Computed tomographic correlates of auditory brainstem responses in alcoholics.

A previous study has shown a high incidence of abnormal auditory brainstem responses in alcoholics, particularly when cerebral and/or cerebellar atrophy was present in CT scans. To correlate the electrophysiological findings with definable morphological alterations, quantitative measurements of the brainstem structures in CT scans were made. To determine the relative size of the brainstem, the ratio between the sizes of the brainstem and its cisterns was obtained at the midbrain, upper and lower pons. When compared to the aged-matched control group, the alcoholics as a whole and the alcoholics with abnormal auditory brainstem responses had a decrease in the ratio at all three brainstem levels, but these ratios were not decreased in the alcoholics with the normal auditory brainstem responses. The present data indicate that abnormal brainstem responses in the alcoholics correlated with an increased size of the brainstem cisterns and possible brainstem atrophy.