ANTERIOR HIPPOCAMPAL VOLUME DEFICITS IN NONAMNESIC, AGING CHRONIC-ALCOHOLICS

Magnetic resonance imaging was used to quantify the volume of the hipp ocampus in 47 men with chronic alcoholism and 72 healthy male control subjects, The subjects ranged in age from 21 to 70 years, thus permitt ing a test of whether older alcoholics suffer greater brain tissue vol ume reduction than do younger ones. Comparison brain regions included temporal lobe gray matter, white matter, and cerebrospinal fluid, as w ell as measures of the lateral ventricles, third ventricle, and tempor al horns. The results of this cross-sectional study showed that the an terior, but not the posterior, portions of the hippocampus in both hem ispheres were significantly smaller in the alcoholic than the healthy control group. Furthermore, the bilateral anterior hippocampal volume loss was greater in older than younger alcoholics. Despite the hippoca mpal volume deficit, these alcoholics did not demonstrate an explicit memory impairment; furthermore, memory test scores did not correlate s ignificantly with hippocampal volumes. In the alcoholics, the age-rela ted volume loss, which was over and above that expected in normal agin g, was also evident in the temporal cortex and white matter, Likewise, alcoholic ventricular enlargement was age-related. Analysis of covari ance revealed that the anterior hippocampal deficit persisted after ac counting for the temporal robe gray matter volume deficit. Multiple re gression analysis revealed that the age-related brain volume abnormali ties observed in the alcoholics could not be attributed to duration of alcoholism or total lifetime consumption of alcohol.