Neurologic disease due to HTLV-1 infection

Human T-cell leukemia virus type 1 (HTLV-1) was the first human retrovirus discovered when it was linked to an unusual T-cell lymphoma in 1980. It was later linked to a number of other diseases, particularly neurologic ones. These include encephalomyelitis, myelopathy, polymyositis, inclusion body myositis, peripheral neuropathy, autonomic neuropathy, amyotrophic lateral sclerosis-like disease, and uveitis. This chapter will provide an overview of the virus discovery, the epidemiology of HTLV-1 infection, basic virology, and basic aspects of the immunologic response to the infection. It will briefly discuss features of adult T-cell leukemia and aspects of its pathogenesis. The primary focus of the chapter is the neurologic diseases associated with HTLV-1. It will discuss clinical features, diagnosis, imaging, laboratory features, electroencephalogram and evoked potential studies, attempted treatment strategies, and prevention measures. In addition many aspects of pathogenesis are discussed.