Korsakoff syndrome

Neurological disorder marked by severe amnesia despite clear perception and full consciousness, resulting from chronic alcoholism, head injury, brain illness, or thiamin deficiency. Persons with the syndrome typically cannot remember events in the recent or even immediate past; some retain memories only a few seconds. Longer periods—up to 20 years—may also be forgotten. Confabulation (recounting detailed, convincing “memories” of events that never happened) sometimes coexists with the syndrome, which may be transient or chronic.