Urge Intolerance and Impairment Among Youth with Tourette's and Chronic Tic Disorders

Advancements in the phenomenology, assessment, and treatment of Tourette syndrome

PURPOSE OF REVIEW

Tourette syndrome (TS) and chronic tic disorders, collectively referred to as TS, are relatively common childhood onset neuropsychiatric conditions associated with functional impairment and distress. Over the past several years, clinical research has contributed to the advancement of the field's understanding of mechanisms and clinical correlates of TS. This progress has led to the development of key assessment tools and the implementation of novel interventions for individuals with TS.

RECENT FINDINGS

This article provides a review of innovative TS research focusing on four key themes: investigation of clinical phenomenology of TS; validation of assessment tools for TS; dissemination of current evidence-based treatments for TS; and exploration of new intervention programs.

SUMMARY

Cumulatively, this growing body of work presents considerable progress and provides a path forward to improve the assessment and treatment of TS.

Biomarkers of tic severity in children with Tourette syndrome: Motor cortex inhibition measured with transcranial magnetic stimulation

AIM

To compare transcranial magnetic stimulation (TMS)-derived measures of primary motor cortex (M1) physiology between children with and without Tourette syndrome, and to dimensionally analyze TMS measures with Tourette syndrome-related symptom severity.

METHOD

We used a cross-sectional experimental design. Sixty 8- to 12-year-old children participated (30 with Tourette syndrome: three females, mean age 10 years 10 months, standard deviation [SD] 1 year 3 months; 30 typically developing children: seven females, mean age 10 years 7 months, SD 1 year 3 months). In the group with Tourette syndrome, 15 (one female, mean age 10 years 11 months, SD 1 year 3 months) had comorbid attention-deficit/hyperactivity disorder (ADHD), rated with the Conners, Third Edition and the parent-reported ADHD rating scales. Tic severity was rated with the Yale Global Tic Severity Scale and urge severity with the Individualized Premonitory Urge for Tics Scale. M1 short-interval cortical inhibition (SICI) and intracortical facilitation were compared between diagnostic groups and, within the group with Tourette syndrome, correlated with symptom severity using linear mixed-effects models for repeated measures.

RESULTS

Accounting for ADHD, we found no difference in SICI or intracortical facilitation in those with Tourette syndrome versus typically developing children (p > 0.1). In the group with Tourette syndrome, reduced M1 SICI predicted greater total (p = 0.012) and global (p = 0.002) tic severity. There were no associations with urge severity (p > 0.5).

INTERPRETATION

Reduced M1 SICI is robustly associated with increased tic, but not urge, severity.

WHAT THIS PAPER ADDS

Increased tic severity is associated with reduced motor cortex short-interval cortical inhibition (SICI). Children with Tourette syndrome with increased urge severity also show increased tic severity. However, reduced motor cortex SICI is associated with tic, but not urge, severity.

Tourette syndrome research highlights from 2021

We summarize selected research reports from 2021 relevant to Tourette syndrome that the authors consider most important or interesting. The authors welcome article suggestions and thoughtful feedback from readers.

Urge intolerance predicts tic severity and impairment among adults with Tourette syndrome and chronic tic disorders

BACKGROUND

Individuals with Tourette Syndrome and Persistent Tic Disorders (collectively TS) often experience premonitory urges-aversive physical sensations that precede tics and are temporarily relieved by tic expression. The relationship between tics and premonitory urges plays a key role in the neurobehavioral treatment model of TS, which underlies first-line treatments such as the Comprehensive Behavioral Intervention for Tics (CBIT). Despite the efficacy of CBIT and related behavioral therapies, less than 40% of adults with TS respond to these treatments. Further examination of the relationship between premonitory urges, tic severity, and tic impairment can provide new insights into therapeutic targets to optimize behavioral treatment outcomes. This study examined whether urge intolerance-difficulty tolerating premonitory urges-predicted tic severity and tic-related impairment among adults with TS.

METHODS

Participants were 80 adults with TS. Assessments characterized premonitory urge, distress tolerance, tic severity, and tic impairment. We used structural equation modeling (SEM) to examine the construct of urge intolerance-comprised of premonitory urge ratings and distress tolerance ratings. We first evaluated a measurement model of urge intolerance through bifactor modeling, including tests of the incremental value of subfactors that reflect premonitory urge severity and distress tolerance within the model. We then evaluated a structural model where we predicted clinician-rated tic severity and tic impairment by the latent variable of urge intolerance established in our measurement model.

RESULTS

Analyses supported a bifactor measurement model of urge intolerance among adults with TS. Consistent with theoretical models, higher levels of urge intolerance predicted greater levels of clinician-rated tic severity and tic impairment.

CONCLUSION

This investigation supports the construct of urge intolerance among adults with TS and distinguishes it from subcomponents of urge severity and distress tolerance. Given its predictive relationship with tic severity and tic impairment, urge intolerance represents a promising treatment target to improve therapeutic outcomes in adults with TS.