Active clinical trials for "Pure Autonomic Failure"

Anti alfa-3 and alfa-7 ganglionic cholinergic receptors (anti-AChRs) antibodies (Abs) plasma removal by plasmapheresis (1,2) acutely improved dysautonomia symptoms in case reports with Pure Autonomic Failure (PAF) (3). We shall assess the prevalence of anti-AChRs Ab and the relationship among Ab titer, cardiovascular autonomic profile and symptoms in neurodegenerative diseases characterized by similar dysautonomia symptoms such as PAF, Amyotrophic Lateral Sclerosis (ALS) and Postural Orthostatic Tachycardia Syndrome (POTS) (4). Ab positive patients will undergo selective immunoabsorption once a week up to achievement of Ab titer lower than 65% of baseline followed by immunosuppressive therapy with prednisone. Both Ab positive and negative groups will undergo anti-AChR Abs, autonomic profile and dysautonomia symptoms assessment, every 4 months up to 3 years. Evidence of correlation among reduced Ab titer and autonomic profile and symptoms improvement may result in new effective therapy.

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 evaluate the effect of the antihypertensive drug, nebivolol (Bystolic), compared to metoprolol (Lopressor) and sildenafil (Viagra) on blood pressure in patients with autonomic failure and supine hypertension.

Alprazolam (Xanax) will blunt the body's ability to defend itself from low blood sugar.

It is unclear what effect selective serotonin reuptake inhibitors (SSRIs) have on hypoglycemia. Thus, the American Hospital Formulary Service recommends careful monitoring of blood glucose levels in all patients with diabetes initiating or discontinuing SSRIs (Katz et al., 1996). Because of the increased prevalence of depression in those with diabetes, it is critical to discover what affect the antidepressant therapy may have on counterregulatory responses to hypoglycemia. This study hypothesizes that chronic administration of SSRIs may result in a blunted counterregulatory response to hypoglycemia, thereby leaving individuals more susceptible to hypoglycemia.

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.

Study on orthostatic Hypotension in Parkinson's disease

Elevations of plasma cortisol, a stress hormone, during prior episodes of low blood sugar (hypoglycemia) appear to be responsible for the deficient responses during subsequent hypoglycemia. Our specific aim is to determine if dehydroepiandrosterone (DHEA), a hormone with anti-corticosteroid actions, can prevent hypoglycemia associated autonomic failure in type 1 diabetic volunteers.

This research study will be conducted in patients with primary autonomic failure, a disabling condition that is associated with low blood pressure upon standing. These patients are also not able to control for changes in their blood pressure due to a loss of cardiovascular reflexes that are mediated within the brain. The purpose of this study is to determine whether magnetic resonance spectroscopy (MRS), a non-invasive imaging technique, can measure levels of chemicals (neurotransmitters) in the dorsal medulla, a brain area important for control of cardiovascular function, in autonomic failure patients. Importantly, this study will determine whether there are differences in brain chemicals between patients with peripheral versus central origins of their autonomic failure. The hypothesis is that the neurotransmitter profile in the medulla will be intact in patients with peripheral autonomic failure compared to those with central impairment. Overall, this study will provide insight into understanding the mechanisms involved in autonomic failure and will determine whether a single session of MRS imaging can improve the ability to make an accurate diagnosis in these patients. This would lessen the need for more extensive and invasive clinical testing.

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.