Exacerbation of psychotic symptoms as clinical presentation of Wernicke encephalopathy in an Alzheimer's disease patient.

Although there have been recent reports of nonalcoholic thiamine deficiency (TD), no association has been reported between the exacerbation of the psychiatric symptoms of Alzheimer's disease patient and TD. An 89-year-old woman with dementia visited our hospital because of acute deterioration in behavioral and psychological symptoms of dementia (BPSD). Her medical history revealed a decrease in oral food intake lasting more than 2 weeks, so that TD was suspected and abnormal behavior improved significantly after thiamine administration. Thiamine deficiency should be suspected in patients with dementia who demonstrate acute deterioration in BPSD possibly related to poor oral food intake.