Anodal transcranial direct current stimulation of motor cortex does not ameliorate spasticity in multiple sclerosis

PURPOSE: To assess whether anodal transcranial direct current stimulation (tDCS) is effective in modulating lower limb spasticity in MS patients. Previously, anodal tDCS has been shown to improve motor deficits in several neurological diseases and, recently, it has been proposed as effective in decreasing spasticity after stroke. However, the effect of anodal tDCS on spasticity is not examined in MS. METHODS: We performed a single-centre randomized, double-blind, sham-controlled study to investigate efficacy of anodal vs sham tDCS in 20 relapsing-remitting MS patients. Ten patients received anodal tDCS stimulation to the primary motor cortex of the more affected side, 20 minutes/day for 5 consecutive days. Ten patients received sham tDCS stimulation. Spasticity was assessed by using the modified Ashworth scale (MAS), the self-scoring MSSS-88 (Multiple Sclerosis Spasticity Scale) and Multiple Sclerosis Walking Scale (MSWS-12) at baseline and at the end of protocol stimulation. RESULTS: No side effects were detected during either anodal tDCS or sham. In both groups, there was no significant improvement in MAS, MSSS-88 and MSWS-12 scores. Moreover the comparison between anodal tDCS and sham showed no difference. CONCLUSIONS: Five-daily sessions of anodal tDCS to the primary motor cortex does do not improve lower limb spasticity in MS patients.