Bush Alan, Nuñez Maximiliano, Brisbin Alyssa K, Friedlander Robert M, Goldschmidt Ezequiel
1Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
2Department of Physics, FCEN, University of Buenos Aires and IFIBA-CONICET, Buenos Aires, Argentina.
J Neurosurg. 2019 Nov 22;133(6):1960-1969. doi: 10.3171/2019.9.JNS192151. Print 2020 Dec 1.
Cortical folding places regions that are separated by a large distance along the cortical surface in close proximity. This process is not homogeneous; regions such as the insular opercula have a much higher cortical surface distance (CSD) to euclidean distance (ED) than others. Here the authors explore the hypothesis that in the folded brain the CSD, and not the ED, determines regions of common irrigation, because this measure corresponds more closely with the distance along the prefolded brain, where the subarachnoid arterial vascular network starts forming.
The authors defined a convergence index that compared the ED to the CSD and applied it to the cortical surface reconstruction of an average brain. They then compared cortical convergence to the irrigation patterns of major sulci and fissures of the brain, by assessing whether these structures were crossed or not crossed by arterial vessels in 20 fixed hemispheres.
The regions of highest convergence (top 1%) were clustered around the sylvian fissure, which is the only brain depression with high convergence values along its edges. Arterial crossings were commonly observed in every major sulcus of the brain, with the exception of the sylvian fissure, constituting a highly significant difference (p < 10-4).
Arteries do not cross regions of high convergence. In the adult brain the CSD, rather than the ED, predicts the regional irrigation pattern. The distant origin of the frontal and temporal lobes creates a region of high cortical convergence, which explains why arteries do not cross the sylvian fissure.
大脑皮质折叠使沿皮质表面相距甚远的区域彼此靠近。这一过程并不均匀；岛盖等区域的皮质表面距离（CSD）与欧几里得距离（ED）之比远高于其他区域。在此，作者探讨了这样一种假说，即在折叠的大脑中，决定共同灌注区域的是CSD而非ED，因为该测量值与蛛网膜下动脉血管网络开始形成的折叠前大脑中的距离更为接近。
作者定义了一个比较ED与CSD的汇聚指数，并将其应用于平均大脑的皮质表面重建。然后，通过评估20个固定半球中这些结构是否被动脉血管穿过，作者将皮质汇聚与大脑主要脑沟和脑裂的灌注模式进行了比较。
汇聚程度最高的区域（前1%）聚集在外侧裂周围，外侧裂是唯一边缘具有高汇聚值的脑沟。除外侧裂外，在大脑的每个主要脑沟中都普遍观察到动脉交叉，构成了高度显著的差异（p < 10-4）。
动脉不会穿过高汇聚区域。在成人大脑中，CSD而非ED可预测区域灌注模式。额叶和颞叶的远侧起源形成了一个高皮质汇聚区域，这解释了为什么动脉不会穿过外侧裂。
