Active clinical trials for "Primary Dysautonomias"

An assessment of the effectiveness of Stellate Ganglion Block in alleviating symptoms of Long COVID-19.

Post-Covid syndrome is defined as symptoms that develop in addition to respiratory symptoms in individuals who have had Covid-19 infection for more than 12 weeks. Symptoms such as fatigue, headache, cognitive impairment, dyspnea, heart palpitations, heat intolerance, digestive system disorders, sleep disorders, dermal problems, orthostatic intolerance come to the fore in individuals with post-Covid syndrome. It has been tried to be revealed in some studies that Covid-19 infection affects the autonomic nervous system (ANS) and the relationship between Post-Covid 19 syndrome and ANS dysfunction. Heart rate variability (HRV) measurement method can be used to evaluate ANS activity. HRV is a non-invasive method and is a measure of the change in heart rate over a period of time. HRV is a scalar quantity that shows the time between two beats of the heart and defines the oscillations between the R-R intervals. In HRV measurements, time-dependent and frequency-dependent measurement results are obtained and from these measurements, time-dependent RMSSD (square root of the square of the difference of the R-R intervals) and frequency-dependent high-frequency (HF) and low frequency (LF) measurement components are used in relation to the sympathetic nervous system (CNS) and parasympathetic nervous system (PSS). HRV can be measured in short-term (5 minutes) in terms of measurement time. The aim of this study is to clearly reveal the relationship between Post-Covid 19 syndrome and ANS dysfunction and to provide standardization related to HRV measurement method and sub-parameters.

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

To determine whether the changes in blood pressure (BP) which occur following meals in normal people and patients who have substantial falls in BP after a meal postprandial hypotension (PPH)) are associated with changes in cardiac function. Eligible subjects who have been previously diagnosed with PPH will report to the Queen Elizabeth Hospital, on two occasions, following an overnight fast. Subjects will be cannulated and have a BP cuff placed around their upper arm. Following this, subjects will ingest either a drink containing 75 grams of glucose and 150mg of a C13 Acetate (which is metabolised and excreted in the breath, enabling noninvasive measurements of gastric emptying), made up to 300mL water, or on the other study day, 300mL water alone. The order of the study days will be randomised. Following the drink, for 3 hours, measurements will be taken at regular intervals of BP, heart rate, breath samples (on the study day with the Acetate only), blood samples (for measurement of blood glucose and gut hormones) and transthoracic echocardiography (TTE) (for assessment of end systolic and diastolic cardiac volume, cardiac output, cardiac contractility and diastolic function). After the 3 hours of measurements, the cannula will be removed and subjects will be offered lunch prior to leaving the department. Following lunch, on one study day, subjects will have their autonomic nerve function tested noninvasively, using an ECG.

The American College of Sports Medicine (ACSM) recommends that resistance exercise performed at greater than 70% one repetition maximum (1 RM) is necessary to induce strength gains and muscular hypertrophy (ACSM, 2009). However, previous work has shown resistance exercise at high intensity increases the rate of injury. Blood flow restriction (BFR) exercise is a method that is used to compress the blood vessels to the exercising muscle in order to reduce blood flow to the limb with the use of low-intensity resistance. Researchers have suggested that resistance exercise at intensities as low as 20-30% 1-repetition maximum with BFR increases in muscle mass, muscular endurance, and gains in strength. However, the acute heart and blood vessel changes in response to BFR are not clear. Work by our laboratory (Tai et al., 2016) has demonstrated that immediately following acute resistance exercise at moderate intensity (75% 1 RM) without BFR, there are no changes in aortic and brachial systolic and diastolic blood pressure (BP), but there are increases in the pressure of the reflective wave (augmentation pressure). This suggests that the arterial wall is stiff, and may in turn result in thickening of the arterial wall. However, the data are limited and these responses may not be universally accepted. In addition, these studies used primarily lower-body resistance exercises (squat, leg extension, and leg flexion), and did not assess changes in heart and blood vessel function. Previous researchers have demonstrated that upper-body exercise induces higher BP and heart rate (HR) than lower-body exercise. However, the effects of upper- and lower-body resistance exercise with BFR on heart and blood vessel function are still unclear. Therefore, understanding the effects of upper- and lower-body resistance exercise with BFR on heart and blood vessel function using weight machines, specifically the chess press, latissimus dorsi pulldown, knee extension, and knee flexion may significant impact how the resistance training program is prescribed.

