[A case of pontine infarction with persistent primitive proatlantal artery].

A 61-year-old woman was admitted to the hospital on September 18, 1991 because of left hemiparesis, dysphagia, and dysarthria since five days before. She was formerly pointed out diabetes mellitus and hypertension, but she did not receive any treatment. The MRI showed a high signal area in the right paramedian portion of the upper pons on T2 weighted image and proton image. The angiography showed that persistent primitive proatlantal artery originated from the left internal carotid artery and joined to the horizontal portion of the left vertebral artery. The image of carotid-vertebrobasilar system and proatlantal artery showed so severely arteriosclerotic. This is the first report of brainstem infarction with persistent primitive proatlantal artery. In this case, the pontine infarction was thought to occur on the basis of the arteriosclerosis of blood vessels and change of blood flow of carotid-vertebrobasilar system due to persistent primitive proatlantal artery.