View clinical trials related to Primary Dysautonomias.
Filter by:The purpose of this study is to see if using a micro-current through a device called a TENS (Transcutaneous Electrical Nerve Stimulator) unit helps to improve functional gastrointestinal disorder (FGID) symptoms in children by stimulation of the vagus nerve. The study will compare two methods of stimulation to determine if there is a difference in the two methods.
This study will explore whether ivabradine lowers heart rate, and thus improves exercise capacity, in survivors of lymphoma who have an elevated resting heart rate as a side effect of prior radiation treatment. The drugs involved in this study are: - Ivabradine - Placebo
Neurogenic Orthostatic Hypotension (NOH) is clinically defined as a consistent drop in systolic blood pressure (SBP) ≥30mmHg upon standing from a seated or lying position. However, 50% of NOH patients also have associated supine hypertension. It has been proposed that supine hypertension is the result of intact post-ganglionic sympathetic nerves and therefore due to residual sympathetic tone. Furthermore, research investigating the effects of melatonin shows blood pressure implication of this naturally secreted hormone. Specifically, melatonin has been investigated as a non-traditional anti-hypertensive agent for patients with essential and nocturnal hypertension. Central and peripheral mechanisms have been proposed to help explain how melatonin reduces blood pressures. Therefore, we aim to identify NOH patients as having either intact or denervated post-ganglionic sympathetic nerves, monitor the correlation to supine hypertension and subsequently investigate the effects of melatonin on blood pressure in these patients.
Pharmacologic approaches to increase levels or actions of the vasodilatory peptide angiotensin-(1-7) are currently in development for the treatment of hypertension based on findings from animal models. There are limited and contradictory clinical studies, however, and it is not clear if this peptide regulates blood pressure in humans. The purpose of this study is to better understand the cardiovascular effects angiotensin-(1-7) in human hypertension, and to examine interactions of this peptide with the autonomic nervous system. The investigators propose that the difficulties in showing angiotensin-(1-7) cardiovascular effects in previous clinical studies relates to the buffering capacity of the baroreceptor reflex to prevent changes in blood pressure. Autonomic failure provides the ideal patient population to test this hypothesis. These patients have loss of baroreflex buffering and have low levels of angiotensin-(1-7) in blood. The investigators will test if angiotensin-(1-7) infusion can lower blood pressure in patients with autonomic failure, and will determine the hemodynamic and hormonal mechanisms involved in this effect.
Background: - The autonomic nervous system helps control things that happen automatically in the body, like blood pressure, heart rate, and digestion. When it doesn t work properly, it s called dysautonomia. Researchers want to learn more about dysautonomias and train doctors to learn how to better diagnose them. Objectives: - To allow people with autonomic disorders to be evaluated. - To help fellows in the NIH Autonomic Disorders fellowship program see a variety of diseases in their training. Eligibility: - People age 18 and older with dysautonomia; children over age 2 if they might benefit - Healthy adult volunteers Design: - Participants will have different procedures depending on their symptoms. They will have one or more visits. They will have some but not all of the tests below. - Participants will have a medical history and physical exam. They may be tested for problems thinking. They may complete a symptom questionnaire. They may have their temperature and blood pressure taken. - Participants may have an intravenous line placed. A needle will guide a thin plastic tube into an arm vein. - Participants may have blood drawn several times. They may give a urine sample. - Participants may have an electrocardiogram. - How much blood a participant s heart is pumping and/or how much blood is flowing through their arm may be measured. The total amount of blood in their bloodstream may be measured. - Participants may have their ability to sweat and/or sense of smell tested. - Breathing, bowel sounds, and/or body functions may be monitored. - Pupil size, response to environmental temperature changes, and/or breathing may be measured. - Participants may have a bladder ultrasound. - Small pieces of skin may be taken for study.
To demonstrate that spinal cord stimulator has an effect on sympathetic function (the one that give us the fight and flight response). Therefore, if the spinal cord stimulator has an effect on sympathetic function, the responses from CRPS patients to different stimuli will differ significantly pre and post SCS implant. If CRPS patients exhibit autonomic, CRPS patients could be stratified according to their sympathetic function pre-implant. It is expected that patients with a moderate/mild form of autonomic dysfunction will have better outcomes with the SCS.
The purpose of this study is to try different medications in patients with low blood pressure and other problems with their involuntary (autonomic) nervous system. The pharmacological trials in this study will perhaps lead to more effective treatment. The protocol includes single dose trials, dose-selection trials, 5-day trials and chronic (approximately 2 months) trials, although only dose-selection trials were consistently performed and have results presented.
