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NCT04620382
The purpose of this study is to learn more about the effects of abdominal compression and the medication midodrine, two interventions used for the treatment of orthostatic hypotension (low blood pressure on standing), on hemodynamic markers of cardiovascular risk. The study will be conducted at the Vanderbilt University Medical Center and consists of a screening and 2 testing days, one with abdominal compression and one with midodrine. The total length of the study will be about 5 days.
NCT05908760
Neurogenic orthostatic hypotension (nOH) is a chronic condition associated with increased cardiovascular risk and reduced quality of life. On standing, patients with nOH experience a large reduction in blood pressure (BP; at least ≥20/10mmHg, but often much more), which is often accompanied by debilitating symptoms and syncope. A previous study (unpublished) showed that hypercapnia significantly increases standing BP in patients with nOH. Human bodies naturally produce and exhale CO2. Rebreathe devices offer a simple, cost-effective technology to increase arterial CO2. In brief, rebreathe devices work by capturing expired CO2, which is then re-inhaled. The net effect is a transient increase in CO2. A CO2 rebreathing device may offer a novel hemodynamic therapy for patients with nOH. This is a pilot, proof-of-concept study to evaluate a CO2 rebreather to improve blood pressure and orthostatic tolerance in patients with nOH. The hypothesis is that a rebreather will increase CO2 sufficiently enough to improve BP in patients with nOH. Male and female patients (n=28) will be asked to complete two randomized 70° head-up tilt (HUT) tests breathing either room air or using a CO2 rebreather. Hemodynamics (BP, heart rate, stroke volume, brain blood flow) and orthostatic symptoms will be assessed throughout. Breath-by-breath data will include O2, CO2, respiration rate and tidal volume. The primary outcome measure will be the magnitude of the BP response (ΔBP = HUT - Supine) during Room Air vs. Hypercapnia. The primary outcome will be compared between room air and hypercapnia using a paired t-test.
NCT07089043
This is a study to evaluate the effects of CST-3056 on orthostatic symptoms and signs in subjects with neurogenic orthostatic hypotension (nOH).
NCT01799915
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.
NCT06751888
This study focuses on neurogenic orthostatic hypotension (nOH), which is a disorder characterized by an abnormal drop in blood pressure (BP) within 3-minutes of standing. Patients with nOH experience debilitating symptoms including light-headedness, falls, and fainting. Patients often struggle with day-to-day tasks that require standing, with a reduced quality-of-life. Current therapies for nOH have limited effectiveness and unwanted side effects. Our lab has found that raising blood CO2 levels (hypercapnia) in the lab increases BP when standing in patients with nOH. We now aim to test the CarboHaler, an exogenous controlled CO2 delivery device, in this study to see if increasing CO2 levels through controlled CO2 inhalation can improve BP and reduce symptoms in patients with nOH when standing up. On the study day, participants will undergo two Head-up Tilt (HUT; upright) tests with different breathing protocols: one with and one without exogenous CO2 delivery provided by a CO2 inhalational device. We will record heart rate, blood pressure, and breathing parameters. We will also assess upright symptoms using the Vanderbilt Orthostatic Symptoms Score. Our primary outcome is the magnitude of the change in systolic BP from lying down to standing, which will be compared with and without exogenous CO2 delivery. We hypothesize that exogenous CO2 delivery provided by a CO2 inhalational device will raise CO2 enough to increase standing BP, which could reduce the debilitating symptoms experienced by patients with nOH. We hope that these data will support future clinical trials, with the long-term goal of creating a simple, low-cost treatment for increasing quality-of-life for patients with nOH.
NCT01132326
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.
NCT02784535
Drug therapy for patients suffering from autonomic failure and neurogenic orthostatic hypotension are scarce and not effective. If left untreated, these patients have the highest risk of syncope, falls and fall-related injuries. The proposed study will determine the clinical benefit of a commercially available drug, atomoxetine, to reduce symptoms associated with neurogenic orthostatic hypotension in patients with autonomic failure.
