“Horseshoe cord terminus” sans filum around a bone spur: a rare composite of faulty gastrulation with agenesis of secondary neurulation

Case report

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Split cord malformation (SCM) is classified based on the presence of a bone spur and double dural sac. The authors report on a 6-year-old child with primary enuresis in whom MRI findings were suggestive of Type I SCM, and who had unique intraoperative findings of a horseshoe-shaped split cord terminus anchored by a bone spur without the normally tapering conus and filum. The typical appearance of cauda equina was absent, with all the roots arising from the horseshoe cord terminus. This composite anomaly is probably due to the rare combination of faulty gastrulation with abnormal persistence of endomesenchymal tract causing SCM, with concurrent agenesis of secondary neurulation in turn causing absence of filum.

Abbreviation used in this paper:SCM = split cord malformation.

Article Information

Address correspondence to: Sivashanmugam Dhandapani, M.Ch., Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi 110029, India. email: ssdhandapani.neurosurg@gmail.com.

Please include this information when citing this paper: published online August 16, 2013; DOI: 10.3171/2013.7.PEDS13221.

© AANS, except where prohibited by US copyright law.



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    Upper: Coronal lumbar spine MRI study showing split horse-shoe-shaped cord terminus (hollow arrow) anchored by a median bone spur (solid arrow). Lower: Axial lumbar spine MR image at the level of the bone spur showing Type I SCM with double dural sac.

  • View in gallery

    Left: Intraoperative photograph showing a bone spur (arrowhead) wedging the split cord terminus. Right: Photograph obtained at the end of surgery showing the horseshoe-shaped cord terminus without the normally tapering conus and filum.



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