Pilot Study of Respiratory-Swallow Coordination in Amyotrophic Lateral Sclerosis

Purpose: Amyotrophic lateral sclerosis (ALS) impacts bulbar and respiratory musculature, which may contribute to impaired swallow function (dysphagia) and respiratory-swallow coordination. The purpose of this pilot study was to examine if respiratory-swallow coordination in individuals with ALS was per-turbed compared to healthy controls. We further explored relationships between measures of respiratory function and self-reported swallowing outcomes on respiratory-swallow coordination. Method: We employed a cross-sectional design with eight participants with ALS and eight age-and sex-matched healthy participants. Respiratory inductance plethysmography and a nasal cannula were used to capture respiratory-swallow phase patterns during a standardized clinical swallow examination. The advanta-geous respiratory-swallow phase pattern was defined if exhalation surrounded the swallow (E-E). Spirometry was used to capture indices of respiratory function (forced vital capacity % predicted, peak cough flow [PCF]). Validated question-naires were used to collect information regarding ALS-related bulbar functional status and swallowing-related concerns. Results: Compared to the matched healthy cohort, individuals with ALS dem-onstrated higher rates of non-E-E respiratory-swallow phase patterning and worse bulbar/swallow dysfunction. Group (ALS), swallow tasks, and PCF were significantly associated with respiratory-swallow phase pattern. Conclusions: These preliminary findings support altered respiratory-swallow phase patterning in ALS. Future work should employ an instrumental assess-ment to quantify swallowing physiology and elucidate the relationship between perturbed respiratory-swallow coordination and swallowing function.