Demographic information for and clinical characteristics of the participants.

Data are presented as minimum - maximum (mean ± SD). PD, Parkinson's disease; NC, normal control; TPD, Tremor-dominant PD; NTPD, Non-tremor-dominant PD; MMSE, Mini-Mental State Examination; UPDRS, Unified Parkinson's Disease Rating Scale; H-Y, Hoehn & Yahr Scale; Edu, education in years; ID, illness duration The p-value was obtained using a two-tailed Pearson chi-squared test. The p-values were obtained using two-sample, two-tail t tests. Demographic information for and clinical characteristics of the participants.