Exploring obstructive sleep apnea and sleep architecture in Parkinson's disease motor subtypes.

INTRODUCTION: Parkinson's disease (PD) can be divided into motor subtypes: postural instability/gait difficulty (PIGD), tremor dominant, and indeterminate. This study aimed to assess differences in sleep structure and obstructive sleep apnea (OSA) between the PIGD and non-PIGD subtypes. METHODS: PD participants with or without OSA (defined as apnea-hypopnea index (AHI) ≥ 15 events/hour on overnight polysomnography) were included. Patients were separated into two groups: PIGD and non-PIGD. Linear regression was used to explore differences in sleep, AHI, and other respiratory parameters between groups (adjusted for variables determined a priori). Logistic regression adjusted for the same variables was used to determine if the proportion of patients with OSA differed across groups. Subset analyses were performed: subset 1 excluding patients on psychoactive medication; subset 2 excluding patients taking levodopa or dopaminergic agonists (DAs) at nighttime and subset 3 excluding patients on either of the abovementioned drugs. RESULTS: 146 participants were studied. The non-PIGD group had less N3 sleep compared to the PIGD group (12.4% vs 16.9% p = 0.06), reaching significance in subsets 1 and 3. The AHI was significantly lower in the PIGD group (p = 0.047), including when medication effects were removed (p < 0.05). OSA was more frequent in the non-PIGD group, but only significantly in subset 3 (adjusted OR 0.3, p = 0.04). CONCLUSION: OSA may be more severe in non-PIGD subtypes, and more frequent, in a subset free of psychoactive medication, and of levodopa and DAs, possibly owing to motor complications and dyskinesia. Future studies are required to confirm this.

Long term effects of continuous positive airway pressure treatment of obstructive sleep apnea-hypopnea syndrome in multiple sclerosis patients.

BACKGROUND: Obstructive sleep apnea-hypopnea (OSAH) is common in MS patients and is associated with fatigue. We recently published a randomized, controlled trial (RCT) of active vs sham continuous positive airway pressure (CPAP) treatment in MS patients with fatigue, poor sleep quality, and (OSAH) (Mult Scl J 2022;28:82-92). Our aim was to evaluate the long-term effects of CPAP treatment on fatigue (Fatigue Severity Scale, FSS, primary outcome) and other clinical outcomes in MS patients with OSAH. METHODS: Following the RCT, participants were offered treatment with CPAP and participation in an open label study. Patients were re-evaluated with RCT outcome measures at least 6 months after completion of the RCT. RESULTS: Twenty-eight of 34 (82 %) RCT-completers participated in this study a mean of 2.7 years after the RCT. Sixteen (57 %) patients were treated with CPAP (mean use 5.4 ± 1.0 h/night during the 6 months prior to follow-up visit), while the other 12 patients declined CPAP use and received no other OSAH treatments. Baseline clinical characteristics, including MS related disability and sleep outcomes, were not significantly different between CPAP-treated vs non-CPAP treated patients. Patients using CPAP at follow-up (n = 16) demonstrated significant improvements from RCT baseline in FSS (p = 0.005), Fatigue Scale for Motor and Cognitive Functions (p = 0.008, p = 0.012), Pittsburgh Sleep Quality Index (p = 0.016), Center of Epidemiological Studies-Depression Scale (p = 0.05), and Multiple Sclerosis Quality of Life-54 (MSQOL-54) physical and mental component scores (p = 0.012, p = 0.023), but no improvements in Epworth Sleepiness Scale, Pain Visual Analog Scale, or Expanded Disability Status Scale. Patients not using CPAP (n = 12) had no significant improvements in outcome measures. Using a linear mixed model, FSS (p = 0.03), morning fatigue (p = 0.048), and MSQOL-54 physical component score (p = 0.02) improved significantly in CPAP treated patients compared with non-CPAP treated patients from RCT baseline. CONCLUSION: In this post-RCT open label study, long-term CPAP use was associated with improved fatigue (FSS, our primary outcome) and physical quality of life in MS patients with OSAH.