甲状腺機能亢進症を合併し，脳虚血症状を反復した内頸動脈形成不全症の1例

A CASE OF HYPOPLASIA OF THE INTERNAL CAROTID ARTERY ASSOCIATED WITH HYPERTHYROIDISM, IN WHICH RECURRENT CEREBRAL ISCHEMIC SYNDROME DEVELOPED

　心疾患および脳卒中の濃厚な家族性負因を有する27歳の女性において，23歳時に甲状腺機能亢進症を発症以来，身体の過労を誘因として，急性に発現する構音障害と右半身不全麻痺を主症状とする発作が5度間歇性に繰り返され，おのおの2〜3週間の経過の後に完全に寛解した。頸動脈撮影，頸部試験切開により，左内頸動脈の分岐部より1.5cm以上に先天性形成不全と考えられる奇形が確認された。かくて，本例において，先天性に内頸動脈狭窄症が23年湖潜在し，脳循環は副行路により一応保たれて，無症状に経過していたが，脳代謝の充進を伴う甲状腺機能亢進症の発症によつて，間歇性脳循環障害が誘発された過程を推論した。甲状腺機能亢進症における中枢神経系の合併症については，従来中毒性要因が一般に想定されているが，本例は診断上の1つの示唆を与えるものと考える。両疾患の併存は，従来の文献上には見出されず，発生学の立場からも検討を加えた。

In a 27 year old woman with hyperthyroidism, the recurrent episode of right hemiparesis intermittently developed five times during four years, since her age of 23 when symptoms of hyperthyroidism started on. Left carotid angiogram and surgical exploration disclos-ed marked narrowing of the left internal carotid ar-tery, beginning 1.5 c.m. above the bifurcation, which was diagnosed as congenital hypoplasia and unable to be taken further therapeutic approach. Treatment for hyperthyroidism by administration of radioactive iodi-ne brought fairly improved state of the thyroid func-tion, and prevented further appearance of the neu-rological symptoms.

The role of hyperthyroidism on precipitating the recurrent syndrome of cerebrovascular insufficiency in this rare lesion was discussed, pointing out unbalance of collateral circulation caused by increased metabol-ism of the brain in the former.

Involvement of the central nervous system in hyper-thyroidism has been occasionally discussed in the lit-erature, stressing no definite conclusion of the cause-effect relation. Our case, however, suggested a diag-nostic procedure in these cases, allowing to emphasize that investigation of the intra-or extracranial vascular system should be taken whenever any focal neurolog-ical deficit developed in cases with hyperthyroidism.

Some comment on coexistence of hypoplasia of the internal carotid artery and hyperthyroidism which had not been reported, was stressed from embryological point and concluded it was probablly incidental.