HTLV-1-Associated Myelopathy / Tropical Spastic Paraparesis (HAM / TSP) By Michael Rubin, MDCM, New York Presbyterian Hospital-Cornell Medical Center Reviewed / Revised Feb 2023 View Patient Education Symptoms and Signs Diagnosis Treatment Key Points HTLV-1-associated myelopathy / tropical spastic paraparesis (HAM / TSP) is a slowly progressive viral immune-mediated disorder of the spinal cord caused by the human T-lymphotropic virus 1 (HTLV-1).