Study aim: The effects of short-term and long-term anodal tDCS over M1 cortex concurrent with pelvic floor muscle training on pelvic floor muscle function and incontinency in patients with multiple sclerosis Design: A randomized clinical trial study with parallel groups, Double-blinded on 30 patients, Randomization will be done simply by random numbers table. Settings and conduct: This study is performed with the voluntary participations with multiple sclerosis at the Neuromuscular Rehabilitation Research Center of Semnan University of Medical Sciences. Both groups of study are taught progressive pelvic floor muscle exercises. The intervention group is also received anodal tDCS on M1 region but the other group will receive sham tDCS on this region. In both groups, treatment sessions include 18 treatment sessions 3 sessions per week for 6 consecutive weeks. To evaluate the short-term and long-term effects of tDCS, participants in both groups were evaluated before, 4 and 6 weeks after the start of the intervention and also one month after the end of the intervention. Patients and evaluator are blind. Participants/Inclusion and exclusion criteria: Inclusion criteria: Women with definitive diagnosis of MS with stable disease over the previous 4 months; Age is between 18 and 45 Years; Having symptoms of urinary incontinence; Patient's EDSS score should be less than 6.5. Exclusion criteria: History of MS relapse during treatment; Being pregnant or in the first 6 months post-partum; Urinary tract infection Intervention groups: The first group will receive anodal tDCS with progressive pelvic floor muscle exercises during 18 sessions of rehabilitation treatment. The second intervention group will receive sham tDCS with progressive pelvic floor muscle exercises during 18 sessions of rehabilitation treatment. Main outcome variables: Pelvic floor muscle function; Urinary incontinency