View clinical trials related to Pure Autonomic Failure.
Filter by:The purpose of this study is to learn more about the effects of midodrine and droxidopa, two medications used for the treatment of orthostatic hypotension (low blood pressure on standing), on the veins of the abdomen of patients with autonomic failure. The study will be conducted at Vanderbilt University Medical Center, and consists of 2 parts: a screening and 2 testing days. The total length of the study will be about 5 days. About 34 participants will be screened for the study.
Compression garments have been shown to be effective in the treatment of orthostatic hypotension in autonomic failure patients. The purpose of this study is to determine the hemodynamic mechanisms by which abdominal compression (up to 40 mm Hg) improve the standing blood pressure and orthostatic tolerance in these patients, and to compare them with those of the standard of care midodrine. The investigators will test the hypothesis that abdominal compression will blunt the exaggerated fall in stroke volume and the increase in abdominal vascular volume during head up tilt.
Synucleinopathies are a group of rare diseases associated with worsening neurological deficits and the abnormal accumulation of the protein α-synuclein in the nervous system. Onset is usually in late adulthood at age 50 or older. Usually, synucleinopathies present clinically with slowness of movement, coordination difficulties or mild cognitive impairment. Development of these features indicates that abnormal alpha-synuclein deposits have destroyed key areas of the brain involved in the control of movement or cognition. Patients with synucleinopathies and signs of CNS-deficits are frequently diagnosed with Parkinson disease (PD), dementia with Lewy bodies (DLB) or multiple system atrophy (MSA). However, accumulation of alpha-synuclein and death of nerve cells can also begin outside the brain in the autonomic nerves. In such cases, syncucleinopathies present first with symptoms of autonomic impairment (unexplained constipation, urinary difficulties, and sexual dysfunction). In rare cases, hypotension on standing (a disorder known as orthostatic hypotension) may be the only clinical finding. This "pre-motor" autonomic stage suggests that the disease process may not yet have spread to the brain. After a variable period of time, but usually within 5-years, most patients with abnormally low blood pressure on standing develop cognitive or motor abnormalities. This stepwise evolution indicates that the disease spreads from the body to the brain. Another indication of this spread is that acting out dreams (i.e., REM sleep behavior disorder, RBD) a problem that occurs when the lower part of the brain is affected, may also be the first noticeable sign of Parkinson disease. The purpose of this study is to document the clinical features and biological markers of patients with synucleinopathies and better understand how these disorders evolve over time. The study will involve following patients diagnosed with a synucleinopathy (PD/DLB and MSA) and those believed to be in the "pre-motor" stage (with isolated autonomic impairment and/or RBD). Through a careful series of follow-up visits to participating Centers, we will focus on finding biological clues that predict which patients will develop motor/cognitive problems and which ones have the resilience to keep the disease at bay preventing spread to the brain. We will also define the natural history of MSA - the most aggressive of the synucleinopathies.
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.