Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
Neurosurg Focus. 2011 Sep;31(3):E4. doi: 10.3171/2011.6.FOCUS11106.
Resolution of syringomyelia is common following hindbrain decompression for Chiari malformation, yet little is known about the kinetics governing this process. The authors sought to establish the volumetric rate of syringomyelia resolution.
A retrospective cohort of patients undergoing hindbrain decompression for a Chiari malformation Type I with preoperative cervical or thoracic syringomyelia was identified. Patients were included in the study if they had at least 3 neuroimaging studies that detailed the entirety of their preoperative syringomyelia over a minimum of 6 months postoperatively. The authors reconstructed the MR images in 3 dimensions and calculated the volume of the syringomyelia. They plotted the syringomyelia volume over time and constructed regression models using the method of least squares. The Akaike information criterion and Bayesian information criterion were used to calculate the relative goodness of fit. The coefficients of determination R(2) (unadjusted and adjusted) were calculated to describe the proportion of variability in each individual data set accounted for by the statistical model.
Two patients were identified as meeting inclusion criteria. Plots of the least-squares best fit were identified as 4.01459e(-0.0180804)(x) and 13.2556e(-0.00615859)(x). Decay of the syringomyelia followed an exponential model in both patients (R(2) = 0.989582 and 0.948864).
Three-dimensional analysis of syringomyelia resolution over time enables the kinetics to be estimated. This technique is yet to be validated in a large cohort. Because syringomyelia is the final common pathway for a number of different pathological processes, it is possible that this exponential only applies to syringomyelia related to treatment of Chiari malformation Type I.
小脑扁桃体下疝畸形（Chiari malformation）后路减压后，通常会出现脊髓空洞症（syringomyelia）缓解，但对于控制这一过程的动力学机制却知之甚少。作者旨在建立脊髓空洞症缓解的容积变化率。
本研究回顾性纳入了一组因 Chiari 畸形Ⅰ型行后路减压术的患者，这些患者术前存在颈段或胸段脊髓空洞症。如果患者至少有 3 次神经影像学检查，且术后至少 6 个月内详细记录了术前脊髓空洞症的全部情况，则纳入本研究。作者对磁共振成像（MRI）进行三维重建并计算脊髓空洞症的体积。作者将脊髓空洞症的体积随时间的变化绘制出来，并使用最小二乘法构建回归模型。使用赤池信息量准则（Akaike information criterion）和贝叶斯信息量准则（Bayesian information criterion）来计算相对拟合优度。还计算了未调整和调整后的决定系数 R²（unadjusted and adjusted），以描述统计模型对每个个体数据集的可变性的解释程度。
确定了 2 例符合纳入标准的患者。最小二乘最佳拟合图确定为 4.01459e(-0.0180804)(x) 和 13.2556e(-0.00615859)(x)。两名患者的脊髓空洞症均呈指数衰减（R²=0.989582 和 0.948864）。
脊髓空洞症容积随时间的三维分析可以估计其动力学变化。该技术尚需在大样本中验证。由于脊髓空洞症是多种不同病理过程的最终共同途径，因此这种指数衰减可能仅适用于与 Chiari 畸形Ⅰ型治疗相关的脊髓空洞症。
