SPLIT CERVICAL SPINAL-CORD WITH KLIPPEL-FEIL-SYNDROME - 7 CASES

We report seven cases of rare high cervical split spinal cord associat ed with extensive vertebral fusions (Klippel-Feil anomaly). In light o f previous embryological theories and recent research findings we atte mpt to explain the origin of split cord and vertebral fusions. Two dis tinctly separate mechanisms are suggested for the development of split cords observed in our cases: a midline lesion bisecting the neuroepit helium and the notochordal plate could be responsible for complete spl itting of the cervical cord with anterior bony defect while a localize d disturbance of cervical neural tube closure would account for cases with partial dorsal splitting of the cord with posterior vertebral def ect. Vertebral fusion anomalies are likely to be associated with distu rbance 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 t hree patients had neurological deficit which was mild and has remained stable, and they had no radiological evidence of tethering; the minim al disproportionate growth of the cord and spine and the rarity of a b ony spur in the cervical region are the likely reasons. A conservative policy was therefore pursued in these cases with careful long-term fo llow-up.