Wernicke's encephalopathy

n. A chronic debilitation from lesions in the brain due to thiamine deficiency, usually occasioned by long-term alcoholism. These lesions first produce ataxia, acute confusion, gaze palsy, and nystagmus. In later stages damage occurs throughout the brain and particularly in the mammillary bodies and dorsomedial nuclei, leading to memory loss, deterioration of executive functions, and dementia. Acute phases of the disease can be treated by administration of thiamine, but deterioration continues in the case of alcohol abuse despite thiamine treatment.