目的

探讨学龄前孤独症谱系障碍（ASD）患儿杏仁核体积及杏仁核白质纤维连接强度，并对其与ASD 相关量表评分进行相关性分析。

方法

选择2022年9月至2023年9月于中国人民解放军总医院第一医学中心小儿内科确诊的64例ASD 患儿为研究对象，纳入ASD 组（n=64）；选择同期从北京市招募的23例典型发育（TD）儿童为对照，纳入对照组（n=23）。采用前瞻性研究方法，利用3.0 T MRI扫描仪采集2组受试儿颅脑弥散张量成像（DTI）数据，采用深度弥散脑区解剖分割（DDParcel）工具与FreeSurfer中的DK atlas脑模板，对2组受试儿杏仁核进行精准分割并计算体积，通过基于双张量无迹卡尔曼滤波（t UKF）的纤维示踪技术，追踪2组受试儿杏仁核白质纤维连接，评估杏仁核白质纤维连接强度。由2 名儿科主任医师采取《精神障碍诊断与统计手册（5 版）》（DSM-5）、《儿童孤独症评定量表（CARS）》与《孤独症行为量表（ABC）》，对2组受试儿实施双盲测评。对2组受试儿杏仁核体积、杏仁核白质纤维连接强度比较，采用独立样本t 检验。采用Pearson相关性分析方法，对ASD 组患儿杏仁核体积及杏仁核白质纤维连接强度与ABC、CARS评分进行相关性分析。本研究遵循的程序符合中国人民解放军总医院医学伦理委员会制定的标准，并获得该伦理委员会批准（批准文号：S2022-646-01），与所有受试儿监护人在入组前签署临床研究知情同意书。2组受试儿年龄比较，差异无统计学意义（P ＞0.05）。

结果

①ASD 组患儿DSM-5 评分为（4.0±1.5）分，CARS评分为（31.1±5.6）分，ABC 总评分为（45.7±18.0）分。ASD 患儿DSM-5评分、ABC各维度评分及总评分、CARS 评分，均显著高于对照组，并且差异均有统计学意义（P ＜0.001）。②ASD 组患儿右侧杏仁核体积大于左侧杏仁核体积，差异有统计学意义（t=-3.36，P=0.001）。2组受试儿左、右侧杏仁核体积组间分别比较，差异均无统计学意义（P＞0.05）。③ASD 组患儿左侧杏仁核与左侧眶额叶及左侧颞极间的白质纤维连接强度，以及右侧杏仁核与右侧距状旁回间的白质纤维连接强度，均显著低于对照组受试儿，差异均有统计学意义（t=2.30、3.02、2.70，P=0.024、0.003、0.008）。④ASD 组患儿的左侧杏仁核与左侧眶额叶间的白质纤维连接强度与其ABC 的躯体运动能力维度评分呈负相关关系（r=-0.269，P=0.032）。

结论

ASD 患儿右侧杏仁核体积大于左侧，其杏仁核与颞极、眶额叶、距状旁回等脑区纤维连接强度存在异常，杏仁核与眶额叶间的白质纤维连接强度异常与ASD 患儿躯体运动障碍相关。

Objective

To investigate the amygdala volume and amygdala white matter fiber connection intensity in preschool children with autism spectrum disorder （ASD），and their correlation with ASD assessment scale scores.

Methods

A total of 64 children with ASD diagnosed in the Department of Pediatrics，First Medical Center，Chinese PLA General Hospital from September 2022 to September 2023 were enrolled into ASD group（n=64），And other 23 typically development（TD）children recruited from Beijing during the same period were prospectively enrolled into control group （n=23）.Brain diffusion tensor imaging（DTI）image data of children in two groups were acquired using a 3.0 T MRI scanner by prospective research method.The deep diffusion parcellation（DDParcel）tool and the DK atlas brain template in FreeSurfer were employed for precise segmentation and volumetric measurement of the amygdala.White matter connections with the amygdala were tracked with two-tensor unscented Kalman filter （t UKF）tractography to evaluate the strength of amygdala white matter fiber connectivity.Two chief physician of pediatrics conducted double-blind assessments on two groups of subjects using the DiagnosticandStatisticalManualof MentalDisorders5thEdition （DSM-5），ChildhoodAutismRatingScale （CARS），and Autism BehaviorChecklist（ABC）.The comparison of the amygdala volume and the intensity of amygdala white matter fiber connection between two groups was performed by independent-samples t test.Pearson correlation analysis was used to analyze the correlation between the amygdala volume and amygdala white matter fiber connection intensity with the ABC and CARS scores in ASD group.The procedures followed in this study were in accordance with the standards set by the Medical Ethics Committee of the Chinese PLA General Hospital and were approved by this committee （Approval No.S2022-646-01）.Written informed consents were obtained from all guardians of the children before their inclusion in the study.There was no significant difference in the age of the subjects between the two groups （P＞0.05）.

Results

①The DSM-5 score of children in ASD group was （4.0±1.5）points，the CARS score was（31.1±5.6）points，and the total ABC score was （45.7±18.0）points.The DSM-5 score，the scores of each dimension and the total score of ABC，and the CARS score of children in ASD group were significantly higher than those in control group，and the differences were statistically significant （P＜0.001）.②The volume of right amygdala in ASD group was larger than that of the left amygdala，and the difference was statistically significant （t=-3.36，P=0.001）.There was no statistically significant difference in the volume of the left and right amygdala between two groups （P＞0.05）.③The white matter fiber connection intensity between the left amygdala and the left orbitofrontal lobe and the left temporal pole，as well as the white matter fiber connection intensity between the right amygdala and the right paracalcarine gyrus in ASD group were significantly lower than those in control group （t=2.30，3.02，2.70；P=0.024，0.003，0.008）.④In ASD group，the white matter fiber connection intensity between the left amygdala and the left orbitofrontal lobe was negatively correlated with the physical motor ability dimension score of the ABC（r=-0.269，P=0.032）.

Conclusions

The volume of right amygdala in children with ASD is larger than that of the left amygdala.The fiber connection intensity between the amygdala and the temporal pole，orbitofrontal lobe，paracalcarine gyrus and other brain regions in children with ASD is abnormal.The abnormal white matter fiber connection intensity between the amygdala and orbitofrontal lobe is associated with somatic movement disorders in children with ASD.