119 Clinical Trials for Various Conditions
This research is designed to compare the impact of high-intensity interval training and high-velocity circuit resistance training on heart rate variability, gait, and functional performance in patients with Parkinsons disease.
This research proposal has two main objectives. The first is to increase understanding of the underlying physiological interactions that occur between the cardiovascular, pulmonary, and ANS during transition between positive pressure mechanical ventilation (MV) and spontaneous breathing. The second is to determine if heart rate variability, (HRV) a reflection of autonomic nervous system (ANS) activity, and autonomic information flow (AIF), a set of nonlinear measures derived from HRV, both measured in the intensive care unit (ICU) can predict patient outcomes including successful weaning and in-hospital recovery time after an episode of cardiopulmonary compromise requiring MV. Hypothesis 1. Transitions between mechanically supported ventilation and spontaneous breathing will disturb cardiovascular synchrony, altering the relationship of HRV, AIF, respiratory rate, and blood pressure; Hypothesis 2. More normal HRV and AIF values, measured during baseline MV and sedation awakening (a period immediately prior to SBT when sedative medications are discontinued) will be associated with easier weaning, and shorter intensive care unit (ICU) and hospital lengths of stay; more abnormal measurements will be associated with longer lengths of stay; Hypothesis 3. AIF is a more sensitive predictor of successful weaning from MV than HRV.
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.
Multiple system atrophy (MSA) is a disorder of the nervous system of unclear cause. In MSA there is degeneration (progressive loss) of nerve cells in several brain and spinal cord regions. The result is a variety of symptoms, from physical (parkinsonism, ataxia, incoordination, falls, slowness) to autonomic (fainting, bladder incontinence, sexual dysfunction) to sleep problems (dream enactment, sleep apnea). This research aims to help us better understand the patterns and timing of nerve degeneration relatively early in the disease, and how this affects symptoms and progression. For instance: 1. Does MSA affect certain nerves that stimulate heart pumping? If so, does the severity of loss of heart nerves affect disease progression and survival? 2. It is thought that MSA does not affect memory and thinking much, unlike other diseases (such as Parkinson's). Is this accurate? Is there loss of nerves that transmit acetylcholine (a neurochemical important in mental functioning)? 3. What can we learn about mood and sleep in MSA, through visualizing the serotonin system in the brain? How does this relate to symptoms that subjects report in these often underappreciated areas? To answer these and other questions, investigators will take images of specific nerves in the brain and heart using Positron Emission Tomography (PET) scans. Such imaging gives us information that cannot be obtained from MRIs and CT scans. We will measure the levels of several nerve cell types: serotonin, acetylcholine, and norepinephrine. Subjects will also have many standardized assessments including quality-of-life and symptom assessments, neurological examination, autonomic assessments, neuropsychological assessments, coordination tests, and even assessments of vision and sense of smell. By pooling these results from many MSA patients, and comparing with other diseases (such as Parkinson's disease) we hope to gain a better understanding of what is happening early in MSA. Such knowledge could be very valuable in future efforts to develop better therapies in this rare disease.
The heart and brain are regulated by the autonomic nervous system. Control of these organs can be disrupted in people with spinal cord injury (SCI). This may affect their ability to regulate blood pressure during daily activities and process the high-level information. Previous studies show that high-intensity exercise induces better outcomes on heart and information processing ability in non-injured people compared to moderate-intensity exercise. However, it is unknown the effects of high-intensity exercise on heart and brain function in people with SCI. Therefore, this study aims to examine the effects of a single bout of high-intensity interval training on heart and brain function in this people with SCI compared to age- and sex-matched non-injured controls.
The primary purpose of this pilot study is to specifically examine the effect of parental reading on the ANS of mother and neonate in the hospital setting. The investigators will examine the effect of live maternal-infant reading on typically developing infants to better understand the physiological benefits of live reading on newborns.
The purpose of this study is to conduct an interventional, one year, randomized, double blind, placebo-controlled trial with Liraglutide in patients with type 2 diabetes (diabetes duration of \>6 months and \<10 years, HbA1c \<10%) to evaluate its effects on the peripheral autonomic nervous system, as well as inflammatory markers, and measures of oxidative and nitrosative stress.
The purpose of this study is to determine the cause of low blood pressure in selective patients who have problems with their involuntary (autonomic) nervous system. These patients frequently have had symptoms throughout their life, and their disorder might have a genetic basis. The biochemical, physiological and pharmacological procedures in this study should help us define the problem and perhaps lead to more effective treatment.
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.
