Empty sellaを伴い診断に苦慮した偽脳腫瘍の1例

Diagnostic difficulties in a case of pseudotumor cerebri with empty sella

　49歳女性が，両眼の眼痛と右眼視力障害で受診した。初診時の矯正視力は右0.9，左1.0で，眼底に異常所見はなかった。半年後に両眼とも視力が0.5に低下し，上方視野に感度低下が生じた。磁気共鴫画像検査（MRI）でempty sellaがあり，ほかに異常はなかった。乳頭浮腫はなかったが，身長150cm，体重94kgの高度肥満があり，偽脳腫瘍が疑われた。髄液圧は220mmH₂Oとやや高値であった。頭蓋内圧低下のため炭酸脱水酵素阻害薬を投与した。自覚症状は著明に改善し，3か月後には視力，視野ともに回復した。乳頭浮腫がなくても，高度肥満者にはempty sellaを伴った偽脳腫瘍が生じうることを示す1例である。

A 49-year-old female presented with bilateral ocular pain and visual disturbance in her right eye. Her corrected visual acuity was 0.9 right and 1.0 left. No funduscopic abnormalities were present. Six months later, the corrected visual acuity became 0.5 in either eye associated with decreased sensitivity in the superior visual field. Magnetic resonance imaging (MRI) showed empty sella as the sole disorder. She had no papilledema but was extremely obese, suggesting pseudopapilledema. The cerebreospinal fluid pressure was elevated to 220 mmH₂O. Systemic carbonic anhydrase inhibitor induced immediate improvement in her symptoms followed by normalization in her visual acuity and visual field 3 months later. This case illustrates that pseudotumor cerebri with empty sella may occur in a highly obese person in the absence of papilledema.