David K M, Copp A J, Stevens J M, Hayward R D, Crockard H A
Department of Surgical Neurology, National Hospital for Neurology and Neurosurgery, London, UK.
Brain. 1996 Dec;119 ( Pt 6):1859-72. doi: 10.1093/brain/119.6.1859.
We report seven cases of rare high cervical split spinal cord associated with extensive vertebral fusions (Klippel-Feil anomaly). In light of previous embryological theories and recent research findings we attempt to explain the origin of split cord and vertebral fusions. Two distinctly separate mechanisms are suggested for the development of split cords observed in our cases: a midline lesion bisecting the neuroepithelium and the notochordal plate could be responsible for complete splitting of the cervical cord with anterior bony defect while a localized disturbance of cervical neural tube closure would account for cases with partial dorsal splitting of the cord with posterior vertebral defect. Vertebral fusion anomalies are likely to be associated with disturbance of Pax-1 gene expression in the developing vertebral column. We confirm with our cases the frequent association of failure of normal segmentation and split cord in the cervical region. Clinically, only three patients had neurological deficit which was mild and has remained stable, and they had no radiological evidence of tethering; the minimal disproportionate growth of the cord and spine and the rarity of a bony spur in the cervical region are the likely reasons. A conservative policy was therefore pursued in these cases with careful long-term follow-up.
我们报告了7例罕见的与广泛椎体融合（Klippel-Feil畸形）相关的高位颈段脊髓纵裂病例。根据先前的胚胎学理论和最近的研究结果，我们试图解释脊髓纵裂和椎体融合的起源。对于我们病例中观察到的脊髓纵裂的发生，提出了两种截然不同的机制：中线病变将神经上皮和脊索板一分为二，可能导致颈髓完全分裂并伴有前方骨质缺损，而颈神经管闭合的局部紊乱则可解释脊髓部分背侧分裂并伴有后方椎体缺损的病例。椎体融合异常可能与发育中的脊柱中Pax-1基因表达紊乱有关。我们通过病例证实了颈段正常节段化失败与脊髓纵裂之间的频繁关联。临床上，只有3例患者有轻度神经功能缺损且保持稳定，并且他们没有影像学证据显示脊髓栓系；脊髓和脊柱最小程度的不成比例生长以及颈段骨赘罕见可能是原因所在。因此，对这些病例采取了保守策略并进行仔细的长期随访。
