradycardia, acute heart failure. Must be by patient’s bedside if you are giving this on the ward (cycle blood pressure q2-5 minutes)
3. If patient becomes hypotensive - consider fluid bolus (ensure no heart failure on
recent echo)

Bradyarrhythmia

Unstable (ischemic chest pain, sBP < 90, altered LOC):
1. CCRT - transcutaneous pacing
2. Order STAT ECG, CXR, troponin

Stable:
1. Telemetry (if patient is not in Level 2), hold AV nodal agents (Beta blockers, Calcium channel blockers, Digoxin), order TSH/echo/serial troponins
2. Keep atropine 1 mg IV at the bedside in case HR < 40 and hypotensive (Atropine 0.5 mg IV push q3-5min | Max dose: 3 mg)

Level 2 Infusion Orders

Indications: Varies case by case; can be used if requiring frequent prns (e.g q1-2h) or tight blood pressure targets (e.g. sBP 110 - 140)Hypertension
Labetolol 0.125 - 3 mg/min with sBP range _ to _ (typically start at 1 mg/min)
Hypotension
Levophed 0.02 - 0.35 mcg/kg/min with sBP range _ to _
CAUTION: If patient is persistently hypotensive requiring levophed - call ICU

Coma & Brain Death

By Dr. Andrea Kuczynski

Definitions

  • Alert: normal state of arousal

  • Obtunded: loss of responsiveness to some stimuli but still able to communicate

  • Stupor: only arousable to vigorous, repetitive stimuli with inability to communicate

  • Coma: unarousable, unresponsive individual with reflexes present

  • Brain death: comatose patient without intact reflexes

(Click image to enlarge)

[Source: The ICU book - Paul Marino 2013]

Herniation Syndromes

  • Uncal: inner portion of the temporal lobe is pushed down causing lateral deviation and pressure onto the midbrain; commonly compresses CN3 and motor tracts resulting in a unilateral dilated pupil and ipsilateral hemiparesis (Kernohan’s phenomenon)

  • Central: due to lesions higher up in the brain causing downward pressure and deviation through a notch in the tentorium; causes small, equal pupils (early) to mid-position fixed pupils (late), bilateral Babinski response, and decorticate posturing

  • Subfalcine: subfalcine compression under the falx; often presenting with contralateral leg weakness and frontal behavioural changes, or asymptomatic in the majority

  • External: common in cases of malignant MCA syndrome/edema

  • Upward: due to infratentorial ischemic/hemorrhagic events or mass lesions with edema resulting in cerebellar (i.e., nystagmus, ataxia) and brainstem signs (i.e., respiratory changes, obtunded state)

  • Tonsillar: compression of the medulla due to cerebellar tonsil herniation through the foramen magnum; often presenting with medullary signs (i.e., Cheyne-Stokes respiration to respiratory arrest) and Cushing’s reflex (widened pulse pressure, bradycardia, hypertension)

(Click image to enlarge)

Investigations

  • Stat CT head to rule out intracranial cause (i.e., stroke, hemorrhage, mass lesion)

  • CBC

  • Lytes, extended lytes (Mg, Ca, PO4), creatinine

  • Blood glucose

  • Liver enzymes

  • Toxicology screen if indicated

  • Blood, urine, CSF cultures if indicated

  • LP with cell count and differential, protein, glucose, bacterial/viral/fungal cultures, cytology/flow cytometry, autoimmune/paraneoplastic panels as indicated

  • EEG

  • MRI brain with contrast depending on the clinical scenario and when the patient is clinically stable

Treatment

  • ABCs (airway, breathing, circulation) and consultation of ICU if the patient may require intubation and/or pressor support

  • Correction of metabolic derangements

  • Reduction of elevated ICP - raise head of the bed to 30 degrees, hyperventilation (if possible) to PCO2 35-40 mmHg, avoid hypotension, hypertonic saline 150-300 cc over 15-30 min (avoid in patients with serum Na+ >160) or mannitol 1-1.5 g/kg bolus q4-6h PRN (avoid in patients with disrupted blood brain barrier or renal dysfunction)

  • CIWA protocol for suspected alcohol withdrawal

  • Consultation of Neurosurgery or other specialties if indicated

  • Consultation of Poison Control depending on investigations and clinical scenario

  • For more information in managing specific acute level 2/ICU scenarios, please see the Level 2 Guide

(Click image to enlarge)

