Pattern of motor and cognitive deficits in detoxified alcoholic men

Background: Chronic excessive consumption of alcohol produces marked defici ts in cognitive and motor abilities, although not all functions are affecte d to the same extent. Furthermore, although the occurrence of neuropsycholo gical deficits in recently detoxified alcoholics is firmly established, the relative severity of these deficits, the specific neural systems that unde rlie the deficits, and their relationship to age and alcohol consumption va riables either are less established or have proven elusive altogether. Methods: We administered an extensive battery of neuropsychological tests, chosen for their known sensitivity to brain lesions in specific locations, to 71 recently (1 month) detoxified alcoholic men and 74 healthy controls w ho spanned the adult age range. Test scores were standardized to the contro ls for age and grouped a priori into composites that reflected performance in six functional domains: executive functions, short-term memory, upper li mb motor ability, declarative memory, visuospatial abilities, and gait and balance. Analogous verbal and nonverbal materials and left- and right-hand upper limb motor tasks were used to test whether alcohol-related deficits w ere greater for left or right hemisphere. Results: Compared with controls, the alcoholics were impaired on executive functions, visuospatial abilities, and gait and balance even after we accou nted for group differences in estimated premorbid IQ and education. Within the alcoholic group, the most salient deficits were in gait and balance and visuospatial abilities. No consistent lateralized deficit was observed acr oss the four domains tested. Unlike the cognitive composites, the upper lim b motor ability and gait and balance composites both showed increasing vuln erability to age, with an independent contribution to the gait and balance dysfunction from the amount of alcohol consumed over a lifetime. Conclusions: The pattern of functional deficits implicates at least two pri ncipal neural systems: the cerebellar-frontal system and the corticocortica l system between the prefrontal and parietal cortices. In addition, age and amount of alcohol consumption were better predictors of motor than cogniti ve impairments.