Table 1 Demographic characteristics.

Age at symptom onset, years

63.99 ± 9.69

62.25 ± 9.81

64.50 ± 9.62

0.075

Female subjects, no. (%)

177 (53.1%)

37 (48.7%)

140 (54.5%)

0.449

Disease duration, months

16.87 ± 15.23

18.41 ± 15.81

16.45 ± 15.09

0.326

UPDRS-III score

23.10 ± 10.45

20.29 ± 9.66

23.93 ± 10.55

0.007

Education, years

9.49 ± 5.09

10.58 ± 4.85

9.17 ± 5.13

0.035

Striatal volume, ratio to ICV

 Right caudate

0.21 ± 0.03

0.21 ± 0.03

0.21 ± 0.03

0.383

 Right putamen

0.28 ± 0.04

0.29 ± 0.05

0.28 ± 0.04

0.260

 Left caudate

0.20 ± 0.03

0.20 ± 0.03

0.20 ± 0.03

0.366

 Left putamen

0.28 ± 0.04

0.28 ± 0.05

0.27 ± 0.04

0.119

DAT availability

 Anterior caudate

2.12 ± 0.69

2.25 ± 0.60

2.08 ± 0.71

0.067

 Posterior caudate

1.42 ± 0.57

1.52 ± 0.47

1.39 ± 0.59

0.049

 Anterior putamen

2.23 ± 0.64

2.41 ± 0.58

2.18 ± 0.65

0.006

 Posterior putamen

1.38 ± 0.47

1.49 ± 0.45

1.35 ± 0.47

0.015

 Ventral putamen

1.48 ± 0.43

1.58 ± 0.39

1.45 ± 0.43

0.014

 Ventral striatum

2.15 ± 0.61

2.30 ± 0.57

2.10 ± 0.61

0.015

MR estimates

0.19 ± 0.57

−0.07 ± 0.61

0.048