RT Journal Article SR Electronic T1 HTLV-1 encephalitis JF Practical Neurology JO Pract Neurol FD BMJ Publishing Group Ltd SP practneurol-2021-003053 DO 10.1136/practneurol-2021-003053 A1 Josh King-Robson A1 Timothy Hampton A1 Carolina Rosadas A1 Graham P Taylor A1 Biba Stanton YR 2021 UL http://pn.bmj.com/content/early/2021/08/29/practneurol-2021-003053.abstract AB 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.