Vagal Nerve Dysfunction

Swallowing disorders are common in intensive care unit (ICU) patients, especially those with tracheostomies that can cause changes affecting swallowing. These disorders are linked to serious problems like respiratory issues, poor nutrition, and even death. Current clinical exams lack precision, while existing tests like videofluoroscopy or Fiberoptic Endoscopic Evaluation of Swallowing (FEES) are invasive, resource-heavy, and hard to access. Researchers are exploring ultrasound imaging as a non-invasive and precise method to assess swallowing disorders in difficult-to-wean tracheostomised ICU patients. This observational study will enroll 119 difficult-to-wean tracheostomised patients over nineteen months at multiple hospitals. Each patient will undergo FEES and ultrasound evaluations within a two-hour window. Ultrasound will assess movements and structures including the tongue, larynx, and suprahyoid muscles. The ultrasonographer will be blinded to other assessments. The goal is to develop a diagnostic ultrasound model using selected variables, which will be transformed into an easy-to-use scoring system to predict swallowing disorders. Participants will be assessed through clinical data collection and swallowing tests. Ultrasound exams will measure features like tongue thickness and muscle contractions, while FEES will evaluate swallowing function and residue severity. Reliability tests will be done with multiple examiners. Researchers will analyze data statistically to create and validate the ultrasound score’s accuracy and reliability. The study aims to improve early detection and management of swallowing disorders non-invasively, over the course of the study period ending in April 2026.

Researchers are studying how different heart rates affect stroke volume and cardiac output in patients with vasovagal syncope who have permanent pacemakers. This study aims to clarify how increasing heart rate impacts the heart's ability to fill with blood and pump effectively, both when lying down and when upright. The investigation addresses a gap in understanding the relationship between heart rate and cardiac function in this group. The study involves pacing the heart at various rates ranging from 50 to 130 beats per minute while monitoring stroke volume and cardiac output using non-invasive methods. After completing pacing runs while lying down, participants rest for 10 minutes before being tilted upright at an angle greater than 70 degrees for about 10 minutes, followed by additional pacing sessions. Blood pressure is measured and the equipment calibrated between pacing runs. Participants will undergo assessments that include continuous monitoring of stroke volume and cardiac output during different pacing rates and positions. The primary outcome is the change in cardiac output during atrial pacing at different rates while lying down. Secondary outcomes include changes in cardiac output and stroke volume during various pacing modes and body positions. The entire study procedure occurs within one day, and safety is ensured by using non-invasive techniques and secure positioning during upright testing.

Researchers are studying Hypermobile Ehlers-Danlos Syndrome (hEDS), a connective tissue disorder that causes very flexible skin and joints, along with other tissue issues. This condition often comes with gastrointestinal and autonomic nervous system problems, such as postural orthostatic tachycardia syndrome (POTS). The study explores the link between hEDS and autonomic regulation and evaluates if two types of non-invasive vagal nerve stimulation therapies can reduce gastrointestinal symptoms in people with hEDS and POTS. It also examines how these therapies might affect stomach function and nerve signaling. The study involves two groups of participants. One group of 60 children with hEDS or Hypermobile Spectrum Disorder will participate in a four-week, randomized, double-blind trial listening to either special filtered vocal music designed to stimulate vagal nerve calming (active therapy) or regular music (sham therapy). The other group of 30 children with autonomic nervous system dysfunction will receive a six-week open-label treatment using a device called IB-Stim, which provides low voltage nerve stimulation through electrodes on the ear. Some participants may also undergo a gastric MRI scan and provide blood samples for additional research. Participants will be assessed before, during, and after therapy using questionnaires about gastrointestinal symptoms, body perception, and nerve function. The study measures changes in these symptoms and uses imaging to observe stomach motor function. Monitoring includes questionnaires and physiological tests over about six weeks of therapy. The trial runs until the end of 2026, and researchers will review outcomes like symptom improvement and nerve efficiency to understand effects of these therapies on hEDS and related autonomic issues.

