Autism Spectrum Disorder Children's Whole Brain Matter Fiber Follow-up Study For Two Years

[Background]Autism spectrum disorder(ASD)is a neurodevelopmental disorder that occurs in early childhood.The essential characteristics of this disorder are deficits in social interaction,and repetition and restriction in patterns of behavior and interests.In previous studies,there is abnormity in integrity of white matter fiber bundle for ASD children.However,most of researches focused on cross-sectional study rather than longitudinal observation,especially it is lacked follow-up research from the beginning of ASD.[Objective]In order to find the abnormal trajectory of the main fiber bundles in the white matter of ASD children,71 ASD children from 2 to 3 and matched DD children were selected as the study subjects.Then the differences in the integrity of the main fiber bundles in the two groups were compared and the correlation between the main fiber bundles and clinical symptoms were analyzed.The changes of white matter fiber bundles in ASD group and DD group were observed by two years of follow-up.[Methods]Forty ASD children and 31 DD children were evaluated by Childhood Autism Rating Scale(CARS),Autism Diagnoses Interview-Revised(ADI-R)and Autism Treatment Evaluation Checklist(ATEC)in the first time,and they were examined by T1-weighted three-dimensional magnetic resonance imaging(3D-MRI)and diffusion tensor imaging(DTI).After two years followed up,they completed above revaluations again.Based on the Region of Interest(ROI),the brain imaging data of the two groups were analyzed and the differences of the structural integrity of the important fiber bundle were compared in different periods.The major fraction anisotropy(FA)of 19 fiber bundles(21 ROIs)was observed and then the research compared the changes of FA values of the fiber bundles in the ASD group with the clinical symptoms(CARS,ADI-R and ATEC).[Results]1.There was no significant difference in the average FA value of white matter bundles in 21 regions of interest in ASD group compared with DD group(p>0.05)at 2 to 3 years old.The correlation between the FA value of the fiber bundle and the clinical symptoms showed that the total score of the ATEC scale was negatively correlated(r=-0.343,p=0.041)with the FA value of the right anterior cartilage.The language score of the ATEC scale were significantly negatively correlated with the mean FA values in corpus callosum(r=-0.347,p=0.038),the corpus callosum knee(r=-0.358,p=0.032),the right anterior cartilage(r=-0.351,p=0.036),the left internal capsule(r=-0.367,p = 0.028)and the left side of the inferior occipital beam(r=-0.337,p=0.044),the left cingulate gyrus(r=-0.33 8,p=0.043),the left uncinate fasciculus(r=-0.337,p=0.044)and the left fronto occipital inferior bundle(r=-0.368,p=0.027).The social score of the ATEC scale were negatively related to the right internal capsule(r=-0.355,p=0.033)and the right posterior capsule(r=-0.362,p=0.030).There was no correlation between the score of CARS,the subscale of ADI-R and the FA value of 21 ROI in ASD group(all p>0.05).2.At 4 to 5 years old,compared with DD group,the FA value of ASD group was significantly reduced in corpus callosum,corpus callosum knee,bilateral uncinate fasciculus,left cingulum,bilateral internal capsule,posterior branch of right internal capsule,left anterior rami of internal capsule and right inferior longitudinal fasciculus(all p<0.05).The correlation between the FA value of 21 ROIs fiber bundle and the clinical symptoms of ASD revealed that:The score of ATEC was positively correlated with the FA value of the right arcuate bundle(r=0.3 70,p=0.029);the social score of ATEC was positively correlated with the FA value of the left arcuate bundle(r=0.362,p=0.033);the sensory score of ATEC was negatively correlated with the FA value of the left inferior occipital(r=-0.376,p=0.026);the onset item of the ADI-R scale was positively correlated with the FA value of the left arcuate bundle(r=0.482,p=0.030).There was no correlation between the CARS,the other ADI-R subscales and the FA values of 21 ROIs(all p>0.05).3.The FA values of 21 fiber bundles in the ASD group were compared and analyzed.The results showed that the FA values of the remaining fiber bundles were increased after two years and there was significant difference(p<0.05).[Conclusion]The degree of damage to the integrity of the fibrous bundle of white matter in ASD children increased from age to age at 2 to 5 years of age,and was associated with core clinical symptoms.