Effects of Non Invasive Brain Stimulation During Prolonged Experimental Pain

Overview

Non invasive brain stimulation (NIBS) of the primary motor cortex (M1) through transcranial direct current stimulation (tDCS) has been widely investigated in research and clinical settings in order to modulate brain plasticity and improve clinical pain. Interestingly, newly developed paradigms i.e. tDCS of the resting state motor network have proved higher modulatory effects in terms of corticospinal excitability when compared to traditional M1 tDCS. However, little is known about the effects of tDCS on the frequency changes of alpha oscillations (alpha peaks). Interestingly, previous studies show a correlation between reduced frequencies of alpha peaks during 1-hour experimental pain in comparison to baseline. The present study aims to investigate the effects of tDCS of the resting state motor network on the frequency and power of alpha peaks during prolonged experimental pain during 24 hours.

There is evidence that chronic pain alters the frequency of alpha peaks. Specifically, recent studies showed a correlation between decreased frequency of alpha peaks and perceived pain. Furthermore, a correlation was found between high pain sensitivity and slower alpha oscillations during prolonged pain during 1 hour. To date, the effects of prolonged experimental pain during 24 hours on brain oscillations has not been explored. Moreover, it is unknown whether non invasive brain stimulation (NIBS) through transcranial direct current stimulation (tDCS) can revert these pain-related feature. It is hypothesized that prolonged pain during 24 hours will reduce the frequency of alpha peaks and tDCS of the resting state motor network will revert it to baseline values. Furthermore, it is thought that decreased frequency of alpha peaks will be correlated with perceived pain intensity on Day 1 (before receiving the first tDCS session).