Deficits in rapid adjustments of movements according to task constraints in Parkinson's disease

• Published in: Movement disorders Vol. 19; no. 8; pp. 897 - 906
• Main Authors: Tunik, Eugene, Adamovich, Sergei V., Poizner, Howard, Feldman, Anatol G.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.08.2004; Wiley
• Subjects: Adaptation, Physiological - physiology; Aged; Analysis of Variance; basal ganglia; Biological and medical sciences; Biomechanical Phenomena; Case-Control Studies; Exercise Movement Techniques - methods; Feedback - physiology; Female; frames of reference; Humans; Male; Medical sciences; Middle Aged; Movement - physiology; multisegmental control; Neurology; Parkinson Disease - physiopathology; Psychomotor Performance - physiology; response to perturbation; trajectory formation; Visual Perception - physiology; Nervous system diseases; Adjustment; Central nervous system disease; Parkinson disease; Degenerative disease; Cerebral disorder; Extrapyramidal syndrome
• ISSN: 0885-3185; 1531-8257
• DOI: 10.1002/mds.20138

The role of the basal ganglia in the adaptive control of movement was investigated by unexpectedly perturbing movements in 8 patients with Parkinson's disease (PD) tested off medication and in 6 aged‐matched healthy subjects. Subjects performed two movement components simultaneously and without visual feedback: touching the nose with the finger while leaning the trunk forward. Subjects wore a harness connected to an electromagnet, which was attached to a wall. The trunk movement was mechanically blocked in randomly selected trials by engaging the electromagnet. While healthy subjects performed the task equally well in both conditions, PD subjects' hand movements significantly deteriorated in trunk‐perturbed compared to trunk‐free trials. Deteriorated hand movements were characterized by segmented hand paths, unsmooth velocity profiles, and prolonged movement times. This finding indicated that the relatively local trunk perturbation had a global effect on the hand movement of PD subjects, necessitating them to reinitiate, after some delay, their arm movement in perturbed trials. Thus, the basal ganglia may be a critical node in brain networks mediating the flexibility of responses to altered motor states. © 2004 Movement Disorder Society