Respiratory-Swallowing Phase Pattern and Swallowing Impairment in Individuals With Parkinson's Disease

Swallowing and respiratory impairments in Parkinson's disease (PD) may contribute to atypical respiratory-swallowing phase patterning. This exploratory study aimed to (a) quantify swallowing impairment and airway protection, (b) determine respiratory-swallowing phase pattern at swallow initiation, and (c) test the association between swallowing impairment, airway protection, and respiratory-swallowing phase pattern in PD.

A total of 31 adults with PD and dysphagia underwent simultaneous videofluoroscopy and respiratory inductance plethysmography following the Modified Barium Swallow Impairment Profile (MBSImP) protocol. Endpoints included MBSImP swallow-by-swallow (SS) and overall impression (OI) scores, Penetration-Aspiration Scale (PAS) scores, and respiratory-swallowing phase pattern at swallow initiation. Historical data from 84 healthy controls aged 40 years and above were used for MBSImP and PAS comparisons. Logistic regression models with random effects assessed impact of patient group on MBSImP, PAS, and respiratory-swallowing phase patterns, and the associations between MBSImP, PAS, and respiratory-swallowing phase patterns.

PD demonstrated significantly increased odds for higher (worse) OI scores on lip closure (p = .0002), tongue control (p < .0001), bolus preparation/mastication (p = .016), oral residue (p = .036), laryngeal elevation (p = .001), laryngeal vestibular closure (p = .001), esophageal clearance (p = .011), and higher maximum PAS scores (p = .017). Additionally, swallowing was initiated during inspiration on 26% of trials and was associated with higher odds of impairment in initiation of pharyngeal swallow (p = .038), laryngeal vestibular closure (p = .026), tongue base retraction (p = .013), and PAS scores (p = .017).

PD patients demonstrated greater frequency of swallows initiated during inspiration with higher MBSImP and maximum PAS scores relative to healthy controls. Replication of these findings in large, homogenous PD samples may clarify the relevance for retraining typical respiratory-swallowing phase patterning benefiting swallowing improvement.