Kinematic features of dysphagia in inclusion body myositis

Dysphagia often threatens the health of individuals with inclusion body myositis (IBM), significantly contributing to premature mortality. Quality evidence defining IBM-associated dysphagia remains scant and restricted to reports of limited utility. To address this gap, our group recently published a preliminary dysphagia profile for IBM using semi-quantitative impression-based kinematic analysis. In the current study, we offer updated evidence that combines our prior approach with quantitative pharyngeal kinematic analysis to better delineate swallowing features associated with dysphagia in IBM. This prospective, cross-sectional study leveraged the Modified Barium Swallow Impairment Profile (MBSImP) and the Analysis of Swallowing Physiology: Events, Kinematics & Timing (ASPEKT) method to perform videofluoroscopic kinematic analysis. We analyzed data from 15 individuals with IBM-associated dysphagia (9 males; mean age = 72.7 years [SD = 5.9]), compared their performance against normative data, and identified measures of clinical concern. A constellation of kinematic disruptions emerged across the swallowing continuum, but pharyngeal impairments were most pervasive and diffuse. Both MBSImP and ASPEKT findings suggest that bolus clearance mechanics were the primary or early culprit. Nonetheless, we identified subclinical airway response deficiencies that warrant clinical monitoring. This evidence provides new quantitative insights into better understanding IBM-associated dysphagia that can meaningfully guide targeted treatment.