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

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.