自閉患者結構性和功能性腦影像的發展變化

Developmental Changes in Structural and Functional Brain Images in Patients with Autism Spectrum Disorder

自閉症類群障礙症，是一種以社交溝通缺陷及重複性行為和侷限興趣，為主要臨床特徵的神經發展疾病。儘管已有大量相關臨床研究，但對於其潛在的神經生物學機制仍缺乏完整的了解。縱貫性腦影像學研究，為探索自閉症患者在整個生命週期中，大腦發展的異常軌跡提供了寶貴的見解。腦部體素形態學和表面形態學分析發現，與正常發展個體相比，自閉症患者在年齡相關變化上呈現獨特的模式。值得注意的是，自閉症患者在青春期和成年早期，在許多特定皮質區域，如下頂葉、下顳葉和背外側前額葉皮質，呈現加速變薄的現象。這些結構性異常與社交缺陷，和執行功能障礙的嚴重程度相關。擴散加權影像研究顯示，自閉症患者的白質發展軌跡存在異常，兒童期延遲成熟，青春期則加速發展，但在成年期這種趨於正常的發育趨勢中止，可能導致自閉症持續存在的認知和行為障礙。功能性磁振造影研究則發現，自閉症患者在發展過程中，大腦預設模式網絡、警覺網絡和中央執行網絡之間的功能連接存在異常。台灣本土研究則發現，自閉症患者在青春期和早期成年時期，與社會認知和執行功能相關的腦區，呈現加速的皮質變薄現象。此外，青春期額頂葉網絡的結構連接異常，與成年早期症狀嚴重程度相關。縱貫性腦影像研究，顯著地促進我們對自閉症患者，在整個生命週期中大腦動態變化的理解，為疾病預後預測、早期介入和精準治療方法，提供了潛在的神經標的。

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by impairments in social communication and restricted repetitive behaviors and interests. Despite extensive research, a comprehensive understanding of the neurobiological mechanisms underlying ASD remains elusive. Longitudinal neuroimaging studies have provided invaluable insights into the atypical brain development trajectories associated with ASD across the lifespan. Voxel-based morphometry and surface-based morphometry studies have revealed distinctive patterns of age-related changes in gray matter volume and cortical thickness in individuals with ASD compared to typically developing controls. Notably, individuals with ASD exhibit accelerated cortical thinning during adolescence and early adulthood in regions implicated in social cognition and executive functioning, such as the inferior parietal, inferior temporal, and dorsolateral prefrontal cortices. These structural alterations have been linked to the severity of social deficits and executive dysfunction. Diffusion-weighted imaging studies have demonstrated atypical white matter development trajectories in ASD, with delayed maturation during childhood followed by accelerated development during adolescence. However, this normalization trend appears to halt in adulthood, potentially contributing to the persistent cognitive and behavioral impairments observed in ASD. Functional magnetic resonance imaging studies have revealed aberrant functional connectivity patterns within and between large-scale brain networks, such as the default mode, salience, and central executive networks, in individuals with ASD across development. Taiwanese studies have corroborated these findings, highlighting the accelerated cortical thinning during adolescence and early adulthood in ASD, particularly in regions associated with social cognition and executive functioning. Additionally, structural connectivity abnormalities in the frontoparietal network have been linked to symptom severity in early adulthood. These longitudinal neuroimaging studies have significantly advanced our understanding of the dynamic brain changes associated with ASD across the lifespan, providing potential neural markers for predicting future outcomes and informing early intervention and precision treatment strategies.