儿童孤独症的脑扩散张量成像研究

Diffusion tensor imaging study of child autism

目的研究孤独症儿童脑扩散张量成像的异常。方法对24例孤独症儿童(孤独症组)和10名正常儿童(正常对照组)进行脑扩散张量成像扫描,测量并比较两组的双侧胼胝体膝部、压部和双侧内囊后肢表观扩散系数(ADC 值)和各向异性分数(FA 值),分析孤独症儿童各被检测部位 ADC 值、FA 值与孤独症治疗评估量表(ATEC)得分的相关性。结果 (1)孤独症组双侧内囊后肢[左右侧分别为(6.8±0.3)×10^(-9)mm^2/s和(6.7±0.4)×10^(-9)mm^2/s]、左侧胼胝体膝部[(8.0±0.5)×10^(-9)mm^2/s]ADC 值高于对照组[分别为(6.6±0.2)×10^(-9)mm^2/s,(6.6±0.4)×10^(-9)mm^2/s,(7.4±O.5)×10^(-9)mm^2/s;P<0.05～0.01];孤独症组右侧胼胝体压部(0.73±0.14)FA 值低于正常对照组(0.84±0.07;P<0.05),孤独症组右侧胼胝体膝部(0.75±0.07)FA 值高于正常对照组(0.68±0.17;P<0.05)。(2)孤独症组右侧胼胝体压部 ADC 值与 ATEC 健康/行为评分呈正相关(r=0.490),右侧胼胝体压部 FA 值与 ATEC 说话/语言评分呈负相关(r=-0.453),右胼胝体膝部FA 值与社交评分呈正相关(r=0.427),均 P<0.05。(3)孤独症组内囊后肢、胼胝体膝部 FA 值左右侧的差异有统计学意义(P<0.05)。结论孤独症儿童胼胝体神经纤维连接存在异常。

Objective To study the abnormality of the diffusion tensor imaging of autistic children. Methods Diffusion tensor images were obtained in 24 children with autism and 10 age-matched normal controls. Regions of interest were drawn to compare apparent diffusion coefficient （ADC） and fractional anisotropy（FA） in bilateral genu, splenium of corpus callosum and posterior limb of the internal capsule. The correlation coefficients between ADC and FA and the Autism Treatment Evaluation Checklist （ATEC） score in autistic children were calculated. Results （ 1 ） ADC of bilateral posterior limb of the internal capsule and left genu was higher in autistic children than in controls. FA of right splenium was lower in autistic subjects than in controls, and FA of right genu was higher in autistic subjects than in controls （ P 〈 0. 05 ）. （2） ADC in right splenium was significantly positively correlated with health/behavior scores in ATEC（r = 0. 490, P 〈 0. 05 ）, decreased FA in right splenium negatively correlated with the severity of speech/language scores （r = - 0. 453, P 〈 0. 05 ）, and FA in right genu positively with communication scores（ r = 0. 427 ,P 〈 0. 05 ）. （3） Significant bilateral differences in FA were observed in posterior limb of the internal capsule and genu in autistic children. Conclusion Aberrant callosal connectivity maybe occur in autistic children.