Therapeutic benefit of uncobotulinum toxin A for spasticity of the triceps surae in patients with multiple sclerosis: An observational study on gait spatiotemporal parameters

Abstract

Few data are available on the use of botulinum toxin for spasticity treatment in multiple sclerosis (MS). In a previous study we found that one of the main therapeutic goals in patients suffering from spasticity of the triceps surae was improvement in walking. In this pilot observational study, we assessed the benefit of an injection of incobotulinumtoxinA in patients with MS suffering from spasticity of the triceps surae. This study enrolled MS patients with Expanded Disability Status Scale (EDSS) scores < 6 who required botulinum toxin for focal spasticity of the triceps surae. Treatment consisted of 200 IU of incobotulinumtoxinA (Xeomin) (100 units in 3 milliliters) injected into the triceps surae at 5 sites. A second injection was allowed, but after a 3 months delay. Outcome measures were assessed before injection, and at 6 weeks and 3 months post-injection, using the Goal Attainment Scale (GAS), Twelve Item MS Walking (MSWS-12) Scale, Timed Up and Go (TUG) Test, and 6 Minute Walk Test (6MWT). Spatiotemporal gait data were obtained by GAITRite. Twenty-two patients with a mean age of 48.2 ± 12 years and a mean EDSS of 4.2 (median 4.7). At 6 weeks, spatiotemporal parameters and the results of the 6MWT were not significantly different even though we observed a significant improvement for the GAS, the MSWS-12 score ( P = 0.015), and the TUG Test ( P = 0.003). However, at 3 months, there was a significant benefit on injected (0.005) and non-injected (0.01) step length measured by GaitRITE but not on support distribution (0.18; 0.38). This may explain the decrease in gait fatigability and the increase of speed on the 6MWT (0.02), although neither the TUG Test nor the MSWS-12 Scale showed improvement. Eighty percent of patients had reached their objective on GAS. These results confirm the interest of toxin as a treatment for focal spasticity of the triceps surae with a significant improvement of gait. Further studies are needed to clarify guidelines for administration (dosage, intervals). The best results on gait parameters are obtained after 3 months, confirmation of the hypothesis of central effect of toxin. Botulinum toxin should probably be discussed early in the management of spasticity in MS patients.