Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands.
J Cereb Blood Flow Metab. 2018 Apr;38(4):719-726. doi: 10.1177/0271678X17737984. Epub 2017 Oct 17.
Clearance of waste products from the brain is of vital importance. Recent publications suggest a potential clearance mechanism via paravascular channels around blood vessels. Arterial pulsations might provide the driving force for paravascular flow, but its flow pattern remains poorly characterized. In addition, the relationship between paravascular flow around leptomeningeal vessels and penetrating vessels is unclear. In this study, we determined blood flow and diameter pulsations through a thinned-skull cranial window. We observed that microspheres moved preferentially in the paravascular space of arteries rather than in the adjacent subarachnoid space or around veins. Paravascular flow was pulsatile, generated by the cardiac cycle, with net antegrade flow. Confocal imaging showed microspheres distributed along leptomeningeal arteries, while their presence along penetrating arteries was limited to few vessels. These data suggest that paravascular spaces around leptomeningeal arteries form low resistance pathways on the surface of the brain that facilitate cerebrospinal fluid flow.
清除大脑中的废物至关重要。最近的出版物表明，血管周围的旁血道可能是一种潜在的清除机制。动脉搏动可能为旁血道流动提供驱动力，但它的流动模式仍未得到很好的描述。此外，软脑膜血管和穿透血管周围的旁血道流动之间的关系尚不清楚。在这项研究中，我们通过颅骨窗薄化术确定了血流和直径搏动。我们观察到微球优先在动脉的旁血管空间中移动，而不是在相邻的蛛网膜下腔或静脉周围移动。旁血道流动是脉动的，由心动周期产生，具有净前向流动。共聚焦成像显示微球沿软脑膜动脉分布，而沿穿透动脉的存在仅限于少数血管。这些数据表明，软脑膜动脉周围的旁血管空间在脑表面形成了低阻力途径，促进了脑脊液的流动。
