Bilateral Transcranial Direct Current Stimulation Reshapes Resting-State Brain Networks: A Magnetoencephalography Assessment.

Giovanni Pellegrino,Cristina Turco,Matteo Maran,Francesco Piccione,Giorgio Arcara,Giovanni Di Pino,Luca Weis

doi:10.1155/2018/2782804

Abstract

Transcranial direct current stimulation (tDCS) can noninvasively induce brain plasticity, and it is potentially useful to treat patients affected by neurological conditions. However, little is known about tDCS effects on resting-state brain networks, which are largely involved in brain physiological functions and in diseases. In this randomized, sham-controlled, double-blind study on healthy subjects, we have assessed the effect of bilateral tDCS applied over the sensorimotor cortices on brain and network activity using a whole-head magnetoencephalography system. Bilateral tDCS, with the cathode (−) centered over C4 and the anode (+) centered over C3, reshapes brain networks in a nonfocal fashion. Compared to sham stimulation, tDCS reduces left frontal alpha, beta, and gamma power and increases global connectivity, especially in delta, alpha, beta, and gamma frequencies. The increase of connectivity is consistent across bands and widespread. These results shed new light on the effects of tDCS and may be of help in personalizing treatments in neurological disorders.

Highlights

IntroductionTranscranial direct current stimulation (tDCS) is a noninvasive neurostimulation technique capable of modulating brain excitability and inducing plastic phenomena outlasting the duration of the stimulation itself [1,2,3].tDCS consists in the application of a weak homogeneous direct current over the scalp using two electrodes of different polarity (anode and cathode) connected to a stimulator, decreasing the cortical excitability under the cathode and increasing it under the anode [4]
Transcranial direct current stimulation is a noninvasive neurostimulation technique capable of modulating brain excitability and inducing plastic phenomena outlasting the duration of the stimulation itself [1,2,3].tDCS consists in the application of a weak homogeneous direct current over the scalp using two electrodes of different polarity connected to a stimulator, decreasing the cortical excitability under the cathode and increasing it under the anode [4]
Because of its ease of use, limited side effects, and low cost [5], tDCS has become very popular in the recent years and has been applied in a number of different frameworks, ranging from cognitive and social neuroscience [6] to clinical research [7]. tDCS application is explored as a promising tool for the treatment of drugresistant epilepsy [8] and, together with physical therapy, to boost brain plasticity and possibly to improve the outcome of disabled stroke patients [9,10,11]

Summary

Introduction

Transcranial direct current stimulation (tDCS) is a noninvasive neurostimulation technique capable of modulating brain excitability and inducing plastic phenomena outlasting the duration of the stimulation itself [1,2,3].tDCS consists in the application of a weak homogeneous direct current over the scalp using two electrodes of different polarity (anode and cathode) connected to a stimulator, decreasing the cortical excitability under the cathode and increasing it under the anode [4]. TDCS application is explored as a promising tool for the treatment of drugresistant epilepsy [8] and, together with physical therapy, to boost brain plasticity and possibly to improve the outcome of disabled stroke patients [9,10,11]. As it happens for other noninvasive brain stimulation techniques, the mechanism by which tDCS is supposed to work is mainly related to the long-lasting changes of brain excitability [2, 12, 13].

Methods

Results

Discussion

Conclusion