PPX groups (n = 24)

Non-PPX groups (n = 12)

Total (n = 36)

P

Mean age (years)

70.9 ± 7.8

69.3 ± 8.9

70.4 ± 8.1

0.4805^*

Male (%)

4 (33.2%)

7 (29.2%)

11 (30.5%)

0.9999^§

Length of illness (months)

49.5 ± 50.9

48.7 ± 42.0

49.3 ± 47.9

0.6846^*

L-DOPA (mg/day)

241.6 ± 112.9

431.8 ± 202.8

301.4 ± 167.1

0.0014^*

UPDRS part 3

16.1 ± 9.2

12.6 ± 10.2

15.0 ± 9.5

0.322^*

MMSE

24.8 ± 4.8

27.0 ± 3.1

25.6 ± 4.4

0.1459^*

Apathy scale

17.3 ± 6.5

12.6 ± 3.9

15.7 ± 6.1

0.0297^*

Apathy

14 (58.3%)

3 (25.0%)

17 (47.2%)

0.1249^§