Combined Effect of Transcranial Direct Current Stimulation (tDCS) and Physical Activity on Gait and Functional Mobility in Participants With Multiple Sclerosis

Inclusion Criteria: * Stable and continuous access to internet service at home * Adequate home facilities (enough space, access to quiet and distraction free area) * Definite MS diagnosis, subtype relapsing-remitting (RR-MS) * Disability Status Scale (EDSS) from 1 to 6.5 with clinically significant gait deviations * Clinically stable and stable on treatment with disease modifying agents at least from 6 months * Able to independently walk with or without an assisting device (i.e. cane, crutches or walking frames) for medium-long distance * Absence of other associated medical conditions that would prevent participants from performing physical activity, such as cardiorespiratory and severe osteoarticular disorders * Able to use study equipment * Able to commit 10 consecutive daily sessions of tDCS while performing physical program with baseline and follow-up visits * Able to understand the informed consent process and provide consent to participate in the study Exclusion Criteria: * Visual, auditory and motor deficits that would prevent full ability to understand study, as judged by treating neurologist or study staff * Primary psychiatric disorder that would influence ability to participate * Receiving current treatment for epilepsy * Uncontrolled headaches and migraines. In addition, if a subject has had a change in the rate or severity of head pressure, headache, or migraine in the past two weeks, they are excluded * History of head trauma (e.g., head injury, brain surgery) or medical device implanted in the head (such as Deep Brain Stimulator) or in the neck (such as a Vagus Nerve Stimulator) * Any skin disorder/sensitive skin (e.g., eczema, severe rashes), blisters, open wounds, burn including sunburns, cuts or irritation, or other skin defects which compromise the integrity of the skin at or near stimulation locations (where electrodes are placed) * Treatment for a communicable skin disorder currently or over the past 12 months * History of uncontrolled or labile hypertension * Other serious uncontrolled medical condition (e.g. cancer or acute myocardial infarction) * Wide Range Achievement Test-4th Edition (WRAT-4) Reading Recognition score \< 85 * History of clinically significant abnormalities on electrocardiogram (EKG) * Presence of chronic medical illness and/or severe ataxia * Botulinum toxin injection within the past 4 months or functional surgery in the past 6 months * Alcohol or other substance use disorder * Pregnant or breastfeeding