脳動脈瘤を伴ったMoyamoya現象

MOYAMOYA PHENOMENON COMBINED WITH CEREBRAL ANEURYSM

I．はじめに

　脳血管撮影上，内頸動脈終末部の狭窄ないし閉塞所見に，脳底部異常血管綱と外頸動脈系と脳表の軟膜血管の吻合を示す疾患はWillis輪閉塞症またはmoyamoya病などと呼ばれている。この疾患において，その内頸動脈終末部の狭窄ないしは閉塞の原因が一元的であるか多元的であるかという点については議論が残つている。しかし，少なくとも異常血管網に関しては内頸動脈の閉塞による二次的に発達した側副血行路であるとする見解が広く認められている。著者らはあくまで脳血管撮影上の特異な所見を重視するという点においてはmoyamoya現象^20），moyamoya effect^21），moyamoya type^4,22），moya—moya syndrome^1〜3,10）などの呼称が適当であると考えている。したがつて本論文ではこの所見をmoyamoya現象という名称で呼び，閉塞の原因・状態とは別に取扱つた。

　本現象と頭蓋内出血との合併については特に成人例では珍しくない。しかしその発現機序についてはまだ十分に解明されているとはいえない。最近われわれが経験したmoyamoya現象に側脳室周辺部の動脈瘤を伴つた3症例を報告し，前述の疑問点について若干の考察を加えた。

Three cases of the moyamoya phenomenon combi-ned with a paraventricular aneurysm which showed the symptoms of acute intracranial hemorrhage were reported.

Case 1, 18-year-old female. Her symptoms were lethagy, left flaccid hemiplegia and neck stiffness, and by conservative treatment she gradually showed improvement on her neurological symptoms. First carotid angiography showed the moyamoya phenomenon and a saccular aneurysm at the region of the right basal ganglia. Second carotid angiography performed two months after the attack revealed that the moyamoya phenomenon un-changed, but the aneurysm became larger. The aneurysm disappeared at the third angiography nine months after the attack.

Case 2, 40-year-old male. He showed neck stiff-ness and vertical nystagmus. Left carotid angio-graphy revealed the moyamoya phenomenon and a saccular aneurysm at the peripheral portion of the posterior cerebral artery. Excision of the aneurysm in the left lateral ventricle was performed. By the microscopical examination this aneurysm was proved to possess vascular structures.

Case 3, 57-year-old female. She showed lethargy, conjugate deviation to the right side and left flaccid hemiparesis. Right retrograde brachial angiography revealed the moyamoya phenomenon and ananeurysm at the peripheral portion of the anterior choroidal artery. This patient was died twenty days after the hemorrhage. At autopsy massive intraventricular hematoma and angiomatous lesion of the choroid plexus was found, but the cerebral aneurysm was not identified due to massivehematoma.

We have reviewed the literatures and discussed about the moyamoya phenomenon combined with a cerebral aneurysm, the source of the intracranial hemorrhage and the prognosis.