圆锥位置正常型脊髓栓系综合征MRI表现与临床对比

摘要

目的 探讨圆锥位置正常型脊髓栓系综合征(TCS)临床及MRI特征性表现.方法 回顾性分析经手术及病理证实的圆锥位置正常型脊髓栓系综合征患儿13例,将其临床表现、术前MRI征象及术中所见情况进行对比.另对12例怀疑有此种圆锥位置正常型TCS患儿在常规MRI检查基础上加做俯卧位扫描加以筛查.患儿全部行MRI检查、尿动力学及双下肢肌电图检查、MSCT检查,手术方式采用终丝离断加椎板成形术治疗.结果 术前MRI及MSCT显示患儿脊髓圆锥末端均位于L2椎体下缘以上,部分伴有骶椎板未融合及脊柱侧弯等其他病变.轴位及矢状位可观察到19例患儿终丝及马尾神经有靠近或紧贴于后硬膜囊的趋势,椎管内马尾神经排列不规则,两侧粗细不等等征象.12例疑似患儿经俯卧位MRI检查排除8例.尿流动力学及双下肢肌电图结果显示部分患儿存在损害.术中可见终丝呈弓弦样紧张,紧贴于硬脊膜后缘,17例终丝直径在1.5 mm以上,4例终丝发黄;3例马尾神经有不同程度的粘连呈束状.显微镜下分离终丝并切断,术中即可见脊髓圆锥末端回缩3例.术后病理示3例终丝脂肪组织异常增生,4例终丝纤维组织及脂肪组织异常增生,10例纤维组织异常增生.结论 圆锥位置正常型TCS可被认为是一种特殊TCS亚型,通过观察患儿终丝及马尾神经MRI影像学特征,并加做俯卧位MRI检查进行对比,可对此种类型TCS进行初步诊断.%Objective To investigate the clinical and MR imaging characteristics of tethered cord syndrome (TCS) with conus medullaris in normal position in children. Methods 13 patients with TCS with normal level of conus medullaris underwent MRI, MSCT, urodynamics and electromyogram examinations. All cases with TCS were confirmed by surgery and pathology. In addition, the other 12 cases suspected with TCS with normal level of conus medullaris in children underwent conventional MRI and MR imaging at prone position. All cases with TCS were surgically treated by transecting the filum terminale and laminoplasty. The clinical findings, the spinal cord tethering condition on MRI and operation were compared. Results Preoperative MRI and MSCT showed the positions of the conus medullaris were all located above the lower edge of 2th lumbar body,and some cases accompanied with spinal deformations. MRI showed that the terminal filum and the cauda equina had a tendency that closed to the post-epidural and the cauda equina showed irregular arrangement in 19 cases. 8 cases in 12 cases suspected with TCS were ruled out with TCS by the prone-positioned MRI. The results of the urodynamic and electromyogram examination were abnormal in some cases. The terminal filums was to be tensed bowstring-like and closed to the post-epidural,the diameter of the terminal filums was more than 1. 5 mm in 17 cases, fatty in the terminal filums in 4 cases, the cauda equina as bundle of adhesion in 3 cases were found during operations. In 3 cases, the conus medullaris were retraction at once during surgery. The postoperative pathology showed that,there were fatty infiltration in 3 cases , the fibrous tissue infiltration in 10 cases and mixed fatty and fibrous tissue infiltration in 4 cases. Conclusion TCS with normal level of conus medullaris should be considered as a special subtype of TCS. MRI is of important value in evaluation of this type of TCS.