Adult-Onset Primary Dystonic Tics: A Different Entity?

Abstract

Based on their phenomenology, tics can be classified as clonic, dystonic, and tonic. Although tic syndromes are considered to be childhood disorders, there are reports on (clonic) tics developing late in life. Literature on dystonic tics is sparse, and it is unclear whether adult-onset dystonic tics are part of the same disorder spectrum that includes Tourette's syndrome or represent a discrete entity. We describe here 11 patients with adult-onset primary dystonic tics. Ten patients (90.1%) were males. Mean age at onset was 42.2±14.9years. More than 60% had both motor clonic and dystonic tics. Dystonic tics most frequently involved the cranial-cervical region and the shoulders and, less frequently, the limbs. Psychiatric comorbidities were present in 5 patients. Family history for any movement disorder or for psychiatric disorders was present in 2 cases. One patient showed a sensory geste, which allowed him to partially control his tics, whereas another developed overt dystonia 3years after his first assessment. The hyperkinesias exhibited by these patients were likely consistent with tics. However, other clinical features would allow us to argue that adult-onset dystonic tics may represent a discrete entity, which is intermediate between tics and dystonia.