H&Y = Hoehn and Yahr stage (Hoehn Neurology 1967) [27
]. No patient was at H&Y stage 5. Due to the case number of patients at H&Y stage 4 (n = 5) we combined the patients at H&Y stage 3 (n = 15) and H&Y stage 4 (n = 5) to one single group. N = number of patients. UPDRS part III = part III (motor part) of the Unified Parkinson’s disease rating scale (UPDRS, Fahn 1987) [28
]. Antiparkinsonian medication had been stopped 12 hours before UPDRS scale was rated. Unless otherwise declared, all values are represented as mean ± SD.