Combined transcranial alternating current stimulation and continuous theta burst stimulation: a novel approach for neuroplasticity induction.

Title:

Combined transcranial alternating current stimulation and continuous theta burst stimulation: a novel approach for neuroplasticity induction.
Authors:
Goldsworthy MR; Vallence AM; Yang R; Pitcher JB; Ridding MC.
Institution Goldsworthy, Mitchell R. The Robinson Research Institute, School of  Medicine, University of Adelaide, Adelaide, 5005, Australia. Vallence, Ann-Maree. The Robinson Research Institute, School of Medicine, University of Adelaide, Adelaide, 5005, Australia. Vallence, Ann-Maree. School of Psychology and Exercise Science, Murdoch University, Perth, WA, Australia.
Yang, Ruiting. The Robinson Research Institute, School of Medicine, University of Adelaide, Adelaide, 5005, Australia. Pitcher, Julia B. The Robinson Research Institute, School of Medicine, University of Adelaide, Adelaide, 5005, Australia. Ridding, Michael C. The Robinson Research Institute, School of Medicine, University of Adelaide, Adelaide, 5005, Australia.
Title:
Combined transcranial alternating current stimulation and continuous theta burst stimulation: a novel approach for neuroplasticity induction.
Source:
European Journal of Neuroscience. 43(4):572-9, 2016 Feb.
Abstract:
Non-invasive brain stimulation can induce functionally relevant p
lasticity in the human cortex, making it potentially useful as a therapeutic tool. However, the induced changes are highly variable between individuals, potentially limiting research and clinical utility. One factor that might contribute to this variability is the level of cortical inhibition at the time of stimulation. The alpha rhythm (~ 8-13 Hz) recorded with electroencephalography (EEG) is thought to reflect pulsatile cortical inhibition; therefore, targeting non-invasive brain stimulation to particular phases of the alpha rhythm may provide an approach to enhance plasticity induction. Transcranial alternating current stimulation (tACS) has been shown to entrain cortical oscillations in a frequency-specific manner. We investigated whether the neuroplastic response to continuous theta burst stimulation (cTBS) was enhanced by timing bursts of stimuliton the peak or the trough of a tACS-imposed alpha rhythm. While motor evoked potentials (MEPs) were unaffected when cTBS was applied in-phase with the peak of the tACS-imposed oscillation, MEP depression was enhanced when cTBS was applied in-phase with the trough. This enhanced MEP depression was dependent on the individual peak frequency of the endogenous alpha rhythm recorded with EEG prior to stimulation, and was strongest in those participants classified as non responders to standard cTBS. These findings suggest that tACS may be used in combination with cTBS to enhance the plasticity response. Furthermore, the peak frequency of endogenous alpha, as measured with EEG, may be used as a simple marker to pre-select those individuals likely to benefit from this approach.
Copyright:
2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.
Publication Type:
Journal Article. Research Support, Non-U.S. Gov’t.