髄液異常を認めた一酸化炭素中毒間歇型の26歳女性例

A 26-year-old Woman of Interval Form of Acute Carbon Monoxide Intoxication with Cerebrospinal Fluid Abnormalities

要旨　症例は26歳女性。練炭を用いた調理後に急性一酸化炭素中毒に罹患したが，高圧酸素療法を23回施行後，臨床症状は改善した。その1カ月後に行動異常，尿失禁が出現し一酸化炭素中毒間歇型と診断した。髄液所見では髄液蛋白とIgG indexの増加を認め，画像所見では，頭部MRI拡散強調画像にて両側大脳白質と脳梁に異常信号域を認めた。治療として，高圧酸素療法を38回追加し，臨床症状，髄液所見ならびに画像所見のいずれも改善した。

　拡散強調画像を用いた画像所見の検討から，一酸化炭素中毒間歇型の白質変化は，従来から言及されている脱髄のみでなく，血管原性浮腫も関与していることが示唆された。また，当疾患における髄液所見の推移に関する報告は本例が初めてであり，間歇型の発生機序と治療を考察する上で貴重な1例と考えられた。

A 26-year-old woman was admitted to our hospital for the treatment of hyperbaric oxygen therapy to acute carbon monoxide intoxication. The consciousness disturbance improved and she was discharged after 23 times of the hyperbaric oxygen therapy. However, she was readmitted because of dementia and urinary incontinence after 22 days. Diffusion-weighted images showed bright high signal intensities in the periventicular white matter and corpus callosum. The condition was considered to be an interval form of carbon monoxide intoxication. She was treated by 38 times of the hyperbaric oxygen therapy with cytochrome C and fully recovered. MRI images and cerebrospinal fluid abnormality （high protein content and IgG index） became normalized somewhat later than the improvement of the symptoms.

　By an investigation utilizing diffusion-weighted images, we thought that not only the demyelination which mentioned formerly, but the vasogenic edema was involving in the mechanism of these high signal intensities in the periventicular white matter of the interval form. And in the range which we searched, this is the first report which mentioned the abnormal findings of cerebrospinal fluid in an interval form of carbon monoxide intoxication. So we believe this case is very important for telling us suspected the mechanism and some indications about the treatment of an interval form.

（Received : January 10, 2005）