The alcoholic brain: CT scan and psychological findings

Abstract

One hundred male alcoholics without overt clinical signs of brain damage were interviewed, psychologically tested and scanned by means of a CT 1010 EMI scanner. Fifty age-matched controls, lifelong abstainers or light drinkers, were used for comparison. Fifty-six alcoholics from the initial sample were followed up after periods varying from 30 to 152 weeks, and radiological changes during the follow-up were assessed. The main results of the study can be summarized as follows: (1) All CT scan indices were significantly different in alcoholics and controls. Alcoholics had larger ventricles, wider cerebral sulci and wider Sylvian and interhemispheric fissures. Cerebellar sulci were visible only in alcoholics. These differences were greater for older alcoholics and controls, but were also present in the younger subjects. (2) In the alcoholic group the size of the ventricular system, and the width of the sulci, Sylvian and interhemispheric fissures were positively and significantly correlated with age. The duration of the drinking history and the age of onset were not significantly correlated with CT scan indices. (3) In those alcoholics whose age was greater than the mean for the whole group, the size of the ventricular system and width of the Sylvian fissure were significantly and negatively correlated with the duration of abstinence prior to scanning. (4) Other features such as decreased tolerance, a positive family history of alcoholism and 'social decline' were not significantly related to the severity of CT scan abnormalities. (5) When the effects of age and premorbid intelligence were controlled, alcoholics showed significant cognitive impairment when compared with controls. The differences in the scores of psychological tests and CT scan indices were greater between alcoholics and controls of high IQ than between those of low IQ. This discrepancy is likely to be due to a selection bias. (6) No significant correlations were found between the degree of cognitive impairment and clinical features. The size of the ventricular system was positively and significantly correlated with the discrepancy between immediate and delayed recall of verbal material. There were no other significant correlations between cognitive impairment and CT scan indices. (7) Those subjects who had remained abstinent during the follow-up period, when considered as a group, showed a significant reduction in the size of the ventricular system. When cortical indices and V/B ratio were combined, patients whose scans had improved at follow-up differed from the rest with regard to the length of abstinence prior to re-scanning.