Factors associated with corticosteroid therapy failure in HTLV–associated spastic paraparesis in an endemic region of Peru

Introduction. HTLV-1/2–associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic progressive myelopathy with variable response to corticosteroids. In endemic regions such as central Peru, evidence on predictors of treatment failure remains limited. Methods. Analytical cross-sectional study of patients with confirmed HTLV-1/2–associated spastic paraparesis treated with corticosteroids (2018–2024) at a tertiary hospital in Huancayo, Peru. Treatment failure was defined as no improvement or worsening on the Osame Motor Disability Score (OMDS). Sociodemographic data, disease duration, comorbidities, and OMDS were extracted from medical records. Bivariate (chi-square) and multivariable logistic regression analyses were performed (p<0.05). Results. Thirty-eight patients were included (median age 55 years, 63.2% female; median disease duration 4 years). In bivariate analysis, disease duration >7 years, comorbidities, and severe disability OMDS >7) were associated with treatment failure. After multivariable adjustment, only severe disability remained independently associated (OR 14.77; 95% CI 2.08–104.93; p=0.007). Disease duration >7 years and comorbidities lost significance (p>0.05). Conclusions. Severe neurological disability (OMDS >7) is the main independent predictor of corticosteroid treatment failure in HAM/TSP. Baseline functional status appears more relevant than disease duration or sociodemographic factors. Early intervention is needed in advanced cases.