TMS-EEG as a Tool to Study the Neuromodulatory Effects of Theta Burst Stimulation

TMS-EEG as a Tool to Study the Neuromodulatory Effects of Theta Burst Stimulation

To assess the effect of continuous (cTBS) and intermittent theta burst stimulation (iTBS) stimulation on motor cortex excitability using TMS-EEG. Based on prior literature, the investigators hypothesized that N100 amplitude would be differently modulated by these two modalities.

Each participant underwent three experimental sessions, at least one week apart in a cross-over design, assessing the effects of a single TBS train over the motor cortex on TMS-evoked potentials measured at the same location and resting-state EEG, immediately before and after the intervention. At each session a different type of TBS was applied (cTBS, iTBS or sham) in a randomized sequence. Subjects were uninformed about the expected effects of each intervention. Sham stimulation was achieved by adding a plastic spacer (25mm thickness) between coil and scalp, preventing effective cortical stimulation.

Inclusion Criteria:

• Age 18-65 years
• Male
• Right handed subjects
• IQ > 70
• Healthy participants, as determined by history, clinical investigation and investigator's judgment
• No history of central nervous system condition
• No chronic intake of neurotropic drugs
• TMS Safety Screening questionnaire and informed consent signed

Exclusion Criteria:

• Pregnancy, short-term birth wish or childbearing age without adequate birth control
• Intracranial metal hardware (excluding dental filling): surgical clips, shrapnell, electrodes under the stimulation area
• Presence of pacemaker, implantable cardioverter-defibrillator (ICD), permanent medication pumps, cochlear implants or deep brain stimulation (DBS)