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Wernicke Encephalopathy — RACP Adult Medicine MCQ

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EasyNeurologyWernicke EncephalopathyRACP Adult Medicine

A 45-year-old man with chronic alcohol use presents with confusion, ophthalmoplegia (lateral rectus palsy), and ataxia. He is malnourished. MRI shows mamillary body hyperintensity on T2-weighted images. What is the most likely nutritional deficiency?

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Correct answer: B — Thiamine (B1) deficiency

The classic triad of confusion, ophthalmoplegia, and ataxia (Wernicke encephalopathy) with mamillary body changes on MRI in a malnourished alcoholic patient is thiamine (B1) deficiency. IV thiamine (Pabrinex — 500 mg TDS for 3–5 days) must be given BEFORE glucose (glucose metabolism consumes thiamine, potentially worsening encephalopathy). Untreated, it progresses to Korsakoff syndrome.

Reference: eTG Neurology – 2024 – Wernicke Encephalopathy; NICE 2024