tDCS is a non-invasive brain stimulation technique that is believed to exert clinical benefits through modulation of cortical excitability and plasticity, thereby enhancing and prolonging training gains. While tDCS has been increasingly studied for the reduction of severity of MS symptoms such as cognitive impairment, fatigue, and spasticity with promising results, its potential for improving motor deficits have been understudied. We address this gap by investigating the synergistic effects of tDCS combined with physical activity.

To determine the effect of multiple sessions of transcranial direct current stimulation (tDCS) combined with aerobic physical activity on balance and walking in patients with multiple sclerosis (MS).

MS participants (EDSS<6.5) are recruited for an ongoing randomized controlled trial to receive 10 sessions of either active or sham tDCS paired with unloaded cycling for 20 minutes. Stimulation is administered over the primary motor cortex (2.5 mA; anode over C3/cathode over FP2).  The primary outcome is walking ability, endurance, and static balance quantitatively assessed using a single inertial sensor placed on the lower back (gait and 2 minutes walking test) and a force platform (postural sway). Measurements are collected at baseline, at the end of tDCS intervention, and 4-weeks post-intervention.

A male 59 year-old-patient (secondary progressive subtype; EDSS: 5.5) completed the full 10 sessions. Compared to baseline visit, the participant showed improvement in gait speed (from 1.16 to 1.35 m/s) and stride length (from 1.12 to 1.46 m). Similarly, there was a reduction of 30% in sway area and an increase of 35% in the overall distance walked over 2 minutes. Lingering benefits were observed at 4-weeks following tDCS treatment. Full results from the study will be included at the time of presentation.

Our preliminary results showed cumulative and long-lasting benefits of multiple sessions of tDCS combined with physical activity on motor functions.