Modulation of iTBS after-effects via concurrent directional TDCS: A proof of principle study
Sara Tremblay1, Ricci Hannah1, Vishal Rawji1
1Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK.
Background:
Polarising currents can modulate membrane potentials in animals, affecting the after-effect of theta burst stimulation (TBS) on synaptic strength.
Objective:
We examined whether a similar phenomenon could also be observed in human motor cortex (M1) using transcranial direct current stimulation (TDCS) during monophasic intermittent TBS (iTBS).
Methods:
TDCS was applied during posterior-anterior iTBS using three different conditions: posterior-anterior TDCS (anode 3.5 cm posterior to M1, cathode 3.5 cm anterior to M1), anterior-posterior TDCS (cathode 3.5 cm posterior to M1, anode 3.5 cm anterior to M1), and sham TDCS.
Results:
When the direction of TDCS (posterior-anterior) matched the direction of the electrical field induced by iTBS, we found a 19% non-significant increase in excitability changes in comparison with iTBS combined with sham TDCS. When the TDCS was reversed (anterior-posterior), the excitatory effect of iTBS was abolished.
Conclusion:
Our findings suggest that excitatory after-effects of iTBS can be modulated by directionally-specific TDCS.
More Related Videos
06:42Continuous Theta Burst Stimulation of the Posterior Medial Frontal Cortex to Experimentally Reduce Ideological Threat Responses
Published on: September 28, 2018
08:53Randomized, Triple-Blind, and Parallel-Controlled Trial of Transcranial Direct Current Stimulation for Cognitive Rehabilitation after Stroke
Published on: June 6, 2025