Disentangling Tourette syndrome heterogeneity through hierarchical ascendant clustering. (10th May 2018)

• Record Type: Journal Article
• Authors: Cravedi, Elena; Deniau, Emmanuelle; Giannitelli, Marianna; Pellerin, Hugues; Czernecki, Virginie; Priou, Tiphanie; Xavier, Jean; Consoli, Angèle; Hartmann, Andreas; Cohen, David
• Is Part Of: Developmental medicine & child neurology. Volume 60:Number 9(2018)
• Page Start: 942
• Page End: 950
• Publication Date: 2018-05-10
• Subjects: Child development -- Periodicals; Pediatric neurology -- Periodicals; 616.8
• DOI: 10.1111/dmcn.13913
• Languages: English
• ISSNs: 0012-1622

Abstract

Abstract : Aim: To explore the heterogeneity of Tourette syndrome as part of a neurodevelopmental spectrum. Method: Using hierarchical ascendant clustering based on tic symptoms, developmental milestones, and neurodevelopmental comorbidities, we analyzed the heterogeneity of Tourette syndrome phenotypes in a sample of 174 children and adolescents with Tourette syndrome referred to a tertiary university clinic. Results: The model yielded three distinct clusters characterized as follows. In cluster 1, we found many neurodevelopmental comorbidities (including intellectual disabilities, autism spectrum disorder, attention‐deficit–hyperactivity disorder [ADHD], and learning disabilities) and academic impairments. In cluster 2, patients had no other neurodevelopmental comorbidities. In cluster 3, patients had higher intelligence, a high frequency of attentional impairment, school problems related to both ADHD and unspecific attention difficulties, and handwriting problems related to the tics themselves. Interestingly, clusters did not differ in terms of family history or anxious‐depressive comorbidities. The only other differences that emerged were related to prenatal or perinatal risk factors (more represented in cluster 1) and treatment profiles (higher rates of stimulants in cluster 1). Interpretation: We conclude that from a phenotypical perspective, Tourette syndrome is a heterogeneous syndrome with at least three main clusters that may help in addressing the etiological basis of Tourette syndrome and specific rehabilitative and therapeutic approaches. What this paper adds: The clustering of Tourette syndrome based on comorbidity with other neurodevelopmental conditions reveals three clusters. A group of patients with Tourette syndrome show school difficulties related to non‐specific attention and writing problems. Analysing only children and adolescents helps to distinguish between developmental comorbid conditions and coexistent disorders. What this paper adds: The clustering of Tourette syndrome based on comorbidity with other neurodevelopmental conditions reveals three clusters. A group of patients with Tourette syndrome show school difficulties related to non‐specific attention and writing problems. Analysing only children and adolescents helps to distinguish between developmental comorbid conditions and coexistent disorders. This article is commented on by Reynolds and Day on pages858–859 of this issue. This article's abstract has been translated into Spanish and Portuguese. Follow the links from theabstract to view the translations.