title: Primary complex motor stereotypies in older children and adolescents: clinical features and longitudinal follow-up.
abstract: BACKGROUND
  Complex motor stereotypies are rhythmic, repetitive, fixed, and purposeless movements that stop with distraction. Once believed to occur only in children with autism spectrum or other developmental disorders, their presence in otherwise typically developing children (primary) has been well-established. In primary complex motor stereotypies, little information is available about the long-term outcome of these movements or existing comorbidities.
  
  
  METHODS
  Forty-nine healthy participants (31 boys), ages 9 to 20 years with primary complex motor stereotypies who were previously diagnosed at a pediatric movements disorder clinic, were identified from medical records. Parents or the young adult (if older than age 18), completed a telephone interview evaluating family history, outcome, and comorbidities including attention-deficit hyperactivity disorder, obsessive compulsive disorder, anxiety, and tics/Tourette syndrome. Standardized questionnaires assessing attention-deficit hyperactivity, obsessive compulsive disorder, and anxiety were used to validate parent report of comorbidities.
  
  
  RESULTS
  Stereotypy onset occurred before age 3 years in 98%. In all but one individual, stereotypies persisted at the time of phone follow-up (follow-up range: 6.8-20.3 years). Positive family history of complex motor stereotypies was identified in 39%. Most participants (92%) had concern for at least one comorbid disorder, including parent-/patient-reported clinically elevated levels of anxiety (73%), attention-deficit hyperactivity (63%), obsessive compulsive disorder (35%), and tics/Tourette syndrome (22%).
  
  
  CONCLUSIONS
  Primary motor stereotypies typically begin in early childhood and, although reduced in frequency and duration, persist at least through the teenage years. Repetitive movements are associated with a variety of comorbidities that often have a greater functional impact than the stereotypic behavior.
authors: Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Christopher
authors: C
authors: Oakley
authors: Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Neuropsychology, Kennedy Krieger Institute, Baltimore, Maryland.
authors: E Mark
authors: EM
authors: Mahone
authors: Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Christina
authors: C
authors: Morris-Berry
authors: Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Tina
authors: T
authors: Kline
authors: Johns Hopkins University School of Medicine, Baltimore, Maryland. Electronic address: hsinger@jhmi.edu.
authors: Harvey S
authors: HS
authors: Singer
mesh_terms: D000293:Adolescent; D002648:Child; D015897:Comorbidity; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D012720:Severity of Illness Index; D019956:Stereotypic Movement Disorder / Q000453:epidemiology* / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: ADHD; Tourette syndrome; executive function; movement disorder; obsessive compulsive disorder; pediatric; stereotypies