Table 2 Six months after surgery (V3), both conditions (OS and DS) showed significant therapeutic efficacy with regard to segmental (MDS-UPDRS III) and axial motor (FOG-AC) symptoms compared to Stim Off during the acute evaluation (i.e., 30 min stimulation periods); however, there were no significant differences between the omnidirectional (OS) and directional (DS) conditions

MDS-UPDRS III

30.00 ± 13.55

30.72 ± 10.87

39.63 ± 12.92

0.001

−3.298

15

0.003

−2.985

15

0.521

−0.641

17

 Task accuracy

0.71 ± 0.27

0.69 ± 0.27

0.65 ± 0.31

0.181

−1.338

15

0.440

−0.772

16

0.860

−0.176

16

 Task reaction time

2.56 ± 0.63

2.51 ± 0.59

2.56 ± 0.38

0.379

−0.879

14

0.532

−0.625

15

0.925

−0.094

15

 Oddball accuracy

0.94 ± 0.07

0.90 ± 0.21

0.89 ± 0.17

0.676

−0.418

15

1.000

0.000

16

0.324

−0.986

16

 Oddball reaction time

0.92 ± 0.23

0.90 ± 0.26

1.18 ± 0.51

0.061

−1.875

15

0.002

−3.131

16

0.227

−1.087

16

 Task accuracy

0.27 ± 0.10

0.30 ± 0.07

0.29 ± 0.08

0.553

−0.593

15

0.288

−1.063

14

0.475

−0.714

15

 Task reaction time

1.76 ± 0.78

1.73 ± 0.60

1.80 ± 0.68

1.000

0.000

15

0.925

−0.094

14

0.532

−0.625

15

 Oddball accuracy

0.64 ± 0.22

0.64 ± 0.21

0.65 ± 0.23

0.864

−0.171

15

0.861

−0.175

14

0.527

−0.633

15

 Oddball reaction time

1.04 ± 0.41

1.04 ± 0.34

1.11 ± 0.42

0.826

−0.220

14

0.363

−0.910

14

0.875

−0.157

14

 FoG-AC

14.83 ± 13.66

13.92 ± 13.32

17.83 ± 15.05

0.021

−2.307

12

0.024

−2.251

12

0.591

−0538

12

 Steps

38.36 ± 22.26

43.50 ± 33.56

38.75 ± 26.29

0.119

−1.561

12

0.285

−1.069

12

0.166

−1.385

14

 Time (s)

33.07 ± 43.95

37.86 ± 58.97

37.58 ± 51.46

0.073

−1.795

12

0.349

−0.936

12

0.244

−1.166

14

 Freezing episodes

0.93 ± 1.73

2.50 ± 5.97

1.67 ± 3.42

0.273

−1.095

12

1.000

0.000

12

0.225

−1.214

14