Source: The Calgary Guide to Understanding Disease

Prognosis for Coma

For a Decision Algorithm for Use in Outcome Prediction for Comatose Survivors of Cardiac Arrest, see Figure 2 in this article: Neurologic Prognosis after Cardiac Arrest

Indications for Ancillary Testing

  • Components of the brain death exam cannot be completed because of the underlying medical condition

  • Uncertainty about the reliability of parts of the neurologic examination

  • Apnea test cannot be performed

Ancillary Testing for Brain Death

  • CTA Head & CT Perfusion

  • Transcranial Dopplers

  • Radionuclide brain perfusion scan

End of Life Care

By Dr. Caz Zhu

Clinical Symptoms

It is important to acknowledge that prognostication is very challenging and it is impossible to predict when someone may pass away; it can be anywhere from hours to a week. Some of the common signs of a patient nearing end of life include:

  • Unresponsive to voice or touch

  • Changes in breathing, increased apnea, Cheyne-stokes breathing pattern

  • Mottling in the skin and cooler extremities

  • Anuria

  • Decreased/no oral intake

The purpose of the End of Life Order set is to ensure patient comfort and quality of life

End of Life Order Set

  • Discontinue vitals, bloodwork, telemetry , POCTs

  • Monitor patient q1h for comfort (e.g. pain, dyspnea)

  • Insert subcutaneous butterfly

  • Oxygen via Nasal Prongs as needed, titrate to patient comfort NOT SpO2

  • Diet as tolerated

  • Artificial saliva Q1H PRN

  • Discontinue all medications except the following: *

  • For pain: Hydromorphone 0.25 - 0.5 mg SC q1h PRN for pain (can increase up to 0.5 - 1 mg, also used for breathlessness)

  • For agitation/delirium: Haldol 1 mg SC q4h PRN for agitation or Methotrimeprazine 6.5 - 12.5 mg SC q4h PRN for agitation (very sedating, only use in cases where comfort is the focus)

  • For breathlessness: Lorazapam 0.5 mg SC q4h PRN for breathlessness or anxiety

  • For secretion management: Glycopyrrolate or Scopolamine 0.2 - 0.4 mg SC q4h PRN for secretions

  • For dry mouth: Artificial saliva spray or gel q2h for dry mouth

*Caveat - might continue medications if they provide patients with comfort (e.g. anti-epileptics to prevent further seizures, levodopa PR for Parkinson's Disease) if patient is able to tolerate the medication

Neuro-inflammatory

Autoimmune Encephalitis

By Dr. Andrea Kuczynski

Definition

  • Syndrome of subacute onset of neurological and/or psychiatric dysfunction affecting one or more brain systems and associated with an immune-response compromising function

Pathophysiology and Epidemiology

  • Peak incidence <40 years

  • Female predominance

  • 60-75% of patients have a preceding infectious prodrome

  • Malignancy is common in up to 50% of females between 20-50 years old

  • Several antibodies have been identified with variable clinical presentations: anti-NMDA, anti-LGI1, anti-DPPX, anti-Caspr2, anti-GABA, anti-AMPA, anti-IgLON5, thyroid antibodies among others

Clinical Features

  • Altered level of consciousness/mental status

  • Psychosis - delusions, hallucinations

  • Seizures

  • Agitation, aggression

  • Catatonia

  • Disinhibition

  • Short-term memory impairment

  • Dysautonomia

  • Abnormal movements - dystonia, myoclonus, chorea, rigidity

  • Language dysfunction - mutism, echolalia, aphasia

  • Sleeping disorders - insomnia at onset, hypersomnia later

Investigations

  • Stat CT head to rule out acute intracranial abnormality (i.e., hemorrhage, stroke, mass lesion)

  • CBC

  • Lytes, extended lytes (Mg, Ca, PO4), creatinine

  • Blood glucose

  • Liver enzymes

  • TSH, free T3 and T4, and thyroid antibodies

  • MRI brain with contrast: may be normal or show T2/FLAIR hyperintensities or contrast uptake depending on associated antibody

  • LP: may see pleocytosis, normal glucose, normal to high protein

  • Serum and CSF autoimmune/paraneoplastic panels (see Requisition Forms section)

  • Autoimmune blood work: ESR, CRP, ANA, anti-dsDNA, ENA, RF, ANCA, C3/C4

  • HIV, VDRL [Remember to send CSF Oligoclonal bands with Serum SPEP test]

