Neuroplasticity in chronic pain patients undergoing tACS: EEG, behavioral data and pain measures

• Grant number: 22/05234-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2022
• End date: May 31, 2024
• Field of knowledge: Humanities - Psychology
• Principal Investigator: Pedro Jose Montoya Jimenez
• Grantee: Maria Helena Faria Coura
• Host Institution: Centro de Matemática, Computação e Cognição (CMCC). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil

Abstract

Chronic pain is an extremely prevalent disease in the population, with an estimated 30% of the global population suffering from it. In addition, it is currently much studied with advances in medicine, especially in neurological research that managed to observe that there are functional changes, seen from the electroencephalogram, in the brain of chronic pain patients. The treatment of this disease is still much discussed, since pharmacology generates adverse effects and is not 100% proven.Some studies show that brain stimulation in patients with chronic pain can be effective by improving the clinical condition, but the neurological mechanisms that are present in this positive change in the condition are not yet known. So, treatments that have fewer adverse effects and that can be equivalently effective are being researched, and research began on the use of tACS in chronic pain. tACS is a non-invasive neurological stimulation that has shown positive effects in the treatment of several pathologies, psychiatric and neurological, being a brain stimulation technique that manages to modulate brain oscillations and, given that patients with pain have changes in brain processing at rest and affective, it may be plausible that tACS can bring about relevant changes. The objective of this project is to observe the neurophysiological mechanism of tdcs neuromodulation in pain reduction in patients with chronic pain. The project is based on the observation of brain functionality before and after stimulation, via EEG, to observe possible neuromodulation. The project will have two groups, one with healthy patients and the other with patients with chronic pain. In the group of patients with chronic pain, the EEG will be measured before and after a tACS session. In the group of healthy people, only one EEG session will be performed to collect resting and emotional processing data. The active tACS session will be performed with anodic stimulation in CP3 and cathodic stimulation in the right supraorbital region, with an intensity of 0.4 mA and a frequency of 10 Hz for twenty minutes with the patient at rest. In the tACS sham session, a tACS session will be simulated. Pain measurements, as well as changes in EEG parameters well at rest or well in response to affective stimuli will be considered the main outcomes of this research. It is expected that significant differences will be observed in the group of patients with chronic pain after active tACS (compared to the session before tACS) and that tACS will produce similar values to the group of healthy people in the main outcomes.