A chronic alcoholic presents with complaints of confusion, ataxia, ophthalmoplegia and peripheral neuropathy. Diagnosis is

Wernicke&;s encephalopathy:This is an acute reaction due to severe thiamine deficiency (Vit. B-1), the commonest cause being chronic alcohol abuse. Characteristically, the onset occurs aftera period of persistent vomiting.Signs and Symptoms:i. Ocular: Coarse nystagmus and ophthalmoparesis (usually the VIth cranial nerve is involved). Pupillary irregularity, retinal hemorrhages, papilledema and impairment of vision.ii. CNS: Disorientation, confusion, recent memory disturbances, poor attention span, and distractibility. Apathy and ataxia are early symptoms.iii. Peripheral neuropathy and serious malnutrition are often coexistent.Pathologically, neuronal degeneration and hemorrhage is seen in the thalamus, hypothalamus (mammillary bodies) and midbrain.