The function of the autonomic nervous system can be assessed using baroreflex sensitivity (BRS) and heart rate variability (HRV). Decreased HRV has been shown to be predictive of morbidity and mortality in diverse medical conditions such as acute myocardial infarction, aneurysmal subarachnoid haemorrhage, autoimmune diseases, sepsis and surgery. The function of the autonomic nervous system has not yet been investigated in a "pure hypovolemia" model. The aim of the current study is therefore to investigate and describe the function of the autonomic nervous system prior to, during and after reduction of blood volume in healthy blood donors.

Symptoms of blood pressure dysregulation, impaired swallowing and digestion are common amongst parkinson patients. The overall aim of this study is to examine blood pressure regulation and esophageal motility and gastric emptying in Parkinson's disease (PD) patients. The investigators hypothesize that - compared to age-matched controls - PD patients display an altered regulation of blood pressure, altered gastroesophageal motility, and delayed gastric emptying. These symptoms occur already early in the disease process, but aggravate with progression of the disease. The investigators will perform a 7-day blood pressure measurement, measurement of central blood pressure and pulse wave velocity, assessment of pulse variability, Schellong tests to assess orthostatic function, high resolution manometry assessments during swallowing acts, and a 13C-sodium octanoate breath test to assess gastric emptying, in 18 PD patients (9 each Hoehn&Yahr stages 1,2) and 12 age- and gender-matched healthy controls. Results will be interpreted in relation to the severity of PD motor symptoms. The investigators anticipate that blood pressure dysregulation and gastroesophageal motility disturbances will be present only in PD subjects, but not in matched controls without neurological disorders and without any extrapyramidal motor signs. Furthermore, the investigators expect to find an association between motor impairment and the severity of these autonomic symptoms, however, that according to the Braak staging, subtle disturbances must already be present in the early stages of PD.

This is a study to compare subject response and symptoms resulting from administration of three clinical assessments. * The 3 assessments are passive upright tilt table testing, quantitative sudomotor axon reflex testing (QSART)and punch biopsy. The comparison of results will be from two subject groups: Group A, the migraine suffering patient with or without aura Group B, the migraine suffering patient with or without aura who has diagnosed orthostatic intolerance (i.e.,feeling dizzy or faint when making a body position change).

Background: Sj(SqrRoot)(Delta)gren s Syndrome (SS) is an autoimmune disease that affects the glands that produce saliva and tears, causing dry eyes and dry mouth. Researchers do not know the exact cause of SS, but they believe that it may be caused by abnormalities in the autonomic nervous system (ANS) that stimulate these glands. Objectives: To better understand ANS function in patients with SS. To compare information about ANS function in healthy individuals and in patients with SS. Eligibility: Patients with Sj(SqrRoot)(Delta)gren s Syndrome who are 18 years of age and older, and who are not pregnant or breastfeeding. Participants will be asked to taper or discontinue the use of certain medications or dietary supplements before the ANS testing. Participants must be willing to discontinue the use of alcohol and tobacco 24 hours prior to testing. Design: The study will require one inpatient admission and/or outpatient visits to the NIH Clinical Center. The following tests and procedures will be performed: Saliva, tear, and sweat production measurements to evaluate the function of glands. Testing of changes to the cardiovascular system, including blood pressure and blood flow testing, and an electrocardiogram designed to evaluate hemodynamic changes controlled by the ANS. Testing of changes to the gastrointestinal system, including a swallowing assessment study, barium swallow study, and gastric emptying study designed to evaluate gastrointestinal function controlled by the ANS. Tests to evaluate the ANS function in response to certain drugs (edrophonium, glucagon and acetylcholine). Self-reported questionnaire on ANS function and emotional/psychological well-being. Additional procedures and tests may include the following: Blood samples. Optional skin biopsy to study sweat glands and nerve supply of the skin.

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.