Relationship Between Respiratory Sensory Perception, Speech, and Swallow in Parkinson's Disease

Background It has been suggested that sensory impairments contribute significantly to the motor deficits secondary to impaired sensorimotor integration in Parkinson's disease. Speech and swallowing are likely to become disordered in PD, and there is evidence that impaired upper airway sensation also contributes to these disorders. Objectives The goal of this study was to investigate the relationship between perception of general respiratory sensation, speech, and swallowing in PD. Methods Thirteen people with PD and 14 age-equivalent controls volunteered to participate. Randomized blocks of inspiratory resistive loads were delivered, and participants gauged the magnitude of the loads using a modified Borg scale. The magnitude estimates were then compared to results of speech and swallowing evaluations using multivariate analysis of variance and a stepwise linear regression model. Results There was a significant overall interaction between the participant group (PD versus control) and respiratory load (F [10, 300] = 2.138; P = .022). A significant regression equation containing a predictor speech variable respiratory rating was found (F [1,22] = 6.946), P = .023), with a moderate effect size of R-2 = .387. Conclusions People with PD have blunted perception of respiratory resistive loads when compared with age-equivalent healthy adults. Results also suggest that blunted ME of resistive loads could contribute to changes in respiratory drive for speech (i.e., loudness).