Abstract:We describe three human T lymphotropic virus type I (HTLV-I) carriers, who are characterized by a dissociation between the clinical features including scarce cognitive impairments and peculiar hyperintensities in the deep and subcortical white matter detected by T2-weighted magnetic resonance imaging (MRI) scans. Unlike spotty MRI findings which are encountered in clinically asymptomatic elderly individuals and are previously described in some HTLV-I carriers, the MRI changes in our patients were diffuse and extensive.Known central nervous system disorders accompanying a cerebral white matter involvement were failed to be diagnosed. These findings support a possibility that extensive lesions in the supratentorial white matter are associated with HTLV-I infection with minimal symptoms, and suggest that MRI scans may detect occult diffuse inflammatory changes associated with the virus infection in these patients.