Table 1
Environmental Factors Associated with Dystonia
| Environmental factor Type of dystonia ref. | Association Strength OR (95% CI) | Time Between Exposure and Dystonia Onset | Exposure Intensity and Risk of Dystonia/Age at Onset |
|---|---|---|---|
| Early childhood illnesses | |||
| DYT1 dystonia16 | 2.71 (1.2–6.2) | > 1 year | Not done |
| Head trauma | |||
| Cranial/extracranial dystonia24 | 3.2 (1.0–10.1) | 4.7 years (range, 1–10) | Not done |
| CD28 | 1.2 (0.7–1.9) | 29 years (range, 1–67) | No correlation with age at dystonia onset |
| WC25 | 3.5 (1.0–5.7) | 17 years (SD, 13) | The more head trauma the greater the risk of dystonia |
| LD26 | 0.5 (0.3–0.9) | Not done | Not done |
| Eye diseases | |||
| BSP24 | 4.5 (1.6–12.5) | 3.2 years (range, 1–5), | Not done |
| BSP31 | 5.53 (2.7–11.4) | <1 year | Not done |
| BSP34 | 2.5 (1.1–6.1) | 1.8 years (SD, 0.7) | Inverse correlation with age at dystonia onset |
| Sore throat | |||
| LD26 | Significant association1 | Not done | No relationship between no. throat/year and risk of dystonia |
| Idiopathic scoliosis | |||
| CD36 | 6.8 (1.5–29.5) | Not done | Not done |
| Repetitive motor action | |||
| WC25 | 5.7 (1.3–33.9) | ≤1 year | OR increased with the writing time |
| LD26 | 2.3 (1.2–4.4) | Not done | Not done |
| Neck and trunk trauma | |||
| CD24 | 11.2 (1.3–95) | 4.2 years (range, 1–7) | Not done |
| Upper limb trauma | |||
| WC25 | 1.9 (0.9–4.0) | Not done | Not done |
| Smoke | |||
| Cranial/extracranial dystonia24 | 0.5 (0.3–0.9) | Current smokers | Not done |
| BSP39 | 0.77 (0.4–1.3) | Never smokers | Not done |
| WC25 | 1.0 (0.5–1.8) | Not done | Not done |
| Coffee | |||
| BSP39 | 0.44 (0.2–0.8) | Not done | Increasing of the inverse association with the amount |
| BSP34 | 0.23 (1–0.8) | Not done | consumed/delayed age at dystonia onset |