HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic and disabling disease caused by the human T-lymphotropic virus type I. Onset of the disease is insidious and the disease usually progresses slowly over years.¹ However, there have been reports of the rapid evolution of HAM/TSP over months or even weeks. The basis for these different progression patterns is poorly understood and only a few studies have dealt with this matter.² The present study aimed at evaluating a Brazilian HAM/TSP population for possible factors implicated in the progression of the disease.

Methods

We reviewed the files of 338 HTLV-I infected patients evaluated at the outpatient clinic of the Reference Centers for Neurological Infections and HTLV-I, Evandro Chagas Clinical Research Institute (IPEC), FIOCRUZ, Rio de Janeiro, Brazil. Patients were included in the study if they fulfilled the World Heath Organization criteria for HAM/TSP,¹ but were excluded if they had concurrent infections or other disabling diseases that could interfere with …