Impaired compensation for mechanical loads in a patient with hemiballismusfollowing stroke

Citation
D. Flament et al., Impaired compensation for mechanical loads in a patient with hemiballismusfollowing stroke, PARKINS R D, 6(1), 2000, pp. 49-56
Citations number
39
Categorie Soggetti
Neurology
Journal title
PARKINSONISM & RELATED DISORDERS
ISSN journal
13538020 → ACNP
Volume
6
Issue
1
Year of publication
2000
Pages
49 - 56
Database
ISI
SICI code
1353-8020(200001)6:1<49:ICFMLI>2.0.ZU;2-9
Abstract
Flexion movements of the wrist were studied in a patient who showed signs o f hemiballismus following a unilateral infarction, which damaged the region neighboring the subthalamic nucleus. The experiments were designed to test whether a lesion of this nature impairs load compensation and, specificall y, whether antagonist activity can be appropriately suppressed when initiat ing a movement. The latency between movement onset and agonist EMG onset ch anged from the normal relationship where agonist onset precedes movement to one where agonist onset followed movement when an extensor load was placed on the affected limb. This was found to result from the inability to inhib it tonic activity in the antagonist and simultaneously activate the agonist muscle. The results suggest that the indirect pathway through the basal ga nglia may be necessary to compensate for mechanical loads and to suppress a ntagonist activity when a movement is initiated. (C) 2000 Elsevier Science Ltd. All rights reserved.