Brain Connectivity and Behaviour Laboratory, Sorbonne Universities, Paris, France.
Groupe d'Imagerie Neurofonctionnelle, Institut des Maladies Neurodégénératives-UMR 5293, CNRS, CEA University of Bordeaux, Bordeaux, France.
Brain Struct Funct. 2022 Mar;227(2):529-544. doi: 10.1007/s00429-021-02382-w. Epub 2021 Nov 3.
Inter-individual differences can inform treatment procedures and-if accounted for-have the potential to significantly improve patient outcomes. However, when studying brain anatomy, these inter-individual variations are commonly unaccounted for, despite reports of differences in gross anatomical features, cross-sectional, and connectional anatomy. Brain connections are essential to facilitate functional organization and, when severed, cause impairments or complete loss of function. Hence, the study of cerebral white matter may be an ideal compromise to capture inter-individual variability in structure and function. We reviewed the wealth of studies that associate cognitive functions and clinical symptoms with individual tracts using diffusion tractography. Our systematic review indicates that tractography has proven to be a sensitive method in neurology, psychiatry, and healthy populations to identify variability and its functional correlates. However, the literature may be biased, as the most commonly studied tracts are not necessarily those with the highest sensitivity to cognitive functions and pathologies. Additionally, the hemisphere of the studied tract is often unreported, thus neglecting functional laterality and asymmetries. Finally, we demonstrate that tracts, as we define them, are not correlated with one, but multiple cognitive domains or pathologies. While our systematic review identified some methodological caveats, it also suggests that tract-function correlations might still be a promising tool in identifying biomarkers for precision medicine. They can characterize variations in brain anatomy, differences in functional organization, and predicts resilience and recovery in patients.
个体间差异可为治疗方案提供信息，如果加以考虑，有潜力显著改善患者的预后。然而，在研究大脑解剖结构时，这些个体间的差异通常没有得到考虑，尽管有报道称大脑解剖结构存在明显差异，包括大体解剖特征、横断面和连接解剖结构。大脑连接对于促进功能组织至关重要，当连接被切断时，会导致功能障碍或完全丧失。因此，研究大脑白质可能是捕捉结构和功能个体差异的理想折衷方案。我们综述了大量使用弥散张量成像技术将认知功能和临床症状与个体束联系起来的研究。我们的系统综述表明，弥散张量成像已被证明是神经病学、精神病学和健康人群中一种敏感的方法，可用于识别变异性及其与功能的相关性。然而，文献可能存在偏差，因为最常研究的束不一定是对认知功能和病理学最敏感的束。此外，研究束的大脑半球通常未被报道，因此忽略了功能的偏侧性和不对称性。最后，我们证明了我们所定义的束与一个但多个认知领域或病理学没有相关性。虽然我们的系统综述确定了一些方法学上的注意事项，但它也表明，束-功能相关性可能仍然是识别精准医学生物标志物的有前途的工具。它们可以描述大脑解剖结构的变化、功能组织的差异，并预测患者的韧性和恢复能力。
