Serial SFEMG studies of orbicularis oculi muscle after the first administration of botulinum toxin.
Serial single fiber electromyography (SFEMG) examinations of orbicularis oculi muscle in patients with blepharospasm or hemifacial spasm treated with botulinum toxin injections were performed. The aim of the study was to evaluate the impairment of neuromuscular transmission, to follow reinnervation after botulinum toxin administration and to find out whether there was a relationship between SFEMG parameters and clinical symptoms. Examinations were performed before injection, during early and late remission of symptoms, and after recurrence of the involuntary movement. Severe impairment of neuromuscular transmission, as revealed by increased jitter and increased presence of abnormal potential pairs and pairs with blocking, was found in early remission, but fiber density remained unchanged when compared with pretreatment values. In late remission, increased fiber density was registered for the first time. The recurrence of involuntary movements was related to the further increase of fiber density and tendency to normalization of jitter parameters. The study therefore suggests that formation of new neuromuscular junctions and their functional maturation is responsible for muscle recovery after botulinum toxin administration.
Bogucki
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Department of Neurology, Dr K. Jonscher Hospital, Milionowa 14, 93-113, Lodz, Poland.
D000200:Action Potentials / Q000187:drug effects; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001764:Blepharospasm / Q000188:drug therapy* / Q000503:physiopathology; D001905:Botulinum Toxins / Q000627:therapeutic use*; D004576:Electromyography; D005260:Female; D019569:Hemifacial Spasm / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008538:Meige Syndrome / Q000188:drug therapy* / Q000503:physiopathology; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000187:drug effects / Q000294:innervation / Q000503:physiopathology*; D012008:Recurrence
D001905:Botulinum Toxins