The clinical syndrome of primary tic disorder associated with dystonia: a large clinical series and a review of the literature.

BACKGROUND The co-occurrence of tics and dystonia as an idiopathic condition has only rarely been reported. We report a series of patients with tics and persistent dystonia, with the aim of determining the prevalence and clinical characteristics of this syndrome. METHODS Analysis of clinical database of patients with tic disorders. RESULTS From our database of 224 patients with tics, 20 had co-occurrence of tics and dystonia as a primary disorder. Six patients had Tourette's syndrome, and 2 had idiopathic chronic motor/phonic tics. Twelve of the 20 had adult onset of tics (9 with motor/phonic tics and 3 with motor tics). Dystonia was focal in 12 patients (cervical most common) and segmental in 8. A sensory geste was present in 8. Mean age of tic onset and dystonia was 28.3 ± 19.7 and 40.5 ± 15.3 years, respectively. Tics preceded dystonia in 12, dystonia preceded tics in 4, and 1 patient had simultaneous onset of tics and dystonia. In 3 patients, symptoms' sequence could not be determined. Only 8 patients required treatment for their tics. Botulinum toxin was the mainstay of dystonia treatment (16 patients), whereas 6 received trihexyphenidyl. Six patients each had depression and obsessive compulsive symptoms, and 5 had attention-deficit and hyperactivity disorder. DISCUSSION We have further characterized the syndrome of a primary condition of tics associated with persistent focal/segmental dystonia. Apart from the presence of dystonia, our data suggest that these patients are differentiated from pure tic disorders by a later age of onset, lesser severity of tics, and lower frequency of associated features.