73 Clinical Trials for Autonomic Nervous System
This trial aims to perform an exploratory, mechanistic, randomized double-blind sham-control trial in healthy participants to assess the physiologic effects of a single 60 minutes session of bilateral taVNS, on neural networks and autonomic function.
Low level transcutaneous vagus nerve stimulation (LLTS) involves delivery of electrical impulses transcutaneously at the auricular branch of vagus nerve and it has been shown to have anti-inflammatory and anti-arrhythmic effects. In previous studies from our laboratory, we found that LLTS significantly suppressed atrial fibrillation (AF) inducibility and decreased AF duration. The anti-arrhythmic effects of LLTS were similar to those delivered to the cervical VN trunk. LLTS for just one hour significantly shortened the AF duration and decreased inflammatory cytokines. We have also shown that LLTS leads to favorable heart rate variability (HRV) changes and cardiac mechanics in patients with diastolic dysfunction. These results support the use of LLTS as a novel non-pharmacological, non-ablative treatment modality for AF and possibly other inflammatory conditions. However, the optimal stimulation parameters of LLTS remain to be determined. In this study, we aim to examine the effect of 2 different frequencies (5Hz and 20Hz) and 2 different amplitudes (50% below the pain threshold and 1mA below the pain threshold) of LLTS on heart rate variability with deep breathing (HRVdb), mental arithmetic stress test (MAST), frequency domain measures of heart rate variability (HRV) and brain stem evoked potentials (BSEVP) in healthy volunteers and patients with AF or heart failure with preserved ejection fraction (HFpEF). HRV is a marker of vagus nerve activity and can be easily measured by software calculating the distance between consecutive R waves on the ECG. BSEVP are a surrogate for the central projections of the vagus nerve. Patients will be randomized into 4 groups in a 2x2 factorial design. LLTS will be delivered through a transcutaneous electrical nerve stimulation (TENS) device for 15 minutes. HRVdb, HRV and BSEVP will be measured before and after LLTS and compared.
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.
Alpha-synucleinopathies refer to age-related neurodegenerative and dementing disorders, characterized by the accumulation of alpha-synuclein in neurons and/or glia. The anatomical location of alpha-synuclein inclusions (Lewy Bodies) and the pattern of progressive neuronal death (e.g. caudal to rostral brainstem) give rise to distinct neurological phenotypes, including Parkinson's disease (PD), Multiple System Atrophy (MSA), Dementia with Lewy Bodies (DLB). Common to these disorders are the involvement of the central and peripheral autonomic nervous system, where Pure Autonomic Failure (PAF) is thought (a) to be restricted to the peripheral autonomic system, and (b) a clinical risk factor for the development of a central synucleinopathy, and (c) an ideal model to assess biomarkers that predict phenoconversion to PD, MSA, or DLB. Such biomarkers would aid in clinical trial inclusion criteria to ensure assessments of disease- modifying strategies to, delay, or halt, the neurodegenerative process. One of these biomarkers may be related to the neurotransmitter dopamine (DA) and related changes in the substantia nigra (SN) and brainstem. \[18F\]F-DOPA is a radiolabeled substrate for aromatic amino acid decarboxylase (AAADC), an enzyme involved in the production of dopamine. Use of this radiolabeled substrate in positron emission tomography (PET) may provide insight to changes in monoamine production and how they relate to specific phenoconversions in PAF patients. Overall, this study aims to identify changes in dopamine production in key regions including the SN, locus coeruleus, and brainstem to distinguish between patients with PD, MSA, and DLB, which may provide vital information to predict conversion from peripheral to central nervous system disease.
Supine hypertension is a common problem that affects at least 50% of patients with primary autonomic failure. Supine hypertension can be severe and complicates the treatment of orthostatic hypotension. The purpose of this study is to assess whether continuous positive airway pressure (CPAP) decreases blood pressure in autonomic failure patients with supine hypertension.
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 during the night would decrease their nocturnal 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 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.
