[Remote effects of local injection of botulinum toxin type A].
OBJECTIVE
To assess the severity and temporal profile of remote effects of botulinum toxin type A, BTX-A (Botox from Allergan Inc, USA and CBTX-A made by Lanzhou Biological Products Institute, China) injected locally on neuromuscular junction.


METHODS
Patients had enrolled in a prospective study for their movement disorders, 18 cases with Botox and 22 cases with CBTX-A were studied. Single fiber electromyography (SFEMG) in the extensor digitorum communis muscle or tibialis anterior muscle was performed before and 2-3 weeks, 5-8 weeks, 4-5 months after injection of Botox or CBTX-A.


RESULTS
It was measured totally 119 times. Significant increase of jitter was demonstrated 2-3 weeks after injections in both groups and MCD was in direct proportion to dose of injections. Fiber density value increased at the same time or later and lasted until 4-5 months after injections.


CONCLUSIONS
Subclinical effects on neuromuscular transmission of remote uninjected muscles after injections of Botox and CBTX-A are demonstrated, which indicates that the toxin spread distantly from the site of injection. SFEMG is valuable for studying the pathogenesis of the remote effects of BTX-A and for avoiding reinjection too frequently.
Wan
X
X
Department of Neurology, PUMC Hospital, CAMS and PUMC, Beijing 100730.
Tang
X
X
Cui
L
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D004576:Electromyography / Q000379:methods; D005260:Female; D019569:Hemifacial Spasm / Q000503:physiopathology*; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
D019274:Botulinum Toxins, Type A