Epidemiology of non-motor symptoms in Parkinson's disease: frequency, characteristics, specificity and course.

Parkinson's syndrome (PS) is a neurodenerative disorder characterized by bradykinesia, rigor, tremor, and postural instability. Up to 2% of the population over 60 years of age develops PS. The etiology of PS is unknown except for some monogenic forms. PS is defined by motor features, but clinical presentation and course of PS are also characterized by non-motor symptoms (NMS). In particular, psychological NMS influence functional level, quality of life, and mortality in addition to motor impairments. In the present application, the frequency, characteristics, and associations of NMS in PS will be investigated in patients and control groups from clinic-based and population-based samples using a comprehensive standardized test battery. In addition, the association of PS with NMS will be investigated: are all or individual NMS specific for PS, do they occur only or clustered in the context of PS, is there evidence for common causes of NMS and PS? This information will enable improved diagnostics of NMS, which, in view of already existing therapies for many NMS, could be directly translated into therapy optimization.