  • EEG if there is concern of altered mental status and/or seizures

  • CT chest/abdo/pelvis to assess for malignancy

  • Transvaginal U/S in female, testicular U/S in males to assess for malignancy

  • In preparation for high dose steroids: Hepatitis B and C serology, TBST, strongyloides serology

Treatment

  • Pulse steroids x5 days with maintenance Prednisone 1 mg/kg thereafter

  • IVIG 2 g/kg over 2-4 days (4 days if patient has cardiac comorbidities)

  • PLEX - can vary from 5-7 sessions

  • Second-line therapy: Rituximab, Cyclophosphamide

  • Management of comorbid symptoms (i.e., seizures, pain, psychosis)

  • Prophylaxis while on high dose steroids: calcium, vitamin D, PPI, PJP prophylaxis

Sarcoidosis

By Dr. Andrea Kuczynski

Pathophysiology and Epidemiology

  • Granulomatous, multisystem disease (commonly in the lungs, lymph nodes, but can also affect other organs including the brain)

  • Pathophysiology not well understood

Risk factors

  • Genetic predisposition - 5-fold higher risk with first- or second-degree relatives

  • High risk occupations - agriculture, healthcare, animal laboratories

  • Smoking

Clinical Features

  • Panhypopituitarism

  • Pulmonary involvement - dyspnea, persistent dry cough

  • Painless lymphadenopathy

  • Cardiac involvement - cardiomyopathy, chest pain, palpitations/arrhythmia, syncope

  • Neurological involvement - cranial nerve palsies, radiculopathy, confusion, myelopathy

  • Orbital involvement - dry eyes, blurry vision, visual loss, uveitis

  • Rashes, erythema nodosum

  • Arthralgias

  • Hepatosplenomegaly

  • Amenorrhea

Investigations

  • Elevated serum ACE level (not specific)

  • Elevated IgG subclasses (not specific)

  • Hypercalcemia

  • MRI brain with contrast: may have meningeal or parenchymal enhancement, involvement of cranial nerves or spinal nerve roots, spinal cord or cauda equina edema

  • LP: may have elevated opening pressure, may have pleocytosis, normal to low glucose, normal to high protein, elevated ACE and IgG index and increased CD4/CD8 ratio (on cytology)

  • CXR: hilar lymphadenopathy

  • Cardiac investigations: TTE, ECG, cardiac MRI

  • Biopsy: non-caseating granuloma

  • EMG/NCS if component of neuropathy

  • In preparation for high dose steroids: Hepatitis B and C serology, TBST, strongyloides serology

Treatment

  • Solumedrol 1g IV x3-5 days followed by maintenance Prednisone 1 mg/kg daily with taper

  • Steroid sparing agents: MTX, Azathioprine, Cyclophosphamide

  • Prophylaxis while on high dose steroids: calcium, vitamin D, PPI, PJP prophylaxis

Functional Neurological Disorders (FND)

By Dr. Caz Zhu
Reviewed by Dr. Matt Burke

Pathophysiology

  • Neurological symptoms due to a “functional” disruption of brain networks than a recognized “structural” disorder of the nervous system

  • Etiology is incompletely understood, multiple aspects of biopsychosocial model involved in the disease (e.g. genetics, childhood adverse events, acute stressors such as trauma)

Diagnostic Criteria

  • A diagnosis made by positive findings from physical examination and semiology

  • Patients do not necessarily need a psychosocial stressor or psychological trigger in making the diagnosis

  • Based on DMS-5 Criteria for Conversion Disorder (Functional Neurological Disorder) - patient must have altered sensory/motor symptom that is incompatible with a recognized medical/neurological condition and causes clinically significant distress or impairment in areas of functioning

Clinical Features

FND sub-typesPositive symptoms
General signsDistractible (if engaging patient on a different task, abnormal movements may stop), Variability (symptoms fluctuate during assessment or when patient is not being tested)
Functional tremor or movementsEntrainable (when copying rhythmic movements with hand, tremor in affected limb may stop or entrained to the same rhythm)
Functional gaitFalling towards support (falling towards objects that will break their fall), excessive slowness, disproportionate hesitation when walking
Functional weaknessInconsistent or “give-away” weakness, Hoover’s Sign, Teapot Sign, Pinky Sign, Pronator drift without pronation
Functional seizuresSee PNES - Long duration of waxing and waning episodes, forced eye closure, tearfulness, side-to-side head shaking, full-body tonic-clonic movements with preserved consciousness

Investigations

  • Functional neurological disorder is a diagnosis made on the basis of positive signs as outlined above, however can consider investigations including bloodwork, imaging, +/- EEG/EMG if there is uncertainty about the diagnosis

