title: Oculomotor executive function abnormalities with increased tic severity in Tourette syndrome.
abstract: BACKGROUND
  Reports conflict as to whether Tourette syndrome (TS) confers deficits in executive function. This study's aim was to evaluate executive function in youths with TS using oculomotor tasks while controlling for confounds of tic severity, age, medication, and severity of comorbid disorders.
  
  
  METHODS
  Four saccade tasks requiring the executive functions of response generation, response inhibition, and working memory (prosaccade, antisaccade, 0-back, and 1-back) were administered. Twenty youths with TS and low tic severity (TS-low), nineteen with TS and moderate tic severity (TS-moderate), and 29 typically developing control subjects (Controls) completed the oculomotor tasks.
  
  
  RESULTS
  There were small differences across groups in the prosaccade task. Controlling for any small sensorimotor differences, TS-moderate subjects had significantly higher error rates than Controls and TS-low subjects in the 0-back and 1-back tasks. In the 1-back task, these patients also took longer to respond than Controls or TS-low subjects.
  
  
  CONCLUSIONS
  In a highly controlled design, the findings demonstrate for the first time that increased tic severity in TS is associated with impaired response inhibition and impaired working memory and that these executive function deficits cannot be accounted for by differences in age, medication or comorbid symptom severity.
authors.affiliation: Department of Diagnostic and Biomedical Sciences, The University of Texas School of Dentistry at Houston, Houston, TX, USA.
authors.forename: Cameron B
authors.initials: CB
authors.lastname: Jeter
authors.forename: Saumil S
authors.initials: SS
authors.lastname: Patel
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Morris
authors.forename: Alice Z
authors.initials: AZ
authors.lastname: Chuang
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Butler
authors.forename: Anne B
authors.initials: AB
authors.lastname: Sereno
mesh_terms: D000293:Adolescent; D002648:Child; D015897:Comorbidity; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D012438:Saccades / Q000502:physiology*; D012720:Severity of Illness Index; D020323:Tics / Q000503:physiopathology*; D005879:Tourette Syndrome / Q000503:physiopathology*
keywords: Attention deficit hyperactivity disorder; cognitive control; executive function; n-back; obsessive-compulsive disorder; saccades