Researchers are evaluating the effects of transcutaneous electrical stimulation of the auricular vagus nerve (TENS) on heart rate variability (HRV), a marker of autonomic nervous system activity. This study aims to determine a reliable biomarker for successful vagus nerve activation using TENS, which is a non-invasive alternative to invasive cervical vagus nerve stimulation used for depression, epilepsy, and other conditions. The trial addresses inconsistent data on how TENS affects HRV due to varied study methods and control conditions. The study compares two groups: one receiving active TENS applied to the tragus of the left ear at 20 Hz and 200 microseconds below discomfort threshold, and a sham group receiving similar stimulation at the left earlobe, which lacks vagus nerve innervation. Each stimulation lasts 10 minutes. Researchers will assess HRV parameters before stimulation, during two consecutive 5-minute intervals of stimulation, and after stimulation ends. Participants will undergo heart rate and HRV monitoring throughout the study periods. The main outcome measured is the change in the LF/HF ratio of HRV, evaluated at rest, during stimulation, and post-stimulation. Secondary outcomes include various HRV components and heart rate dynamics measured at the same intervals. The total participation spans these assessments, focusing on objective measures of autonomic response to TENS. The study is randomized and single-masked, involving adults aged 18 to 75 years with sinus rhythm.

Researchers are exploring new treatments to improve outcomes for patients with ST-segment elevation myocardial infarction (STEMI), a serious type of heart attack. Despite effective invasive strategies like primary percutaneous coronary intervention (PCI), many patients still face high mortality and disability. This research focuses on studying transcutaneous vagus nerve stimulation (TENS) as a potential way to protect the heart, reduce injury caused by restoring blood flow, and improve heart function after a heart attack. The study compares two groups: one receiving active TENS applied to the tragus of the left ear, and the other receiving sham TENS applied to the earlobe. The stimulation starts upon admission to PCI, continues during the procedure, and lasts for 30 minutes afterward. This noninvasive device-based treatment aims to evaluate whether vagus nerve stimulation can reduce heart damage and improve clinical outcomes in patients undergoing primary PCI for STEMI. Participants will be monitored for safety and effectiveness through hospital and 30-day mortality rates, as well as non-lethal cardiac events up to 14 days after treatment. The study uses randomization and quadruple masking to ensure reliable results. Throughout the study, patients will receive assessments including clinical evaluations and follow-up to observe changes in heart function and overall health during and after the intervention. The total study period spans from admission through one month post-treatment.

This research aims to develop a screening tool for oropharyngeal dysphagia, a swallowing disorder common in neurological patients such as those with Parkinson's disease, stroke, or amyotrophic lateral sclerosis. Dysphagia can lead to serious complications like malnutrition, dehydration, and pneumonia, increasing hospital stays and healthcare costs. Currently, there are no fast and effective screening methods available outside specialized clinical settings. Participants in this study perform various voice tasks during a single session, including sustained phonation, rapid syllable repetition, standardized sentences, and free speech. The recorded voice signals are analyzed using machine learning algorithms to identify changes related to swallowing difficulties. The study includes patients with neurological disorders both with and without dysphagia, as well as healthy individuals, to help develop the classification algorithm. During the study visit, participants provide voice recordings and clinical and medical history information. Researchers use these data to extract acoustic features for the machine learning model. The main goal is to create an algorithm that can quickly and non-invasively screen for swallowing disorders in neurological patients. The study is observational and involves a single recording session with no additional treatments or interventions.

