Tethered cord: natural history, surgical outcome and risk for Chiari malformation 1 (CM1): a review of 110 detethering

Abstract

The surgical results of this series of occult spina bifida seem better than the natural history registered in the long pre-operative period in terms of neurological deterioration. The major contribution to this result is attributed to neurophysiological monitoring that lowers the risks of permanent damage and increases the percentage of effective detethering. The present series of TCS, due to conus and filar lipoma, documents that CM1 is a really rare association occurring in less than 6% of the patients, despite the low position of conus. The detethering procedure did not influence the tonsillar position, thus excluding the correlation between the tethering and the tonsillar descent. The genetic alteration documented in a girl reinforces the hypothesis of a rare complex polymaformative picture deserving multiple procedures according to the prevailing clinical symptoms.

Fig. 1

Neurological picture evolution

Fig. 2

Cranial migration of the conus medullaris. a Preoperative RMI of RR, 9-month-old male, harboring a typical caudal conus lipoma: despite the relevant traction of the conus (positioned at L4 level before surgery), documented intraoperatively (c) and solved by surgery, as documented by the significant cranial migration (b) toward L2, the tonsillar position (d) was normal preoperatively and remained the same after surgery