Dystonic motor and phonic tics in Tourette syndrome

J Neurol. 2022 Oct;269(10):5312-5318. doi: 10.1007/s00415-022-11174-z. Epub 2022 May 14.

Abstract

Background: Dystonic tics differ from clonic tics by their slower and more sustained nature. Dystonic tics are often present in patients with Tourette syndrome (TS) and other tic-disorders. However, their phenomenology and impact on overall impairment have not been extensively studied.

Materials and methods: We assessed clinical history and tic duration in video-recordings from patients with TS evaluated at our movement disorders clinic. Dystonic tics were defined as those lasting ≥ 1000 ms (ms).

Results: Of the total of 201 patients with TS, there were 156 with video-recordings suitable for tic duration analysis, of their tics, 57 (36.5%) of whom had dystonic motor tics, including 9 (5.7%) with dystonic phonic tics. Dystonic motor tics had a duration range between 1033 and 15,000 ms and dystonic phonic tics between 1132 and 17,766 ms. Patients with dystonic tics were older 24.4 vs. 16.5 years (P = 0.005) and had an older age at onset 12.9 vs. 7.2 years (P < 0.001), than patients without dystonic tics. The bivariate analysis showed an association between the presence of dystonic tics, greater tic severity and wider body distribution. The multivariate regression analysis showed a statistical association with older age at evaluation (P = 0.001), greater tic severity on video-recordings (P = 0.001) and co-occurrence with complex motor tics (P = 0.020). The presence of dystonic tics increased the risk for being considered for deep brain stimulation therapy, odds ratio: 15.7 (P = 0.002).

Conclusion: Dystonic tics, observed in about a third of patients with TS, are associated with increased severity of TS.

Keywords: Botulinum toxin; Deep brain stimulation; Obsessive–compulsive disorder; Tics; Tourette syndrome.

MeSH terms

  • Age of Onset
  • Humans
  • Tic Disorders* / complications
  • Tics* / etiology
  • Tourette Syndrome* / complications
  • Tourette Syndrome* / drug therapy