An interventional study of Monophasic iTBS and Biphasic iTBS in Neuromodulation, sponsored by Université de Sherbrooke. Recruiting at 1 site in Canada. Open to participants aged 18 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-02-10.
Sponsored by Université de Sherbrooke · Not applicable, Interventional, and Basic science
Repetitive TMS (rTMS) is a well-established method for modulating brain activity. Through successive stimulations in the form of magnetic fields, it is possible to modify the sensitivity of neurons in the brain, also known as cortical excitability. Cortical excitability is important for the induction of brain plasticity, the ability of the brain to reorganize itself and form new connections in response to stimuli. A particular class of rTMS, intermittent theta burst TMS (iTBS), is commonly used to modulate cortical excitability and induce plasticity for therapeutic purposes, notably for treatment-resistant depression.
Different iTBS stimulation parameters can be used to induce plasticity. This study will focus on two parameters, namely, the form and duration of the electromagnetic stimulation. The shape of the electromagnetic pulse refers to how the electromagnetic wave is configured over time, while the duration is simply the period during which this electromagnetic pulse remains active. These parameters are expected to influence the effectiveness of iTBS in modulating cortical activity but remain little studied.
The main aim of this study will be to compare the effectiveness of different stimulation parameters in the induction of plasticity, which will then make it possible to improve the rTMS protocols used for treatment-resistant depression.
8,057 studies on the registry are indexed under Depression; 1,641 are open to participants now.
This study's planned enrollment of 30 is below the median of 84 across 6,720 interventional studies indexed under Depression.
Browse Depression studies →Université de Sherbrooke is the lead sponsor of 289 studies on the registry; 68 are open to participants now.
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Exclusion Criteria:
All participants will understand 3 different iTBS protocols, each separated by one week. The order of the iTBS protocols will be randomized.
Device: Monophasic iTBS · Device: Biphasic iTBS · Device: Monophasic-Long iTBS
iTBS protocol with monophasic-shaped pulses. iTBS parameters: * Intensity: 80% of resting motor threshold (rMT) * Frequency: 50 Hz * Duration of pulse train: 2 seconds * Interval between pulse trains: 8 seconds
iTBS protocol with biphasic-shaped pulses. iTBS parameters: * Intensity: 80% of rMT * Frequency: 50 Hz * Duration of pulse train: 2 seconds * Interval between pulse trains: 8 seconds
iTBS protocol with long monophasic-shaped pulses. iTBS parameters: * Intensity: 80% of rMT * Frequency: 50 Hz * Duration of pulse train: 2 seconds * Interval between pulse trains: 8 seconds
TMS derived measure of cortical plasticity
Change in Peak-to-peak motor evoked potential (MEP) amplitude induced by the administration of the test stimulus (stimulation intensity required to produce an MEP of 1 millivolt, approximately 120% of rMT) after iTBS
Time frame: Pre-iTBS, Every 5 minutes post iTBS intervention up to 60 minutes post intervention.
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Université de Sherbrooke