Laryngopharyngeal motor dysfunction and obstructive sleep apnea in Parkinson's disease

Purpose Obstructive sleep apnea (OSA) is a common sleep disorder in Parkinson's disease (PD), but the relationship between these two conditions remains uncertain. Upper airway (UA) dysfunction in PD is well documented in some patients and is believed to be a reflex of the motor involvement of laryngopharyngeal muscles. The aim of this study is to determine whether UA dysfunction and laryngopharyngeal motor dysfunction (LMD) are involved in the obstructive phenomenon of OSA in PD. Methods Forty-eight PD patients underwent polysomnography for OSA diagnosis, functional evaluation of the UA by spirometry and a clinical protocol for analysis of laryngopharyngeal muscles and physical examination. Results Thirty-one participants (64.6%) fulfilled the criteria for OSA according to the International Classification of Sleep Disorders- third edition (at least respiratory disturbance index of five or higher per hour of sleep plus specific symptoms). UA obstruction was observed in 25% of participants and LMD in 60.4%. Among the clinical indicators of LMD, hypophonia was the most common (58.3%). Participants with LMD had a threefold greater chance of presenting with OSA than those without LMD did (OR=3.49; 95% CI, 1.01-12.1; p=0.044). Individuals with LMD had more UA dysfunction (37.9 vs 10.5%, p=0.037), higher scores on UPDRS III (20 vs 15, p=0.0005) and the Hoehn-Yahr scale (2.5 vs 2.0, p=0.008), and higher frequencies of postural changes (51.7 vs 21.1%, p=0.033) and motor phenomena (65.5 vs 31.6%, p=0.021). Obesity, snoring, neck circumference, and the Mallampati score did not correlate with OSA in PD. Conclusion LMD should be considered a factor that is involved in the obstructive phenomenon of UA in patients with OSA and PD.