Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
Neuroimage. 2010 Apr 15;50(3):873-82. doi: 10.1016/j.neuroimage.2010.01.011. Epub 2010 Jan 11.
Diffusion tensor imaging (DTI) studies in adolescents with autism spectrum disorders (ASD) indicate aberrant neurodevelopment of frontal white matter (WM), potentially underlying abnormal social cognition and communication in ASD. Here, we further use tract-based spatial statistics (TBSS) to examine the developmental change of WM skeleton (i.e., the most compact whole-brain WM) during adolescence in ASD. This whole-brain DTI used TBSS measures fractional anisotropy (FA) and longitudinal and radial diffusivities in fifty adolescents, 25 ASD and 25 controls. Results show that adolescents with ASD versus controls had significantly reduced FA in the right posterior limb of internal capsule (increased radial diffusivity distally and reduced longitudinal diffusivity centrally). Adolescents with ASD versus controls (covarying for age and IQ) had significantly greater FA in the frontal lobe (reduced radial diffusivity), right cingulate gyrus (reduced radial diffusivity), bilateral insula (reduced radial diffusivity and increased longitudinal diffusivity), right superior temporal gyrus (reduced radial diffusivity), and bilateral middle cerebellar peduncle (reduced radial diffusivity). Notably, a significant interaction with age by group was found in the right paracentral lobule and bilateral superior frontal gyrus as indicated by an age-related FA gain in the controls whilst an age-related FA loss in the ASD. To our knowledge, this is the first study to use TBSS to examine WM in individuals with ASD. Our findings indicate that the frontal lobe exhibits abnormal WM microstructure as well as an aberrant neurodevelopment during adolescence in ASD, which support the frontal disconnectivity theory of autism.
弥散张量成像（DTI）研究表明，自闭症谱系障碍（ASD）青少年的额白质（WM）神经发育异常，这可能是 ASD 患者异常社会认知和交流的基础。在这里，我们进一步使用基于束的空间统计学（TBSS）来检查 ASD 青少年时期 WM 骨架（即最紧凑的全脑 WM）的发育变化。这项全脑 DTI 使用 TBSS 测量了 50 名青少年（25 名 ASD 患者和 25 名对照组）的分数各向异性（FA）和纵向及横向扩散率。结果表明，与对照组相比，ASD 患者右侧内囊后肢的 FA 显著降低（远端横向扩散率增加，中央纵向扩散率降低）。与对照组相比（协方差为年龄和智商），ASD 患者额叶（横向扩散率降低）、右侧扣带回（横向扩散率降低）、双侧岛叶（横向扩散率降低，纵向扩散率增加）、右侧颞上回（横向扩散率降低）和双侧小脑上脚（横向扩散率降低）的 FA 显著增加。值得注意的是，在右侧旁中央小叶和双侧额上回，发现了一个显著的组间与年龄的交互作用，这表明对照组的 FA 随年龄增加而增加，而 ASD 患者的 FA 随年龄增加而减少。据我们所知，这是第一项使用 TBSS 检查 ASD 个体 WM 的研究。我们的研究结果表明，在 ASD 中，额叶表现出异常的 WM 微观结构和异常的神经发育，这支持了自闭症的额叶失连接理论。
