[Medulla oblongata compression by tortuous vertebral artery: case report].

We reported a case of a 58-year-old woman who suffered from progressive tetraparesis and sensory disturbance caused by compression of the medulla oblongata brought about by bilateral tortuous vertebral arteries. The neurological examination on admission revealed tetraparesis, sensory disturbance in all modalities below the level of C2, onion-skin pattern sensory disturbance of the face, and motor weakness of the sternocleidomastoid muscles. X-ray films of the cervical spine showed OPLL at the level of C2.3, but on MRI the dural theca was not seen to be compressed at that level. MRI and vertebral angiography demonstrated ventrolateral compression of the medulla oblongata by bilateral tortuous vertebral arteries. After suboccipital craniectomy and C1.4 laminectomy, decompression of the medulla oblongata was performed. Both vertebral arteries were compressing the medulla oblongata at the ventrolateral side. Transposition of the vertebral arteries seemed impossible due to perforating branches to the medulla. After section of the dentate ligaments at C1 level, the medulla oblongata was decompressed and moved backward. Some small pieces of Dacron were inserted between the arteries and the medulla, in order to decrease the pulsatile effect of the vertebral arteries. Postoperatively, the patient's tetraparesis and sensory disturbance gradually improved. There are 6 reported cases concerning compression of the medulla oblongata by the vertebral artery. As MRI becomes more frequently used in neurological situations, it is important to keep the presence of such an entity in mind.