Citrullinaemiaを伴う肝性脳脊髄症

A CASE OF HEPATIC ENCEPHALOMYELOPATHY ASSOCIATED WITH CITRULLINAEMIA

はじめに

　肝疾患患者における神経症状としては最近まで，昏睡を主徴とする肝性脳症に関心が向けられており，また，肝疾患症例の剖検に際し脊髄の検索が少ないためもあり，脊髄の病変について従来あまり注目されていなかった。

　我々の症例は全経過約2年であるが，多発性硬化症の疑いで入院し諸検査の結果，高アンモニァ血症と肝線維症がみとめられた。その経過中，痙性対麻痺が出現し臨床的に肝性脳脊髄症と診断され，ついで，尿中，血中Citrullineの増加が認められた。この臨床経過について報告し文献的に考察を加える。

A 21-year-old male entered our hospital in May 26, 1967 with the chief complaints of recurrent epi-sodes of delirium and visual disturbance. Following initial episode of brief unconsciousness in July, 1966, the patient developed irritability, insomnia, saliva-tion, slurred speech, visual disturbance and urinary incontinence which apperad intermittently. On admission the patient was delirious and bilateral extensor toe sign was noted. Consciousness became normal several days later and neurological examina-tion revealed no abnormality except mild finger tremor. Routine liver function test was normal.The only abnormality in laboratory study was ele-vated blood and CSF ammonia level (350 and 320 γ/dl. respectively). Portal venography and liver scintigram failed to disclose significant amount of shunting in protocaval or intrahepatic system. Liver biopsy revealed mild fibrosis. Neomycine, 1-arginine were given with restriction of protein in diet. No cerebral symptoms recurred thereafter, but gradual development of spasticity was noted from the middle of October, 1967 and reached its maximum in Jan-uary, 1968 for which adductor tenotomy was under-taken in March, 1968. No significant functional improvement of legs was observed and the patient's neurological status remained essentially unchanged. He wears long leg brace on walking.

Urinary amino acid was analysed in December, 1967 which desclosed large amounts of citrulline in urine (maximum 3. 8 g/day). Highest blood citrul-line level was 15. 5 mg/dl. Although no direct enzyme study was made, it may be interpreted as the deficiency of argininosuccinate synthetase.

Significance of citrullinemia in relation to hepatic encephalomyelopathy must be determined in future.