title: Involvement of the anterior thalamic radiation in boys with high functioning autism spectrum disorders: a Diffusion Tensor Imaging study.
abstract: BACKGROUND
  Autism has been hypothesized to reflect neuronal disconnection. Several recent reports implicate the key thalamic relay nuclei and cortico-thalamic connectivity in the pathophysiology of autism. Accordingly, we aimed to focus on evaluating the integrity of the thalamic radiation and sought to replicate prior white matter findings in Korean boys with high-functioning autism spectrum disorders (ASD) using Diffusion Tensor Imaging (DTI).
  
  
  METHODS
  We compared fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in 17 boys with ASD and 17 typically developing controls in the anterior thalamic radiation (ATR), superior thalamic radiation (STR), posterior thalamic radiation (PTR), corpus callosum (CC), uncinate fasciculus (UF) and inferior longitudinal fasciculus (ILF).
  
  
  RESULTS
  The two groups were group-matched on age, IQ, handedness and head circumference. In whole-brain voxel-wise analyses, FA was significantly reduced and MD was significantly increased in the right ATR, CC, and left UF in subjects with ASD (p<0.05, corrected). We found significantly lower FA in right and left ATR, CC, left UF and right and left ILF and significantly higher MD values of the CC in the ASD group in region of interest-based analyses. We also observed significantly higher RD values of right and left ATR, CC, left UF, left ILF in subjects with ASD compared to typically developing boys and significantly lower AD values of both ILF. Right ATR and right UF FA was significantly negatively correlated with total SRS score within the ASD group (r=-.56, p=.02).
  
  
  CONCLUSIONS
  Our preliminary findings support evidence implicating disturbances in the thalamo-frontal connections in autism. These findings highlight the role of hypoconnectivity between the frontal cortex and thalamus in ASD.
authors: Department of Child and Adolescent Psychiatry and Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea. kacheon@yuhs.ac
authors: Keun-Ah
authors: KA
authors: Cheon
authors: Young-Shin
authors: YS
authors: Kim
authors: Se-Hong
authors: SH
authors: Oh
authors: Sung-Yeon
authors: SY
authors: Park
authors: Hyo-Woon
authors: HW
authors: Yoon
authors: John
authors: J
authors: Herrington
authors: Aarti
authors: A
authors: Nair
authors: Yun-Joo
authors: YJ
authors: Koh
authors: Dong-Pyo
authors: DP
authors: Jang
authors: Young-Bo
authors: YB
authors: Kim
authors: Bennett L
authors: BL
authors: Leventhal
authors: Zang-Hee
authors: ZH
authors: Cho
authors: F Xavier
authors: FX
authors: Castellanos
authors: Robert T
authors: RT
authors: Schultz
mesh_terms: D000293:Adolescent; D016880:Anisotropy; D001931:Brain Mapping; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000473:pathology*; D013788:Thalamus / Q000473:pathology*