Medidas de sensibilização cental no contexto da dor lombar crônica

Abstract

Background: Chronic low back pain (CLBP) is the leading global cause of disability. In patients with nonspecific CLBP, central sensitization is the physiological mechanism often used to explain pain. Psychosocial and cognitive factors are considered to contribute to and support the central sensitization mechanism, including negative beliefs about low back pain. Direct determination of central sensitization cannot be done in humans, however, some instruments and procedures have been used to infer its presence, such as the Central Sensitization Inventory (CSI) and the Conditioned Pain Modulation (CPM) test. Objectives: The thesis had as main objectives: (1) to investigate whether beliefs about low back pain are associated with CSI in patients with CLBP (2) to investigate the responsiveness of CS measures, such as CSI and CPM, in elderly individuals with CLBP after an exercise program and to compare this responsiveness with measures of pain and disability. Methodology: Two studies were conducted. The first was a crosssectional study with 119 patients with nonspecific CLBP. Demographic data and clinical characteristics such as pain intensity, disability, beliefs about low back pain (Back Beliefs Questionnaire) and CS-related symptoms (CSI) were collected. Multivariable linear regression analysis was used in the analysis. The second study was a prospective responsiveness study with a pre-post-interventional study design. 118 elderly individuals with chronic low back pain were recruited and demographic and clinical data were collected before and after an 8-week group exercise program. CSI, CPM test, pain intensity and disability were collected at baseline and after the intervention. The global perception of change scale was collected after the intervention. Responsiveness was determined by calculating effect sizes, standardized response mean (SRM) and area under the curve (AUC). Results: The results of the first study suggested that CS is present in a subgroup of patients with CLBP and is associated with more negative beliefs about LBP and greater disability. The second study found that measures of pain and disability were the most responsive to the exercise program. On the other hand, measures of central sensitization were not sufficiently responsive to detect significant changes after the intervention. Conclusion: Negative beliefs about low back pain were strongly associated with CSI, suggesting that educational interventions focused on modifying these beliefs may be effective in improving clinical outcomes in patients with CLBP. Furthermore, the findings suggest that measures such as pain and disability are highly responsive to exercise-based interventions, while instruments such as the CPM and CSI have limitations in detecting significant changes, especially in the elderly. The thesis concludes that managing CS and beliefs about pain should be a priority in the treatment of CLBP to reduce chronicity and improve the quality of life of individuals.