Idiopathic Ventral Spinal Cord Herniation: An Illustrative Case and Literature Review

Background and Importance: Idiopathic spinal cord herniation (ISCH), or spontaneous spinal cord herniation, is a rare but serious condition that can cause progressive myelopathy and irreversible neurological deficits if left untreated. The condition is marked by the gradual herniation of the spinal cord through a ventral defect in the dura, leading to compromised blood flow and neurological deficits. Common symptoms include Brown-Séquard syndrome or asymmetrical paraparesis. Treatment options typically focus on reducing the strangulated spinal cord and closing the dural defect with a synthetic patch. Case Presentation: We present the case of an adult woman with progressive asymmetrical weakness of the lower limbs compatible with spastic paraparesis. Thoracic magnetic resonance imaging (MRI) revealed characteristic features of ISCH at the T3-T4 level. Intraoperative neurophysiological monitoring was used during the surgical intervention, which involved a 3-level laminectomy, dura opening, excision of the dentate ligament, and reduction of the cord across the dural defect. The defect was then filled with an autogenous piece of muscle, followed by the closure of the defect with an artificial dural patch and dural closure. At the 6-month follow-up, the patient showed favorable improvement. Conclusion: Patients with slowly progressive paraparesis or Brown-Séquard syndrome should consider the possibility of ISCH as a potential cause, despite its rarity. In symptomatic cases, the preferred treatment option often involves reducing the incarcerated spinal cord followed by covering the dural defect.