Korsakoff's syndrome

Korsakoff's syndrome, amnesic state in which, because of an inability to record new memory traces, a person can carry out complex tasks learned before his or her illness but cannot learn the simplest new skills. The syndrome is often transient and has a good prognosis in head injury. In alcoholism (where the syndrome, sometimes called alcoholic dementia, is caused by a lack of thiamine, a B vitamin that is destroyed by alcohol) and in other conditions where destruction is irreversible, the prognosis is poor and prolonged institutional care may be required.