脊柱转移瘤瘫痪状态与影像学特征相关因素分析

The relationship between the paraplegia caused by metastatic epidural spinal cord compression and its radiological features

目的探讨转移瘤硬膜外脊髓压迫症(MESCC)瘫痪状态与影像学特征的相关性。方法 2006年7月-2008年12月,对连续收治的56例MESCC患者按Frankel分级进行瘫痪状态评估,并对86个主要病变脊椎进行MRI及CT扫描。主要病变脊椎影像学评估因素包括:病变脊椎节段、侵犯硬膜囊、累及椎板、椎体后壁向后突出、病变脊椎连续、累及椎弓根、椎体前柱骨折、椎体后壁骨折、病变脊椎位于上胸椎和(或)颈胸交界。结果多重回归方程表明MESCC瘫痪状态与侵犯硬膜囊、椎体后壁向后突出、椎体前柱骨折、病变脊椎位于上胸椎和(或)颈胸交界等主要病变脊椎影像学特征存在线性回归关系。回归方程决定系数R^2=0.856,校正决定系数R_c ~2=0.841。标准化回归系数显示,侵犯椎管内硬膜外间隙对MESCC瘫痪状态影响最大。结论采用侵犯椎管内硬膜外间隙的影像学特征预测MESCC患者瘫痪状态的发生具有明显滞后性。椎体后壁向后突出可预示MESCC患者的神经学不稳定。位于上胸椎和(或)颈胸交界的主要病变脊椎常连续发生且易发生运动功能损害。累及椎板的转移瘤易于向椎管内硬膜外间隙侵犯。椎体前柱骨折不能用以预测MESCC患者的运动功能损害。

Objective To investigate the relationship between the paraplegia caused by metastatic epidural spinal cord compression （MESCC） and its radiological features. Methods From July 2006 to December 2008, 56 consecutive patients in our department who sustained MESCC were evaluated by Frankel grading system for their condition of paraplegia. 86 vertebraewith evident lesion underwent MRI and CT scan. The radiological evaluation factors were the location of the affected segment, invasion to the dural sac, the affected vertebral plate, rearward protrusion of the posterior vertebral wall, consecutive affected vertebral bodies, affected pedicles, fracture of the anterior column of the spine, fracture of the posterior vertebral wall, and the fact that the affected vertebral body located in the upper thoracic spine and/or at the cervicothoracic juncture. Results Multiple regression equation showed that paraplegia had a linear relationship with invasion to the dural sac, rearward protrusion of the posterior vertebral wall, fracture of the anterior column of the spine, and the fact that the affected vertebral body locates in the upper thoracic spine and/or at the cervicothoracic juncture. The coefficient of determination for the equation was R2=0.856. The correction coefficient of determination was Rc2=0.841. Standardard regression coefficient showed that the invasion to the epidural space had the biggest influence on the paraplegia. Conclusions From the radiological manifestations of the invasion to the dural space, we discovered that the paraplegia caused by MESCC showed obvious hysteresis. Rearward protrusion of the posterior vertebral wall suggests neurological instability. The affected segments in the upper thoracic spine and/or at the cervicothoracic juncture often consecutively and are prone to encounter motor function impairment. The metastatic tumor affecting the vertebral plate is prone to invade the dural space. Fracture of the anterior column cannot be used to predict the impairment of motor function for patients with MESCC.