TABLE 1.
Clinical characteristics of focal limb dystonia
| All | Focal Onset | Versus | Nonfocal Onset | χ2 or t | P | |
|---|---|---|---|---|---|---|
| Number of participants | 367 | 292 (80%) | 75 (20%) | |||
| Female | 210 (57%) | 157 (54%)a | 53 (71%)a | 7.0 | 0.008 | |
| Mean age of onset, y | 37.5 ± 18.1 | 35.8 ± 17.5a | 44.4 ± 18.4a | −3.6 | 0.001 | |
| Task specificity | 246 (67%) | 205 (70%) | 41 (55%) | 6.5 | 0.011 | |
| Sensory trick | 153 (42%) | 107 (37%)a | 46 (61%)a | 15.0 | <0.001 | |
| Onset, dominant limb | 303 (83%) | 239 (82%) | 64 (85%) | 0.5 | 0.478 | |
| BFM total | 10.2 ± 11.2 | 9.6 ± 11.6 | 12.2 ± 9 | −2.3 | 0.023 | |
| No Spread | Versus | Spread | χ2 or t | P | ||
| Number of participants | 195 | 97 | ||||
| Female | 105 (54%)b | 52 (54%) | 0.001 | 0.969 | ||
| Mean age of onset, y | 38.9 ± 15.4b | 29.5 ± 19.6b | 4.1 | <0.001 | ||
| Dystonia duration, y | 14.5 ± 12.9b | 24.1 ± 16b | −5.1 | <0.001 | ||
| Sensory trick | 57 (29%)b | 50 (52%)b | 13.9 | <0.001 | ||
| Onset dominant limb | 164 (84%) | 75 (77%)b | 2.0 | 0.157 | ||
| BFM total | 4.9 ± 4.2b | 18.6 ± 15.6b | −8.4 | <0.001 | ||
a
Significant differences across focal versus nonfocal upper limb onset following focal upper limb onset.
b
Significant differences across no spread versus spread following focal upper limb onset.
All participants reporting upper limb involvement at onset, then divided into (top) focal onset versus nonfocal (limb plus another body region) onset and (bottom) without and with spread to other body regions. Pearson χ2 or t statistic are reported for nominal or continuous group comparisons, respectively. Significant results appear in bold font. Data are n (%) or mean ± standard deviation.
Abbreviation: BFM, Burke-Fahn-Marsden scale.