Estimulação transcraniana por corrente contínua sobre o córtex pré-frontal dorsolateral melhora a dor e saúde mental na doença renal terminal: um estudo controlado randomizado

Abstract

Chronic kidney disease (CKD) is a worldwide public health problem, with an estimated prevalence of 10% of the population and a significant increase each year. Patients with end-stage renal disease (ESRD) on hemodialysis have a prevalence of 50 to 80% of moderate to severe chronic pain. However, chronic pain in ESRD is often undertreated and neglected, which directly interferes with the quality of life, mood and functional capacity of affected individuals. In addition to the traditional analgesic therapy proposed for this condition, complementary techniques for pain control are suggested. Non-invasive brain stimulation can be considered an innovative and promising resource, such as transcranial direct current stimulation (tDCS). tDCS is a non-invasive neuromodulation technique applied by electrodes attached to the scalp in specific areas of the brain, with the aim of promoting changes in cortical excitability. Previous studies have already shown good results in the adjuvant treatment of physical and behavioral disorders, with a reduction in depressive symptoms, anxiety and pain. The current study aimed to evaluate the effects of anodic tDCS over the left dorsolateral prefrontal cortex (DLPFC) on pain (primary outcome), anxiety and depression in individuals with ESRD undergoing hemodialysis. A double-blind, parallel, randomized and sham-controlled clinical trial was conducted. Ten non-consecutive tDCS sessions were performed (anodal F3/Sp2 montage), with an intensity of 2mA, for 20 minutes. Pain was assessed using the Visual Analogue Scale (VAS), anxiety using the Hamilton Anxiety Scale and depression using the Beck Depression Inventory. All assessments were performed at baseline and after the intervention, with a seven-day follow-up. ANOVA was used for statistical analysis, where a significant interaction was found between time and group for pain, F(3.54) = 10.220, p = 0.0005, partial η2 = 0.362. It was also possible to observe the interaction of time, F(3.54) = 34.787, p = 0.0005, partial η2 = 0.659. The ANCOVA showed a significant difference between groups for anxiety, F(1.17) = 5.915, p < 0.02, partial η2 = 0.258 and depression F(1.17) = 4.426, p = 0.05, partial η2 = 0.207. Conclusion: It is suggested that anodic tDCS over DLPFC may improve pain and mood in patients with ESRD. This new approach brings new perspectives for the adjuvant treatment of pain and mood disorders.