Although the Wernicke-Korsakoff syndrome occurs in nonalcoholic populations, it is most common among alcoholics. The full-blown Wernicke's syndrome consists of ocular abnormalities, ataxia, and a confusional state, but patients vary considerably in their presentation. Gait ataxia may be severe and is caused by cerebellar dysfunction, vestibular dysfunction, or both.
Drowsiness is also common.
Stupor and coma occur rarely. Most patients who survive the acute stages of Wernicke's syndrome will subsequently exhibit the clinically apparent symptoms of Korsakoff's psychosis. This disorder is characterized by anterograde and retrograde amnesia. The disease may be the most common cause of chronic cognitive impairment in alcoholics. The memory impairment is produced by damage to the dorsomedial nucleus of the thalamus and the mamillary bodies of the hypothalamus.