a common condition in patients with long-term alcoholism, resulting largely from thiamin deficiency and characterized by disturbances in ocular motility, pupillary alterations, nystagmus, and ataxia with tremors. An organic-toxic psychosis is often an associated finding, and Korsakoff syndrome often coexists; the characteristic cellular pathology is found in several areas of the brain, particularly the mammillary bodies and regions adjacent to the third and fourth ventricles. SYN: superior hemorrhagic polioencephalitis, Wernicke disease, Wernicke encephalopathy.