Spastic ataxia associated with human T-cell lymphotropic virus type II infection.

Human T-cell lymphotropic virus type one (HTLV-1) is associated with tropical spastic paraparesis or HTLV-I--associated myelopathy. We report 2 women with a spastic ataxic illness similar to HTLV-I--associated myelopathy infected solely with HTLV-II. Identification of HTLV-II infection was made serologically, by polymerase chain reaction, and by viral culture (in 1 woman). One woman, treated with 200 mg of danazol orally, three times daily, had pronounced improvement in ambulation, nocturnal spasticity, and nighttime urinary frequency. It appears that infection with HTLV-II may cause an illness similar to HTLV-I--associated myelopathy, but distinguished by the presence of ataxia.