This study is designed to use PET scans in order to measure activity of the sympathetic nervous system. The sympathetic nervous system is the portion of the nervous system that maintains a normal supply of blood and fuel to organs during stressful situations. PET scan or Positron Emission Tomography is an advanced form of an X-ray. It is used to detect radioactive substances in the body. During this study researchers plan to inject small amounts of the radioactive drug fluorodopamine into patients. Fluorodopamine is very similar to the chemicals found in the sympathetic nervous system. It can attach to sympathetic nerve endings and allow researchers to view them with the aid of a PET scan. One area of the body with many sympathetic nerve endings is the heart. After giving a dose of fluorodopamine, researchers will be able to visualize all of the sympathetic nerve endings involved in the activity of the heart. In addition, this diagnostic test will help researchers detect abnormalities of the nervous system of patient's hearts.
Brain and nerve cells communicate with each other by releasing and picking up chemicals called neurotransmitters. Norepinephrine is a neurotransmitter used by part of the nervous system activated during stress called the sympathetic nervous system. The sympathetic nervous system is involved with regulating blood pressure and pulse rate. Researchers believe the level norepinephrine in the blood can be used to measure activity of the sympathetic nervous system. This study is designed to answer important questions about rates of release of norepinephrine into the blood stream, removal of released norepinephrine, and the sympathetic nervous system response to stress. Researchers will attempt to measure levels of norepinephrine and activity of the sympathetic nervous system in patients with high blood pressure, normal patients with family histories of high blood pressure, patients taking drugs that can effect levels of norepinephrine, and patients with diseases or conditions directly affecting the sympathetic nervous system.
This study involves sampling blood from both normal volunteers and patients with diseases known or suspected to involve body chemicals called catecholamines. The blood will be used to establish normal values for plasma levels of catecholamines and related neurochemicals; to test for abnormal neurochemical patterns in patients; and to establish a "bank" of DNA from normal volunteers and from patients to be used in future studies about possible alterations of catecholamine-related genes. Study participants will report to NIH after fasting overnight except for water or noncaloric, noncaffeinated beverages. They must not have taken Tylenol for at least 5 days. Blood will then be drawn. DNA will be extracted and stored in the freezer for future studies.
Hypermobile Ehlers-Danlos Syndrome (hEDS) is a connective tissue disorder characterized by hyperextensible skin, joint hypermobility and additional connective tissue manifestations. For unclear reasons, hEDS is associated with many gastrointestinal (GI) and autonomic nervous system (ANS) complaints such as postural orthostatic tachycardia syndrome (POTS). This study will address the clinical relationship between hEDS/Hypermobile Spectrum Disorders and autonomic regulation and see if there is a benefit of two forms of non-invasive vagal nerve stimulation therapies to reduce GI symptoms in hEDS and POTS. The study will also investigate plausible effects of these nerve stimulation therapies on gastric function and autonomic signaling.
Biomarkers can be evaluated to provide information about disease presence or intensity and treatment efficacy. By recording these biomarkers through noninvasive clinical techniques, it is possible to gain information about the autonomic nervous system (ANS), which involuntarily regulates and adapts organ systems in the body. Machine learning and signal processing methods have made it possible to quantify the behavior of the ANS by statistically analyzing recorded signals. This work will aim to systematically measure ANS function by multiple modalities and use decoding algorithms to derive an index that reflects overall ANS function and/or balance in healthy able-bodied individuals. Additionally, this study will determine how transcutaneous auricular vagus nerve stimulation (taVNS), a noninvasive method of stimulating the vagus nerve without surgery, affects the ANS function. Data from this research will enable the possibility of detecting early and significant changes in ANS from "normal" homeostasis to diagnose disease onset and assess severity to improve treatment protocols.
The purpose of this study is to see if some people with postural tachycardia syndrome (POTS) have higher levels of immune proteins (autoantibodies) directed against receptors of the autonomic nervous system, and if these autoantibodies make a difference in their POTS symptoms. The investigators also want to see if the levels of these autoantibodies stay the same over time.
The purpose of this study is to evaluate if the variability of biological signals, such as heart rate and temperature, can predict weaning from mechanical ventilation in patients with failure to wean.
This study (https://pdrisk.ninds.nih.gov) will determine if people who have risk factors for Parkinson disease (PD) have biomarkers (objective ways to measure a disease process) that show that the disease process is actually going on, and if people who have abnormal biomarkers go on to develop PD during several years of follow-up. Biomarkers of Parkinson disease (PD) might identify people who are healthy now but may develop the disease later in life. Healthy volunteers and people who have certain risk factors for developing PD who are between 18 and 70 years of age may be eligible for this study. People with the following risk factors are included: * Family history of PD * Loss of sense of smell * Fall in blood pressure when standing up * REM behavior disorder (a type of sleep disturbance) Participants undergo the following tests and procedures: * Screening examination * Medical and neurological history and physical examination * Tests or rating scales for movement, sense of smell, mood, attention, fatigue, pain, and thinking. * Measurement of blood pressure and pulse rate while lying down and then standing up * Blood draw for genetic testing * Inpatient testing at the NIH Clinical Center for 2-3 days, including: * Measurements while blowing against a resistance * Measurements of blood pressure and pulse rate * Blood draws for levels of various chemicals * PET and MRI scanning * Lumbar puncture (spinal tap) * Electrocardiogram * Skin electrical conduction test (test of sweat production) * Skin and core temperature measurements * Transcranial ultrasound (sound-wave test of the head) * Follow-up testing (up to five visits in 18-month intervals) to repeat some of the tests listed above, excluding the genetic testing and spinal tap
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.
