EFFECTS OF TRANSCRANIAL DIRECT CURRENT STIMULATION VERSUS SHAM IN SUBACROMIAL PAIN SYNDROME: A RANDOMIZED CLINICAL TRIAL
Transcranial direct current stimulation; Neuromodulation; Shoulder pain; Chronic Pain; Treatment
Introduction: Subacromial pain syndrome (SAPS) is one of the most common shoulder-related diagnoses, characterized by persistent symptoms that reduce functionality and quality of life in affected individuals. Transcranial direct current stimulation (tDCS) has been widely studied and presented as a promising clinical practice tool for modulating pain perception. Objective: To analyze the effects of tDCS on pain intensity, upper limb function, quality of life, global perception of change, muscle strength, and shoulder range of motion in individuals with subacromial pain syndrome. Methodology: This is a randomized controlled trial. Individuals aged 20 to 69 years, of both sexes, with a medical diagnosis of subacromial pain syndrome will be randomly assigned to two distinct groups: active tDCS (n=16) and sham tDCS (n=16). Both groups will undergo 20 minutes of stimulation for 5 consecutive days in a climate-controlled and quiet room. For the sham group, the device will be turned on, but the current will be interrupted 30 seconds after initiation. Adverse effects, if any, will be recorded throughout the intervention. The primary outcome will be pain intensity, assessed using the numerical pain scale. Secondary outcomes will include the range of motion in flexion, extension, medial, and lateral shoulder rotation; muscle strength of shoulder flexors, extensors, and medial and lateral rotators; upper limb function (DASH); quality of life (SF-36); and global perception of change (PGIC). Assessments will be repeated at the end of the intervention and during a 1-week follow-up, during which participants will receive a guide for shoulder pain management. Expected Results: This study aims to analyze the effects of tDCS in individuals with SAPS to provide a scientific basis to support physical therapists in treating SAPS patients, aiding in the selection of the most appropriate therapeutic tools. It is expected that patients will become independent and strengthened, with improved quality of life and upper limb function. Finally, the study results may contribute to a better understanding of the effectiveness of tDCS in individuals with SAPS.