tDCS and magnetic resonance imaging
Johnstone A., Hinson E., Stagg CJ.
Transcranial direct current stimulation (tDCS) is an increasingly promising potential therapeutic intervention in the treatment of a range of psychiatric and neurological conditions. However, before its full potential can be utilized, more must be understood about its effects on the underlying brain tissue, both in regions local to the site of stimulation and those more anatomically distant. Magnetic resonance imaging approaches have the potential to study the modulation of brain activity by tDCS, and here we review the functional MRI and MR spectroscopy studies involving tDCS. We review the basis of the most commonly used approaches for both fMRI acquired at rest and during a task performance. We then go on to summarize the studies that have been performed to date in healthy controls and in patients with a range of psychiatric conditions, before discussing what conclusions can be drawn. It is to be hoped that this will prove a useful summary both for clinicians who wish to understand more about the neurophysiological basis of tDCS and for researchers who wish to perform their own tDCS/MR experiments.