MRI to Assess the Effects of Dysautonomia and Chronic Nausea on Brain Transmitters

Study Overview
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Brief Summary
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The purpose of this research study is to better understand what causes dysautonomia and how this affects blood pressure and pulse. Dysautonomia is a condition of the autonomic nervous system. It is associated with fluctuations in blood pressure and pulse and may cause symptoms of nausea and belly pain, fatigue, excessive thirst, lightheadedness, dizziness, feelings of anxiety or panic, and fainting. A common example of dysautonomia is postural orthostatic tachycardia syndrome or POTS. Sometimes symptoms worsen when people move from lying down to standing, called orthostatic intolerance. We would like to learn more about the link between orthostatic intolerance and nausea. While medications currently used to treat orthostatic intolerance and nausea have proven to be effective in some patients, this may not be the best treatment for everyone as long term use could pose certain risks including high blood pressure. In order to provide a more focused and safer treatment for patients suffering from nausea and orthostatic intolerance, we have looked at how the blood pressure, pulse, and certain blood tests change during a tilt table test. This test helps to create the same circumstances that patients with orthostatic intolerance experience when they stand. To better understand if some of these problems are associated with the brain, we will study MRI in patients with dysautonomia compared to children without dysautonomia. This information may allow us to use alternative and safer treatments in the future.

Official Title
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Study Title: Brain Transmitters/Metabolites, Magnetic Resonance Spectroscopy, and Brain Connectivity: Diagnostic Strategies to Study the Effects of Non-Pharmacologic Therapies for Dysautonomia and Chronic Nausea

Conditions
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Dysautonomia

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: subjects who have completed tilt autonomic testing subjects from 9 - 18 years of age Exclusion Criteria: subjects who have a metabolic, mechanical, or mucosal inflammatory cause which has been defined to explain their gastrointestinal symptoms Patients with cardiac or cardiovascular disease, malignancy, psychiatric illness, neurodevelopmental delay, or other co-morbid conditions Patients with with pacemakers, implanted devices, or any other MRI contraindications will be excluded from this study.

Ages Eligible for Study
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Minimum Age: 9 Years
Maximum Age: 18 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| normaL<br>Healthy subjects without symptoms of dysautonomia. | |
| Neurocardiogenic syncope<br>Fainting due to sudden drop in blood pressure. | |
| Orthostatic hypotension<br>Sudden decrease in blood pressure while standing. | |
| Postural Orthostatic Tachycardic Syndrome<br>Increased heart rate when standing. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assessment of the implication of dysautonomia on the brain and better evaluate its potential mechanistic process. | The first objective of the proposed project is to study central transmitter/metabolite profiles using in vivo 1H Magnetic Resonance Spectroscopy (MRS) in children with dysautonomia diagnosed by tilt table testing compared to healthy children without symptoms of dysautonomia. The second objective will be to determine whether dysautonomia associated with nausea and cardiovascular instability shares common alterations in brain networks. We will be using cognitive and sensory processing tasks based on our prior experience with both traditional fMRI and network analyses. | Assessments will occur in a one and a half hour visit. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dysautonomia, Postural orthostatic tachycardic hypotension, Neurocardiogenic vasovagal syncope