Background

Sleep disturbances are prevalent and debilitating non-motor symptoms in patients with Parkinson's disease (PD).

Objective

This study aimed to explore sleep architecture and the prevalence of polysomnographic (PSG) sleep findings in PD, examining the associations between sleep parameters and other clinical characteristics.

Methods

The study included 97 PD patients (age: 67.1 ± 7.9) and 42 non-PD controls (age: 64.7 ± 9.7). Participants underwent clinical assessment and video-PSG. Sleep parameters, apnea-hypopnea index (AHI), periodic limb movements index (PLMI), and REM sleep without atonia (RSWA) were obtained. General linear models were used to explore interactions between disease duration and sleep variables in predicting PD symptoms.

Results

Nearly 94% of PD patients showed at least one video-PSG-assessed sleep finding, including AHI-defined obstructive sleep apnea (OSA), periodic limb movements, and RSWA. Sleep alterations correlated with disease severity, with reduced sleep duration and efficiency, higher sleep latency, and higher AHI being associated with worse PD severity. Sleep efficiency was more strongly associated with motor symptoms and disease severity at longer disease duration, while AHI exhibited a stronger relationship with motor symptoms at shorter disease duration. Finally, PD patients showed significant alterations in sleep macrostructure compared to controls, including reduced sleep duration (d = 0.75) and efficiency (d = 1.15) and decreased percentage of stage 3 non-REM sleep (d = 0.37).

Conclusions

The study showed a high prevalence of video-PSG-defined sleep findings in PD, with interactions between disease duration, sleep efficiency, and AHI. The present results support personalized management of sleep disturbances in PD to potentially improve symptoms and reduce the burden of illness.

Plain language summary

Sleep problems are very common in people with Parkinson's disease (PD). Our study aimed to understand the specific sleep issues occurring in people with PD using video-polysomnography, the gold-standard sleep study technique. We focused on understanding the current prevalence of polysomnographic sleep findings and their link to the disease motor burden.

We included 97 people with PD, with an average age of 67 years (23 women and 74 men), sleep monitored overnight using video-polysomnography, which records sleep structure, oxygen saturation parameters, limb movements in sleep, and nocturnal breathing, along with video recording. People with PD was also compared to 42 participants without neurodegenerative disorders of the same age (14 women and 28 men) as controls.

We found that nearly 94% of the participants with PD had at least one polysomnographic sleep finding, such as: obstructive sleep apnea (OSA, breathing problems during sleep identified by a pathological apnea-hypopnea index or AHI), periodic limb movements during sleep (PLMS, frequent movements of the limbs during sleep), REM sleep without atonia (loss of the normal muscle paralysis that occurs during the sleep stage known as rapid eye movement sleep). These sleep disturbances were linked to PD motor severity. We found that lower sleep efficiency (a marker of sleep continuity) was more strongly associated with worse symptoms in people who had PD for a longer time. By contrast, breathing problems during sleep (as measured by AHI) had a greater impact on symptoms when PD was in its earlier stages. Other sleep problems, such as PLMS or REM sleep without atonia, did not show a strong link with symptom severity in our models. Finally, when comparing people with PD to controls, PD patients spent more time awake during the night and had pathological changes in specific sleep stages.

Our findings show that sleep is significantly disturbed in people with PD. These sleep problems can affect the symptoms of the disease differently depending on how long a person has had PD. This suggests that personalized treatments for sleep disturbances could potentially improve symptoms of PD at different stages of the illness.