title: Volumetric analysis and three-dimensional glucose metabolic mapping of the striatum and thalamus in patients with autism spectrum disorders.
abstract: OBJECTIVE
  In patients with autism, behavioral deficits as well as neuroimaging studies of the anterior cingulate cortex suggest ventral rather than dorsal striatal and thalamic abnormalities in structure and function. The authors used imaging studies to map volumetric and metabolic differences within the entire dorsoventral extent of the striatum and thalamus.
  
  
  METHODS
  Magnetic resonance imaging (MRI) and positron emission tomography (PET) were used to measure volumes and metabolic activity in the thalamus, caudate, and putamen in 17 patients with autism or Asperger's disorder and 17 age- and sex-matched comparison subjects. Subjects performed a serial verbal learning test during the [(18)F]-fluorodeoxyglucose uptake period. The regions of interest were outlined on contiguous axial MRI slices. After PET/MRI coregistration, region-of-interest coordinates were applied to the PET scan for each individual. Between-group differences in metabolism were assessed by three-dimensional statistical probability mapping.
  
  
  RESULTS
  The patients with autism spectrum disorders had greater volumes of the right caudate nucleus than comparison subjects as well as a reversal of the expected left-greater-than-right hemispheric asymmetry. Patients also had lower relative glucose metabolic rates bilaterally in the ventral caudate, putamen, and thalamus. Patients with autism had lower metabolic activity in the ventral thalamus than those with Asperger's disorder, but they did not differ from comparison subjects in metabolic activity in the caudate nucleus.
  
  
  CONCLUSIONS
  These results are consistent with a deficit in the anterior cingulate-ventral striatum-anterior thalamic pathway in patients with autism spectrum disorders. The results also suggest an important role for the caudate in helping support working-memory demands.
authors.affiliation: Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1505, New York, NY 10029, USA. mehmet.haznedar@mssm.edu
authors.forename: M Mehmet
authors.initials: MM
authors.lastname: Haznedar
authors.forename: Monte S
authors.initials: MS
authors.lastname: Buchsbaum
authors.forename: Erin A
authors.initials: EA
authors.lastname: Hazlett
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: LiCalzi
authors.forename: Charles
authors.initials: C
authors.lastname: Cartwright
authors.forename: Eric
authors.initials: E
authors.lastname: Hollander
mesh_terms: D000293:Adolescent; D000328:Adult; D020817:Asperger Syndrome / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D001321:Autistic Disorder / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D001931:Brain Mapping; D002421:Caudate Nucleus / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D007839:Functional Laterality / Q000502:physiology; D005947:Glucose / Q000378:metabolism*; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data*; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data; D011699:Putamen / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D013788:Thalamus / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*
chemical_list: D019788:Fluorodeoxyglucose F18; D005947:Glucose