Thyroid disease in cervical dystonia.

There are many possible etiologies for cervical dystonia (CD), but a cause cannot be identified in most cases. Most recent attention has focused on genetic causes, although a few prior studies have highlighted autoimmune mechanisms instead. Because autoimmune disorders frequently co-exist, the current study evaluated the hypothesis that autoimmune disorders might be more common in CD than neurological controls. The frequency of 32 common autoimmune disorders was evaluated using a systematic survey comparing 300 subjects with CD with 391 neurological controls. The frequency of thyroid disease was significantly higher in CD (20%) compared with controls (6%). Regression analyses that accounted for age and sex revealed an odds ratio of 4.5 (95% CI 2.5-8.1, p < 0.001). All other autoimmune disorders occurred with similar frequencies in CD and controls. Although these studies do not establish a mechanistic link between CD and autoimmune disease, they suggest the need for further attention to a potential relationship, and more specifically with thyroid disease.