Autonomic Dysfunction

The aim of this study is to investigate the effects of repetitive transcranial magnetic stimulation (rTMS) added to conventional neurological rehabilitation on heart rate variability (HRV), quality of life, upper extremity muscle strength and autonomic symptoms in patients with stroke.

Post-COVID Condition (PCC) affects roughly 2.1 million Canadians, carrying an annual economic burden of CAD $7.8-50.6 billion. It presents across multiple organ systems with symptoms including fatigue, brain fog, palpitations, and orthostatic intolerance, at an annual cost of CAD $1,675-$7,340 per case. A key mechanism underlying many treatment-resistant PCC symptoms appears to be dysautonomia abnormal autonomic nervous system function driven by immune-mediated sympathetic overactivity. Persistent inflammation (cytokine storms, T/B-cell dysfunction, microclots) sustains sympathetic hyperactivity, which in turn perpetuates systemic inflammation and "sickness behaviors" resembling PCC symptoms. Current treatments including beta blockers, ivabradine, fludrocortisone, and rehabilitation are limited by variable responses, side effects, and the complication of post-exertional symptom exacerbation. Emerging therapies (SSRIs, low-dose naltrexone, antihistamines, HBOT) show promise but lack robust trial evidence. Cervicothoracic sympathetic chain block (CSB) a local anesthetic block of the cervical and upper thoracic sympathetic ganglia is a promising intervention that reduces sympathetic outflow, improves cerebral blood supply, and lowers pro-inflammatory cytokines. Small observational studies (16 studies, 224 patients) show benefit for PCC symptoms, but all lack placebo controls and have significant methodological heterogeneity. The proposed study aims to fill this gap with a double-blind, placebo-controlled RCT to rigorously evaluate CSB's efficacy, magnitude of benefit, and durability in PCC patients.

Chronic musculoskeletal (MSK) pain affects an estimated 20-33% of the global population and is frequently associated with autonomic nervous system dysfunction, characterised by symptoms such as orthostatic intolerance, palpitations, gastrointestinal dysmotility, and fatigue. Conventional treatments often fail to address this autonomic component, limiting their effectiveness. This pilot study investigates whether non-invasive vagus nerve stimulation (nVNS) using the gammaCore Sapphire device can reduce autonomic symptom severity and improve pain in adults with chronic MSK pain and confirmed autonomic dysfunction. RESTORE-MSK is a randomised, single-blind, sham-controlled, crossover pilot study. Twelve participants with chronic MSK pain (lasting 12 weeks or longer) and autonomic dysfunction (COMPASS-31 score of 17 or more) will be recruited from musculoskeletal clinics at Chapel Allerton Hospital, Leeds. Participants will be randomly allocated to receive either active nVNS or sham stimulation first, followed by a 2-week washout period, then crossover to the alternative treatment. Each treatment period lasts 14 days, with participants self-administering the device twice daily (morning and evening). The primary outcome is change in autonomic symptom severity measured by the Composite Autonomic Symptom Score-31 (COMPASS-31). Secondary outcomes include physiological response to the NASA Lean Test, pain severity and interference (Brief Pain Inventory), anxiety and depression (Hospital Anxiety and Depression Scale), quality of life (EQ-5D-5L), intervention acceptability, and recruitment feasibility. This pilot study aims to establish feasibility and proof of concept for a larger randomised controlled trial investigating nVNS as a non-pharmacological treatment option for chronic MSK pain with autonomic dysfunction.

Limiting perioperative tachycardia (aiming for a heart rate \<90 beats per minute throughout the perioperative period) using the ultra-short acting beta-blocker landiolol in patients with cardiovascular risk factors undergoing major surgery might lower the incidence of perioperative myocardial injury. Feasibility of the intervention needs to be proven prior to conduction of a larger trial.

Down syndrome (DS), the most common genetic cause of intellectual disability, is associated with widespread organ dysfunction, including abnormalities in the autonomic nervous system (ANS). The ANS regulates critical functions such as heart rate (HR) and blood pressure (BP), both essential for maintaining homeostasis and supporting physical activity. Individuals with DS often exhibit blunted HR responses to exercise-typically \~30 beats per minute below expected levels-suggesting reduced sympathetic nervous system (SNS) activity. The SNS governs rapid changes in HR and BP during stress by releasing catecholamines: epinephrine (from the adrenal medulla) and norepinephrine (from sympathetic nerve endings). Despite its importance, SNS function has not been comprehensively assessed among individuals with DS. This study addresses a critical knowledge gap by evaluating SNS responses to physiological stressors in individuals with DS. The investigators will measure beat-to-beat HR and BP, along with plasma catecholamine levels, in response to sympathetic activation, comparing individuals with DS to age- and sex-matched controls. Understanding the mechanisms of SNS dysfunction in DS is vital, as it likely underlies reduced exercise capacity and contributes to broader clinical challenges. These insights may guide targeted interventions to improve cardiovascular function, physical capacity, and overall quality of life in this understudied population.

