Brain fMRI activation associated with self-paced finger tapping in chronic alcohol-dependent patients.
BACKGROUND
Fine and gross motor dysfunction in chronic alcoholic patients is prevalent, but not extensively studied. Brain autopsy studies of brain regions involved in motor movements indicate cerebellum and frontal lobes are particularly sensitive to alcohol-induced damage, in contrast to motor cortex.


METHODS
Using functional magnetic resonance imaging (fMRI), we compared the pattern of activation of the cerebral cortex and cerebellum during repetitive, self-paced dominant (DH) and nondominant (NDH) index finger tapping in eight uncomplicated alcohol-dependent patients after approximately 2 weeks of abstinence and in nine normal controls.


RESULTS
Whereas alcoholic patients tapped significantly more slowly than normal controls, a greater percentage of pixels were activated in the ipsilateral cortex during DH tapping. Furthermore, alcoholics tapped significantly less efficiently (tapping rate divided by percent pixels activated [weighted by pixel intensity] in a given region of interest [ROI]) than normal controls in every ROI examined while using DH, but only in ipsilateral hemi-cerebellum using NDH. Finally, the alcohol-dependent patients did not demonstrate the greater mean pixel activation, percentage activated pixels, and lesser activation efficiency in the ipsilateral cortex during NDH compared to DH tapping that was observed in the normal control group.


CONCLUSIONS
These findings are compatible with motor inefficiency and compensatory alterations of cortical-cerebellar circuits. Further studies are needed to determine whether these deficits recover with prolonged abstinence and how they relate to cognitive inefficiency throughout the clinical course of alcoholism.
Parks
Mitchell H
MH
Vanderbilt Addiction Center, Vanderbilt University Medical Center, Nashville, TN 37232-2647, USA.
Morgan
Victoria L
VL
Pickens
David R
DR
Price
Ronald R
RR
Dietrich
Mary S
MS
Nickel
Mark K
MK
Martin
Peter R
PR
D000328:Adult; D000437:Alcoholism / Q000503:physiopathology*; D001921:Brain / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology*; D018709:Statistics, Nonparametric; D013695:Temperance