Safety and Feasibility of Transcranial Direct Current Stimulation in Amyotrophic Lateral Sclerosis – A pilot study with a single subject experimental design.

Introduction: Transcranial direct current stimulation (tDCS) has been explored as a neuromodulatory tool to prime motor function in several neurological disorders. Studies using tDCS in amyotrophic lateral sclerosis (ALS) are limited. We investigated the safety, feasibility and effects of long term tDCS in an individual with ALS. Methods: A 36 year old male diagnosed with clinically definite ALS received twelve sessions each of anodal, sham and cathodal tDCS. Outcome measures included disease progression (revised ALS functional rating scale (ALSFRS-R)), clinical measures of endurance and mobility, and corticomotor excitability. Results: No adverse events or change in disease progression were noticed during the study. Small improvement in gait speed (15% increase) was noticed with anodal tDCS only. Conclusions: This case study demonstrates the safety and feasibility of long term facilitatory and inhibitory tDCS on a single participant with ALS. This study serves as a guideline for implementing tDCS in future ALS trials.