title: Anomalous Putamen Volume in Children With Complex Motor Stereotypies.
abstract: Complex motor stereotypies in children are repetitive rhythmic movements that have a predictable pattern and location, seem purposeful, but serve no obvious function, tend to be prolonged, and stop with distraction, e.g., arm or hand flapping, waving. They occur in both "primary" (otherwise typically developing) and secondary conditions. These movements are best defined as habitual behaviors and therefore pathophysiologically hypothesized to reside in premotor to posterior putamen circuits. This study sought to clarify the underlying neurobiologic abnormality in children with primary complex motor stereotypies using structural neuroimaging, emphasizing brain regions hypothesized to underlie these atypical behaviors.
  
  
  
  High-resolution anatomic magnetic resonance images, acquired at 3.0 T, were analyzed in children aged eight to twelve years (20 with primary complex motor stereotypies and 20 typically developing). Frontal lobe subregions and striatal structures were delineated for analysis.
  
  
  
  Significant reductions (P = 0.045) in the stereotypies group were identified in total putamen volume but not in caudate, nucleus accumbens, or frontal subregions. There were no group differences in total cerebral volume.
  
  
  
  Findings of a smaller putamen provide preliminary evidence suggesting the potential involvement of the habitual pathway as the underlying anatomic site in primary complex motor stereotypies.
authors.affiliation: Department of Neuropsychology, Kennedy Krieger Institute, Baltimore, Maryland; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland. Electronic address: mahone@kennedykrieger.org.
authors.forename: E Mark
authors.initials: EM
authors.lastname: Mahone
authors.affiliation: Department of Neuropsychology, Kennedy Krieger Institute, Baltimore, Maryland.
authors.forename: Deana
authors.initials: D
authors.lastname: Crocetti
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Laura
authors.initials: L
authors.lastname: Tochen
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Tina
authors.initials: T
authors.lastname: Kline
authors.affiliation: Department of Neuropsychology, Kennedy Krieger Institute, Baltimore, Maryland; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Stewart H
authors.initials: SH
authors.lastname: Mostofsky
authors.affiliation: Department of Neuropsychology, Kennedy Krieger Institute, Baltimore, Maryland; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Harvey S
authors.initials: HS
authors.lastname: Singer
mesh_terms: D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011699:Putamen / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D019956:Stereotypic Movement Disorder / Q000150:complications / Q000000981:diagnostic imaging*
keywords: childhood; goal-directed behaviors; habitual behaviors; motor stereotypies; movement disorders