Ataxia DDx


Ataxia is impaired coordination in the absence of weakness. Acute ataxia is a neurological emergency, and vascular lesions of the cerebellum (infarction, hemorrhage) must be considered/ excluded.


Acute onset (minutes/ hours)

  • cerebellar hemorrhage or infarction (particularly suspect this if hemiataxia or other brainstem signs)
  • Intoxication with alcohol or drugs is perhaps the most common etiology (truncal/ gait, bilateral, altered mental state) e.g. alcohol, antiepileptics
  • Migraine (basilar migraine variant can present with cerebellar ataxia and brainstem signs; headache may not be prominent)
  • Post-traumatic/post-concussive

Subacute ataxia (hours/days)

  •  Infectious causes: most common in children
    — viral cerebellitis, especially 2–10 years old (pyrexia, limb/gait ataxia, and dysarthria, with recovery over a period of weeks)
    — Postinfectious encephalomyelitis, especially varicella.
  • Intoxication (see acute)
  • Multiple sclerosis, consider this especially in young adults (history of relapse, other brainstem signs)
  • Paraneoplastic syndromes (especially neuroblastoma in children and lung carcinoma in adults)
  • Others
    — Foramen magnum compression
    — Hydrocephalus
    — Labyrinthitis/vestibular neuritis ( vertigo, nausea, and vomiting are more prominent)
    — Miller-Fisher variant of Guillain-Barré syndrome (ophthalmoplegia, ataxia, areflexia)
    — Posterior fossa lesions (features of  increased intracranial pressure)
    — Post-concussion


  • Autosomal dominant spinocerebellar ataxia (SCA)
  • Recessively inherited and X-linked ataxia
    — ataxia telangiectasia
    — Friedreich ataxia
    — other rare causes

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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