Therapeutic benefit of botulinum toxin A for the spasticity of the triceps surae in patients with multiple sclerosis: An observational study.

INTRODUCTION: Few data are available on the use of botulinum toxin for spasticity treatment in multiple sclerosis. In a previous study, we found that one of the main therapeutic goals was the improvement ok walking, in patients suffering from spasticity of the triceps surae.

OBJECTIVE: This is a pilot observational study, with the aim to assess the benefit of an injection of 200 UI of incobotulinumtoxin A in multiple sclerosis patients suffering from spasticity du triceps surae.

MATERIAL/PATIENTS AND METHODS: This study concern patients with multiple sclerosis with EDSS score lower than 6, needing botulinum toxin for focal spasticity of the triceps surae. The last injection, if the patient had previous botulinum treatment must be performed more than 3 months later. Outcome measure were goal attainment scale, MSWS-12 scale, TUG, and 6mn walk test (WT), before 6 weeks and 3 months after the injection. Treatment consists of 200 UI of incobotulinumtoxin A (xeomin) injected in the triceps surae in 5 points according the anatomic technique, with a dilution of 100U in 3mL. This study was approved by the local ethic comity of the University Hospital of Rennes (France).

RESULTS: We present the result of 28 patients, with a mean age of 48.2+-12 years, and a mean EDSS of 4.2 (median 4.7). 6 weeks after the injection, we observed a significant improvement for the GAS, the MSWS-12 score (p=0.015), and the TUG (p=0.003). 6mn WT was improved but not significantly. At 3 months, neither TUG nor MSWS-12 were improved, however 6mnWT was significantly increase (0.0241) and 80% of the patient had reached their objective on the GAS.

DISCUSSION/CONCLUSION: These results tend to confirm the interest of botulinum toxin A for the treatment of focal spasticity of the triceps surae with a significant improvement of gait and posture. Further studies are needed to confirm the place of botulinum toxin in this indication, but also the modalities of use in term of dosage and interval between injections. The best results are obtained after 6 weeks, with a decrease of the benefit at 3 months, even if at this time an improvement on endurance is observed. These results support the place of botulinum toxin in the focal spasticity of the triceps surae in MS and are in concordance with the French recommendations about focal spasticity treatment. Botulinum toxin should probably be discussed early in the management of spasticity in MS patients.