Age-specific proportion and grades of basal ganglia lesions in this study participants with head MRI (n=2239) (Cochran-Mantel-Haenszel statistic)
| Age group | Number of basal ganglia lesions (%) | ||||
| 40–49 | 50–59 | 60–69 | ≥70 | All ages | |
| Grade 0 | 548 (99.6) | 581 (97.3) | 524 (94.6) | 443 (82.3) | 2096 (93.6) |
| Grade I | 2 (0.4) | 16 (2.7) | 13 (2.3) | 63 (11.7) | 94 (4.2) |
| Grade II | 0 (0) | 0 (0) | 17 (3.1) | 32 (5.9) | 49 (2.2) |
| p<0.0001 | |||||
All percentages may not total 100% due to rounding.