Trigeminal Brainstem Mapping

Study Overview
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Brief Summary
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To what extent the somatotopy of the 3 branches of the trigeminal nerve (V1,V2,V3) as well as the greater occipital nerve (GON) in the brainstem but also in the thalamus and the insula can be mapped using functional imaging and BOLD in humans is not known but might play an important role in imaging headache diseases. The aim is to map their somatotopy by random stimulation of V1, V2, V3 and the GON with painful electrical input during acquisition of BOLD-fMRI.

Official Title
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Brainstem Mapping of Nociceptive Trigeminal Input

Conditions
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Headache Disorders, Primary, Migraine

Intervention / Treatment
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* Device: Electric Current Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy suitable fo MRI Exclusion Criteria: headache disease psychological disorder pregnancy all exclusion criteria necessary for imaging in a 3 T MRI scanner

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Electric Stimulation<br> | Device: Electric Current Stimulation<br>* Electric stimulation with a Digitimer DS7AH HV Current Stimulator delivered with 4 shielded electrodes mounted on the participants head<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Statistical Parametric Map calculated from the fMRI data on brainstem level | At a statistical threshold of T-value 3 we will observe a somatotopical arrangement in the brainstem below the pons: Expected location for V1: within radius of 10 mm around the MNI coordinates (-1,-48,-75); Expected location for V2: within radius of 10 mm around the MNI coordinates (-4,-47,-69) Expected location for V3: within radius of 10 mm around the MNI coordinates (-1,-46,-66) Expected location for GON: within radius of 10 mm around the MNI coordinates (-1,-45,-64) | through study completion, an average of 9 months | 
| Statistical Parametric Map calculated from the fMRI data in the thalamus | At a statistical threshold of T-value 4 we will observe a somatotopical arrangement in the thalamus: Expected location for V1: within radius of 10 mm around the MNI coordinates (11,-5,6); Expected location for V2: within radius of 10 mm around the MNI coordinates (13,-11,5) Expected location for V3: within radius of 10 mm around the MNI coordinates (12,-10,5) Expected location for GON: within radius of 10 mm around the MNI coordinates (15,-12,-7) | through study completion, an average of 9 months | 
| Statistical Parametric Map calculated from the fMRI data in the insula | At a statistical threshold of T-value 4 we will observe a somatotopical arrangement in the insula: Expected location for V1: within radius of 10 mm around the MNI coordinates (38,-15,8); Expected location for V2: within radius of 10 mm around the MNI coordinates (37,-8,-5) Expected location for V3: within radius of 10 mm around the MNI coordinates (39,2,-11) Expected location for GON: within radius of 10 mm around the MNI coordinates (38,-12,-3) | through study completion, an average of 9 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Statistical Parametric Map calculated from the fMRI data in the cerebellum |  | through study completion, an average of 9 months | 
| Statistical Parametric Map calculated from the fMRI data in the periaqueductal gray (PAG) |  | through study completion, an average of 9 months |