Ataxia

Subacute onset

Guillain-Barre syndrome

Tick paralysis

Acute onset

Vascular lesion

ADEM

Acute cerebellar ataxia

Sx usually unilateral; accompanied by cranial nerve abnormalities; often associated with headache

Examples: vertebral artery occlusion (including dissection), cerebellar stroke, cavernous angioma, posterior fossa AVM, venous sinus thrombosis

Typical age range: 2-10yo

Accompanied by encephalopathy not explained by fever (= any change in mental status -> irritability, sleepiness, confusion, obtundation)

Post-infectious (especially associated with varicella [or varicella vaccine], EBV)

Associated with lateral gaze nystagmus

Post-infectious (usually 2-3 weeks after infection)

NOT typically accompanied by encephalopathy

Neuroblastoma

Intracranial mass

Ingestion

Postural vertigo (BPPV)

Ethanol

Benadryl

Benzodiazepines

AEDs: phenytoin (especially), phenobarbital, carbamazepine

Look for opsoclonus-myoclonus (but not always present!)

If ataxia is symmetric, consider midline posterior fossa tumor (most common = medulloblastoma)

If mass is significant enough to cause ataxia, there should also be signs of increased ICP

Most common presentation: areflexia with ascending weakness

Variant: areflexia with ataxia (and no weakness/paralysis)

Miller-Fisher variant: ataxia + areflexia + ophthalmoplegia

Self-limiting

Sx worsen over days to weeks

Vestibular neuritis

Post-infectious

Accompanied by nystagmus in one direction

Patients fall toward the affected side

If accompanied by hearing loss -> labrynthitis

Hydrocephalus without a mass can also cause a similar picture

Basilar migraine (can also present acutely)

Conversion disorder (can also present acutely)

MRI shows diffuse, >1-2cm lesions of white matter

Typically accompanied by focal neurological deficits

Affects white matter tracts of the brain, brainstem (which may affect respiratory drive), spinal cord, and optic nerves

Acute inflammatory demyelinating disorder

Peak incidence: 5-6yo

Dextromethorphan

Marijuana