This study looks to characterize gradients of dysfunction in the autonomic nervous system in patients with clinically diagnosed multiple sclerosis. The autonomic nervous system plays key roles in regulation of blood pressure, skin blood flow, and bladder health- all issues that individuals with multiple sclerosis typically suffer. Focusing on blood pressure regulation, the most precise metric with broad clinical applicability, the investigators will perform laboratory-based tests to probe the body's ability to generate autonomic responses. For both individuals with multiple sclerosis and uninjured controls, laboratory-based experiments will utilize multiple parallel recordings to identify how the autonomic nervous system is able to inhibit and activate signals. The investigators anticipate that those with autonomic dysfunction with multiple sclerosis will exhibit abnormalities in these precise metrics. The investigators will look to see if any substantial connections exist between different degrees of preserved autonomic function and secondary autonomic complications from multiple sclerosis. In accomplishing this, the investigators hope to give scientists important insights to how the autonomic nervous system works after multiple sclerosis and give physicians better tools to manage these secondary autonomic complications.
Disorders of gut-brain interaction (DGBI) affect up to 25% of U.S. children. Patients often suffer from disabling, multisystem comorbidities that suggest a common root (sleep disturbances, fatigue, anxiety, etc). Yet, DGBI are defined and treated based on GI symptom origin (cyclic vomiting, dyspepsia, irritable bowel) rather than underlying pathophysiology. Many patients manifest comorbidities suggesting an underlying autonomic nervous system (ANS) dysregulation (palpitations, dizziness, cognitive dysfunction). Unfortunately, due to common features of anxiety and visceral hyperreactivity and lack of obvious pathology, children with DGBI are frequently diagnosed with psychosomatic or 'benign, functional disorders' and treated with empiric antidepressants despite lack of scientific support and risks of serious side effects. Little is known about the underlying brain-gut mechanisms linking these comorbidities. A lack of targeted treatment options naturally follows the paucity of mechanistic data. A dysregulated ANS response circuit via brainstem nuclei is linked to visceral hypersensitivity. As the team's prior research has shown, ANS regulation can be non-invasively measured via several validated indices of cardiac vagal tone. Using the novel vagal efficiency (VE) metric, the investigators have demonstrated inefficient vagal regulation in cyclic vomiting syndrome and pain-related DGBI and that low VE predicts response to non-invasive, auricular percutaneous electrical nerve field stimulation (PENFS) therapy. PENFS targets brainstem vagal afferent pathways and, along with brain-gut interventions such as hypnotherapy, are the only therapies currently proven effective for pediatric DGBI. Individualizing neurostimulation based on sensory thresholds while assessing dynamic ANS reactivity offers a path towards personalized medicine using the most effective therapies to date. This proposal will test the feasibility of an ANS tracking software in assessing real-time, autonomic regulation and providing individualized neurostimulation in children with nausea/vomiting and ANS imbalance.
This study seeks to determine if diagnosing cardiac autonomic dysfunction (AD) can be done remotely with the same accuracy as in-person testing. If so, the identification of AD could happen sooner, facilitating remote studies of the condition and potentially reducing the risk of illness. Childhood cancer survivors, particularly survivors of acute lymphoblastic leukemia (ALL) and Hodgkins's lymphoma (HL), appear to be at increased risk for AD. Primary Objectives: * To determine the sensitivity and specificity of heart rate variability (HRV), measured remotely with biosensor technology (Actigraph LEAP), compared to in-person assessment using the Ewing battery as the reference standard to identify cardiac autonomic dysfunction (AD) among survivors of leukemia and lymphoma. * To determine the sensitivity and specificity of the Composite Autonomic Symptom Scale 31 (COMPASS31) compared to the Ewing battery to identify AD among leukemia and lymphoma survivors.