Background: The investigational device, "Task Force® CORE" (TFC, CNSystems Medizintechnik GmbH, Graz, Austria) together with the "Task Force® CARDIO" (TFCARDIO, CNSystems Medizintechnik GmbH, Graz, Austria) medical device software, is a new CE-marked medical device for continuous non-invasive determination of blood pressure (BP), cardiac output (CO) and derived parameters based on the well established CNAP® (continuous non-invasive arterial pressure) technology by CNSystems. Aim: The primary aim of this prospective, method comparison, open study is data acquisition for the performance evaluation of the TFC during autonomic function testing in comparison with an clinically accepted reference method. Setting: The setting of the clinical investigation will be the autonomic function testing laboratory at the Department of Neurology, the University Hospital Center Zagreb. Inclusion criteria: Patients who are over 18 years and who provide written informed consent. Sample size: The study has an calculated sample size of 70 patients. Considering a drop-out rate of 5%, a total of 75 patients will be included. Statistics: Descriptive statistics, values for the percentage error and correlation estimates will be derived. Furthermore, scatterplot, Bland-Altman analysis, concordance analysis of parameter changes and further comparative statistics will be performed.

The goal of this observational study is to assess arterial stiffness and autonomic regulation of blood pressure and heart rate in healthy adults and people with arterial hypertension during orthostatic stress and graded physical exercise. The main objective is to analyze cardiovascular responses to exercise on a cycle ergometer in different subgroups of participants with hypertension. The study includes healthy young adults and older adults with hypertension. Participants undergo standardized assessments including orthostatic testing, graded exercise testing on a cycle ergometer, electrocardiography, and measurement of arterial stiffness parameters such as pulse wave velocity, as well as other vascular and hemodynamic parameters. The results of this study are expected to improve understanding of cardiovascular physiology and autonomic regulation in people with hypertension and may contribute to earlier recognition of autonomic dysfunction and improved clinical management.

The investigators are looking to determine the safety and efficacy of non-invasive transcutaneous spinal cord stimulation (TSCS) in promoting recovery of lower urinary tract (LUT), bowel, sexual, and cardiovascular function, as well as spasticity in individuals with subacute and chronic SCI (time since injury 3-6 months) and the impact on quality of life. The study will be conducted at two sites; site 1 in Canada and site 2 in the Ukraine. Up to 60 subjects will be enrolled; 10 adults at the ICORD, University of British Columbia (UBC), Vancouver, Canada site and 50 adults at the Rivne Regional War Veterans Hospital, Rivne, Ukraine. Eligible participants will be randomized (1:1 ratio) either to Group 1 (G1) or Group 2 (G2). G1 will receive therapeutic TSCS for 8 weeks (3 times per week; 1 hour per session) in conjunction with conventional rehabilitation (3-4 hours per day; 5 days per week). G2 will receive 8 weeks of sham stimulation in conjunction with conventional rehabilitation. After 8 weeks, G2 will cross over and receive therapeutic TSCS for 8 weeks, whereas G1 will continue to receive TSCS therapy for another 8 weeks, for a total of 16 weeks. Eligible participants enrolled into the study will attend fifty eight (58) visits for assessments, therapy, and follow-up. The expected duration of study participation for each participant will be 33 weeks.

Parasympathetic nervous system (PNS) is part of the body's autonomic nervous system(PNS) protects body against inflammation. Study shows that reduced PNS function activity is associated with persistent inflammation. Preliminary data from the studies shows, that post-COVID-19 POTS patients have reduced parasympathetic (PNS) function. Given that the PNS protects against inflammation, this clinical trial aims to prove that post-COVID-19 POTS is caused by reduced PNS activity, which in turn, contributes to persistent inflammation, orthostatic intolerance, and OI symptoms. The study will evaluate immune cell activation in post-COVID-19 POTS and patients with history of COVID-19 infection without sequelae and correlate this with the degree of decreased PNS activity.

Studying the causal roles of components of the renin-angiotensin-aldosterone system (including angiotensin-(1-7) (Ang-(1-7)), angiotensin-converting enzyme 2 (ACE2), Ang II, and ACE), uric acid, and klotho in pediatric hypertension and related target organ injury, including in the heart, kidneys, vasculature, and brain. Recruiting children with a new hypertension diagnosis over a 2-year period from the Hypertension and Pediatric Nephrology Clinics affiliated with Brenner Children's Hospital at Atrium Health Wake Forest Baptist and Atrium Health Levine Children's Hospital. Healthy control participants will be recruited from local general primary care practices. Collecting blood and urine samples to analyze components of the renin-angiotensin-aldosterone system (Ang-(1-7), ACE2, Ang II, ACE), uric acid, and klotho, and measuring blood pressure, heart structure and function, autonomic function, vascular function, and kidney function at baseline, year 1, and year 2. Objectives are to investigate phenotypic and treatment response variability and to causally infer if Ang-(1-7), ACE2, Ang II, ACE, uric acid, and klotho contribute to target organ injury due to hypertension.

