The role of language areas in motor control dysfunction in Parkinson's disease

We evaluated the differences in motor control organization between parkinso nian patients with (seven cases) and without(ten cases) gait disorder. We u sed positron emission tomography (O-15-H2O-PET) to measure regional cerebra l blood flow as a correlate for local neuronal activation. This has been as sessed during repetitive joystick movements of the right hand, externally t riggered using a metronome as an auditory cue. In patients with Parkinson's disease (PD) without gait disorder, the contralateral supplementary motor cortex and the bilateral cerebellum were activated, while in PD patients wi th gait disorder the contralateral Broca's area, the contralateral sensory motor cortex and the homolateral cerebellum were activated. Our results sug gest that PD patients with gait disorder creates an internal verbal cue in order to control the output of the movement of joystick, supplying the loss of control of the supplementary motor cortex that is activated in patients without gait disorder.