Cortical Excitability
Conditions
Brief summary
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.
Detailed description
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.
Interventions
DEVICEtheta burst stimulation
TBS over the left motor hotspot, delivered at 80% of resting motor threshold (RMT), according to the Huang et al. protocol, consisting of bursts of stimuli that are presented every 200ms (5Hz), with bursts consisting of 3 stimuli at 50 Hz. A total of 600 pulses are delivered.
Sponsors
University Hospital, Ghent
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DIAGNOSTIC
Masking
DOUBLE (Subject, Outcomes Assessor)
Intervention model description
three experimental sessions at randomized order, at least one week apart, in a cross-over design
Eligibility
Sex/Gender
MALE
Age
18 Years to 65 Years
Healthy volunteers
Yes
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)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| TBS-induced modulation of single-pulse TMS-evoked EEG responses (TEPs) - peak latency/amplitude of TEP components at Cz | measurement takes place immediate before and after TBS stimulation train |
| TBS-induced modulation of single-pulse TMS-evoked EEG responses (TEPs) - Local Mean Field Power (LMFP) across a region of interest (ROI) | measurement takes place immediate before and after TBS stimulation train |
| TBS-induced modulation of single-pulse TMS-evoked EEG responses (TEPs) - divergence index (DI) across all EEG channels | measurement takes place immediate before and after TBS stimulation train |
Secondary
| Measure | Time frame |
|---|---|
| TBS-induced modulation of paired-pulse TMS-evoked EEG responses (TEPs) | measurement takes place immediate before and after TBS stimulation train |
| TBS-induced modulation of resting-state EEG | measurement takes place immediate before and after a single TBS stimulation train |
Countries
Belgium
Outcome results
None listed