ABSTRACT
According to several studies for diagnosis of Parkinson’s disease various markers are needed to differentiate neurodegenerative disorders and predict PD before the onset of symptoms (Robichaud et al. 2009, Shtilbans & Henchcliffe 2012, Haas et al. 2012). While many PD features are relying on motor PD markers, studies showed that, for example rapid eye movement behavior disorder can precede clinical motor symptoms associated with PD (Haas et al. 2012). Among these there are other clinical biomarkers such as bowel dysfunction, olfactory deficits and mood disorders.