This study is a randomized, single-blind, two-arm sham-controlled clinical trial to evaluate the safety and efficacy of transcutaneous spinal cord stimulation (tSCS) over the lower thoracic and upper lumbar spinal cord segments for cardiovascular function in adults (21-65 years old) with cervical and upper thoracic spinal cord injury (SCI) (≥T6) AIS A-D during inpatient rehabilitation and outpatient visits within three months after the onset. We will recruit 26 individuals with SCI, admitted to inpatient rehabilitation facilities (IRFs) or after discharged from IRFs. We will also examine the effect of tSCS on lower urinary tract (LUT) and bowel functions as secondary outcomes. The main questions this study aims to answer are: 1. Assess the safety of single and repeated tSCS session(s) on cardiovascular function in the acute SCI: We will test the safety of single tSCS at T10-L2 session at rest and during orthostatic challenge (i.e., situ-up tests) at the baseline and the effect of five tSCS sessions on cardiovascular function in individuals with SCI ≥ T6. 2. Assess the effect of long-term tSCS on autonomic function in the subacute SCI phase: We will investigate the efficacy of long-term (total 18 sessions) tSCS on cardiovascular and pelvic organ functions. 3. Evaluate the sustained effect of tSCS on autonomic recovery six months after the onset of SCI: We will assess the sustained effect of repeated tSCS sessions (18 sessions) on cardiovascular and pelvic organ functions at 6-month post-SCI. Participants will: * Receive either transcutaneous spinal cord stimulation or "sham" spinal cord stimulation while inpatient in the first 8 weeks (Part A). * Those willing and able to come after discharge or after the 8 weeks will be asked to come back and complete additional tSCS for a total of 18 weeks (Part B), with a follow-up period of 6 months. All participants will receive tSCS during this outpatient follow-up portion of the study. * During assessment visits the researchers will perform a variety of exams including a neurologic, cardiovascular, pulmonary, bladder and bowel, physical, and autonomic exam, and will ask questions about quality of life and functioning. Participants will be asked to complete a test of how well their bowels are functioning (colonic transit test) and an abdominal X-Ray. Researchers will compare those who receive tSCS to those who receive sham stimulation to see if tSCS is an effective treatment for improving the body's autonomic functioning following recent-onset SCI.
This is a longitudinal study to determine the influence of the menopause transition on autonomic and vascular function. PI Keller-Ross has published data demonstrating that postmenopausal females have greater sympathetic neural reactivity during a stressor compared with age-matched males and younger females and males. A paucity of literature exists, however, on the role of the menopause transition in autonomic function because the majority of experimental studies on menopause physiology are cross-sectional and/or focused on older, postmenopausal females . The influence of age on HTN is robust, whereas the effects of menopause are still unclear. Preliminary data demonstrate a clear association between age and sympathetic activity in females; how the transition through menopause influences these relations, however, remains unknown. The study will enroll 80 midlife (45-55 years of age) females to measure longitudinally the trajectory of autonomic and vascular function during the transition through menopause. The study hypothesizes that through the menopause transition, an increase in sympathetic activity and an impaired baroreflex sensitivity and endothelial function will emerge.
The VIBRANT study aims to validate biosensors to objectively and directly measure symptoms in Rett syndrome and create confidence in the use of these devices in clinical trials. VIBRANT will use several FDA-cleared wearable biosensors and a non-wearable device to collect symptom data from patients with Rett syndrome for up to 9 weeks. Symptoms of interest include heart rate, breathing, sleep, blood oxygen levels, and movement. Participants will use the biosensors intermittently at home, document device use and symptom status, and will come to the clinic for 1 overnight sleep study. A cohort of up to 10 participants receiving an intervention in a separate clinical trial may also enroll and participate on a custom device schedule for up to 1 year. The study will provide information on the feasibility and ease of use for families at home, biosensor data will be compared to data collected at the same time from the overnight sleep study to demonstrate how well they work in individuals with Rett syndrome, and Emerald will be developed to include movement as a measurable symptom.
This study is a platform protocol designed to be flexible so that it is suitable for a wide range of settings within health care systems and in community settings where it can be integrated into COVID-19 programs and subsequent treatment plans. This protocol is a prospective, multi-center, multi-arm, randomized, controlled platform trial evaluating various interventions for use in the treatment of autonomic dysfunction symptoms, including cardiovascular complications and postural orthostatic tachycardia syndrome (POTS), in PASC participants. The interventions tested will include non-pharmacologic care and pharmacologic therapies with study drugs.
This study is a platform protocol designed to be flexible so that it is suitable for a wide range of settings within health care systems and in community settings where it can be integrated into COVID-19 programs and subsequent treatment plans. This protocol is a prospective, multi-center, multi-arm, randomized, controlled platform trial evaluating various interventions for use in the treatment of autonomic dysfunction symptoms, including cardiovascular complications and postural orthostatic tachycardia syndrome (POTS), in Post-Acute Sequelae of SARS-CoV-2 infection (PASC) participants. The interventions tested will include non-pharmacologic care and pharmacologic therapies with study drugs.
