Task-related EEG-EEG coherence depends on dopaminergic activity in Parkinson's disease.
We investigated whether functional coupling between different cortical areas is impaired in Parkinson's disease, using corticocortical coherence as a surrogate measure of coupling. We recorded scalp EEG from different sites in seven parkinsonian patients while they tracked a visual target using their wrist, or copied the same movement from memory. Differences in EEG-EEG coherence between the tracking and copying tasks and their respective controls, visual tracking alone and fixation of a stationary target, were determined on and off levodopa. After levodopa we found extensive task-specific and broad band cortico-cortical coherence. Off levodopa cortico-cortical coherence was much reduced. Ascending dopaminergic projections from the ventral mesencephalon may therefore be important in determining the pattern and extent of corticocortical coupling during executive tasks.
Cassidy
M
M
MRC Human Movement and Balance Unit, Institute of Neurology, National Hospital for Neurology, London, UK.
Brown
P
P
D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage; D001479:Basal Ganglia / Q000166:cytology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000166:cytology / Q000503:physiopathology; D004298:Dopamine / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways; D010300:Parkinson Disease / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D011597:Psychomotor Performance / Q000502:physiology; D012154:Reticular Formation / Q000166:cytology / Q000503:physiopathology
D000978:Antiparkinson Agents; D007980:Levodopa; D004298:Dopamine