Effects of various factors on sleep disorders and quality of life in Parkinson's disease.

In Parkinson's disease (PD), sleep disorders (SD) occur as a result of the neurochemical changes in sleep centres, neurodegenerative changes in dopaminergic neurons, and other factors. The most common SD include excessive daytime sleepiness, insomnia, restless legs syndrome and nocturia. The aim of the study was to compare quality of sleep, as a factor that greatly impacts quality of life (QoL), between PD patients and a control group and to further examine SD in the PD group with focus on incidence and SD types as well as on effects various factors (age, sex, PD characteristics, medication usage) have on these disorders. The study included 110 patients who met the criteria for the diagnosis of PD and 110 age-matched healthy controls. We used the Pittsburgh Sleep Quality Index, PD Sleep Scale, Epworth Sleepiness Scale, PD QoL Questionnaire-8 and PD Questionnaire-39 (items 30 and 33). In the group with PD, we considered the duration of the disease, the stage of disease according to the Hoehn and Yahr scale, medications and their impact on the SD. The average duration of the disease was 6 years and the mean stage was 2.44. The result showed significant differences in the sleep quality between groups. In the PD group, SD differences were also found according to gender, duration of the disease and medication usage. The most common SD were fragmented sleep, insomnia and nocturia. To improve the QoL of PD patients, it is necessary to pay more attention to detecting and solving SD.