Spontaneous Anterior Thoracic Spinal Cord Herniation through Dura Defect: A Case Report.

Thoracic spinal cord herniation is a rare disease cause of progressive myelopathy. Magnetic resonance image is a useful tool to diagnose preoperatively. Operation is a treatment of option. Sixty-six-year-old female visited Dong-A University Medical Center for progressive gait disturbance with falling tendency to right side. She had radiating pain and tingling sense on both leg. Sense of touch and temperature was decreased below T6 level. Both hip and knee motor power were grade IV. Magnetic resonance imaging scan showed anterior displacement of the spinal cord at T4-T5 vertebral level. Under the diagnosis of thoracic spinal cord herniation with dura defect, operation was performed for the patient with intraoperative neuromonitoring. Laminectomy at T4 and T5 level was done, and intradural exploration of the spinal cord revealed dura defect about 25mm×8mm in size. Spinal cord was released under microscope and dura defect was repaired with Lyoplant. The patient's symptom improved after the surgical procedure, but touch and temperature sense under T6 level had unchanged.