Iohexolによるミエログラフィー後に言語障害を認めた1例

Speech Disturbance following Myelography with Iohexol : A Case Report

要旨　Iohexol（商品名オムニパーク^(R)）は非イオン性水溶性造影剤であり，失語など言語障害に関する合併症の報告は極めて稀である。今回，iohexolを用いたミエログラフィー後に言語障害を認めた症例を経験したので報告する。症例は63歳，右利きの女性であり，ミエログラフィーのため腰椎穿刺によりiohexol投与約12時間後に吃音を主とした言語障害を認めた。発症後のCT，MRIでは異常所見は認められなかったが，脳波では散在性のsharp waveを認め，言語障害は遷延している。これまでiohexolと同じく非イオン性水溶性造影剤であるmetrizamideを用いたミエログラフィー後の言語障害は稀ながら報告されており，シルビウス裂周辺の言語野への影響や軟膜血管の攣縮，局所的な神経毒性の関与が示唆されている。安全性の高いiohexolもmetrizamideと同様な機序で言語障害を誘発し得ることが考えられた。

Iohexol （Omnipaque^(R)） is a non-ionic contrast media for neuroradiology, which causes the neurological complications on rare occasions. A 63-year-old, right-handed female suffered from dysphemia 12 hours after myelography with iohexol via lumbar puncture. The initial cerebral computed tomography scan revealed the generalized contrast media uptake into the cisterns, which was typical to the finding after intrathecal iohexol injection. Although the cerebral magnetic resonance （MR） imaging 7 days after attack also demonstrated no abnormal finding, the electrical encephalogram revealed the sporadic sharp wave activity. Her nonfluent speech deficit had recovered gradually, however, the neurogenic stuttering was still remained. Some literatures previously reported the cases with speech deficits as complications of metrizamide myelography, whereas, a case manifesting as speech disturbance following myelography with iohexol has been not reported. Metrizamide is also a non-ionic agent and had a lower incidence of speech disturbance, which is supposed to be associated with a focal superficial neurotoxic reaction of the cerebrum. Therefore, our unfortunate case suggests that iohexol could rarely cause speech disturbance such as metrizamide.

（Received : May 20, 2005）