A 53-year-old woman developed subacute onset of upper limb weakness, sensory loss and cerebellar dysfunction. She was known to have human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy. MR scan of the brain showed extensive T2 hyperintensity within the deep and subcortical white matter, with punctate contrast enhancement. Cerebrospinal fluid (CSF) was lymphocytic with very high levels of HTLV-1 provirus in both CSF and peripheral blood lymphocytes. We diagnosed HTLV-1 encephalomyelitis and started high-dose methylprednisolone followed by a slow corticosteroid taper. She recovered well and regained functional independence in the upper limbs. Neurological manifestations of HTLV-1 infection extend beyond classical ‘tropical spastic paraparesis’ and are under-recognised. We review the literature on HTLV-1 encephalitis and discuss its diagnosis and management. All data relevant to the study are included in the article or uploaded as supplementary information.

中文翻译：

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HTLV-1脑炎

一名 53 岁女性出现上肢无力、感觉丧失和小脑功能障碍的亚急性发作。已知她患有人类 T 淋巴细胞病毒 1 型 (HTLV-1) 相关的脊髓病。脑部 MR 扫描显示深部和皮层下白质内广泛的 T2 高信号，具有点状对比增强。脑脊液 (CSF) 是淋巴细胞，在 CSF 和外周血淋巴细胞中都含有非常高水平的 HTLV-1 前病毒。我们诊断出 HTLV-1 脑脊髓炎并开始大剂量甲基强的松龙，然后缓慢减量皮质类固醇。她恢复得很好，并恢复了上肢的功能独立。HTLV-1 感染的神经系统表现超出了经典的“热带痉挛性截瘫”，并且未被充分认识。我们回顾了有关 HTLV-1 脑炎的文献，并讨论了其诊断和治疗。所有与研究相关的数据都包含在文章中或作为补充信息上传。