Physiology of Dysphagia in Those with Unilateral Vocal Fold Immobility

Quantitative measures of swallowing function were extracted from modified barium swallowing studies (MBS) to characterize swallowing pathophysiology in patients with unilateral vocal fold immobility (UVFI). All individuals with UVFI completing a MBS during the prior 5 years were included. Demographic information, penetration-aspiration score, timing of aspiration and quantitative measures from the MBS were extracted from electronic medical records and compared across 1, 3, and 20 cc liquid bolus swallows. UVFI patient measures were compared to normal age-matched controls to identify swallowing pathophysiology associated with aspiration. The incidence of aspiration by UVFI etiology groups (i.e., central nervous system, idiopathic, iatrogenic, skull base tumor, or peripheral tumor) was also compared. Of the 61 patients who met inclusion criteria, aspiration was observed in 23%. Maximum pharyngeal constriction was abnormal in 79% of aspirators compared to 34% of non-aspirators (p = .003). Delay in airway closure was the most common swallowing abnormality identified in the study population (62%) but was not associated with aspiration. Among the 14 individuals who aspirated, the iatrogenic and skull base tumor etiology groups comprised the majority (i.e., 36% each). However, the incidence of aspiration for the iatrogenic group was 19% compared to 50% of the skull base tumor group. Aspiration in patients with UVFI was associated with abnormally reduced pharyngeal constriction. Delayed airway closure was common in both aspirators and non-aspirators.