脳動脈瘤を伴ったPersistent Primitive Hypoglossal Arteryの1例

PERSISTENT PRIMITIVE HYPOGLOSSAL ARTERY WITH INTRACRANIAL ANEURYSM

1．はじめに

　胎生期遺残動脈の1つであるpersistent primitivehypoglossal artery （以下PHAと略す）は，1889年Batujeff^1）により報告されて以来，近年の脳血管撮影の普及とともに症例も増加し，調べえた範囲では外国で38例，本邦で54例の計92例が報告されている。

　PHAを含めた胎生期遺残動脈は，一般にクモ膜下出血，脳卒中，脳腫瘍などの精査中に偶然に発見されることが多いとさ項ているが，脳動脈瘤を伴つたPHAは過去16例が報告されているにすぎない。

This 51-year-old man was suffered from the acute onset due to subarachnoid hemorrhage. The carotid angiograms showed a saccular aneurysm at the origin of the right anterior cerebral artery and a persistent primitive hypoglossal artery arising from the left internal carotida artery at the level of the C¹ vertebra. Both vertebral arteries were hypoplastic. The aneurysm was treated successfully with direct surgery eight days after subarachnoid hemorrhage.

Ninety-three cases of persistent primitive hypo-glossal arteries have been reported in literature. Twenty-six cases out of them were related to subarachnoid hemorrhage. Seventeen cases were associated with intracranial aneurysms, three cases with arterio-venous malformations and the remain-ing six cases with spontaneous subarachnoid hemor-rhage. Their frequencies were 18.3%, 3.2% and 6.4% respectively.

The study of seventeen cases associated with intracranial aneurysms revealed that the aneurysms in fourteen cases were on the same side with the persistent primitive hypoglossal artery and in two cases on the opposite side (one of them was our case). Eight of eighteen aneurysms arose from the persistent primitive hypoglossal artery or basilar arterial system. Their frequency was remarkably high at 44.4%.

These facts indicate that the abnormal state of cerebral blood flow as well as a defect of the tunica media may play an important role in the occurrence of intracranial aneurysms.