特発性頭蓋内圧亢進症の1例

A case of idiopathic intracranial hypertension

要約　目的：頭蓋内圧亢進症の1例の報告。症例：34歳の女性が複視を主訴として受診した。所見：矯正視力は左右眼とも1.5で，両眼に乳頭腫脹，盲点拡大，外転制限があった。身長148cm，体重57kg，BMI値26であった。脳脊髄液圧は280mmH₂Oで，脳液組成は正常であった。頭蓋内占拠性病変と脳室拡大はなかった。磁気共鳴血管造影で両側の横静脈洞の血流障害があり，脳静脈洞血栓症は否定された。以上より頭蓋内圧亢進症と診断された。アセタゾラミドの内服で乳頭浮腫は改善し，2か月後に複視は消失した。結論：日本人での頭蓋内圧亢進症の報告は少ない。横静脈洞の血流障害の左右差が静脈灌流異常を示し，頭蓋内圧亢進の原因になったと推定される。

Abstract.　Purpose：To report a case of intracranial hypertension. Case：A 34-year-old woman presented with diplopia as chief complaint. Findings：Corrected visual acuity was 1.5 in either eye. Both eyes showed papilledema, enlarged blind spot, and restricted abduction. She was 148 cm in height, 57 kg in body weight, and showed BMI value of 26. Cerebrospinal fluid showed pressure of 280 mmH₂O and normal composition. Intracranial space-occupying lesion or enlarged cerebral ventricles were ruled out. Magnetic resonance venography showed flow gaps between transverse sinuses. No findings were present suggestive of cerebral venous sinus thrombosis. Peroral acetazolamide was followed by improved papilledema. Diplopia disappeared 2 months later. Conclusion：There are few reports of intracranial hypertension in Japan. Flow gaps between right and left transverse sinuses suggest the presence of impaired intracerebral venous flow that may have resulted in intracranial hypertension.