Wernicke-Korsakoff syndrome

n. A chronic debilitation with lesions in the brain due to thiamine deficiency, usually occasioned by long-term alcoholism. These lesions are often located in the midbrain, cerebellum, and diencephalon and 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.