Reduced cognitive function in patients with Parkinson disease and obstructive sleep apnea

Abstract

<h3>Objective:</h3> To assess the association between obstructive sleep apnea (OSA) and nonmotor symptoms (NMS), including cognitive dysfunction, in patients with Parkinson disease (PD). <h3>Methods:</h3> Patients with idiopathic PD, recruited from a movement disorder clinic, underwent overnight polysomnography. OSA was defined as an apnea-hypopnea index (AHI) ≥15/h. PD severity was assessed using the Hoehn &amp; Yahr (H&amp;Y) scale and the Movement Disorder Society Unified Parkinson9s Disease Rating Scale (MDS-UPDRS). NMS were assessed using the Montreal Cognitive Assessment (MoCA), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale, Apathy Scale, Beck Depression Inventory, Hospital Depression and Anxiety Scale, and PD sleep Scale. <h3>Results:</h3> Sixty-seven patients (61.2% male), mean age 64.4 (SD 9.9) years and motor MDS-UPDRS 21.9 (12.6) using levodopa equivalent dose (LED) 752.4 (714.6) mg/d, were studied. OSA occurred in 47 patients (61.6%, mean AHI 27.1/h, SD 20.2/h), and NMS in 57 patients (85%). ESS and MoCA were associated with the AHI (ESS β = 0.0670, <i>p</i> = 0.031; MoCA β = −0.0520, <i>p</i> = 0.043, adjusted for age, sex, body mass index, LED, and H&amp;Y). ESS was associated with respiratory arousals (β = 0.1015, <i>p</i> = 0.011) and intermittent hypoxemia (β = 0.1470, <i>p</i> = 0.006). MoCA was negatively associated with respiratory arousals (β = −0.0596, <i>p</i> = 0.049) but not intermittent hypoxemia. <h3>Conclusions:</h3> OSA is associated with sleepiness and cognitive dysfunction in PD, suggesting that OSA may be a reversible contributor to these NMS. Further studies will be required to evaluate whether OSA treatment can improve excessive sleepiness and cognitive dysfunction in PD.