クリプトコッカス髄膜炎に併発した視神経障害の1例

A case of cryptococcal meningitis with optic neuropathy

要約　目的：クリプトコッカス髄膜炎に視神経障害が併発した症例の報告。症例：56歳女性が右眼の視力低下と複視で紹介受診した。1か月前から頭痛と意識消失発作があった。所見と経過：矯正視力は右0.05，左1.0で，両眼に外転制限と乳頭浮腫，右眼に中心暗点，左眼に盲点拡大があった。MRIで脳室拡大と髄膜炎を示す所見があり，髄液にクリプトコッカス（C. neoformans）が検出され，クリプトコッカス髄膜炎と診断された。抗真菌薬などによる加療で外転制限と乳頭浮腫は改善したが，2か月後に右眼は視神経萎縮になった。病像は左後頭葉に拡大し，右半盲になった。結論：クリプトコッカス髄膜炎は成人に発症し，視神経障害が合併することがある。

Abstract.　Purpose：To report a case of cryptococcal meningitis with optic neuropathy. Case：A 56-year-old woman presented with diplopia and impaired vision in the right eye. She had had attacks of headache and unconsciousness since one month before. Corrected visual acuity was 0.05 right and 1.0 left. Both eyes showed restricted abduction and papilledema. The right eye showed central scotoma. The left eye showed enlarged blind spot. Magnetic resonance imaging showed enlarged lateral ventricles and findings suggestive of meningitis. Cryptococcus neoformans was identified in the cerebrospinal fluid. Treatment including antifungal agents was followed by improvement in abduction and papilledema but resulted in right optic atrophy 2 months later. Cryptococcal lesions extended to the left occipital lobe manifesting right hemianopsia. Conclusion：This case illustrates that an apparently healthy adult may be affected by cryptococcal infection with optic neuropathy.