M1 and Cerebellar tDCS for MSA-C: a Double-Blind, Randomized, Sham-Controlled, Crossover Study

Area of Science:

• Neurology
• Neurorehabilitation
• Movement Disorders

Background:

• Multiple-system atrophy with cerebellar-dominant symptoms (MSA-C) presents significant gait and balance challenges.
• The therapeutic potential of transcranial direct current stimulation (tDCS) for MSA-C remains largely unexplored.

Purpose of the Study:

• To investigate the efficacy of tDCS targeting the primary motor cortex (M1) and cerebellum in patients with MSA-C.
• To evaluate the impact of tDCS on motor function, specifically gait and balance, in MSA-C patients.

Main Methods:

• A randomized, sham-controlled study involving probable MSA-C patients.
• Three single tDCS sessions (M1, cerebellum, sham) administered in a randomized order.
• Assessment of cerebellar ataxia using the International Cooperative Ataxia Rating Scale (ICARS) and objective gait/balance analyses pre- and post-stimulation.

Main Results:

• Significant improvements in gait velocity, step time, and single support time were observed following both M1 and cerebellar tDCS compared to sham.
• No significant differences were found in ICARS scores or posturography results across the three stimulation conditions.
• Factors influencing gait velocity improvement varied between M1 (disease duration, baseline gait speed, single support time) and cerebellar stimulation (higher ICARS score, baseline gait speed).

Conclusions:

• Both M1 and cerebellar tDCS are safe and effective interventions for improving gait in MSA-C patients.
• The distinct factors correlating with improvement suggest different underlying mechanisms for M1 and cerebellar tDCS.
• Further research is warranted to elucidate the specific neurophysiological mechanisms driving these improvements.