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.
A common complaint among patients with Postural Tachycardia Syndrome (POTS) is "brain fog" or difficulty concentrating. This problem is poorly understood. The purpose of this study is to better understand the cognitive dysfunction associated POTS, and to determine optimal treatment strategies for this condition. In this study, the investigators will test the hypothesis that acute administration of the psychostimulant drug modafinil can improve seated measures of cognitive function in patients with POTS.
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.
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.
The purpose of this study is to learn more about the effectiveness of a prescription wrist-wearable device called NightWare (NW) on improving sleep in Veterans with nightmares related to posttraumatic stress disorder (PTSD). The investigators also want to learn whether it improves cardiovascular health among this population.
Levodopa is a precursor of dopamine and is the treatment of choice to treat the motor symptoms of Parkinson's disease (PD); however, the effect of levodopa on cardiovascular autonomic function in PD is poorly understood. Orthostatic hypotension has been documented as a potential side effect of levodopa. As a result, clinicians may be reluctant to prescribe levodopa in patients with PD with neurogenic orthostatic hypotension (PD+OH), which leads to suboptimal management of motor symptoms. On the other hand, other studies failed to show any clear relationship between levodopa and orthostatic hypotension in patients with PD. Important limitations of prior studies include the lack of detailed investigation of baroreflex cardiovagal and sympathetic noradrenergic functions and the fact that the same patients were not tested on and off levodopa. The investigators propose to investigate the effects of levodopa on cardiovascular autonomic function in patients with PD+OH and PD without neurogenic orthostatic hypotension (PD-OH) by performing standardized autonomic testing in the same patients on and off levodopa.
The purpose of this study is to perform first-in-human PET imaging studies of two new cardiac sympathetic nerve imaging agents, 4-\[18F\]fluoro-meta-hydroxyphenethylguanidine (\[18F\]4F-MHPG) and 3-\[18F\]fluoro-para-hydroxyphenethylguanidine (\[18F\]3F-PHPG).
The primary objective of this trial is to measure changes in physiologic signals to quantify the status of the autonomic nervous system during opioid withdrawal and cravings.
This trial's main aims are to investigate the feasibility of implementing our novel assessment battery in tandem with normal and customary chiropractic care in a practice-based setting using a pediatric population with parent-reported SPD. More specifically, our primary endpoints are 1) recruitment rate, 2) tolerability, 3) adherence, 4) retention, 5) efficiency, and 6) data quality.
Alcohol use disorder (AUD) is a major health concern amongst Veterans as it causes functional impairments and decreased quality of life. Current AUD treatments show limited effectiveness in reducing withdrawal-related psychological and physical distress, which drives the urge to drink to relieve these symptoms. The investigators propose the vagus nerve, which is the primary nerve of the "rest and digest" branch of the autonomic nervous system via its bidirectional connections between the brain and the body, as a novel treatment target for AUD. The goal of this study is to assess treatment efficacy and mechanism of action. Noninvasive neuromodulation technologies offer the possibility for innovative, low risk treatments to support the rehabilitation and community reintegration of Veterans with AUD.
The goal of this flexible single-subject design vagus nerve stimulation (VNS) study is to examine the behavioral, cognitive, and biorhythmic effects of VNS in children and adults with autism and developmental disabilities. The main aims are: * Pilot the creation of a profile for those who will respond to VNS with the long-term goal of designing clinical trials. * Examine the effects of VNS on a broad range of symptoms. Participants will select between 1, 2, or 3 months of daily VNS treatment and complete study visits each month.
Heart rate variability biofeedback (HRVB) is an biobehavioral intervention involving rhythmic breathing at resonance frequency that stimulates cardiovascular regulatory systems to help individuals better regulate affect and bolster cognitive control. This intervention has already shown its potential as a substance use disorder (SUD) treatment tool, but practical limitations of its accessibility, labor intensiveness, and cost have previously prevented this intervention from going to scale. Second-generation, ambulatory HRVB technology, however, has overcome these limitations and now allows patients to practice HRVB in-the-moment when its needed most. This study is testing the efficacy of second-generation, ambulatory HRVB for the first time with individuals with SUD.