Cervical Compressive Myelopathy due to Anomalous Bilateral Vertebral Artery
A 70-year-old woman, recently diagnosed with hypertension, presented with symptoms of gradually progressive gait disturbance and weakness in lower extremities for about 8 months. When she was admitted, she could not go up a flight of stairs alone. Neurologic examination revealed grade III paraparesis of both upper and lower extremities. Sensory examination was intact to pain, touch, temperature and proprioception. The long tract signs were positive on both sides such as hyperreflexia, toe sign and the Hoffmann sign.\nMRI revealed large flow voids in the region of the craniovertebral junction that resulted in compression of the cord (). Computed tomography (CT) angiography revealed bilateral vertebral arteries looped medially, like having the appearance of kissing each other on the dorsal surface and deeply indented into the cord substance (). There were no other bone or soft tissue anomalies in the region.\nA midline suboccipital craniotomy with C1 laminotomy and C2 partial laminectomy for preserving paraspinal muscle of C2 was performed. Dura was incised from foramen magnum to C2 level. Both vertebral arteries were showed tortuous, looped medially each other on the posterolateral surface of the cord, and spinal cord was compressed by them. First, right side arachnoid membrane around VA was dissected and excised dentate ligament to release VA from spinal cord. And then anchoring suture from VA to the arachnoid membrane and dentate ligament was made using 6-0 nylon. And then Teflon sponge was inserted to the space between VA and the spinal cord for microvascular decompression. Same procedure was performed to left VA and enough decompression was achieved. At the end of the operation we repaired occipital bone flap & C1 lamina.\nA postoperative CT angiography was immediately obtained and it showed that the bilateral.\nVAs were separated from each other without interruption in blood flow at the C1 level (). She could walk and go up a flight of stairs at the one month follow-up and the symptoms of the patient gradually improved over 2 years of the postoperative period. Six months after the operation, the MRI showed the full recovery of the spinal cord contour and the laterally transposed VA ().