Background: Parkinson’s Disease Sleep Scale (PDSS) has been recently developed for clinical evaluation of sleep problems in PD. The modified PDSS (MPDSS) has been developed in the presented study.
Objective: To evaluate the usefulness of MPDSS and sleep problems in Thai PD patients.
Material and Method: A cross sectional study in 50 PD patients was conducted at King Chulalongkorn Memorial Hospital. Sleep problems were assessed by the MPDSS, which has more items to cover more aspects of sleep problems in PD than PDSS.
Results: MPDSS showed good reliability (Cronbach’s Alpha = 0.842). Some Problems regarding the clinical use of MPDSS in Thai patients were detected especially related to the meaning of visual analogue scale. Selfassessment of sleep in PD patients reveal sleep problems only 58%, while MPDSS probed sleep problems in 76% of PD patients. Nocturnal motor symptoms, snoring, sleep initiation and maintenance problem and nocturia were common in Thai PD patients. Disease staging had significant correlation with MPDSS. Prevalence of sleep disorders and trend of each score in PDSS were similar to previous studies in Western countries.
Conclusion: MPDSS is useful for screening and evaluation of sleep problems in Thai PD patients. Nevertheless, some modifications, especially the visual analogue scale, may be needed to simplify its practical utility. Prevalence and trend of sleep problems in Thai PD patients were similar to the previous studies in Western countries.

Keywords: Modified Parkinson’s disease sleep scale (MPDSS), Sleep disorders, Parkinson’s disease