What is the Effect of Motor Level Peripheral Electrical Stimulation on Corticospinal Excitability and Functional Outcome Measures in Both Healthy Participants and those with Neurological Disorders? A Systematic Review and Meta-Analysis

Introduction: To explore the effect of Motor Level peripheral Stimulation (MLS) on Corticospinal Excitability (CSE) in healthy participants and those with neurological disorders, and to establish stimulation parameters best suited to this purpose. Methods and Materials : A comprehensive search strategy was developed for identification of papers answering the review question. The studies identified were used to do meta-analyses. Results: Following motor-level stimulation, there was a significant change in CSE from baseline: 57.66% (95% CI). Subgroup analysis showed that there was a significant change in the 100Hz subgroup: 68.31% (95% CI) and the 20-50Hz subgroup: 80.14% (95% CI), but not in the 30mins: 53.14% (95% CI). CSE showed no significant changes following ‘no stimulation”: 69.61% (95% CI). Conclusions: The findings indicate that MLS leads to increases in CSE; however, magnitude of change depends on the stimulation frequency and the area stimulated. It also appears that stimulation durations of longer than 30mins do not result in greater changes. Significance: The present review article hopes to catalyze further research into the determination of appropriate MLS treatment parameters for specific muscle groups.