NCT04976101
Neurogenic orthostatic hypotension occurs in a significant number of people and has no effective treatment. Neurogenic orthostatic hypotension is associated with intermittent episodes of fainting which can be debilitating for the patients. Using sinusoidal galvanic vestibular stimulation, an oscillating current between the two ears, collaborators have discovered an effective technique to habituate anesthetized rats that develop vasovagal responses. The investigators propose to determine whether a similar use of sinusoidal galvanic vestibular stimulation can eliminate or alleviate neurogenic orthostatic hypotension and the associated syncope in susceptible human subjects. If so, then sinusoidal galvanic vestibular stimulation, which is safe and widely used to study muscle sympathetic nerve activity, can be used in humans, who have a history of syncope and a positive tilt test to habituate vasovagal responses. Habituation will be accomplished using repetitive periods of sinusoidal galvanic vestibular stimulation in two 30min sessions three times/week for 2 weeks. Similar 1 hour sessions are routinely used by others when activating muscle sympathetic nerve activity with sinusoidal galvanic vestibular stimulation without harm to the subjects. The 30 min periods were chosen because this was effective in producing habituation of vasovagal responses. The habituating stimulus will be given by applying paste electrodes over the mastoid processes and plugging the leads into a battery driven-stimulus box, which when activated by a switch, will provide a very low frequency bipolar, ± 2 mA, 0.025 Hz oscillating current sinusoidal galvanic vestibular stimulation between the mastoids. Subjects will be seated during the stimulation. The onset and end of the stimulation period will be denoted by tones, and the subjects will be free to watch television, read, or listen to music while they are being stimulated. The effectiveness of the habituation will be determined in several ways: 1) Subjects will keep a history of the number of episodes of syncope in the inter-test intervals. 2) They will have tilt tests at the beginning and end of habituation. 3) Their blood pressure and heart rate will be recorded and the investigators will determine if there is a loss of low frequency (0.025 Hz) oscillations, which the investigators have found in animal models to disappear when the animals are habituated. 4) Habituation should be accompanied by an increase in heart rate to counteract the fall in blood pressure.
NCT03750552
A Phase 3 study to evaluate efficacy, safety, and tolerability of ampreloxetine (TD-9855) in subjects with primary autonomic failures (MSA, PD, or PAF) and symptomatic nOH with up to 4 weeks of treatment.
NCT03229174
This is a double blind placebo controlled trial in Parkinson's disease (PD) patients with neurogenic orthostatic hypotension (NOH). Investigators hypothesize that the study drug (droxidopa) may improve cerebral perfusion more robustly than systemic BP, possibly by direct action within the CNS vasculature. This study is designed to determine if droxidopa improves cerebral perfusion measures in PD patients with NOH, in addition to peripheral BP measures and subjective responses.
NCT00977171
A subset of patients suffering from chronic fatigue syndrome exhibit symptoms of neurally mediated hypotension. While the underlying pathophysiology of chronic fatigue syndrome is not precisely understood, a dysfunction of the autonomic nervous system is thought to play a role in this subset of patients. In several small studies, subjects within this subset have noted improvement in their chronic fatigue symptoms when treated for their neurally mediated hypotension. As droxidopa acts on the autonomic nervous system and has been shown to ameliorate symptoms of neurally mediated hypotension, it is hypothesized that droxidopa could aid in the treatment of chronic fatigue symptoms. Neurally mediated hypotension has been associated with patients suffering from chronic fatigue syndrome. Droxidopa meanwhile has been approved in Japan for the treatment of the symptoms of neurogenic orthostatic hypotension. As such, it is hypothesized that regulating the autonomic nervous system in patients with Chronic fatigue syndrome may prove to be clinically beneficial.
NCT00758849
The purpose of this study is to determine whether Fipamezole is effective in the treatment of orthostatic hypotension and related symptoms in multiple system atrophy and Parkinson's disease.