Vinje V, Brucker J, Rognes M E, Mardal K A, Haughton V
1 Simula Research Laboratory, Norway.
2 Department of Radiology, University of Wisconsin, USA.
Neuroradiol J. 2018 Oct;31(5):482-489. doi: 10.1177/1971400918795482. Epub 2018 Aug 17.
Purpose How fluid moves during the cardiac cycle within a syrinx may affect its development. We measured syrinx fluid velocities before and after craniovertebral decompression in a patient and simulated syrinx fluid velocities for different heart rates, syrinx sizes and cerebrospinal fluid (CSF) flow velocities in a model of syringomyelia. Materials and methods With phase-contrast magnetic resonance we measured CSF and syrinx fluid velocities in a Chiari patient before and after craniovertebral decompression. With an idealized two-dimensional model of the subarachnoid space (SAS), cord and syrinx, we simulated fluid movement in the SAS and syrinx with the Navier-Stokes equations for different heart rates, inlet velocities and syrinx diameters. Results In the patient, fluid oscillated in the syrinx at 200 to 210 cycles per minute before and after craniovertebral decompression. Velocities peaked at 3.6 and 2.0 cm per second respectively in the SAS and the syrinx before surgery and at 2.7 and 1.5 cm per second after surgery. In the model, syrinx velocity varied between 0.91 and 12.70 cm per second. Increasing CSF inlet velocities from 1.56 to 4.69 cm per second increased peak syrinx fluid velocities in the syrinx by 151% to 299% for the three cycle rates. Increasing cycle rates from 60 to 120 cpm increased peak syrinx velocities by 160% to 312% for the three inlet velocities. Peak velocities changed inconsistently with syrinx size. Conclusions CSF velocity, heart rate and syrinx diameter affect syrinx fluid velocities, but not the frequency of syrinx fluid oscillation. Craniovertebral decompression decreases both CSF and syrinx fluid velocities.
目的 脊髓空洞症患者在心动周期中液体的流动方式可能会影响其发展。我们测量了一名患者颅颈减压术前和术后脊髓空洞内的液体流速，并在脊髓空洞症模型中模拟了不同心率、脊髓空洞大小和脑脊液（CSF）流速下的脊髓空洞内液体流速。材料与方法 采用相位对比磁共振成像技术，测量了一名Chiari畸形患者颅颈减压术前和术后的脑脊液及脊髓空洞内液体流速。利用理想化的蛛网膜下腔（SAS）、脊髓和脊髓空洞的二维模型，我们用Navier-Stokes方程模拟了不同心率、入口流速和脊髓空洞直径下SAS和脊髓空洞内的液体流动。结果 在该患者中，颅颈减压术前和术后脊髓空洞内的液体以每分钟200至210次的频率振荡。术前SAS和脊髓空洞内的流速峰值分别为每秒3.6厘米和2.0厘米，术后分别为每秒2.7厘米和1.5厘米。在模型中，脊髓空洞内的流速在每秒0.91厘米至12.70厘米之间变化。将脑脊液入口流速从每秒1.56厘米增加到4.69厘米，在三种心率下脊髓空洞内的液体流速峰值增加了151%至299%。将心率从每分钟60次增加到120次，在三种入口流速下脊髓空洞内的流速峰值增加了160%至312%。峰值流速随脊髓空洞大小的变化不一致。结论 脑脊液流速、心率和脊髓空洞直径会影响脊髓空洞内的液体流速，但不影响脊髓空洞内液体振荡的频率。颅颈减压术会降低脑脊液和脊髓空洞内的液体流速。
