Exploring the Cortical Hemodynamic Variability of Four Weeks iTBS on a Healthy Participant: a Case Study

Study Overview
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Brief Summary
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This study will investigate the effect of caffeine and time of day on brain excitability using excitatory brain stimulation. The investigators will recruit a healthy participant and conduct a concurrent iTBS/fNIRS protocol for 20 consecutive sessions over four weeks with or without caffeine consumption before the stimulation. Moreover, the experiment will be conducted at different times of the day (morning or afternoon)

Detailed Description
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One healthy participant will be recruited for this study. The participants will be subjected to concurrent TBS/fNIRS, to which the iTBS will be applied on the left DLPFC and the NIRS will measure the prefrontal hemodynamic response simultaneously.

Official Title
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Exploring the Cortical Hemodynamic Variability of Four Weeks iTBS on a Healthy Participant: a Case Study

Conditions
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Healthy

Intervention / Treatment
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* Other: caffeine
* Other: Experimental time


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Right-handed Exclusion Criteria: history of epilepsy, seizures, or convulsions current or past diagnosis of neurological disorders, such as head injuries, strokes, encephalitis, epilepsy, Parkinson's, or Alzheimer's current or past diagnosis of psychiatric disorders, such as depression, anxiety, schizophrenia, or autism with metal implants, such as a cochlear implant, neurostimulator, or cardiac pacemaker

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: One healthy participant will undergo four weeks of concurrent TBS/fNIRS to investigate the cortical hemodynamic variability
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cortical hemodynamic variability of four weeks iTBS<br>One healthy participant will be included in this study, which lasts for 4 weeks, 5 visits per week, involving 20 visits in total. The participant will receive the following instructions the night before: to take 200 mg of caffeine one hour before the visit (no other caffeine intake since the wake-up) or avoid caffeine intake at all before the visit; to attend the visit in the morning or afternoon. These assignments will be randomized in a counterbalanced manner. | Other: caffeine<br>* The investigators will ask participant to only intake 200 mg of caffeine one hour before the experiment (no other caffeine intake since the wake-up) or avoid caffeine intake at all before the experiment<br>Other: Experimental time<br>* The investigators will ask participant to attend the experiment in the morning or afternoon<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxygenated hemoglobin (HbO) change compared to baseline | iTBS-induced HbO change in the DLPFC before, during and after stimulation | During and post TBS-fNIRS measurement, up to 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Deoxygenated hemoglobin (HbR) change compared to baseline | iTBS-induced HbO change in the DLPFC before, during and after stimulation | During and post TBS-fNIRS measurement, up to 1 month | 
| Oxygen saturation change compared to baseline | iTBS-induced HbO change in the DLPFC before, during and after stimulation | During and post TBS-fNIRS measurement, up to 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Theta-Burst stimulation (iTBS), Functional near-infrared spectroscopy (fNIRS), Concurrent TMS/fNIRS, Prefrontal hemodynamic response, Longitudinal effects