A Systematic Review of Dysphonia in Multiple Sclerosis

To explore the vocal complaints and presentation of people with multiple sclerosis (PwMS).

A comprehensive search was conducted through PubMed, Science Direct, Cochrane Central Register of Controlled Trials, and ASHAWire until August 30, 2025. Risk of bias was assessed using the Joanna Briggs Institute's Critical Appraisal Checklists. The primary method of data synthesis was vote counting based on sign tests to estimate the direction of effects with Wilson score interval. Narrative summary was utilized when results were not compared with controls.

Of the 1140 articles identified, 58 were included. PwMS demonstrated a variety of vocal presentations across each domain: (1) self-perception of voice and impact on quality of life, (2) auditory-perceptual assessment, (3) acoustic and aerodynamic measures, and (4) visualization of laryngeal function. The only statistically significant effects compared with controls were increased degree of dysphonia (100% [95% CI {confidence interval} 68% to 100%], P = 0.008), breathiness, (100% [95% CI 65% to 100%], P = 0.016), jitter (90% [95% CI 60% to 98%], P = 0.021) and shimmer (100% CI [68% to 100%], P = 0.008); and decreased maximum phonation time (90% [95% CI 60% to 98%], P = 0.021).

This systematic review identifies that PwMS present with diverse vocal symptoms. It is unclear if this diversity of presentation is expected variability given the nature of MS, or the result of significant heterogeneity in nomenclature, outcome measures, methodology, statistical analysis, data reporting, and study quality. Future studies should utilize updated, standardized metrics and analyze findings based on comprehensive participant demographic information and disease details.