title: Environmental circumstances influencing tic expression in children.
abstract: OBJECTIVE
  To assess the clinical features and severity of tics and environmental factors influencing tic expression in a cohort of children with tic disorders.
  
  
  METHODS
  We performed a cross-sectional study in a cohort of children and adolescents (N = 92) with tic disorders referred to the outpatient clinic of a tertiary-level paediatric centre in Barcelona. The severity of tics was evaluated using the Yale Global Tic Severity Scale (YGTSS). A questionnaire including a list of environmental factors and common daily activities that might influence tic occurrence was completed for patients greater than 5 years old.
  
  
  RESULTS
  Children were classified as having Tourette syndrome (TS) (52 patients), chronic motor or phonic tics (22 patients) and tics of less than 12 months' duration (18 patients). Tics worsened with stressful situations, activities related to school, playing video games and watching TV. A significant proportion of children reported a reduction in tics while they were concentrating on artistic or creative activities or when playing sports and participating in outdoor activities. The YGTSS scores were higher for TS patients (P < .001) and correlated positively with the time of evolution of tics (r = .273, P = .026). Poor school performance was associated with TS (p = .043) and higher scores on the YGTSS (P = .018), as well as attention deficit/hyperactivity disorder (P = .007).
  
  
  CONCLUSIONS
  Several activities of daily living were identified as modifying tic severity in children and may be important clues for tic management. In a subgroup of children with TS, tics were associated with significant morbidity and poor academic performance. Our results emphasise the importance of developing specific school programmes and tailored recommendations in patients with TS.
authors.affiliation: Department of Child Neurology, Hospital Sant Joan de Déu, Universitat de Barcelona, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Caurín
authors.affiliation: Department of Child Neurology, Hospital Sant Joan de Déu, Universitat de Barcelona, Spain; Centre for Biomedical Research on Rare Diseases (CIBER-ER), Instituto de Salud Carlos III, Barcelona, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Serrano
authors.affiliation: Department of Child Neurology, Hospital Sant Joan de Déu, Universitat de Barcelona, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Fernández-Alvarez
authors.affiliation: Department of Child Neurology, Hospital Sant Joan de Déu, Universitat de Barcelona, Spain; Centre for Biomedical Research on Rare Diseases (CIBER-ER), Instituto de Salud Carlos III, Barcelona, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Campistol
authors.affiliation: Department of Child Neurology, Hospital Sant Joan de Déu, Universitat de Barcelona, Spain; Centre for Biomedical Research on Rare Diseases (CIBER-ER), Instituto de Salud Carlos III, Barcelona, Spain. Electronic address: bperez@hsjdbcn.org.
authors.forename: Belén
authors.initials: B
authors.lastname: Pérez-Dueñas
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000293:Adolescent; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D012720:Severity of Illness Index; D012931:Social Environment; D011795:Surveys and Questionnaires; D013981:Tic Disorders / Q000523:psychology
keywords: ADHD; Children; Movement disorders; Tics; Tourette syndrome