Tourette's syndrome and associated disorders: a systematic review

Abstract

Objective: To compile data on Tourette's syndrome (TS), tics and associated disorders. Methods: A systematic review of the literature was conducted using the 5S levels of organization of healthcare research evidence (systems, summaries, synopses, syntheses, studies), based on the model described by Haynes. The search keywords were Tourette, tics and comorbidity, which were cross-referenced. Studies provided by publishers and articles being processed on July 31, 2013, were also included. Results: Of all studies retrieved during the search, 64 were selected because they analyzed the epidemiology, clinical features and etiopathogenesis of TS and its comorbidities. TS is classified as a hyperkinetic movement disorder, and at least 90% of the patients have neuropsychiatric comorbidities, of which attention deficit hyperactivity and obsessive-compulsive disorders are the most common. The syndrome is clinically heterogeneous and has been associated with a dysfunction of cortico-striatal-thalamic-cortical circuits involving various neurotransmitters. Although its genetic etiology has been widely studied, other factors may be important to understand this syndrome and its associated disorders. Conclusions: TS is a neurodevelopmental disorder that results from the impact of stress factors on a vulnerable biological substrate during the critical periods of neurodevelopment. The study of TS and its comorbidities may contribute, at different levels, to the understanding of several neuropsychiatric disorders of clinical and therapeutic relevance. Keywords: Attention deficit disorder with hyperactivity, comorbidity, obsessive-compulsive disorder, tics, Tourette's syndrome. ResumoObjetivo: Compilar o conhecimento existente sobre a síndrome de Tourette (ST), tiques e patologias associadas. Metodologia: Foi realizada uma revisão sistemática da literatura usando os níveis 5S (sistemas, sumários, sinopses, sínteses e estudos) de organização de evidência de pesquisa em saúde, com base no modelo proposto por Haynes. Os termos de busca foram Tourette, tiques e comorbidades, completados por pesquisa por referência cruzada. Os artigos fornecidos pelos editores e aqueles a serem processados para publicação em 31 de julho de 2013 também foram incluídos. Resultados: De todos os artigos encontrados durante a pesquisa, 64 foram selecionados porque analisavam a epidemiologia, as características clínicas e a etiopatogenia da ST. A ST define-se como um distúrbio hipercinético do movimento, e pelo menos 90% dos pacientes apresentam comorbidades neuropsiquiátricas, das quais as mais comuns são a perturbação de déficit de atenção com hiperatividade e a perturbação obsessivo--compulsiva. Esta síndrome é clinicamente heterogênea e tem sido relacionada com a disfunção dos circuitos córtico-estriado--tálamo-corticais envolvendo vários neurotransmissores. Apesar de sua etiologia genética ter sido amplamente estudada, outros fatores podem ser importantes para entender esta síndrome e as perturbações relacionadas. Conclusões: A ST resulta de uma p...

Migraine: A Review on Its History, Global Epidemiology, Risk Factors, and Comorbidities

“…The evidence and possible pathological mechanisms justify the comorbidity of migraine with some basal ganglia disorders, such as restless legs syndrome, Tourette's syndrome, Parkinson's disease, essential tremors, dystonia, and Sydenham's chorea (112). The high prevalence of migraine among individuals with movement disorders highlights the role of common pathogenic pathways, such as the serotonin system dysregulation in Tourette's syndrome and dopaminergic dysfunction and dysfunctional brain iron metabolism in both restless leg syndrome and Parkinson's disease (113)(114)(115)(116).…”

Baclofen‐induced Tourette‐like Syndrome: tics and echolalia

“…Tourette syndrome usually occurs in childhood [3]. It often presents with motor and vocal tics [3]. The causes are still not well elucidated.…”

Social Deficits and Autism Spectrum Disorders in Tourette’s Syndrome

“…TS impacts approximately 1-10 in 1000 children [2][3][4] and is commonly associated with other psychiatric disorders including attention deficit hyperactivity disorder (ADHD) [5][6][7], obsessive-compulsive disorder (OCD) [6], mood disturbances [8,9], disruptive behaviors [10], and learning disorders [11]. In addition, youth with TS often experience peer victimization [12, 13•], self-concept deficits [14•], and interpersonal difficulties [15, 16•], particularly those with comorbid autism spectrum disorders (ASD) [17,18].…”