Table 1.
Subject characteristics.
| Healthy controls (n = 241) | Parkinson's disease (n = 489) | SWEDD (n = 81) | |
|---|---|---|---|
| Age at study entry (mean ± SD) | 60.3 ± 11.2 | 61.1 ± 9.7 | 60.4 ± 9.9 |
| Age at disease onset (mean ± SD) | — | 59.7 ± 10.0 | 58.7 ± 10.4 |
|
| |||
| Gender | n (%) | ||
| Female | 84 (34.9) | 175 (35.8) | 35.8 (29) |
| Male | 157 (65.1) | 314 (64.2) | 64.2 (52) |
|
| |||
| Ethnicity | n (%) | ||
| Caucasian | 226 (90.8) | 459 (90.9) | 78 (92.9) |
| African American | 12 (4.8) | 7 (1.4) | 1 (1.2) |
| Hispanic | 7 (2.8) | 10 (2.0) | 2 (2.4) |
| Asian | 1 (0.4) | 14 (2.8) | 1 (1.2) |
| Indian/Alaska native | 1 (0.4) | 4 (0.8) | 1 (1.2) |
| Not specified | 2 (0.8) | 11 (2.2) | 1 (1.2) |
|
| |||
| Handedness | n (%) | ||
| Left | 24 (12) | 40 (9.3) | 10 (15.2) |
| Right | 165 (82.5) | 380 (88.2) | 53 (80.3) |
| Ambidextrous | 11 (5.5) | 11 (2.6) | 3 (4.5) |
|
| |||
| Laterality of motor predominance | n (%) | ||
| Female | |||
| Left | — | 75 (50.3) | 4 (16.7) |
| Right | — | 73 (49.0) | 19 (79.2) |
| Bilateral | — | 1 (0.7) | 1 (4.2) |
| Male | |||
| Left | — | 107 (37.9) | 12 (28.6) |
| Right | — | 165 (58.5) | 26 (61.9) |
| Bilateral | — | 10 (3.5) | 4 (9.5) |
|
| |||
| Hoehn and Yahr stage | n (%) | ||
| Stage 0 | 196 (99.0) | 0 | 0 |
| Stage I | 2 (1.0) | 187 (43.5) | 38 (57.6) |
| Stage II | 0 | 241 (56.0) | 27 (40.9) |
| Stage III | 0 | 2 (0.5) | 1 (1.5) |
Demographic data for all subjects. SWEDD = scans without evidence of dopaminergic degeneration.