Intraspinal neurenteric cyst revealed by a cauda equina syndrome

BACKGROUND: Intraspinal neurenteric cysts are exceptional formations which develop from incomplete separation of the neural tube and the endodermis du ring the third week of gestation. Symptoms generally appear before the age of 40 years and are associated with spinal malformations Mast neurenteric c ysts lie in an extraspinal position in the lower cervical and upper dorsal spine. We report a case involving the cauda equina with no associated spina l lesion. CASE REPORT: A 63-year-old woman was admitted for low back pain and right L 3 radiculalgia triggered by exertion. Urinary disorders had developed over the preceding year. Physical examination found a spinal syndrome with hypoe sthesia of the right para-anal area, an atonic anal sphincter and a globula r bladder Plain films showed a widened interpedicular space between L1 and L2 interpreted as the consequence of an expansive intraspinal lesion. Sacco radiculography led to the diagnosis of an intradural lesion involving L1 an d L2. At magnetic resonance imaging, the lesion's signal intensity was simi lar to cerebrospinal fluid on T1 and T2 sequences, deforming the cauda equi na and displacing the nerve roots. Surgical resection of the cyst was incom plete due to adherences to several roots and was followed by persistent rad iculalgia and sphincter disorders. DISCUSSION: This case demonstrates an exceptional cause of cauda equina syn drome. Fissuration or rupture of the cyst might explain symptom exacerbatio n following trauma. Magnetic resonance imagining can confirm the cystic nat ure of the intradural lesion and help guide surgery. Resection is often inc omplete with the risk of long-term recurrence.