SEVERE GLOBAL AMNESIA PRESENTING AS WERNICKE-KORSAKOFF-SYNDROME BUT RESULTING FROM ATYPICAL LESIONS

A female alcoholic presented with Wernicke's encephalopathy subsequent to administration of diazepam and glucose (without thiamine) for trea tment of withdrawal seizures. Nystagmus and cerebellar ataxia quickly resolved when administered thiamine, although severe global amnesia co nsistent with Korsakoffs syndrome persisted. Magnetic resonance imagin g (MRI) revealed infarction of the right temporal lobe with hippocampa l atrophy, but no lesions of thalamus or atrophy of mammillary bodies. Positron emission tomography (PET) confirmed decreased cerebral metab olic rates for glucose (CMRglu) in the right temporal lobe correspondi ng to MRI findings, but also significant metabolic asymmetry of dorsal thalamus, i.e reduced CMRglu in left versus right. This patient is un ique in that neuroradiological findings revealed intact mammillary bod ies and suggest asymmetrical dysfunctions (structural right temporal a nd functional left diencephalic) to produce her profound amnesia.