Muscle fiber atrophy in leg muscles after botulinum toxin type A treatment of cervical dystonia.

Abstract

Previous electrophysiologic studies on the effects of local injections of botulinum toxin type A (BTX-A) have indicated impaired neuromuscular transmission in distant muscles. To further study possible distant effects of repeated BTX-A injections, we obtained percutaneous muscle biopsies of the vastus lateralis muscle from 11 patients with cervical dystonia. We examined the biopsies with histopathology and morphometry, and compared them with age-matched healthy controls. There was an increased frequency of angular atrophic type IIB fibers in the patient group, and the mean size of IIB fibers was significantly smaller (p < 0.05). In addition, there was a negative correlation between accumulated dose of botulinum toxin and relative size of type IIA fibers (p < 0.05). We postulate that the observed atrophy is due to distant effects of botulinum toxin causing progressive denervation-like changes in non-treated muscle. This observation calls for further, prospective studies of the long-term effects of the treatment.

• Authors: T Ansved, T Odergren, K Borg
• Journal: Neurology (Neurology) Vol. 48 Issue 5 Pg. 1440-2 (May 1997) ISSN: 0028-3878 [Print] United States
• PMID: 9153487 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Neuromuscular Agents
• Botulinum Toxins, Type A

Topics

• Adult
• Botulinum Toxins, Type A (administration & dosage, adverse effects, therapeutic use)
• Dose-Response Relationship, Drug
• Dystonia (drug therapy)
• Humans
• Injections, Intramuscular
• Leg
• Middle Aged
• Muscle Fibers, Skeletal (pathology)
• Muscle, Skeletal (drug effects, pathology)
• Neck Muscles
• Neuromuscular Agents (administration & dosage, adverse effects, therapeutic use)