1989 Volume 29 Issue 2 Pages 146-150
A 57-year-old male was hospitalized with stroke on the day of onset. An initial computed tomography revealed a hemorrhage in the left caudate nucleus. Common carotid angiography demonstrated a carotid-vertebral anastomosis. Complete selective external carotid angiography disclosed the proatlantal intersegmental and occipital arteries arising from the external carotid artery at the level of the atlas. The proatlantal intersegmental artery, which is one type of persistent primitive carotid-vertebrobasilar anastomosis, is rarely associated with hypertensive intracerebral hemorrhage, according to the literature.