Is functional electrical stimulation effective in improving gait in people with multiple sclerosis? A systematic review

Introduction: One of the reasons for difficulty with walking in people with multiple sclerosis (PwMS) is foot drop; the inability to dorsiflex the ankle during the swing phase of the gait. One approach to correct foot drop is to passively support the ankle joint with an ankle foot orthosis (AFO) or a foot up splint. Another approach is to use functional electrical stimulation (FES).

Objective: Is FES effective in improving gait in people with foot drop due to multiple sclerosis (MS)?

Materials and methods: AMED, EMBASE, BNI, MEDLINE, and CINAHL were searched. Meta-analysis, randomized control trials (RCTs) and non-RCTs, and case series involving investigating FES for foot drop in PwMS were reviewed. Conference abstracts, non-English articles, expert opinions, and FES for other indications were excluded. Full texts of the articles were reviewed by two authors independently using the Physiotherapy Evidence Database (PEDro) scale. The strength of evidence was graded from 1 to 5.

Results: Among the 172 results, we excluded 130 after reading the titles (duplicates, articles not in English, and articles on use of FES for indications other than foot drop). After reviewing the abstracts, we excluded further 27 (conference presentations, opinions, and reviews). The PEDro scores of the articles varied between 3 and 7. None of the studies blinded the participants and only one study used blinded assessors. Two RCTs and one meta-analysis found an orthotic effect of FES causing improvement in speed of walking by 0.05 to 0.08 m/s. Two RCTs reported 73 to 83% reduction in number of falls. There were no RCTs comparing effect of FES with AFO in this cohort.

Conclusion: There is level-1 evidence that the FES increases speed of walking through an orthotic effect. There is level-2 evidence that it reduces number of falls in PwMS. Further appropriately powered multicenter studies are required to assess the comparison of FES with AFO in this cohort.