SPASTIC PARAPARESIS OF OBSCURE ORIGIN - A CASE-CONTROL STUDY OF HTLV-I POSITIVE AND NEGATIVE PATIENTS FROM RIO-DE-JANEIRO, BRAZIL

In order to find clinical findings that could significantly discrimina te between HTLV-I-associated myelopathy/tropical spastic paraparesis ( HAM/TSP) and HTLV-1 negative spastic paraparesis of obscure origin (SP O(neg)) prior to serological testing, and to find risk factors signifi cantly associated with HAM/TSP we devised a case-control study. Sixty consecutive SPO patients were studied without previous knowledge of th eir HTLV-1 serological status. Thirty-four (56.7%) turned out to be HT LV-1 positive and 26 (43.3%) HTLV-1 negative. HTLV-1 infected patients tended to have more commonly motor and bladder disturbances at the be ginning of their illness and a disease that was still in progression a t the time of the examination. Bladder dysfunction, constipation and p enile impotence, and more widespread pyramidal signs, were also more f requent during the whole course of their illness. Likewise, an increas ed intrathecal synthesis of IgG was found more often in the HTLV-I pos itive group. The only risk factor for HTLV-1 infection significantly a ssociated to HAM/TSP was at prior history of sexually transmitted dise ases. These results suggest that, at least in RJ, HAM/TSP might be mai nly sexually acquired.