title: Regional cerebral blood flow in children with autism spectrum disorders: a quantitative ⁹⁹mTc-ECD brain SPECT study with statistical parametric mapping evaluation.
abstract: BACKGROUND
  Autism spectrum disorders (ASD), which include autism, asperger syndrome (AS) and pervasive developmental disorder-not otherwise specified (PDD-NOS), are devastating neurodevelopmental disorders of childhood resulting in deficits in social interaction, repetitive patterns of behaviors, and restricted interests and activities. Single photon emission computed tomography (SPECT) is a common technique used to measure regional cerebral blood flow (rCBF). Several studies have measured rCBF in children with ASD using SPECT, however, findings are discordant. In addition, the majority of subjects used in these studies were autistic. In this study, we aimed to investigate changes in rCBF in children with ASD using SPECT.
  
  
  METHODS
  A Technetium-99m-ethyl cysteinate dimmer (⁹⁹m)Tc-ECD) brain SPECT study was performed on an ASD group consisting of 23 children (3 girls and 20 boys; mean age (7.2 ± 3.0) years) who were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria and an age-matched control group with 8 children (1 girl and 7 boys, mean age (5.5 ± 2.4) years). Image data were evaluated with Statistical Parametric Mapping, 5th version (SPM5). A Student's t test for unpaired data was used to compare rCBF and asymmetry in the autism and corresponding control group. The covariance analysis, taking age as covariance, was performed between the ASD and control group.
  
  
  RESULTS
  There was a significant reduction in rCBF in the bilateral frontal lobe (frontal poles, arcula frontal gyrus) and the bilateral basal ganglia in the autism group, and a reduction in the bilateral frontal, temporal, parietal, legumina nucleus and cerebellum in the AS group compared to the control. In addition, asymmetry of hemispheric hypoperfusion in the ASD group was observed. Inner-group comparison analysis revealed that rCBF decreased significantly in the bilateral frontal lobe (42.7%), basal nucleus (24.9%) and temporal lobe (22.8%) in the autism group, and in the bilateral cerebellum (22.8%), basal nucleus (19.3%) and right thalamencephalon (16.6%) in the AS group (P < 0.05).
  
  
  CONCLUSIONS
  The decrease in rCBF in ASD is a global event, which involves the bilateral frontal, temporal, limbic system and basal ganglias. Asymmetry of hemispheric hypoperfusion was more obvious in the AS group than the autism group, which indicates a different neurobiological mechanism from that of autism.
authors: Faculty of Child and Maternal Health, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors: Wen-Han
authors: WH
authors: Yang
authors: Jin
authors: J
authors: Jing
authors: Li-Juan
authors: LJ
authors: Xiu
authors: Mu-Hua
authors: MH
authors: Cheng
authors: Xin
authors: X
authors: Wang
authors: Peng
authors: P
authors: Bao
authors: Qing-Xiong
authors: QX
authors: Wang
mesh_terms: D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000473:pathology* / Q000503:physiopathology*; D002675:Child, Preschool; D003545:Cysteine / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D008297:Male; D015609:Organotechnetium Compounds; D012039:Regional Blood Flow / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D015609:Organotechnetium Compounds; C059659:technetium Tc 99m bicisate; D003545:Cysteine