A medial to lateral shift in pre-movement cortical activity in hemi-Parkinson's disease.
OBJECTIVE
Recent evidence suggests that cortical activity associated with voluntary movement is relatively shifted from medial to lateral premotor areas in Parkinson's disease. This shift occurs bilaterally even for unilateral responses. It is not clear whether the shift in processing reflects an overall change in movement strategy, thereby involving alternate cortical areas, or reflects a compensatory change whereby, given the appropriate conditions, less impaired cortical areas are able to provide a similar function in compensation for those areas which are more impaired. This issue was examined in patients with hemi-Parkinson's disease, in whom basal ganglia impairment is most pronounced in one hemisphere.


METHODS
Fourteen patients with hemi-Parkinson's disease and 15 age-matched control subjects performed a Go/NoGo finger movement task and the contingent negative variation (CNV) was recorded from 21 scalp positions.


CONCLUSIONS
Maximal CNV amplitudes were found over central medial regions for control subjects, but were shifted more frontally for Parkinson's disease patients, reduced in amplitude over the midline and lateralized towards the side ipsilateral to the greatest basal ganglia impairment. This shift in cortical activity from medial to lateral areas in Parkinson's disease patients appears to reflect a compensatory mechanism operating predominantly on the side of greatest basal ganglia impairment.
Department of Neurology, University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
R
R
Cunnington
W
W
Lalouschek
G
G
Dirnberger
P
P
Walla
G
G
Lindinger
S
S
Asenbaum
T
T
Brücke
W
W
Lang
D000200:Action Potentials / Q000502:physiology; D000368:Aged; D001479:Basal Ganglia / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology*; D003265:Contingent Negative Variation; D004576:Electromyography; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010300:Parkinson Disease / Q000503:physiopathology*