Nonmotor Symptoms Affect Sleep Quality in Early-Stage Parkinson's Disease Patients With or Without Cognitive Dysfunction

Abstract

Purpose: Parkinson's disease (PD) patients frequently present with sleep disorders. This study was designed to assess the impact of nonmotor symptoms (NMSs) on sleep quality in early-stage PD patients with and without cognitive dysfunction. Materials and Methods:A sample of 389 early-stage PD patients (modified Hoehn and Yahr score ≤2.5, duration ≤5 years) was recruited for the present study. The Non-Motor Symptoms Questionnaire (NMS-Quest) was used to screen for global NMSs. Depressive symptoms were assessed using the Hamilton Rating Scale for Depression (HAMD). PD motor symptoms were measured with the Unified PD Rating Scale (UPDRS), part III. The Montreal Cognitive Assessment (MoCA) was used to evaluate global cognitive status, and the PD Sleep Scale (PDSS) was used to quantify sleep quality. Polysomnography (PSG) was used for objective assessment of sleep.Results: In our sample, approximately one-quarter of the PD patients suffered from sleep disturbances (23.7%). Our results also confirmed the high prevalence of cognitive dysfunction in patients with PD (39.8%). In patients with cognitive dysfunction, higher percentage of sleep disorders (34.8 vs. 16.2%, P < 0.01) was observed. They also with lower PDSS score, sleep efficiency (SE) and longer sleep lantency (SL) and wake after sleep onset (WASO) (All P < 0.05). In total, the patients who suffered from NMSs, such as depressive symptoms, anxiety symptoms, urinary tract symptoms and hallucinations/delusions, had poorer sleep quality. Better cognition may predict better sleep quality. In patients with cognitive dysfunction, the NMS-Hallucinations/delusions score was the most important risk factor for sleep disorders. In patients without cognitive dysfunction, NMSs such as anxiety and cognition and medication were related to sleep disorder. Conclusions:NMSs in early-stage PD are highly associated with and are determinants of subjective sleep quality. Future studies should focus on elucidating the pathophysiology of these symptoms.

The Neurophysiology of Sleep in Parkinson's Disease

“…25 Furthermore, the presence of comorbidities and non-PD medications, which could serve as cofounders, are not described in many studies. For example, some studies suggest that nocturnal motor symptoms (rigidity, reemergence of tremor in light sleep, PLMS), 84 pain, 59 nocturia, 85 and hallucinations 40,86,87 can contribute to sleep changes, although such symptoms are not always systematically evaluated. Finally, the majority of these studies describe group-level differences, which limits inferences on whether the identified spectral changes index disease progression or represent dynamic withinsubject biomarkers.…”

Characteristics of sleep structure in Parkinson's disease patients with hallucinations based on polysomnography

“…Total sleep time (TST), wake time after sleep onset (WASO), sleep efficiency (SE), sleep latency (SL), and REM sleep latency (RSL) were recorded. Sleep disorders were determined for WASO ≥ 60 min, SL ≥ 30 min, and SE < 85% on the PSG as well as PDSS < 105 ( 21 ).…”

Relationship between sleep disorders and neuropsychiatric symptoms in Parkinson's disease: A narrative review

“…Better cognition is associated with better sleep quality, and may as well predict it. NMS hallucinations/delusions score was the most crucial determinant condition for sleep disorders in the patients with CI; among those without CI, NMS such as anxiety and medication were associated with sleep disorders (62). One metaanalysis showed a big influence of sleep (or, rather, lack thereof) on global cognitive function, long-term verbal recall, long-term verbal recognition, shifting, updating and fluent reasoning.…”