Maintaining Mobility and Balance in Multiple Sclerosis: A Systematic Review Examining Potential Impact of Symptomatic Pharmacotherapy.

Abstract

Background: Mobility disability (MD) manifests as walking dysfunction and postural instability in more than 90% of people with multiple sclerosis (MS) within 10 years of disease onset. Disease-modifying pharmacotherapies reduce rates of relapses and new lesions and slow disease progression, but ongoing decline in MD can persist or result from secondary, symptomatic pharmacotherapies. This systematic review focuses on symptomatic pharmacotherapies that potentially impact markers of MD in MS.

Methods: PubMed/Medline, Google Scholar, and Scopus were searched between January 1990 and December 2024. Eligible studies were included on the basis of the following criteria: (1) randomized, placebo-controlled trials (RCTs); (2) confirmed MS diagnosis; (3) one MD-related outcome; and (4) one symptomatic pharmacotherapy; OR (5) multiple doses of a symptomatic pharmacotherapy. Results were uploaded to Rayyan: Intelligent Systematic Review software and screened by two blinded reviewers for eligibility. Risk of bias was assessed using the PEDRo Scale for quality assessment.

Results: This review included 23 RCTs (all RCTs scored good-to-excellent on PEDRo Scale); 13 RCTs examined fampridine (4-aminopyridine) for its direct effects on MD, and 10 RCTs assessed indirect effects of symptomatic pharmacotherapies, including cannabinoids (n = 9), and baclofen (n = 1) on MD. The MD outcomes included gait (25-foot walk [T25FW], kinetics, and kinematics), community mobility (12-item MS Walking Scale [MSWS-12]), endurance (6-min walk [6MW]), balance (Berg Balance Scale [BBS], Dynamic Gait Index [DGI], Six-Spot Step Test, posturography, and falls), and functional mobility (Timed Up and Go [TUG] and 5 Times Sit-to-Stand [5STS]). Fampridine significantly improved gait (T25FW, MSWS-12), endurance (6MW), and functional mobility (5STS, TUG), with the largest effect on gait speed; changes in balance were inconclusive. Indirect pharmacotherapies, specifically cannabinoids mainly reduced spasticity (Modified Ashworth Scale, nine out of nine studies), but rarely improved pain (Numerical Rating Scale, two out of nine studies) or MD outcomes (two out of nine studies). Both direct and indirect pharmacotherapies resulted in adverse effects, notably dizziness (n = 366), urinary tract infection (n = 216), and nausea (n = 150), potentially impacting MD in MS.

Conclusions: Fampridine may improve gait and functional mobility in MS, but its effect on balance requires further investigation in RCTs. Cannabinoids and baclofen may alleviate spasticity and pain, but seemingly have limited secondary effect on markers of MD, such as gait and postural stability. Clinicians should consider the impact of symptomatic pharmacotherapies on MD in MS, including potential side effects. Future research should explore integrating rehabilitation (e.g., balance training) with symptomatic pharmacotherapies, as this might enhance positive effects or combat deleterious effects on markers of MD.