Effect of Transcranial Direct Current Stimulation (tDCS) in Somatosensory Evoked Potential (SSEP) in Normal Adolescents

Abstract

tDCS is a noninvasive brain stimulation technique in which a mild electrical direct current is applied through the scalp to send electrical impulses to the brain to increase or decrease the excitability in the neurons. Weak transcranial direct current stimulation can induce long lasting changes in cortical excitability. The electrodiagnostic approaches like Motor Evoked Potentials (MEP), Somato Sensory Evoked Potential (SSEP) and electromyography are used to measure the effect of tDCS on the human cortex. The aim of the study is to analyze the changes in the latency (N9, N18, and P20) and amplitude (N9-P9 and N18-P20) values of SSEP immediately after tDCS and also focusing to know the side effect like nausea and headache after tDCS. This was a pre post experimental study done on 11 normal females of age group 22–25 years. tDCS was applied with active electrode at the C3 region of the scalp at an intensity of 2 mA for 20 min. SSEP was recorded pre and post stimulation for the latency (N9, N18, and P20) values and the amplitude (N9-P9 and N18-P20) values by stimulating the median nerve. Any kind of symptoms of nausea and headache were noticed after tDCS. There were no symptoms of nausea and heads ache. The results had shown that there was no significant effect of tDCS on latency value N9, N18 and amplitude values N9-P9 and N18-P20. The latency value P20 after tDCS had shown a significant increase. It was concluded that Cathodal tDCS shows significant inhibitory effect in the motor area of the cortex. Further researches are required to support its utility and effectiveness. This study can be helpful in enlightening the use of tDCS for further future neuro scientific studies.