脳深部静脈血栓症を合併したホモシスチン尿症の1例

HOMOCYSTINURIA ACCOMPANIED WITH CEREBRAL DEEP VENOUS THROMBOSIS : A CASE REPORT

　ホモシスチン尿症は，シスタチオニン合成酵素欠損などが原因とされるメチオニン代謝異常である。今回，本症の経過中，脳静脈血栓症によると思われる脳室内出血を合併した症例を経験したので報告する。症例は，複雑な血族結婚の両親を持つ29歳女性で，13歳時，ホモシスチン尿症の診断を受けていた。1984年12月5日，午後8時頃，突然の意識障害，四肢麻輝が出現し，同月7日，入院。CTscanにて，脳室内出血，基底核部および白質部の低吸収域を認め，また，脳血管撮影では，静脈相のいずれのPhaseでも，深部静脈系が出現せず，上矢状静脈洞の描出も悪く，シルビウス静脈へ流出している所見を認めた。以上より，本例における脳室内出血，基底核部および白質部の低吸収域は，深部静脈血栓症による出血性梗塞と考えられた。ホモシスチン尿症に合併する血管障害として，脳血栓症が報告されている。しかし，本症に合併する静脈洞血栓症は稀であり，ことに本症例の如く深部静脈血栓症を合併する報告は認められなかった。

Homocystinuria is an inborn error of methionine metabolism, of which cause is mainly deficiency of cystathionine synthetase. The major clinical ma-nifestations of homocystinuria are mental retarda-tion, seizures, ectopia lentis, skeletal deformities and occlusive vascular disease. A case of homocy-stinuria accompanied with deep cerebral venous thrombosis was reported. A 29-year-old woman was admitted to our hospital with unconsciousness and tetraparesis on December 7, 1984. She was diagnosed as homocystinuria due to cystathionine synthetase deficiency at 13-year-old. Amino acid analysis of serum revealed homocystinaemia (1. 37 mg/dl, normal 0), hypermethioninaemia (1. 27 mg/ dl, normal 0. 2-0. 48) and low cystathionine cont-ent. CTscan revealed intraventricular hemorrha-ge and diffuse low density in basal ganglia and white matter. Cerebral angiograms showed that deep cerebral veins and superior sagittal sinus can not be recognized clearly in any phase, and Sylvian veins are opacified markedly. It is suggested that intraventricular hemorrhage, and low density area in basal ganglia and white matter is due to hemor-rhagic infarction by venous thrombosis of internal cerebral vein. The major clinical manifestations of homocystinuria result from the elevated plasma homocysteine level. The excitotoxic effect of ho-mocysteic acid accounts for mental retardation and seizures. Interference with collagen cross-linking by sulfhydryl groups of homocysteine causes ecto-pia lentis and skeletal deformities. Sulfation fac-tor-like effects contribute to disruption of vascular endothelium, which is followed by platelet throm-bosis and widespread arterial and venous occlusi-ons. Cerebral venous thrombosis complicated with this disease is rare, especially deep venous throm-bosis has not been reported. Cerebral deep ven-ous thrombosis is rare in the venous sinus throm-bosis. Most of reported cases in the deep venous thrombosis occurred in succession after other dis-ease such as Behcet's disease, pemphigus vulgaris, scarlet fever, tuberculous meningitis. It is sugge-sted that most cases of deep venous thrombosis have a systemic disease before onset.