Relation between changes in long-latency stretch reflexes and muscle stiffness in Parkinson's disease - comparison before and after unilateral pallidotomy

Citation
R. Hayashi et al., Relation between changes in long-latency stretch reflexes and muscle stiffness in Parkinson's disease - comparison before and after unilateral pallidotomy, CLIN NEU, 112(10), 2001, pp. 1814-1821
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
CLINICAL NEUROPHYSIOLOGY
ISSN journal
1388-2457 → ACNP
Volume
112
Issue
10
Year of publication
2001
Pages
1814 - 1821
Database
ISI
SICI code
1388-2457(200110)112:10<1814:RBCILS>2.0.ZU;2-H
Abstract
Objective: To study the effects of posteroventral pallidotomy on both the s ize of long-latency stretch reflex (LLR) and the muscle stiffness in the wr ist flexor muscles. Patients and methods: Eleven consecutive patients (right-handed, 6 men and 5 women) underwent left-side microelectrode-guided pallidotomy. The LLR of the contralesional forearm was studied at baseline and 2-3 months after sur gery while patients continued to take their optimal medical regimens ('on' period). Patients were instructed not to respond to the perturbation (passi ve mode) or to oppose the mechanical extensor perturbation (active mode). Results: The stretch reflex evoked by extension perturbations of the wrist consisted of a short-latency reflex, (M1) and an LLR (M2). Pallidotomy had no effects on the size of M1 components in both passive and active mode and on that of M2 component in the passive mode, however, it significantly red uced M2 component in the active mode (P < 0.05). The inherent muscle stiffn ess over 60 ms period of mechanical stretch was not influenced by pallidoto my in any experimental condition (preoperative vs. postoperative or passive mode vs. active mode). The hand displacement following M2 component increa sed significantly after pallidotomy in both passive (P < 0.005) and active mode (P < 0.05). The inverted value of the displacement following M2 compon ent correlated with the size of M2 component (r = 0.60, P < 0.001). Conclusions: Pallidotomy decreased the transcortical reflex gain, probably at cortical level, and consequently reduced muscle stiffness. (C) 2001 Publ ished by Elsevier Science Ireland Ltd.