Dystonia spread characteristics based on onset site
| Cervical (n=286) | Blepharospasm (n=116) | Hand (n=47) | Laryngeal (n=38) | |
| Spread, n (%) | 24 (8.4) | 58 (50.0) | 8 (17.0) | 6 (15.8) |
| No spread, n (%) | 262 (91.6) | 58 (50.0) | 39 (83.0) | 32 (84.2) |
| Time to first spread, mean (SD), years | 3.5 (2.1) | 2.3 (1.9) | 3.3 (2.0) | 3.1 (2.1) |
| First spread, body region, n (% of those who spread) | ||||
| Cervical | – | 26 (44.8) | 6 (75.0) | 6 (100) |
| Blepharospasm | 5 (20.8) | – | 0 (0) | 1 (16.7) |
| Hand | 10 (41.7) | 2 (3.4) | – | 0 (0) |
| Laryngeal | 5 (20.8) | 2 (3.4) | 1 (12.5) | – |
| Oromandibular | 4 (16.7) | 49 (84.5) | 0 (0) | 1 (16.7) |
| Upper arm | 6 (25.0) | 0 (0) | 1 (12.5) | 0 (0) |
| Trunk | 0 (0) | 1 (1.7) | 0 (0) | 0 (0) |
| Foot | 1 (4.2) | 0 (0) | 0 (0) | 0 (0) |
| Any spread, body region, n (% of those who spread) | ||||
| Cervical | – | 34 (58.6) | 6 (75.0) | 6 (100) |
| Blepharospasm | 5 (20.8) | – | 0 (0) | 1 (16.7) |
| Hand | 11 (45.8) | 7 (12.1) | – | 2 (33.3) |
| Laryngeal | 6 (25.0) | 5 (8.6) | 1 (12.5) | – |
| Oromandibular | 5 (20.8) | 49 (84.5) | 0 (0) | 1 (16.7) |
| Tongue | 1 (4.2) | 5 (8.6) | 0 (0) | 0 (0) |
| Upper arm | 6 (25.0) | 2 (3.4) | 1 (12.5) | 0 (0) |
| Trunk | 0 (0) | 2 (3.4) | 0 (0) | 0 (0) |
| Foot | 1 (4.2) | 1 (1.7) | 0 (0) | 0 (0) |