Linking Oropharyngeal Swallowing Physiology and Functional Clinical Predictors in Amyotrophic Lateral Sclerosis

We aimed to quantify oropharyngeal swallowing physiology in amyotrophic lateral sclerosis (ALS) and examine relationships between swallowing impairments and ratings of pulmonary function (forced vital capacity percent predicted, FVC % pre) and functional status (ALS Functional Rating Scale-Revised, ALSFRS-R).

A retrospective analysis of swallowing-related data of persons with ALS (PALS) was completed. Their Modified Barium Swallow Impairment Profile component, Oral Total (OT), and Pharyngeal Total (PT) scores were compared with data from age- (±1 year) and sex-matched healthy controls retrieved from an archival normative data set using Mann-Whitney U tests. Relationships between PALS' OT and PT scores, FVC % pre, and ALSFRS-R were examined using Pearson product-moment correlations and multiple linear regression modeling.

Twenty-one PALS (12 women), with a mean age of 62.2 ± 9.9 years, were included in the analyses. Compared to healthy controls, PALS exhibited significantly worse function across 13 (76%) physiological swallowing components (all p < .05). OT and PT scores significantly differed between PALS and healthy controls (each p < .001), with higher scores (worse impairment) observed in the former. When adjusting for age and sex, FVC % pre was a significant predictor of OT score (p = .045). An inverse relationship was found with ALSFRS-R and OT score (p = .052). FVC % pre (p = .061) and ALSFRS-R (p = .54) did not significantly predict PT score.

PALS demonstrated swallowing impairments across oropharyngeal domains and the esophageal component. In our PALS cohort, FVC % pre was a useful clinical indicator of oral swallowing impairment.