Hand functioning in progressive multiple sclerosis improves with tDCS added to daily exercises: A home-based randomized, double-blinded, sham-controlled clinical trial

Background: Many individuals with progressive multiple sclerosis (PMS) are challenged by reduced manual dexterity and limited rehabilitation options. Transcranial direct current stimulation (tDCS) during motor training can improve rehabilitation outcomes. We developed a protocol for remotely supervising tDCS to deliver sessions of stimulation paired with training at home.Objective: This study evaluated the effectiveness of at-home tDCS paired with manual dexterity training for individuals with PMS.Methods: Sixty-five right-hand dominant participants with PMS and hand impairment were randomized to receive either active or sham M1-SO tDCS paired with manual dexterity training over 4 weeks. Clinical outcomes were measured by the changes in Nine-Hole Peg Test (9-HPT) and Dellon-Modified-Moberg-Pick-Up Test (DMMPUT).Results: The intervention had high rates of adherence and completion (98% of participants completed at least 18 of 20 sessions). The active tDCS group demonstrated significant improvement for the left hand compared with baseline in 9-HPT (-5.85 +/- 6.19 vs -4.23 +/- 4.34, p = 0.049) and DMMPUT (-10.62 +/- 8.46 vs -8.97 +/- 6.18, p = 0.049). The active tDCS group reported improvements in multiple sclerosis (MS)-related quality of life (mean increase: 5.93 +/- 13.04 vs -0.05 +/- -8.27; p = 0.04).Conclusion: At-home tDCS paired with manual dexterity training is effective for individuals with PMS, with M1-SO tDCS enhancing training outcomes and offering a promising intervention for improving and preserving hand dexterity.