亜急性経過の認知症状を呈し癒合性白質病変を呈した孤立性中枢神経サルコイドーシスの1例

A Case of Isolated CNS Sarcoidosis with Diffuse Confluent High Intensity Lesions at Bilateral Deep White Matter

　要旨　認知症状を主訴とした孤立性中枢神経サルコイドーシスの1例を経験した。患者は60歳女性。亜急性に持続性の発熱と認知機能障害が出現し，髄液検査において蛋白・細胞数の上昇がみられ，感染性髄膜脳炎が疑われたが病原体を検出できなかった。経過中，頭部MRIで両側白質深部に癒合性高信号域が出現した。確定診断のため脳病変部位の組織生検を行った。類上皮細胞を中心とした非乾酪性肉芽腫性病変を認めた。他の疾患を除外し，神経サルコイドーシスと診断した。

　We reported a 60-year-old woman who suffered from isolated neurosarcodosis. She was presenting comprehensive dysfunction and intermittent high fever. In several months she gradually developed dysorientation, amnesia, dementia. However, no focal sign such as paralysis or sensory disturbance was demonstrated. Her blood chemistry showed normal including ACE（angiotensin converting enzyme） and lysozyme. Cerebrospinal fluid revealed elevated mononuclear cells, protein, and decreased glucose level. At first we treated with antibiotics including antiviral drugs in suspect of the infectious encephalomeningitis. But no improvement was observed. The elevation of ACE in spinal fluid made us suspect of neurosarcoidosis. So intravenous predonizoron （1,000mg） was given, improving. Her high fever and mental disturbance improved. Second spinal fluid showed improvement. During the course her brain MRI revealed new bilateral diffuse confluent high intensity lesions at the deep white matters. Brain biopsy of deep matter at the right anterior lobe showed noncaseating granuloma. Since systemic work-up to detect sarcoidosis did not reveal lesions other than CNS, we considered this patient as having isolated CNS sarcoidosis.