Marano Giuseppe, Kotzalidis Georgios D, Anesini Maria Benedetta, Barbonetti Sara, Rossi Sara, Milintenda Miriam, Restaino Antonio, Acanfora Mariateresa, Traversi Gianandrea, Veneziani Giorgio, Picilli Maria, Callovini Tommaso, Lai Carlo, Mercuri Eugenio Maria, Sani Gabriele, Mazza Marianna
Unit of Psychiatry, Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, 00168 Rome, Italy.
Department of Neurosciences, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.
Brain Sci. 2025 Jul 31;15(8):824. doi: 10.3390/brainsci15080824.
: Autism spectrum disorder (ASD) has been extensively studied through neuroimaging, primarily focusing on grey matter and more in children than in adults. Studies in children and adolescents fail to capture changes that may dampen with age, thus leaving only changes specific to ASD. While grey matter has been the primary focus, white matter (WM) may be more specific in identifying the particular biological signature of the neurodiversity of ASD. Diffusion tensor imaging (DTI) is the more appropriate tool to investigate WM in ASD. Despite being introduced in 1994, its application to ASD research began in 2001. Studies employing DTI identify altered fractional anisotropy (FA), mean diffusivity, and radial diffusivity (RD) in individuals with ASD compared to typically developing (TD) individuals. : We systematically reviewed literature on 21 May 2025 on PubMed using the following strategy: ("autism spectrum"[ti] OR autistic[ti] OR ASD[ti] OR "high-functioning autism" OR Asperger*[ti] OR Rett*[ti]) AND (DTI[ti] OR "diffusion tensor"[ti] OR multimodal[ti] OR "white matter"[ti] OR tractograph*[ti]). Our search yielded 239 results, of which 26 were adult human studies and eligible. : Analysing the evidence, we obtained regionally diverse WM alterations in adult ASD, specifically in FA, MD, RD, axial diffusivity and kurtosis, neurite density, and orientation dispersion index, compared to TD individuals, mostly in frontal and interhemispheric tracts, association fibres, and subcortical projection pathways. These alterations were less prominent than those of children and adolescents, indicating that individuals with ASD may improve during brain maturation. : Our findings suggest that white matter alterations in adults with ASD are regionally diverse but generally less pronounced than in younger populations. This may indicate a potential improvement or adaptation of brain structure during maturation. Further research is needed to clarify the neurobiological mechanisms underlying these changes and their implications for clinical outcomes.
自闭症谱系障碍（ASD）已通过神经影像学进行了广泛研究，主要集中在灰质上，且在儿童中的研究比在成人中更多。对儿童和青少年的研究未能捕捉到可能随年龄减弱的变化，因此仅留下了ASD特有的变化。虽然灰质一直是主要关注点，但白质（WM）在识别ASD神经多样性的特定生物学特征方面可能更具特异性。扩散张量成像（DTI）是研究ASD中WM的更合适工具。尽管DTI于1994年被引入，但其在ASD研究中的应用始于2001年。与典型发育（TD）个体相比，采用DTI的研究发现ASD个体的分数各向异性（FA）、平均扩散率和径向扩散率（RD）发生了改变。
我们于2025年5月21日在PubMed上使用以下策略系统地回顾了文献：（“自闭症谱系”[标题]或“自闭症的”[标题]或ASD[标题]或 “高功能自闭症” 或阿斯伯格*[标题]或雷特*[标题]）且（DTI[标题]或 “扩散张量”[标题]或多模态[标题]或 “白质”[标题]或纤维束成像*[标题]）。我们的搜索产生了239条结果，其中26项是符合条件的成人研究。
分析证据时，与TD个体相比，我们发现成人ASD中白质改变在区域上存在差异，具体表现在FA、MD、RD、轴向扩散率和峰度、神经突密度以及方向离散指数方面，主要集中在额叶和半球间束、联合纤维以及皮质下投射通路。这些改变不如儿童和青少年明显，这表明ASD个体在大脑成熟过程中可能有所改善。
我们的研究结果表明，成人ASD中的白质改变在区域上存在差异，但总体上不如年轻人群明显。这可能表明大脑结构在成熟过程中存在潜在的改善或适应。需要进一步研究以阐明这些变化背后的神经生物学机制及其对临床结果的影响。
