Human T-Cell Lymphotropic Virus Type 1 Myositis, Peripheral Neuropathy, and Cerebral White Matter Lesions in the Absence of Spastic Paraparesis

BACKGROUND: The human T-cell lymphotropic virus type 1 (HTLV-1) is associated with a chronic, progressive myelopathy termed tropical spastic paraparesis or HTLV-1-associate myelopathy. An increasing number of reports suggest that the spectrum of neurologic diseases associated with HTLV-1 is quite diverse. DESIGN: Case study. SETTING: A university teaching hospital (Ottawa General Hospital, Ottawa, Ontario). RESULTS: Serum creatine kinase levels were elevated (1091 U/L). Antibodies for HTLV-1 were detected by Western blot analysis and confirmed by polymerase chain reaction. Human immunodeficiency virus antibodies were not detected. Findings of nerve conduction studies revealed an axonal neuropathy, while results of needle electromyography were consistent with mixed neuropathic and myopathic changes. Findings of a muscle biopsy supported the presence of polymyositis. Magnetic resonance imaging scans of the brain showed chronic, extensive cerebral white matter involvement of more than 7 years' duration. Treatment with oral steroids resulted in an approximate 40% decrease in serum creatine kinase levels within 1 month and a marked improvement in strength. CONCLUSIONS: A broad spectrum of neurologic disorders is associated with HTLV-1, which may or may not include spastic paraparesis. Patients with myopathies and/or neuropathies of unknown origin who are from areas endemic for HTLV-1 should be screened for this retrovirus, even in the absence of spastic paraparesis.