Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Histologic evaluation was conducted on 12 orbicularis oculi specimens from 11 patients with essential blepharospasm and Meige's disease who had received an average of 11.3 injections of botulinum A toxin over 3.5 years. Denervation was demonstrated by the spread of acetylcholinesterase staining on muscle fibers when specimens were evaluated within 11 weeks of the last injection. When specimens were taken after 12 weeks, spread of acetylcholinesterase was confined to the neuromuscular junctions, with little fiber size variability resembling normal muscle. Fibrosis seen in three specimens could be correlated to prior surgery. Repeated injections of botulinum toxin into human muscle do not appear to cause irreversible muscle atrophy or other degenerative changes. Denervation changes (fiber size variability, acetylcholinesterase spread) appear to correlate to the time interval since the last injection.
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PMID:Effects of repeated botulinum toxin injections on orbicularis oculi muscle. 138 21

Motor points (areas of maximal sensitivity to electrical stimulation) were found in constant locations over orbicularis oculi when measured in both eyes of six normal subjects. All subjects had a motor point at the lateral terminus of the upper lid crease and the medial extent of the lower lid crease. A study of the innervation zone [distribution of neuromuscular junctions (NMJ)] was conducted on strips of pretarsal and preseptal portions of the upper eyelid orbicularis that had been removed routinely during involutional ptosis surgery. There was no significant difference in NMJ concentration between the medial and lateral sections, as determined by cholinesterase staining. Therefore, we concluded that the innervation zone is diffuse for the orbicularis muscle within this portion of the upper eyelid. Single-point injections of botulinum toxin were then compared to the conventional multiple injection sites on separate eyes in 10 patients with benign essential blepharospasm. Eight of the 10 patients reported greater relief on the side given injections into multiple points; the other two patients experienced no difference between the two methods. Both histologic data and clinical observation of response to botulinum toxin injection suggest the innervation zone for the upper orbicularis is diffuse. Thus, we conclude that multiple injections are superior to the injection of a single motor point.
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PMID:Innervation zone of orbicularis oculi muscle and implications for botulinum A toxin therapy. 170 72

Chemodenervation of cervical muscles with botulinum A toxin, although useful in treating spasmodic torticollis, has been associated with dysphagia. Retrospective analysis of dose and injection site (sternomastoid vs. posterior cervical muscle groups) in 26 patients (49 injections) suggested that dysphagia was related to the quantity of toxin injected into the sternomastoid muscle: dysphagia, median 150 IU (7 injections); and no dysphagia, median 100 IU (42 injections; p = 0.026 Wilcoxon test). In a prospective study (31 injections to 24 patients), limiting the dose administered to the sternomastoid to 100 IU, substantially reduced the incidence of dysphagia (0 of 31, p = 0.27, Fisher's exact test). Denervation of human orbicularis muscle fibers, 5 weeks to 4 months after injection of botulinum A toxin for the treatment of blepharospasm, was successfully demonstrated by intense, diffuse acetylcholinesterase staining. A weight-adjusted dose similar to that given for torticollis was injected into longissimus dorsi muscle in 6 albino rabbits. Using the acetylcholinesterase stain as a marker, a diffusion gradient was noted over a distance of 30 to 45 mm from the point of injection and in contralateral muscle 15 to 25 mm from this point. Thus, denervation was demonstrated to occur within a definable area which crossed anatomic barriers, such as fascia and bone. These clinical and laboratory data suggest that dysphagia following botulinum toxin therapy results from toxin spread to pharyngeal musculature from the sternocleidomastoid injection site. Limiting of the injection dose to 100 IU or less to the sternomastoid substantially decreases the incidence of this complication.
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PMID:Botulinum A toxin for the treatment of spasmodic torticollis: dysphagia and regional toxin spread. 221 Oct 99