tDCS peripheral nerve stimulation: a neglected mode of action?
Luuk van Boekholdt1, Silke Kerstens1, Ahmad Khatoun1
1Exp ORL, Department of Neuroscience, Leuven Brain Institute, KU Leuven, Leuven, Belgium.
Molecular Psychiatry
|December 10, 2020
Summary
Peripheral nerve stimulation may explain some effects of transcranial direct current stimulation (tDCS). This study proposes peripheral mechanisms, like arousal and vigilance, and suggests improved experimental designs to differentiate these from true transcranial effects.
Area of Science:
- Neuroscience
- Neuromodulation
- Psychiatry
Background:
- Transcranial direct current stimulation (tDCS) is a widely used noninvasive neuromodulation technique.
- tDCS is explored for treating psychiatric disorders, but its neurophysiological mechanisms remain unclear.
- Current understanding assumes cortical electric fields cause tDCS effects.
Purpose of the Study:
- To investigate the potential contribution of peripheral mechanisms to tDCS effects.
- To hypothesize that tDCS induces arousal and vigilance via peripheral nerve stimulation.
- To propose experimental improvements for differentiating peripheral from transcranial tDCS mechanisms.
Main Methods:
- Systematic investigation of peripheral mechanisms in tDCS.
- Hypothesizing peripherally-evoked activation of the ascending reticular activating system.
- Suggesting experimental designs beyond sham control, including anesthetics and active controls.
Main Results:
- Peripheral nerve endings experience higher electric fields than the cortex during tDCS.
- Hypothesized peripheral mechanisms involve arousal and vigilance.
- Proposed methods aim to disambiguate peripheral from central tDCS effects.
Conclusions:
- Peripheral mechanisms may play a significant role in tDCS-induced arousal and vigilance.
- Improved experimental designs are crucial for understanding tDCS.
- Further research is needed to elucidate the precise contribution of peripheral nerve stimulation.
