Blocking Tics in Gilles de la Tourette Syndrome.

Introduction

Patients with Gilles de la Tourette syndrome (GTS) may experience blocking tics (BTs) defined as recurrent, brief cessations of motor acts. The aim of this study was to assess the prevalence, age of onset, and clinical correlates of BTs in GTS patients. Materials and

Methods

We performed a one-time registration study in a cohort of 195 consecutive GTS patients aged 5-66 years (mean age: 15.0 ± 9.2; 47 females, 24.1%). All patients were personally interviewed and examined.

Results

At least one BT occurred at some point in the lifetime of 73 patients (37.4%) with a mean age of onset of 10.4 ± 5.9 years. BTs occurred an average of 4.8 ± 5.3 years after tic onset. The most common BT was cessation of walking (n = 59, 80.8%), followed by speech (n = 19, 26.0%), running (n = 18, 24.7%), and writing (n = 9, 12.3%). Most of the patients (n = 52, 71.2%) reported cessation of only one activity. Clinical associations of BTs included more severe tics, overall greater number of tics, and, to a lesser extent, higher age at evaluation and comorbid obsessive-compulsive disorder.

Conclusions

BTs represent complex tics, early and common symptoms of GTS, and are associated with a more severe form of GTS.