What is the influence of fatigue, ALSFRS-R scores, cognitive status, and pain in individuals with Amyotrophic Lateral Sclerosis? A cross-sectional study

<i>Introduction:</i> Fatigue remains a poorly understood symptom in individuals with ALS, and little is known about its associtation with other symptoms, including functional impairment, cognition, and pain. <i>Objective:</i> To identify the levels of fatigue, pain, ALSFRS-R, and cognition of a Brazilian group of individuals with ALS, in order to verify possible influences between these symptoms and fatigue. <i>Methods:</i> This is a cross-sectional study conducted with individuals with ALS who were recruited intentionally, using a non-probabilistic sampling method. After agreeing to participate, they were assessed using a standardized assessment form, and data regarding fatigue level, ALSFRS-R scores, cognition, and pain were collected. Data were analyzed by categorizing fatigue (with and without fatigue) and considering sociodemographic and clinical covariates, followed by comparisons, bivariate analyses, and multiple linear regression analyses. <i>Results:</i> Data were collected from 72 individuals with ALS. Inferential statistics indicated differences between fatigue categories concerning ALSFRS-R scores, cognition, and pain. After multiple linear regression analyses, an association between fatigue and the dependent variables was identified. <i>Conclusion:</i> Fatigue is associated with lower ALSFRS-R scores, poorer cognitive status, and higher levels of pain in a Brazilian cohort of ALS. Additionally, age, sex, education, and length of illness were identified as potential factors for fatigue occurrence, observed more frequently in females than in males with the condition.