Researchers are investigating autonomic dysfunction (AD) and orthostatic intolerance (OI) in patients who have undergone bariatric surgery (BS). This observational study aims to assess how common AD is after BS and to better understand the underlying causes and outcomes. Previous research has shown limited and low-quality evidence on this topic, prompting this study to improve knowledge about AD/OI following bariatric procedures. The study includes both retrospective and prospective phases. Patients who have had BS within the last 3 years or will undergo BS soon are observed to characterize the development of AD/OI after surgery. Bariatric surgeries studied include gastric bypass, sleeve gastrectomy, and biliopancreatic diversion with duodenal switch. The study does not involve any experimental treatments but focuses on monitoring and collecting data about AD/OI symptoms and progression. Participants will provide consent and maintain follow-up with their bariatric surgery team. Researchers will evaluate the prevalence and outcomes of autonomic dysfunction at around 3 months after surgery. Data collection includes medical history, symptom tracking, and follow-up evaluations to better define AD/OI characteristics. The study will end in December 2025, allowing for thorough observation and outcome assessment over time.

Researchers are investigating how the autonomic nervous system controls blood pressure and heart rate during standing and exercise in both healthy adults and people with arterial hypertension. The study focuses on understanding cardiovascular responses to exercise on a cycle ergometer and includes groups with hypertension and related conditions like orthostatic hypotension and diabetes. This observational study aims to improve knowledge of cardiovascular regulation and may help identify autonomic dysfunction earlier for better clinical care. Participants include healthy young adults aged 18 to 35 without cardiovascular disease and several subgroups of older adults with controlled arterial hypertension, with or without orthostatic blood pressure abnormalities or diabetes. All participants undergo tests such as orthostatic testing, graded exercise on a cycle ergometer, electrocardiography, and arterial stiffness measurements like pulse wave velocity. Additional vascular and hemodynamic parameters are also recorded during these procedures. During the single study visit, researchers assess heart rate variability, blood pressure response to exercise, and heart rate recovery immediately after exercise. Clinical data including lab results and ambulatory blood pressure monitoring are collected from medical records for participants with hypertension. The study monitors cardiovascular function and autonomic regulation to contribute to better understanding and management of hypertension and related conditions.

Researchers are evaluating new disease descriptions and management guidelines for breath-holding spells in children under 5 years old in southern Sweden. The study aims to determine if these guidelines reduce unnecessary diagnostic procedures and are safe to use. It also investigates whether iron supplements decrease the frequency and severity of these spells and explores what information and support parents need for managing their children's condition. Children diagnosed with typical breath-holding spells will be managed according to the new guidelines, which include cardiac evaluations like ECG for those with relevant family history or symptoms, and blood tests for anemia and iron deficiency if the child has multiple spells. Children with non-typical spells will be assessed individually using current practices. If iron deficiency is identified, supplementation is recommended. Some parents of children with frequent spells may participate in interviews as part of a sub-study. Participants will be evaluated by medical doctors and monitored through digital surveys over time. Researchers will assess the safety and usability of the guidelines, the effectiveness of iron treatment, and the support needs of parents. The study includes follow-up for up to 36 months to monitor outcomes and uses interviews and surveys to gather detailed information from families. The total participation duration varies, with specific assessments scheduled within weeks to months after inclusion.

Reflex syncope, the most common type of fainting, can cause injuries and reduce quality of life. It results from an imbalance in the autonomic nervous system leading to low blood flow to the brain. Current non-drug and drug treatments often have limited success. This study aims to compare the effectiveness of cardioneuroablation (CNA), a newer catheter-based heart procedure, with permanent pacemaker therapy in reducing episodes of cardioinhibitory reflex syncope in patients over 40 years old. Participants will be randomly assigned to one of two groups: one receiving cardioneuroablation, which targets specific heart nerve clusters using radiofrequency energy to modulate autonomic function, and the other receiving a dual-chamber pacemaker programmed with specialized algorithms. The CNA procedure includes pre- and post-testing to confirm treatment effects, while the pacemaker group receives device implantation. Both groups will be followed for at least 12 months to assess treatment outcomes. Throughout the study, participants will undergo evaluations including heart rhythm monitoring during syncope episodes, tilt table and atropine tests to assess nerve function, and quality of life assessments. Researchers will track the number of syncope and presyncope events, long-term changes in heart nerve activity, complications, heart rhythm changes, and arrhythmia burden. Safety and effectiveness will be monitored over a year to guide optimal treatment choice for this condition.