Determining Swallowing Biomechanics Underlying Modified Barium Swallow Impairment Profile Scoring Using Computational Analysis of Swallowing Mechanics

Abstract

Purpose: The elements of impaired swallowing biomechanics are visually assessed and scored by clinicians using a standardized and validated tool for assessing type and severity of physiological impairments using the Modified Barium Swallow Impairment Profile (MBSImP). However, the functional anatomical correlates that underly noted impairments using MBSImP scoring have not been measured. The purpose of this study was to determine whether differences in MBSImP component scores represent differences in underlying swallowing mechanics as measured by computational analysis of swallowing mechanics (CASM) to better define underlying mechanisms of impairment. Method: A retrospective analysis of modified barium swallow studies from physician-referred adult patients with dysphagia was scored using the MBSImP for laryngeal elevation, anterior hyoid excursion, epiglottic movement, pharyngoesophageal segment opening, and tongue base retraction. A canonical variate analysis (CVA) was performed to determine the movement of anatomical landmarks associated with MBSImP component scores using the CASM method. Mahalanobis distances ( D ) were then used to detect differences among MBSImP scores for each component assessed. Results: CVA showed significant differences ( p < .0001) in Mahalanobis distance ( D > 1) between MBSImP component scores of 0–1, 0–2, 0–3, or 0–4, as applicable, depending on the component. Discriminant function analyses revealed concomitant increase/worsening in MBSImP score with changes in anatomical positioning of structures. Conclusions: Ratings of swallowing impairment and physiology using the MBSImP have distinct biomechanical correlates with anatomical movements of swallowing. These data further demonstrate how swallowing mechanics are highly interrelated. Understanding these linkages between anatomical and physiological movement within impaired swallowing biomechanics is essential in more specific characterization and treatment of dysphagia. Supplemental Material: https://doi.org/10.23641/asha.20816788