The Relevance of Sleep Quality for Clinical Care in Parkinson's Disease: Clinical and Cognitive Differences Between Good and Poor Sleepers: A Cross-Sectional Study.

Background/

Objectives

This study aimed to compare disease severity and cognitive performance between Parkinson's disease (PD) patients with good and poor sleep quality.

Methods

This cross-sectional observational study included 69 patients with PD. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Participants were classified as having good sleep quality (PSQI ≤ 5; n = 32) or poor sleep quality (PSQI > 5; n = 37). Disease severity was evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS) and Modified Hoehn and Yahr Scale (mH&Y). Global cognition, executive functions, and visuospatial performance were assessed using the Montreal Cognitive Assessment (MoCA), Stroop Test TBAG Form, and Clock Drawing Test, respectively.

Results

Patients with poor sleep quality had significantly higher UPDRS scores (p = 0.004), longer disease duration (p = 0.043), and more advanced mH&Y (p < 0.001). They also demonstrated lower MoCA scores (p = 0.039) and lower Clock Drawing Test scores (p = 0.019). In addition, completion times on all Stroop test cards were significantly longer in the poor sleep quality group (p = 0.011-0.042), indicating poorer attention-executive performance. Moderate effect sizes were observed for disease severity and cognitive outcomes.

Conclusions

Poor sleep quality was associated with greater disease severity and lower cognitive performance in early-to-mid-stage PD patients who were largely cognitively preserved. Routine assessment of subjective sleep quality may help identify patients with a higher clinical and cognitive burden and support more individualized, person-centered healthcare strategies in PD.