Diferentes polaridades da estimulação transcraniana por corrente contínua de alta definição na doença pulmonar obstrutiva crônica : um estudo fNIRS

Abstract

Chronic Obstructive Pulmonary Disease (COPD) stands out among chronic diseases as the third leading cause of death worldwide. The observation of neurophysiological components associated with interventions can provide valuable insights into the importance of neurofunctional aspects related to the disease's pathophysiology. Thus, the present study aims to compare the effects of different polarities of High-Definition Transcranial Direct Current Stimulation (HD-tDCS) on the cortical hemodynamic response of individuals with COPD. In the experimental context, an exploratory study was conducted with a quantitative approach, applied nature, and characterized as a double-blind, placebo-controlled, randomized clinical trial. The acute effects of different HD-tDCS polarities on the cortical hemodynamics of COPD patients during hypercapnic stimulus were investigated using a cross-over design, in which each participant underwent all three treatment types, with a minimum 7-day washout period between sessions. Additionally, a technical framework was developed for integrating HD-tDCS with functional near-infrared spectroscopy (fNIRS), based on a theoretical-practical analysis. The hemodynamic effects of HD-tDCS on the left diaphragmatic motor cortex were assessed in COPD patients under hypercapnic conditions. The cathodal HD-tDCS demonstrated selective effects, showing superiority over placebo only in total hemoglobin concentration, while being superior to anodal stimulation in deoxygenated hemoglobin. These findings suggest that cathodal stimulation may influence distinct hemodynamic markers, including cerebrovascular reactivity. However, further analyses are needed to determine its clinical implications, considering the use of repeated sessions of the technique in future studies.