An experimental drug called L-DOPS increases production in the body of a messenger chemical called norepinephrine. Cells in the brain that make norepinephrine are often gone in Parkinson disease. The exact consequences of this loss are unknown, but they may be related to symptoms such as fatigue, depression, or decreased attention that occur commonly in Parkinson disease. This study will explore effects of L-DOPS in conjunction with carbidopa and entacapone, which are drugs used to treat Parkinson disease. We wish to find out what the effects are of increasing norepinephrine production in the brain and whether carbidopa and entacapone augment those effects. Volunteers for this study must be at least 18 years of age and able to give consent to participate in the study. To participate in the study, volunteers must discontinue use of alcohol, tobacco, and certain herbal medicines or dietary supplements, and must also taper or discontinue certain kinds of medications that might interfere with the results of the study. Candidates will be screened with a medical history and physical exam. Participants will be admitted to the National Institutes of Health Clinical Center for two weeks of testing. The study will have three testing phases in a randomly chosen order for each participant: - Single dose of L-DOPS - Single dose of L-DOPS in conjunction with carbidopa - Single dose of L-DOPS in conjunction with entacapone Each phase will last two days, with a washout day between each phase in which no drugs will be given and no testing will be performed. In each phase, participants will undergo a series of tests and measurements, including blood pressure and electrocardiogram tests. Participants who are healthy volunteers will also have blood drawn and will undergo a lumbar puncture (also known as a spinal tap) to obtain spinal fluid for chemical tests.
Within the framework of a prospective double-blind and randomized study evaluating the efficacy of continuous intrathecal baclofen therapy (CIBT) on paroxysmal dysautonomia (main objective) and hypertonia, recovery and tolerance (secondary objectives) during the initial recovery phase of severe head injury, continuous intrathecal baclofen infusion will be delivered. The first week of study is double-blind: the first of two parallel groups receives CIBT and the second group receives placebo. The main outcome (number of neurovegetative episodes) is assessed at the end of first week. The second week of study is open labeled: active treatment is continued in the first group and the second group starts active CIBT treatment. The third week of study, treatment is stopped in both groups.
This study will conduct tests in patients with primary chronic autonomic failure (CAF) to learn more about these disorders, which include pure autonomic failure, multiple system atrophy, Parkinson's disease with autonomic failure, and autoimmune autonomic neuropathy. Healthy volunteers and patients with primary CAF 18 years of age or older may be eligible for this study. Participants undergo some of the following tests: - Blood studies, including arterial catheter insertion to measure blood pressure and collect arterial blood samples, blood flow studies using sensors applied to the skin and a pressure cuff around a limb, and blood draw for genetic studies. - Bladder motility: Ultrasound test of bladder function. - Electrocardiogram and heart ultrasound. - Responses to changes in temperature: Warm water and then room temperature water are passed through watertight pads applied to the back and front of the body and body temperatures are measured. - Gastrointestinal motility: Bowel sounds are recorded using a microphone placed on the abdomen. - Lower body negative pressure: The lower body is placed into an airtight barrel-like chamber. Some air is sucked out of the barrel, causing blood to pool in the legs, as occurs during standing. - Lumbar puncture: A needle is inserted in the space between the bones in the lower back to collect a small sample of cerebrospinal fluid. - Microdialysis to measures levels of chemicals in the body fluid of certain tissues. A solution is passed through a thin tube inserted into the skin. Chemicals in the body tissues enter the solution. The solution is collected and the chemical levels are measured. - PET scanning: A nuclear medicine test to produce images of body organs. For patients with urinary problems, a catheter is inserted into the bladder before starting the scan. - Pupillometry: The pupil of the eye is measured using a special camera in a light-controlled room. - QSART. A small amount of a brain chemical is applied to the skin with a tiny amount of electricity, and the sweat in a nearby patch of skin is measured. - Measurement of saliva production, using a cotton-like material placed between the teeth and gums to absorb saliva. - Skin electrical conduction test, using sensors on the skin to measure sweat production. - Skin and core temperature measurements using sensors on the skin and in the ear canal. - Speech and swallowing assessment for patients with speech and swallowing difficulties. - Stress echocardiogram: A catheter is placed in the subject's arm for sampling blood or giving a drug while the subject exercises. During the test, blood pressure, pulse rate, and EKG are continuously monitored.