Reorganization of Motor System in Parkinson’s Disease

Abstract

Background/Aims: We investigated adaptive reorganization in Parkinson’s disease (PD) by fMRI using a passive movement task and compared the brain activation patterns of 10 patients with left- versus right-sided dominant symptoms. Five healthy controls were also investigated with the same settings. Methods: We grouped patients according to the predominant side of symptoms; thus, a right-sided dominant and a left-sided dominant group was formed. The paradigm consisted of a 4-finger passive movement task, which altered with resting states. For each subject, this examination was performed twice: on the left and on the right hand separately. Results: In healthy controls, motor-related areas contralateral to the moving fingers showed activation on fMRI. Concerning PD patients, motor-related areas of the ipsilateral hemisphere – including the primary motor cortex, supplementary motor area, and basal ganglia – seemed to be involved in the motor reorganization in PD. However, we could only demonstrate this reorganization in patients with right-sided dominant symptoms. Conclusions: We suggest that the human brain in PD tries to compensate for the failure of the basal ganglia motor loop by employing alternative (ipsilateral) motor pathways, indicating that a complex reorganization can also take place in disorders like PD which affect the whole motor-related network.