Severity level (TDSS in frontal)

N

Occipital involvement, %

Male

Female

Male

Female

p-value

−3 SD (1.02 - 1.48)

5

4

0.0

0.0

-

−2 SD (1.49 - 1.96)

148

130

5.4

19.2

0.001*

1 SD (1.97 - 2.43)

478

338

10.3

24.6

<0.001*

+1 SD (2.44 - 2.90)

290

356

17.2

46.6

<0.001*

+2 SD (2.91 - 3.38)

61

97

21.3

50.5

<0.001*

+3 SD (3.39 - 3.85)

14

59

7.1

49.2

0.005*^F

>+3 SD

4

9

0.0

22.2

1.000*^F

Total

1000

993

12.1

35.6

<0.001*