未破裂脳動脈瘤塞栓術後に非イオン性造影剤の神経毒性に起因した中枢性合併症を呈した2例

Cerebral Complications Induced by Neurotoxity of Nonionic Constant Medium after Embolization of Unruptured Cerebral Aneurysms: Report of 2 Cases

Ⅰ．はじめに

　近年，非イオン性造影剤の使用により，脳神経外科領域における造影剤に関連した重篤な副作用の出現頻度は低下しつつある．しかし，脳血管造影検査や血管内治療に際して，痙攣重積や視機能障害の発症についての報告が未だ散見されることから^4,6,8,17,22)，造影剤の神経毒性に起因した周術期合併症は，稀ながらも遭遇し得る合併症^7,9,16)として認識しておく必要がある．今回われわれは，未破裂脳動脈瘤のコイル塞栓術後に生じた，非イオン性造影剤の神経毒性が原因と考えられる一過性皮質盲を呈した症例と痙攣発作を呈した症例を経験したので，各種検査上の知見と文献的考察を加えて報告する．

　We successfully performed endovascular coil embolization for 2 patients with unruptured saccular aneurysms. However, transient cortical blindness and generalized seizure associated with CNS neurotoxity of contrast medium were noted for each patient after the procedure. In the first case of a 62-year-old woman with a right BA-SCA aneurysm, she complained of blindness with restlessness one day after the intervention but no evidence of embolism on MRA. Abnormal EEG with slow, large amplitudes and ^99mTc-HMPAO SPECT-evidenced hyperperfusion were observed in the occipital area. Accompanied by resolution of the edematous changes on MRI in conjunction with normalization of EEG and rCBF by anticonvulsant administration, her visual acuity completely recovered 8 days after the onset. According to these findings, we considered this case as transient cortical blindness. In the second case of a 68-year-old man with a left MCA aneurysm, he exhibited generalized seizure 8 hours after the procedure. CT scan revealed retention of the contrast medium over the left hemisphere. Postictal EEG one day after the seizure showed left frontal slowing but had no evidence of contrast medium retention or hyperperfusion. He recovered well with corticosteroid, anticonvulsant, and intravenous hydration. His follow-up DSA 2 years after the coiling was performed without trouble by reducing the amount/concentration of the contrast medium and by prophylactic steroid and hydration. Non-ionic contrast medium-related neurotoxity as represented by transient cortical blindness or generalized seizure should be recognized as a possible complication of endovascular surgery where patients’ brain areas are locally vulnerable to contrast medium exposure.