Angiographic examination and surgical treatment of bow hunter's stroke.

Anatomically, the vertebral artery courses through six foramina transversaria of the cervical vertebrae, passing through the groove on the surface of the arch of the atlas and then penetrating the dura mater. Because of this anatomical course, the vertebral arteries are often affected by head motion. Stenotic change of the vertebral artery can occur at the atlantoaxial level in head rotation. Such a special type of stroke was named "bow hunter's stroke" by Sorensen. We report three cases of bow hunter's stroke and discuss the angiographic examinations. As surgical treatment, we performed partial transversectomy of the atlas vertebra, with favorable results. The usefulness of this surgical procedure is discussed.