This study is a platform protocol designed to be flexible so that it is suitable for a wide range of settings within health care systems and in community settings where it can be integrated into COVID-19 programs and subsequent treatment plans. This protocol is a prospective, multi-center, multi-arm, randomized, controlled platform trial evaluating various interventions for use in the treatment of autonomic dysfunction symptoms, including cardiovascular complications and postural orthostatic tachycardia syndrome (POTS), in PASC participants. The interventions tested will include non-pharmacologic care and pharmacologic therapies with study drugs.
Observational two phase, retrospective and prospective registry study to assess the prevalence of and characterize outcomes of autonomic dysfunction (AD) in patients who undergo bariatric surgery (BS) and to better define the underlying pathophysiology of AD following BS.
The goal of this interventional crossover study is to determine the effects of transcutaneous spinal cord stimulation (TSCS) on the ability to perform moderate exercise and regulate core body temperature in the chronic spinal cord injury community. The main questions it aims to answer are: * What are the effects of active TSCS targeted for BP control on exercise endurance time and HR recovery during submaximal arm cycle ergometry (ACE) as compared to sham TSCS in participants with chronic, cervical SCI? * What are the effects of active TSCS on Tcore responses to cool ambient exposure and on subjective reporting of thermal comfort and thermal sensitivity as compared to sham TSCS. Participants will receive sham and active stimulation while using an arm bicycle or while in a cold room. Participants are free to participate in either the exercise phase, the cold room phase, or both phases of this study. Please note that there no expected long term benefits of this study.
This study aims to determine the effects of transcutaneous spinal cord stimulation to increase blood pressure and use that device to increase exercise endurance time and heart rate recovery during arm cycle ergometry. In addition, the investigators will see if the stimulation helps regulate body temperature when in a cool environment.
The term post-acute COVID-19 syndrome or Long COVID is a disabling syndrome that persists beyond the 3-month convalescence period after COVID-19 infections. This syndrome affects mostly women (\~80%), present with chronic tachycardia and Orthostatic intolerance symptoms without any identifiable cause. In addition, non-specific symptoms such as fatigue, headache, and "brain fog", commonly described in POTS patients are also present in this novel condition, recently named post-COVID-19 tachycardia syndrome, POTS variant. Reduced Vagal activity and unresolved inflammation is post-COVID-19 POTS is hypothesized as the cause of Long COVID
Prospective cohort study evaluating the electrophysiologic and biochemical effects of stellate ganglion block in patients with ventricular tachycardia.
The prevalence of autonomic dysfunction and sleep disordered breathing (SDB) is increased in individuals with spinal cord injury (SCI). The loss of autonomic control results in autonomic dysreflexia (AD) and orthostatic hypotension (OH) which explains the increase in cardiovascular related mortality in these Veterans. There is no effective prophylaxis for autonomic dysfunction. The lack of prophylactic treatment for autonomic dysfunction, and no best clinical practices for SDB in SCI, are significant health concerns for Veterans with SCI. Therefore, the investigators will investigate the effectiveness of mild intermittent hypoxia (MIH) as a prophylactic for autonomic dysfunction in patients with SCI. The investigators propose that MIH targets several mechanisms associated with autonomic control and the co-morbidities associated with SDB. Specifically, exposure to MIH will promote restoration of homeostatic BP control, which would be beneficial to participation in daily activities and independence in those with SCI.
Many persons with autonomic failure often have high blood pressure when lying down (supine hypertension). This study is exploring the impact of decreased venous return to the heart (achieved by raising the head of the bed) to lessen supine blood pressure. If decreased venous return to the heart is effective at lowering supine blood pressure, these approaches may be utilized to treat supine hypertension non-pharmacologically. Raising the head of the bed decreases the amount of blood returning to the heart due to the effects of gravity. In this case, the decreased blood return to the heart may decrease blood pressure.
This study looks to characterize gradients of dysfunction in the autonomic nervous system after spinal cord injury. The autonomic nervous system plays key roles in regulation of blood pressure, skin blood flow, and bladder health- all issues that individuals with spinal cord injury typically suffer. Focusing on blood pressure regulation, the most precise metric with broad clinical applicability, the investigators will perform laboratory-based tests to probe the body's ability to generate autonomic responses. For both individuals with spinal cord injury and uninjured controls, laboratory-based experiments will utilize multiple parallel recordings to identify how the autonomic nervous system is able to inhibit and activate signals. The investigators anticipate that those with autonomic dysfunction after spinal cord injury will exhibit abnormalities in these precise metrics. The investigators will further have research participants wear a smart watch that tracks skin electrical conductance, heart rate, and skin temperature, which can all provide clues as to the degree of autonomic dysfunction someone may suffer at home. The investigators will look to see if any substantial connections exist between different degrees of preserved autonomic function and secondary autonomic complications from spinal cord injury. In accomplishing this, the investigators hope to give scientists important insights to how the autonomic nervous system works after spinal cord injury and give physicians better tools to manage these secondary autonomic complications.
