Cervical Compressive Myelopathy due to Anomalous Bilateral Vertebral Artery

We report a very rare case of cervical compressive myelopathy by an anomalous bilateral vertebral artery (VA) entering the spinal canal at the C1 level and compressing the spinal cord. A 70-year-old woman had been suffering from progressive gait disturbance. Magnetic resonance imaging revealed that a bilateral VA at the V4 segment had abnormal courses and caused compression to the high cervical cord. VA repositioning was performed by anchoring a suture between the artery and around the arachnoid membrane and dentate ligament, and then, microvascular decompression using a Teflon sponge was done between the VA and the spinal cord. The weakness in the patient improved in the lower extremity after the operation. Anomalous VA could be one of the rare causes of cervical compressive myelopathy. Additionally, an anchoring suture and microvascular decompression around the VA could be a sufficient and safe method to indirectly decompress the spinal canal.