THE DRINKING ACTION OF PARKINSONS-DISEASE SUBJECTS

Using the ELITE system, a kinematic analysis was performed of the uppe r limb drinking action of nine Parkinson's disease patients and nine c ontrol subjects. The aim was to use a natural task to investigate the reported Parkinson's disease dysfunction in the performance of simulta neous and sequential movements. Subjects were required to reach 28 cm, grasp a half-filled glass and then rake a sip of water. Dysfunction f or simultaneous movements was supported by the finding that, in both a bsolute and relative terms, Parkinson's disease subjects often began t o open the hand later than control subjects. Dysfunction for sequentia l movements was supported by the finding that Parkinson's disease subj ects often showed a pause between the first ('reach-grasp') and second ('take-to-lips') parts of the drinking action. Despite these delays a nd pauses, the proportional organization of the action was similar for both groups. This suggested that Parkinson's disease subjects were ab le to compensate for the problem in activating the different component s of the drinking action. The results are discussed in relation to the influence of the abnormal basal ganglia input to cortical motor regio ns.