Treatment

  • Communicating the diagnosis to the patient- critical for the patient's understanding and demonstrating positive symptoms can be helpful. Communicating the diagnosis does not mean telling the patient what diseases they don’t have or that their symptoms are “medically unexplained”

  • Important to validate patients’ experiences and provide education regarding the disease

  • Multidisciplinary approach to treatment depending on presentation e.g. some patients with motor-related FND can benefit from FND-informed physiotherapy or patients with PNES can benefit from Cognitive-behavioral therapy

  • Patients with co-morbid anxiety and depression (which can worsen FND) can benefit from psychotherapy and antidepressants

Patient Education

  • One aspect that can benefit patients is to provide them with resources to learn more about FND and speak to other people living with it - these include www.fndhope.org or www.neurosymptoms.org

Requisition Forms

Antibody/autoimmune/PNP forms

1. UHN serum autoimmune and paraneoplastic profiles - Need serum (gold or red tubes) with the miscellaneous paper requisition form and write "paraneoplastic panel and autoimmune panel"Autoimmune Liver Disease Profile (will include 9 autoantibodies): Anti AMA-M2, Anti M2-3E (BPO), Anti Sp100, Anti PML, Anti gp210, Anti LKM-1, Anti LC-1, Anti SLA/LP, Anti Ro-52Myositis Antibodies Profile (will include 16 autoantibodies): Anti Mi-2 alpha, Anti Mi-2 beta, Anti TIF gamma, Anti MDA5, Anti NXP2, Anti SAE1, Anti Ku, Anti PM-Scl 100, Anti PM-Scl75, Anti Jo1, Anti SRP, Anti PL-7, Anti PL-12, Anti EJ, Anti OJ, Anti Ro-52Paraneoplastic Disease Profile (will include 12 autoantibodies): Anti Amphiphysin, Anti CV2, Anti PNMA2 (Ma2/Ta), Anti Ri (Nova1), Anti Yo, Anti Hu, Anti Recoverin, Anti SOX1, Anti Titin, Anti Zic4, Anti GAD65, Anti Tr (DNER)2. Mitogen Autoantibody Test Requisition for Paraneoplastic/Autoimmune Panel for CSF- Link3. LHSC General Immunology and Neuroimmunology Testing Requisition for Paraneoplastic/Autoimmune Panel for CSF- Link4. SickKids Anti-NMDAR Serology requistion form - Link5. SickKids Biochemistry requisitions (e.g. Toxicology, Genomic Diagnostics) - Link6. North York General Molecular Genetics Requisition (e.g. SCA, OPMD, Fragile X) - Link7. St. Joseph's Immunology Requisition outside of Unity Health (e.g. Myositis, NMOSD) - Link8. BC Neuro Requisition (e.g. MuSK and ACHr antibodies, CIDP - for serum sample, they need gold tubes) - Link

IVIG

Ontario MOHLTC IVIG Request Form Neurology - Link

MTO reporting for driving

Ontario Medical Condition Report Form - Link

NPH Protocol

UHN NPH protocol developed by Dr. Tang-Wai and Dr. Fasano - for use at UHN but can be used as a reference guide at other sites (i.e. but should not be printed and placed in patient's chart)

About & Contact us

This resource was created by Dr. Andrea Kuczynski and Dr. Caz Zhu with support and guidance from Dr. David Chan.To contact us regarding any inquiries or feedback to improve the website (e.g. if there are any sections you would like to see), please fill out the form below.

Last updated: July 2022

Acknowledgment

We thank all the past and current residents who have generously contributed their time to this endeavor as well as faculty members who have reviewed the content. We also thank Dr. Eshita Kapoor for the conception and organization of the initial iteration of creating a resource for residents.

Contributors
Dr. Elliot Cohen
Dr. Conrad Eng
Dr. Kia Gilani
Dr. Priti Gros
Dr. Andrea Kuczynski
Dr. Jane Liao
Dr. Amirah Momen
Dr. Calvin Santiago
Dr. Caz Zhu
Dr. Jeremy Zung
Faculty Reviewers
Dr. Matthew Burke
Dr. David Chan
Dr. Jerry Chen
Dr. David Fam
Dr. Tess Fitzpatrick
Dr. Will Kingston
Dr. Houman Khosravani
Dr. Alex Muccilli
Dr. Jonathan Micieli
Dr. Emily Swinkin
Dr. David Tang-Wai

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