View clinical trials related to Autonomic Failure.
Filter by:Study on orthostatic Hypotension in Parkinson's disease
People with POTS, autoimmune autonomic neuropathy (AAN), pure autonomic failure (PAF), SFN and Ehlers Danlos Syndrome (EDS) do not only suffer from orthostatic symptoms such as dizziness, headache, neck pain, blurred vision or (pre-) syncope. They also experience deficits in attention and concentration (more precisely deficits in selective perspective, operating speed, executive functions and memory performance) mainly in upright position. Only few studies concerning cognitive impairment in autonomic neuropathies, their frequency, aetiology and therapy exist. Many patients concerned, especially with POTS, report attention deficits and "brain fog" with problems in their everyday life and work, predominantly in upright posture. Specific symptomatic or medical therapies do not exist. Medical treatment with Modafinil is discussed and part of a current study at Vanderbilt Autonomic Dysfunction Centre (1-5). The investigators want to investigate if problems of concentration, attention and/or cognitive dysfunction exist in people with POTS, AAN, SFN and EDS compared to healthy controls (HC). Thus the investigators use detailed clinical, autonomic and neuropsychological tests in different body positions (lying, sitting and standing) as also acute therapy (leg crossing).
Patients referred to neurosurgery routinely and safely undergo deep brain stimulation (DBS) for treatment of symptoms related to neurodegenerative conditions, most commonly Parkinson's disease. In the investigators experience, and published evidence shows, that stimulation has effects on the autonomic nervous system. In patients undergoing therapeutic DBS for a particular subtype of Parkinsonism, Multiple System Atrophy, the further effects on autonomic parameters such as blood pressure and bladder symptoms as well as the originally intended indications (gait and movement disorder) will be investigated. The mechanisms of any effects will also be studied by using a number of techniques such as magnetoencephalography (MEG) and Muscle Sympathetic Nerve Activity (MSNA) recording. Key goals are to: 1. Demonstrate that stimulation of the peduculopontine nucleus (PPN) improves autonomic function and has an attendant improvement on patients' quality of life 2. Investigate the role of the PPN and how it interacts with other brain areas. This translational strategy will lead to a larger efficacy study of DBS for MSA as well as revolutionizing neural-based treatments in other autonomic disorders such as orthostatic hypotension and pure autonomic failure.
Patients with autonomic failure are characterized by disabling orthostatic hypotension (low blood pressure on standing), and at least half of them also have high blood pressure while lying down (supine hypertension). Exposure to heat, such as in hot environments, often worsens their orthostatic hypotension. The causes of this are not fully understood. The purpose of this study is to evaluate whether applying local heat over the abdomen of patients with autonomic failure and supine hypertension would decrease their high blood pressure while lying down. This will help us better understand the mechanisms underlying this phenomenon, and may be of use in the treatment of supine hypertension.
The purpose of this study is to assess if abdominal binders that use pull strings to adjust compression (non-elastic) are more effective than standard elastic abdominal binders in attenuating neurogenic orthostatic hypotension.
This study will explore whether an antibody is influencing the autonomic nervous system, and if its removal will eliminate signs and symptoms of failure in that system. The autonomic nervous system is responsible for many automatic changes involved in everyday activities, such as standing up, digesting food, and exercising in the heat. Antibodies fight germs but sometimes cause health problems. Removal of the antibody is done through a procedure called a plasma exchange. Patients with primary chronic autonomic failure and a circulating antibody to what is called the neuronal nicotinic receptor may be eligible for this study. To be eligible, patients will have participated in an earlier study, protocol number 03-N-0004. Patients will undergo tests and procedures that include an electrocardiogram, and blood collection for hepatitis, HIV, and pregnancy. Blood will be tested for a complete blood count, clotting factors, and chemistries. There will also be tests for liver function, kidney function, cortisol, and thyroid. Participants will be tested for signs and symptoms of autonomic failure, and will be asked to complete questionnaires about various symptoms before the plasma exchange, 1 or 2 weeks afterward, and then monthly or bimonthly for up to 1 year. Patients will undergo a series of other tests. In one test, a patient is upright and blows against a resistance (Valsalva maneuver). The quantitative sudomotor axon reflex test (QSART) uses iontophoresis, involving application of acetylcholine, a chemical messenger, and a small amount of electricity. QSART examines the regulation of sweating, a particular aspect of the autonomic nervous system. There will be a test using edrophonium, given intravenously (IV), to evaluate that drug's effects on the heart, skin, glands, gastrointestinal activity, bladder tone, and salivation. A glucagon test, also by IV, will show patients' ability to release the hormone adrenaline. The plasma exchange will be performed by use of an automated cell separator. Patients' blood will be removed continuously through a needle in the arm. Blood cells will be separated from the plasma by a spinning process and continuously returned to circulation through a needle in the patients' opposite arm. Blood cells that are returned will be mixed with albumin, a sterile replacement solution. A blood thinner, citrate, will be given, to prevent clotting of blood. This whole procedure will take about 2 hours. Patients will typically undergo five exchange procedures in about 10 days while they are inpatients at the NIH Clinical Center. The amount of plasma removed in a single session and the number of sessions will be set by the NIH Blood Bank. It is expected that patients' autonomic failure will improve after several days of starting the plasma exchange. Testing for symptoms of autonomic failure and autonomic function testing will occur about 1 month after the plasma exchange and monthly or bimonthly for up to 1 year. For each visit of testing, patients will be inpatients for about 2 days. If autonomic failure recurs, patients may have a second plasma exchange, with the same follow-up tests, for about 1 year.
The autonomic nervous system serves multiple regulatory functions in the body, including the regulation of blood pressure and heart rate, gut motility, sweating and sexual function. There are several diseases characterized by abnormal function of the autonomic nervous system. Medications can also alter autonomic function. Impairment of the autonomic nervous system by diseases or drugs may lead to several symptoms, including blood pressure problems (e.g., high blood pressure lying down and low blood pressure on standing), sweating abnormalities, constipation or diarrhea and sexual dysfunction. Because treatment options for these patients are limited. We propose to study patients autonomic failure and low blood pressure upon standing and determine the cause of their disease by history and examination and their response to autonomic testing which have already been standardized in our laboratory. Based on their possible cause, we will tests different medications that may alleviate their symptoms.