This study is a pilot clinical trial to explore the efficacy of transcutaneous spinal cord stimulation (TCSCS) (proof-of-concept) in mitigating crucial autonomic dysfunctions that impact the health-related quality of life of individuals with spinal cord injury (SCI).

Fibromyalgia is a chronic condition characterized by widespread musculoskeletal pain, fatigue, sleep disturbances, and psychological symptoms. Autonomic nervous system (ANS) dysfunction, marked by increased sympathetic and reduced parasympathetic activity, is considered one of its possible mechanisms. Although exercise is recommended in treatment, low motivation and fatigue often limit participation. Therefore, inspiratory muscle training (IMT), which targets the respiratory muscles, is seen as an easy-to-apply alternative.This randomized, controlled, double-blind study will be conducted at Niğde Ömer Halisdemir University Hospital. Fifty-one women aged 18-65 years who meet the 2010/2016 ACR criteria for fibromyalgia will be randomly assigned to three groups: training (30% of maximal inspiratory pressure), sham (0-10%), and control (no training). ANS functions will be assessed using heart rate variability and the COMPASS-31 questionnaire. Pain, sleep quality, fatigue, anxiety, depression, and respiratory muscle strength will also be evaluated. Training will be performed with the Powerbreathe® device twice daily for six weeks.The study aims to investigate the effects of IMT on ANS functions in fibromyalgia and to explore its relationship with symptoms such as pain, fatigue, sleep disturbances, anxiety, and depression.

The multicentre observational study POL-CA involves a wide spectrum of patients with a history of syncopy. The study recruits patients with diagnosed vasovagal syndrome, cardioinhibitory carotid sinus syndrome, symptomatic sinus bradycardia or atrioventricular block, postural orthostatic tachycardia syndrome, orthostatic hypotension, and inappropriate sinus tachycardia syndrome. This is an observational, controlled study with retrospective, clinical data analysis of previously treated patients and the analysis of syncopal patients prospectively recruited into the study. The aim of the POL-CA registry is to create a platform for physicians to record treatment data for patients undergoing procedures that affect innervation or modify cardiovascular reflexes (cardioneuroablation, cardioneuromodulation) in order to provide a multicentre summary of population characteristics and treatment outcomes based on a standardized POL-CA questionnaire and methodology for various arrhythmias.

The purpose of this study is to learn more about the effectiveness of a prescription wrist-wearable device called NightWare (NW) on improving sleep in Veterans with nightmares related to posttraumatic stress disorder (PTSD). The investigators also want to learn whether it improves cardiovascular health among this population.

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 purpose of this study is to determine whether transcutaneous electrical acustimulation (TEA) alters systemic sclerosis (SSc)-related colonic and anorectal physiology by enhancing autonomic nervous system (ANS) function. The study will examine the effects of TEA on slow colonic transit (SCT) and rectal hyposensitivity (RH), to examine whether TEA improves autonomic dysfunction and modulates inflammatory pathways.

This study aims to evaluate the efficacy and safety of Vespireit, prolonged-release tablets, 15 mg (Valenta Pharm JSC, Russia) in comparison with Arlevert, tablets, 40 mg + 20 mg (Menarini International Operations Luxembourg S.A., Luxembourg) in patients with autonomic dysfunction syndrome accompanied by functional vertigo.

The purpose of this study is to determine whether NightWare therapeutic intervention improves biomarkers of vascular and renal function in premenopausal women with PTSD-related nightmares, and examine whether these improvements restore them to levels observed in age-matched women without PTSD.

Vagal nerve stimulation is a neurosurgical procedure consisting of implantation of an impulse generator battery with leads placed into the vagus nerve in the neck. This procedure was FDA approved for epilepsy in the 1990s and is commonly performed as an outpatient surgery. The mechanism of action is not well understood; however it is increasingly recognized that electrical stimulation of the vagus nerve may impact other organ systems in the body including the immune and gastrointestinal systems. Concrete characterization of the peripheral effects of VNS in human gut microbiome and immune systems will: (1) elucidate peripheral mechanism of action of chronic VNS therapy, (2) identify peripheral preoperative biomarker of VNS efficacy, and (3) create a foundation for research investigating new GM and IM-related disease indications for VNS. The primary objective of this study is to characterize the pre- and post-operative oral and gut microbiome of patients implanted with vagal nerve stimulator (VNS) for epilepsy. Secondary objectives of this study include: (1) to characterize the pre-operative and post-operative immune profile of patients undergoing VNS implantation for epilepsy, (2) to elucidate whether oral and/or gut microbiota changes are related to VNS efficacy for epilepsy and (3) identification of a biomarker predicting VNS efficacy.

POWER Health is a randomized clinical trial with a two-arm parallel design whose objectives are 1) to study metabolic flexibility and autonomic function (both capacities that describe cardiovascular health) in a sample of postmenopausal oncological women vs postmenopausal untreated controls (CT); and 2) to analyze the impact of two different 8-week physical exercise supervised interventions: HIIT training vs strength training focused on muscle power, on both cardiovascular capacities in these populations.