This is a cross-sectional study in which the investigators will determine the impact of premature/early menopause on MSNA, BP and baroreflex sensitivity in younger (≤49 yr old) and older (≥50 yr old) women. Specifically, aim one will determine mechanisms driving autonomic dysregulation of BP in premature and early menopausal women and aim two will determine mechanisms driving autonomic dysregulation of BP in older menopausal women. The study design outlined below will permit testing of aim one and aim two.
Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. It is the most expensive healthcare condition to treat in United States and has a mortality rate of nearly 30%. It is widely known that exaggerated inflammation and imbalance between sympathetic and parasympathetic arms of the autonomic nervous system (ANS) contribute to progression and adverse outcomes in sepsis. The role of unchecked inflammation and unregulated ANS as a potential treatment target is an important gap in our knowledge that should be explored. Cholinergic anti-inflammatory pathway (CAP) is an intricate network where the ANS senses inflammation by vagus nerve afferents and tries to regulate it by vagus nerve efferents to the reticuloendothelial system. The central hypothesis of this pilot clinical trial is that transcutaneous vagus nerve stimulation (TVNS) at tragus of the external ear can activate the CAP to suppress inflammation and improve autonomic imbalance as measured by inflammatory cytokine levels and heart rate variability (HRV) analysis. The investigators plan to randomize patients with septic shock into active and sham stimulation groups and study the effects of vagal stimulation on inflammatory cytokines, HRV and a clinical severity score of sepsis. Both groups will continue to receive the standard of care treatment for sepsis irrespective of group assignments. The investigators hypothesize that 4 hours of TVNS will suppress inflammatory markers and improve the balance between sympathetic and parasympathetic arms of ANS as measured by HRV, resulting in improved Sequential Organ Failure Assessment Score (SOFA). The preliminary data generated from this pilot study will lay the foundation for a larger clinical trial.
The study objective of this project is to examine the mechanisms of the venous distension reflex (VDR) in humans. We hypothesize that COX blockade with ketorolac tromethamine, an intravenous NSAID, will attenuate the muscle sympathetic nerve activity (MSNA) response to limb venous distension. To gain further insight into whether the COX byproducts directly stimulate chemically-sensitive afferents, or enable venodilation and indirectly evoke afferent stimulation, we will measure vein size using 3T MRI during venous distention with and without ketorolac infusions.
This is a minimal risk case-controlled single arm intervention study, including 10 patients with a prior history of takotsubo and 10-age and sex matched healthy controls. Subjects will undergo in laboratory testing to measure autonomic function. They will then undergo a 15-week program of device-guided breathing with remote measures of autonomic function obtained at home. Analysis will determine the reproducibility of home autonomic measures and the provide preliminary data to determine the efficacy of device-guided breathing on autonomic measures and quality of life in patients with takotsubo.
The Center for Autonomic Medicine in Pediatrics (CAMP) has collaborated with doctors from around the world to build the first International ROHHAD (Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation and Autonomic Dysregulation) REDCap (Research Electronic Data Capture) Registry. This registry is an international collaboration with ROHHAD patients and their physicians recruited from around the world. The purpose of this IRB-approved research study is to gain a better understanding of the various health problems ROHHAD patients face with advancing age, and how these relate to each patient's specific medical course. With a better understanding of specific ROHHAD and associated clinical manifestations, we will be able to better anticipate healthcare needs and to provide more accurate guidelines to healthcare providers world-wide in caring for patients with ROHHAD. The study aims to obtain detailed phenotypic information (information about health and well-being) on patients with ROHHAD. Participation would require filling out a confidential survey that asks questions regarding health and past medical history. Involvement in the project is completely voluntary and there is no compensation for taking part. However, this project will help us learn more about this devastating disease, with the goal of advancing treatment.