Effect of chronic alcoholism on the human hippocampus.

The effect of chronic alcoholism on the human hippocampus was studied in 21 patients, divided in 4 groups: Group A under 45 years, group B 46-59 years, group C 60-69, and Group D over 70 years; and compared with age-matched control patients who died without neurological complications. The gyrus dentatus and the ammonic fields CA1 through CA4 were analyzed by counting the number of neurons and the size of the nuclear area. Both parameters were evaluated statistically. The most important findings were a high neuronal loss in alcoholics in the first age group. In addition, the hippocampal neurons failed to display a vicarious reaction, since the nuclei did not show any increase in size despite the intense neuronal loss. Our results point out an early neuronal loss in the hippocampus of alcoholic patients higher than age-matched controls, as well as a lack of reaction to the neuronal insult.