Frequency of non-motor symptoms and their impact on the quality of life in patients with Parkinson's disease: a prospective descriptive case series

Abstract

Aim: In this study, we aimed to show non-motor symptoms (NMS), in addition to motor symptoms, in the foreground of idiopathic Parkinson's disease (IPD). We also examined the prevalence of dopamine dysregulation syndrome, which can be evaluated based on NMS, its risk factors, and its effects on quality of life (QOL) by using various scales and questionnaires.

Methods: In total, 75 patients with IPD (46 men, 29 women) who attend the outpatient neurology clinic of our hospital were included in the study. The motor symptoms and NMS of IPD were examined. The severity of parkinsonism was evaluated with the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr scale. Cognitive tests, the NMS questionnaire, the Parkinson's Disease Sleep Scale, and the Dopamine Dysregulation Syndrome-Patient and Caregiver Inventory were used to identify NMS. The 39-item Parkinson's Disease Questionnaire evaluated QOL.

Results: We observed a significant increase in scores on the tests assessing NMS, specifically the Parkinson's Disease Questionnaire, NMS questionnaire, Parkinson's Disease Sleep Scale, and Geriatric Depression Scale (P < 0.05). These increases correlated with an increase in the Unified Parkinson's Disease Rating Scale score and a stage increase on the Hoehn and Yahr scale. Based on the scores, motor severity most affected QOL.

Conclusion: Ignoring NMS while focusing primary on motor symptoms in IPD can cause serious insufficiencies in treatment plans. Assessing NMS and dopamine dysregulation syndrome with structured scales that employ an integrated approach can improve QOL in IPD.

Keywords: dopamine dysregulation syndrome; idiopathic Parkinson's disease; non-motor symptoms; quality of life.