Hippocampal volume deficits in alcoholic Korsakoff's syndrome.
OBJECTIVE: To examine whether the amnesic syndrome of alcoholic Korsakoff's syndrome (KS) originates from pathology of the hippocampus and not solely the diencephalon. METHODS: The authors studied 5 patients with KS and two comparison groups: 20 patients with Alzheimer's disease (AD) with known bilateral hippocampal volume loss and 36 healthy control subjects. The authors used quantitative MRI to characterize the hippocampus and comparison brain structures (temporal cortex, lateral ventricles, temporal horns, and third ventricle). RESULTS: Relative to healthy control subjects, the KS and AD groups had comparable, significant bilateral hippocampal volume deficits. Although both patient groups also had extensive volume abnormalities in temporal lobe cortical gray matter, temporal horns, and lateral and third ventricles, declarative memory test performance was selectively related to hippocampal volumes in KS and not to any of the comparison volumes. CONCLUSIONS: The characteristic memory deficit of Korsakoff's syndrome involves hippocampal and diencephalic pathology.