Dilatation du ventriculus terminalis chez l’adulte : à propos d’un cas et revue de la littérature

Abstract The ventriculus terminalis (VT) is a virtual cavity of the conus medullaris that appears during embryonic life. The occurrence of its dilatation is very rare in adulthood. Only 27 cases have been documented so far. We present the case of a 47-year-old woman who presented with hypoesthesia and dysesthesia of the lower limb, distal paresis, and urinary dysfunction evolving for the past 5 years. Electrophysiology confirmed radiculopathy. MRI revealed a cystic dilatation of the VT. Surgery consisted in laminectomy with myelotomy and fenestration. Histology showed a simple cubic ependymal epithelium. Progression has been favorable concerning the motor deficit and sphincter dysfunction but neuropathic pain has persisted for 6 months. The data are similar to those found in the literature. The sex ratio is 6:21, the mean age is 45. Symptoms appear on average over 2 years with lower limb pain (71 %), sphincter dysfunction (71 %), lumbago (64 %), motor deficits (57 %), and sensory disorders (47 %). Imaging demonstrated cystic dilatation in the conus medullaris filled with cerebrospinal fluid without contrast enhancement. The histology analysis showed a simple ependymal epithelium with no tumoral process. The fenestration of the cyst allows complete recovery of symptoms in 52 % of cases and partial recovery in 43 %. The VT seems to be a whole nosologic entity in itself. Myelotomy with fenestration provides good results on motor and sphincter symptoms, whereas the benefit in terms of pain is subject to discussion.