Duplicated filum terminale in the absence of split cord malformation: a potential cause of failed detethering procedures

Introduction

A duplicated filum terminale appears to be a rare finding in the absence of a split cord malformation. Herein, we discuss this finding and its potential dysembryology.

Case reports

We report two cases of duplicated filum terminale without split cord malformation. The first case presented as an incidental finding with thickened filum terminale. At time of surgery, a thickened filum was resected and a smaller size filum was transected and both were confirmed with pathologic examination. The second case presented with a lumbar skin hemangioma. Screening MRI showed a duplicated filum terminale with fat signal in both structures. Pathology also confirmed the diagnosis of two fila terminalia.

Conclusions

The neurosurgeon should consider the possibility of two fila terminalia during operation to transect a single filum for tethered spinal cord.