Memory deficits in Korsakoff and non-Korsakoff alcoholics following alcohol withdrawal and the relationship to length of abstinence.

It has been suggested that both Korsakoff and non-Korsakoff alcoholics share certain memory deficits following alcohol withdrawal. Since both groups have in common long-term alcohol abuse, this has been posited as evidence that alcohol per se can cause irreversible cognitive impairment. This hypothesis has been examined by comparing age and IQ matched groups of detoxified Korsakoff and non-Korsakoff alcoholics and normal controls on pencil and paper and computerised (CANTAB) memory tests. The results indicate that Korsakoff but not non-Korsakoff alcoholics have neuropsychological deficits on tests which have demonstrated medial temporal-lobe/diencephalic dysfunction in humans and non-human primates. Although non-Korsakoff alcoholics showed deficits on the Wechsler Memory Scale subtests these could not be related to damage of specific neuronal systems. Furthermore there was evidence that for the non-Korsakoff but not the Korsakoff alcoholics, superior performance on the Wechsler memory scale subtests was related to increased length of abstinence and independent of either age or duration of drinking.