H reflex restitution and facilitation after different types of peripheral nerve injury and repair

Valero-Cabre, A Navarro, X

A. Valero-cabre et X. Navarro, H reflex restitution and facilitation after different types of peripheral nerve injury and repair, BRAIN RES, 919(2), 2001, pp. 302-312

62

INGLESE

Article

Neurosciences & Behavoir

BRAIN RESEARCH

0006-8993 → ACNP

919

2

2001

302 - 312

ISI

0006-8993(20011123)919:2<302:HRRAFA>2.0.ZU;2-J

This study addresses the restitution of monosynaptic H reflex after nerve i njuries and their role in the recovery of walking. Adult rats were submitte d to sciatic crush, complete section repaired by aligned or crossed fascicu lar suture, or an 8-mm resection repaired by autograft or tube repair. The sciatic nerve was stimulated proximal to the injury site and the M and H wa ves were recorded from gastrocnemius (GCm) and plantar (PLm) muscles at mon thly intervals during 3 months postoperation. Walking track tests were also carried out and the sciatic functional index (SFI) calculated to assess ga it recovery. The M and H waves reappeared in all the animals at the end of the follow-up. The H/M amplitude ratio increased during the first stages of regeneration and tended to decrease to control values as muscle reinnervat ion progressed. However, final values of the H/M ratio for the PLm remained significantly higher in all the groups except that with a nerve crush. The walking track pattern showed an appreciable recovery only after crush inju ry. Final SFI values correlated positively with the M wave amplitude and ne gatively with the H/M ratio. In conclusion, H reflex is facilitated after p eripheral nerve injury and regeneration and tends to return to normal excit ability with time. Changes in the H reflex circuitry and excitability corre lated positively with the deficient recovery of walking pattern after sever e nerve injury. (C) 2001 Elsevier Science B.V. All rights reserved.