A primary disease or coexisting with multiple sclerosis?

HTLV-I-associated myelopathy (HAM/TSP) is the most common neurological manifestation of HTLV-I, causing progressive weakness, sensory disturbance, and sphincter dysfunction. Although motor disorders have been well described, few studies have associated cognitive disorders and HTLV-I infection. In areas endemic for HTLV-I infection, the differential diagnosis between HAM/TSP and other myelopathy etiologies can be difficult, particularly if the patient has signs and symptoms of brain involvement, since seropositive HTLV-I patients can present other neurological diseases. Here, we report one case initially diagnosed as Multiple Sclerosis (MS) which, upon further investigation, was found to be HTLV-I seropositive.