The mechanisms behind perivascular fluid flow.
The mechanisms behind perivascular fluid flow.
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DOI：
10.1371/journal.pone.0244442
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发表时间：
2020
期刊：
影响因子：
3.7
通讯作者：
Rognes ME
中科院分区：
文献类型：
--
作者：
Daversin-Catty C;Vinje V;Mardal KA;Rognes ME
脑脊髓液（CSF）在血管周围间隙（PVS）中的流动是脑清除理论中的关键概念之一。实验研究证明了PVS中微球的净运动和振荡运动（Mestre等人（2018），Bedussi等人（2018））。振荡粒子运动具有明确的心脏成分，而涉及净运动的机制仍有争议。使用计算流体动力学，我们计算了CSF的速度和压力在PVS周围的脑动脉受到不同的力量，代表动脉壁扩张，全身CSF压力的变化和刚性运动的动脉。动脉壁扩张产生的速度振幅为60-260 μm/s，处于先前观察值的上限范围内。在没有静压梯度的情况下，预测的净流速很小（<0.5 μm/s），但对于非生理PVS长度可达7 μm/s。在实际几何形状中，生理学上合理幅度的静态体循环压力增加足以诱导20-30 μm/s的净流速。此外，动脉的刚性运动增加了PVS中流动模式的复杂性。我们的研究表明，动脉壁扩张，刚性运动和静态CSF压力梯度的组合产生净和振荡PVS流，定量与实验结果。净流量所需的静态CSF压力梯度很小，表明其来源尚未确定。
Flow of cerebrospinal fluid (CSF) in perivascular spaces (PVS) is one of the key concepts involved in theories concerning clearance from the brain. Experimental studies have demonstrated both net and oscillatory movement of microspheres in PVS (Mestre et al. (2018), Bedussi et al. (2018)). The oscillatory particle movement has a clear cardiac component, while the mechanisms involved in net movement remain disputed. Using computational fluid dynamics, we computed the CSF velocity and pressure in a PVS surrounding a cerebral artery subject to different forces, representing arterial wall expansion, systemic CSF pressure changes and rigid motions of the artery. The arterial wall expansion generated velocity amplitudes of 60–260 μm/s, which is in the upper range of previously observed values. In the absence of a static pressure gradient, predicted net flow velocities were small (<0.5 μm/s), though reaching up to 7 μm/s for non-physiological PVS lengths. In realistic geometries, a static systemic pressure increase of physiologically plausible magnitude was sufficient to induce net flow velocities of 20–30 μm/s. Moreover, rigid motions of the artery added to the complexity of flow patterns in the PVS. Our study demonstrates that the combination of arterial wall expansion, rigid motions and a static CSF pressure gradient generates net and oscillatory PVS flow, quantitatively comparable with experimental findings. The static CSF pressure gradient required for net flow is small, suggesting that its origin is yet to be determined.
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DOI：
10.1177/0271678x17737984
发表时间：
2018-04
期刊：
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
影响因子：
--
作者：
Bedussi B;Almasian M;de Vos J;VanBavel E;Bakker EN
通讯作者：
Bakker EN
影响因子：
1.9
作者：
Eide, Per Kristian;Kerty, Emilia
通讯作者：
Kerty, Emilia
影响因子：
17.1
作者：
Iliff JJ;Wang M;Liao Y;Plogg BA;Peng W;Gundersen GA;Benveniste H;Vates GE;Deane R;Goldman SA;Nagelhus EA;Nedergaard M
通讯作者：
Nedergaard M
影响因子：
11
作者：
Czosnyka, M;Pickard, JD
通讯作者：
Pickard, JD
影响因子：
4.3
作者：
Diem, Alexandra K.;Sharp, Matthew MacGregor;Richardson, Giles
通讯作者：
Richardson, Giles