The remote effect of local injection of botulinum toxin type-A: an evaluation with F-wave / 中华物理医学与康复杂志

ABSTRACT

Objective To evaluate the remote effect of local injection of botulinum toxin by use of the F-wave measures. Methods The F-wave responses as well as M-waves were recorded before injection, and at 1 week,12 to 24 weeks after local injection of botulinum toxin type-A (BTX-A) in 26 patients, including 19 with hemi-facial spasm (HFS),5 Meige syndrome and 2 torticollis spasmodicus (TS).The following parameters were analyzed M-wave latency (ML) and amplitude (Mamp), F-wave minimal latency(Fmin) and average latency(Fave),amplitude (Famp), duration (Fdur), persistence (Fper) and chronodispersion (Fchr). The above parameters were obtained through the electric stimulation of ulnar and tibial nerves, and recorded from the abductor digiti minimi and extensor digitorum brevis, respectively. Results No definite F-wave was obtained by electric stimulation of ulnar nerve at 1 week after injection in 3 HFS patients (5 nerves). The Fave recorded from electric stimulation of ulnar and tibial nerves prolonged significantlyand Fdur from ulnar nerve increased significantly at 1 week after injection, but were not significantly different from those of pre-injection when recorded at 12 to 24 weeks after injection. No significant correlation of the altered F-wave parameters was found with the dosage of BTX-A. Conclusion Fdur and Fave could sensitively assess the remote effect of the local injection of BTX-A, the remote effect might be correlated with the distance between injected muscle and tested muscle, rather than the dosage of BTX-A.