Fine motor speed deficits in alcoholic Korsakoff's syndrome.

Forty-two alcoholic Korsakoff's syndrome (KS) patients (12 in study 1, 30 in study II) averaged slower tapping speeds than 35 alcoholic controls on the Halstead-Reitan manual finger tapping task. KS subjects also tapped slower than 26 normal volunteers in study II. Inverse relationships were found between finger-tapping speed dominant hand and verbal word fluency in one sample, and tapping speed and time to completion on Trail Making Part B and Tactual Performance Test in the other. The most powerful demographic predictors of tapping speed among age, education, length of abstinence, and affective state were age and education. Tapping speed was associated with cognitive tasks measuring frontal systems function (i.e., verbal fluency and Trail Making Part B) in KS subjects. There was no relationship between fine motor performance and general memory scores in the KS subjects. Decreased tapping speed for KS patients was postulated to result from compromised fine motor task initiation and persistence rather than mere slowing, as in Parkinson's disease. These findings suggest disruption of frontocerebellar systems that influence motor generation and set maintenance not previously explored in KS.