Tremulous cervical dystonia is likely to be familial: clinical characteristics of a large cohort

Background: Primary cervical dystonia is the most common form of adult-onset focal dystonia. Although most frequently sporadic, 15-20% of patients report a positive family history, suggesting a possible genetic cause. Head tremor is often present in patients with cervical dystonia and may be a prominent symptom.

Objective: To describe the clinical characteristics of patients with tremulous cervical dystonia.

Methods: Patients with primary cervical dystonia attending our botulinum toxin clinic were assessed with an interview and neurological examination and their notes reviewed. Patients were classified as having either tremulous or non-tremulous cervical dystonia, according to the presence or absence of head tremor on examination. Clinical and demographic data were compared between groups.

Results: From 273 patients included (190 females, 83 males), 125 (46%) were classified as tremulous and 148 (54%) as non-tremulous. Tremulous patients were more likely to have a segmental distribution (61% vs. 25%), often involving the arms (48%), and had more frequently associated arm tremor (55% vs. 10%). A positive family history of dystonia and/or tremor was more frequent in tremulous patients (50% vs. 18%).

Conclusions: Patients with cervical dystonia with associated head tremor are more likely to have a segmental distribution (with frequent arm involvement), associated arm tremor and a positive family history, suggesting a genetic etiology in this subgroup of patients.