The effect of unilateral posteroventral pallidotomy on the kinematics of the reach to grasp movement
- Kerry M B Bennetta,c,
- John D O’Sullivanb,
- Richard F Peppardd,
- Peter M McNeilld,
- Umberto Castielloc,e
- aFaculty of Health Sciences, La Trobe University, Melbourne, Australia, bDepartment of Neurology, Austin and Repatriation Medical Centre, Studley Road, Heidelberg, Victoria, Australia, cCentre for the Study of Perceptuomotor Disorders, St Vincent’s Hospital, Melbourne, Australia, dClinical Neurosciences, St Vincent’s Hospital, Melbourne, Australia, eDepartment of Psychology, University of Melbourne, Australia
- Dr Kerry Bennett, Faculty of Health Sciences, La Trobe University, Bundoora, Victoria, Australia 3053. Telephone 0061 3 9479 5785.
- Received 4 June 1997
- Revised 7 January 1998
- Accepted 12 March 1998
Abstract
OBJECTIVE to assess postoperative effects of unilateral posteroventral pallidotomy on the organisation of upper limb movement.
METHODS A three dimensional kinematic system (ELITE, B∣T∣S∣ Italy) was used to record reach to grasp movements to objects of either small (0.7 cm) or large (8 cm) diameter placed at a reaching distance of either 20 or 30 cm. Four patients with Parkinson’s disease were assessed in “off” (12 hours without medication) and “on” (1 hour after administration of medication) preoperatively and postoperatively.
RESULTS Duration of the movement and the time spent in arm deceleration were significantly reduced after surgery. However, movement patterning according to object size was adversely affected. Postoperatively, all four patients showed an abnormal pattern of a longer movement duration, and three showed a longer time of reaching arm deceleration, for reach to grasp movements to the large object than for those to the small object.
CONCLUSION Posteroventral pallidotomy seems to be beneficial in reducing bradykinesia of upper limb movements but may have “costs” to movement patterning, particularly for reach to grasp movements to objects of differing sizes. This study raises interesting questions about the role of the globus pallidus interna in coordinating stimulus bound visual information with appropriate motor patterning.
