Table 1: Demographic and clinical characteristics.

Gender31 males/9 females
Age in years, mean (SD) 63.4 (6.4)
Estimated IQ*, mean (SD)102.0 (28.3)
Duration of disease in years, mean (SD)12.1 (3.8)
Years of education, mean (SD)13.5 (3.4)
Hoehn and Yahr off, median (range)3 (2 to 4)
Hoehn and Yahr on, median (range)2 (0 to 3)
Mattis DRS, mean (SD)140.1 (3.3)

IQ-score was estimated from the Wechsler Abbreviated Scale of Intelligence (WASI).