The Effects of Repetitive Transcranial Magnetic Stimulation in Healthy Human Subjects
Condition: Healthy
Study type: Interventional

Summary: 
      It has been suggested that the therapeutic effects of repetitive transcranial magnetic
      stimulation (rTMS) are mediated through changes in cortical inhibition (CI). However, in
      healthy subjects the effects of rTMS on CI have been inconsistent. The aim of this study is
      to explore different rTMS - stimulus conditions neurophysiological and molecular mechanisms
      in the human motor cortex. Fifty-six healthy subjects will be randomized into three different
      treatment groups and receive 1 active or sham rTMS session (6000 rTMS pulses) at 90% of their
      motor threshold (MT). Cortical inhibition will be indexed pre and post treatment using
      short-interval intracortical inhibition (SICI), cortical silent period (CSP) and
      long-interval cortical inhibition (LICI).

      Based on previous studies we hypothesize that:

        -  Hypothesis 1: rTMS will result in a greater CI (i.e., prolonged CSP, increased LICI but
           not SICI) compared to sham rTMS.

        -  Hypothesis 2: 20 Hz rTMS will result in a significantly greater CI compared to 1 Hz
           rTMS.

        -  Hypothesis 3: There will be distinctive transcription profiles associated with increases
           in CI from rTMS that can be detected with whole-genome microarray analysis of peripheral
           leukocytes.
    

Detailed description: 
      It has been demonstrated that several neurologic and psychiatry disorders are associated with
      dysfunctional cortical inhibitory mechanisms and alterations in neurotrophins (biological
      markers involved in neuronal survival and plasticity) and that rTMS therapeutic effects are
      associated with changes in cortical excitability. CI produced by rTMS can be demonstrated
      through SICI, CSP and LICI. However it remains unclear which rTMS parameters induce the best
      CI. Exploring different rTMS stimulus conditions versus sham condition effects in CI of human
      motor cortex can be the way to identify the best rTMS therapeutic parameters. Also,
      evaluating the molecular effects produced by rTMS treatment on serum blood levels can help
      identify the mechanisms through which rTMS exerts its therapeutic effects and ultimately
      clarify mechanisms through which treatment effects are mediated.

      This experiment intends to demonstrate the best rTMS parameters to acquire higher CI. If our
      hypotheses are correct, these parameters will help to obtain higher therapeutic effects, and
      consequently, improvement of rTMS treatments.
    

Intervention name(s): repetitive transcranial magnetic stimulation (rTMS); repetitive transcranial magnetic stimulation (rTMS); sham repetitive transcranial magnetic stimulation (rTMS)
Intervention type(s): Device; Device; Device
Intervention description(s): 1 Hz
The rTMS device is the "MagPro X100 Series" (produced by Magventure A/S, Farum, Denmark); 20Hz
The rTMS device is the "MagPro X100 Series" (produced by Magventure A/S, Farum, Denmark); The rTMS device is the "MagPro X100 Series" (produced by Magventure A/S, Farum, Denmark)
Other intervention name(s): MagPro X100 Series; MagPro X100 Series; MagPro X100 Series
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: repetitive transcranial magnetic stimulation; double-blind; sham-controlled; randomized