Background: Disorders of airway protection (cough and swallowing) are pervasive in Parkinson’s disease (PD) resulting in a high incidence of aspiration pneumonia and death. However, there are no randomized controlled trials comparing strength and skill-based approaches to improve airway protection in PD.
Objectives: The goal of this study was to compare Expiratory Muscle Strength Training (EMST) and sensorimotor training for airway protection (smTAP) to improve cough-related outcomes in people with PD.
Methods: Participants with PD and dysphagia were recruited for this prospective phase II randomized-blinded controlled clinical trial. Participants completed baseline assessment, five weeks of EMST or smTAP, and a post-training assessment. Primary outcome measures included maximum expiratory pressure (MEP) and voluntary cough peak expiratory flow rate (PEFR). Mixed effects models were used to assess effects of EMST and smTAP on outcomes.
Results: 65 participants received either EMST (n = 34) or smTAP (n = 31). MEP improved from pre- to post-treatment for smTAP (p < .001, d = 0.19) and EMST (p < .001, d = 0.53). Voluntary PEFR increased from pre- to post-treatment for smTAP (p < .001, d = 0.19) and EMST (p < .001, d = 0.06). Moreover, reflex cough PEFR (p < .001, d = 0.64), reflex cough expired volume (p < .001, d = 0.74), and urge-to-cough (p = .018, OR = 2.70) improved for the smTAP group, but not for the EMST group.
Conclusions: This clinical trial confirmed the efficacy of smTAP to improve reflex and voluntary cough function, above and beyond EMST, the current gold standard