Table 1 Demographics and clinical characteristics of participants

Sex, n (%)

343

49 (14%)

294 (86%)

344

131 (38%)

213 (62%)

1.02 × 10⁻⁷^d

-

-

Age, years

67.0 ± 6.9

66.3 ± 5.9

67.2 ± 7.1

66.6 ± 6.9

66.3 ± 5.9

67.0 ± 6.9

0.71^e

0.39^e

0.16^e

Education, years

14.2 ± 3.6

12.7 ± 3.6

14.5 ± 3.5

-

-

-

-

0.002^e

-

Education, \(\ge\)12, yes/no

66%/34%

42%/57%

54%/46%

-

-

-

-

0.19^d

-

MDS-UPDRS-III

6.5 ± 5.9

5.5 ± 5.2

6.7 ± 6.0

3.1 ± 5.8

4.0 ± 8.3

2.6 ± 3.7

<0.001^f

0.17^f

0.93^f

MoCA

25.5 ± 3.1

25.6 ± 3.9

25.5 ± 3.0

27.0 ± 2.3

27.4 ± 2.5

26.8 ± 2.2

<0.001^f

0.18^f

0.001^f

Possible MCI^g

(42%) 22.8 ± 2.5

(33%) 21.3 ± 3.4

(44%) 23.0 ± 2.3

(22%) 23.9 ± 1.5

(17%) 23.8 ± 1.5

(26%) 24 ± 1.5

6.51 × 10⁻⁷^d

0.20^d

0.15^d

Age of onset of RBD symptoms

59.0 ± 9.1

59.2 ± 6.7

59.0 ± 9.5

-

-

-

-

0.45^e

-

Self-reported duration of RBD symptoms at MRI

7.9 ± 7.1

6.9 ± 4.6

8.1 ± 7.4

-

-

-

-

0.34^e

-

Age at RBD diagnosis (PSG)

65.4 ± 7.1

64.8 ± 6.7

65.6 ± 7.2

-

-

-

-

0.46^e

-

RBD duration since diagnosis at MRI

1.7 ± 2.2

1.5 ± 1.5

1.7 ± 2.3

-

-

-

-

0.50^e

-

Current RBD medication (yes/no)^h

40% / 36%

39% / 31%

40% / 37%

-

-

-

-

0.45^d

-

Olfactory score

Calibrated scoresⁱ

8.6 ± 3.5

9.4 ± 3.7

8.5 ± 3.5

-

-

-

-

0.09^j

-

Sniffin’ Sticks, 12 items (5% dataset)^k

6.8 ± 3.0

9.0 ± 2.6

6.6 ± 3.0

-

-

-

-

0.12^j

-

Sniffin’ Sticks, 16 items (32% dataset)^k

7.6 ± 3.2

9.0 ± 3.7

7.5 ± 3.1

-

-

-

-

0.09^j

-

UPSIT-40 (35% dataset)^k

22.0 ± 7.1

23.3 ± 6.2

21.7 ± 7.2

-

-

-

-

0.25^j

-

UPSIT-12 (28% dataset)^k

7.2 ± 2.9

7.2 ± 2.8

7.2 ± 2.9

-

-

-

-

0.48^j

-