Neural correlates of dysexecutive functions in Parkinson's disease

Background: It is yet unclear whether cognitive dysfunction in Parkinson's disease is caused mainly by striatal dysfunction, altered striatocortical outflow or prefrontal dysfunction. Reports on dopaminergic modulation of cognitive functions in these patients are conflicting. We used fMRI to investigate the neural basis of impaired executive functions in medicated Parkinson's disease patients. Methods: 12 patients (duration of illness: 5.9 +/- 3.8 years, Hoehn and Yahr stage: 2 +/- 1) and 12 age, sex and handedness matched control subjects (mean age 61 +/- 7 years) were studied using fMRI. Dementia and depressio…