View clinical trials related to Pure Autonomic Failure.
Filter by:The aim of the study is to evaluate the autonomic failure in Parkinson's disease by clinical, electrophysiological and neuropathological examination.
Exercise is a cornerstone of diabetes management. It helps reduce blood pressure, promote weight loss, lower insulin resistance and improve glucose and lipid (triglyceride and HDL-cholesterol) profiles. Unfortunately, the benefits of exercise are often not embraced by diabetic individuals because of the fear of low blood sugar (hypoglycemia). My laboratory has demonstrated that Autonomic nervous system (ANS) counterregulatory failure plays an important role in exercise associated hypoglycemia in Type 1 DM. ANS responses are significantly reduced in Type 1 DM and are further blunted by antecedent episodes of hypoglycemia. Furthermore, there is a large sexual dimorphism of reduced ANS responses during submaximal exercise in both Type 1 DM and healthy individuals that is unexplained. Accumulating data are demonstrating that serotonergic pathways can regulate ANS discharge. Generally, serotonergic pathways are inhibitory but both single and longer term administration of selective serotonin reuptake inhibitors (SSRI's) such as Prozac has been demonstrated to increase basal epinephrine levels and enhance baroreflex control of Sympathetic nervous system (SNS) activity. What is unknown is whether fluoxetine can also enhance SNS responses and also override the large ANS sexual dimorphism present during sub maximal exercise. Therefore, the purpose of this study is to determine if the SSRI fluoxetine (Prozac) can improve SNS responses during exercise.
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.
The autonomic or automatic nervous system helps control blood pressure. Diseases of the autonomic nervous system may result in a drop in blood pressure on standing in many cases leading to fainting. Diseases that affect the autonomic nervous system include pure autonomic failure, multiple system atrophy and Parkinson's disease, and can present with very similar symptoms and it is sometimes difficult to determine an exact diagnosis. The purpose of the study is to find out if the blood pressure response from taking a single dose of the medication atomoxetine can help in the diagnosis of these diseases.
The purpose of this study is to test the hypothesis that angiotensin II plays a role in the supine hypertension of primary autonomic failure. To determine the contribution of angiotensin II to renin and blood pressure regulation in autonomic failure, patients with multiple system atrophy [MSA] or pure autonomic failure [PAF] and supine hypertension will undergo medication testing with the angiotensin II receptor blocker losartan. The investigators will compare the biochemical and hemodynamic effects between MSA and PAF patients. In a subset of patients, the investigators will also give the ACE inhibitor captopril. Our primary endpoint will be changes in plasma renin activity, and subsequent components of the circulating renin-angiotensin system, in response to angiotensin II blockade. Our secondary outcome will be changes in hemodynamic measures during administration of these drugs.
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.
Symptomatic NOH in patients with primary autonomic failure is thought to be a consequence of norepinephrine depletion leading to a diminished capacity to effect an appropriate cardiovascular response to an orthostatic challenge resulting in symptomatic cerebral-hypoperfusion. Droxidopa augments norepinephrine levels which should lead to improved cerebral perfusion following orthostatic challenge thereby reducing the symptoms of NOH. The present study will evaluate the long-term safety of droxidopa.
The purpose of this study is to test the hypothesis that endothelin plays a role in the pathogenesis of supine hypertension in pure autonomic failure by increasing vascular resistance. To gauge its contribution to blood pressure regulation, pure autonomic failure and multiple system atrophy patients with supine hypertension will undergo a medication testing with the endothelin blocker, BQ123. We will compare the hemodynamic effects between PAF and MSA patients. Our primary endpoint will be the decrease in blood pressure during the administration of this compound.
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.
The purpose of this study is to see whether droxidopa is effective in treating symptoms of neurogenic orthostatic hypotension in patients with Primary Autonomic Failure (Pure Autonomic Failure, Multiple System Atrophy, Parkinson's Disease), Non-diabetic neuropathy, or Beta Hydroxylase deficiency.