NCT06541808

Balance, Autonomic Response, and Sensory Modulation to Dosage of Mechanical Vagal Stimulation in Healthy Adults

Balance, Sensory Modulation, and Autonomic Response to Different Dosages of Non-invasive Mechanical Vagal Stimulation in Healthy Adults

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 128 (estimated)
• Sponsor: University of Vienna · Academic / Other
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

The vagus nerve (VN) plays a crucial role in regulating vital functions (heart rate, blood pressure, digestion, and immune response) and maintaining communication between internal organs and the brain. Recent studies have highlighted the therapeutic potential of VN stimulation (VNS) in treating various conditions such as drug-resistant epilepsy, postural control deficit, COVID-19 infection, chronic pain, and intestinal disorders. In addition, there is growing evidence that the molecules released by the VN neurons affect the function of the gut microbiota and that the molecules released by the bacteria in our gut affect the activity of the VN neurons. In particular, Dr. Giacomo Carta (the leader of this study) has shown how painless neck movements, i.e. mechanical VNS (mVNS), can be applied without adverse effects, representing a potential alternative to invasive methods commonly used today. To further investigate the impact of this novel mVNS, this study aims to evaluate the changes induced by three mVNS protocols on physiological parameters such as resting heart rate, and Heart Rate Variability (HRV) at rest, balance in standing, the perceived intensity of mechanical stimuli using the established clinical method of QST (quantitative sensory testing), fecal transit speed, and the molecular composition of stool (for this, stool samples are analyzed). In particular, stool analysis is very relevant for understanding normal digestion. The present research aims to define the optimal intensity of mVNS and to investigate the therapeutic potential of VNS in the treatment of autonomic dysfunction (such as too low or too high heart rate, too low or too fast digestion, throbbing headaches), as well as falls prevention and pain.

Detailed description

mechanical VNs in humans, induced by a combination of non-painful physiological neck movements, effectively reduces the HR at rest in humans, without any side effects in the short- and long-term. Indeed, HR reduction is a proxy for the VN increased activity among healthy subjects and patients with systemic diseases or autonomic diseases. Mechanical VNs had been successfully adopted in two clinical trials among chronic pain patients (NCT05345496, NCT05360589), but due to the early stage of these new VNs and the clear advantages of this method, studies refining the stimulation protocol are suitable. Thus, the study aims to investigate the possible dose-dependent effects of mVNs on different physiological parameters in humans. 3 protocols of mVNs will be compared consisting of (1) 4 minutes (2 minutes on each side); (2) 12 minutes (3 sessions of 2 minutes of stimulation, with 2 minutes of rest for each side); (3) 16 minutes (8 minutes on each side). The following outcomes will be assessed before and after the stimulation: HR at rest, HRV, balance on standing, perceived intensity and modulation of mechanical stimuli on the skin of the forehead, and the abdomen, gastrointestinal transit, and a fecal sample from the closest intestinal emptying. A total sample of at least 96 healthy subjects (48 females) aged between 18 and 60 are expected to participate. The bidirectional communication between internal organs and the brain via the VN is a well-established scientific fact. Indeed, VNs has beneficial effects on manifold pathological conditions in humans. However, easy-to-apply, non-invasive, and effective VNs methods and standardized protocols are lacking. The here proposed project aims at refining and critically assessing mVNs methods - a prerequisite for exploring the clinical utility of mVNs and fostering its therapeutic potential given the fundamental role of the VN in regulating health and disease. Results obtained from this project will provide data on mVNs on gut microbiota dynamics and the potential benefits for pain modulation, equilibrium impairments, and gastrointestinal dysfunctions.

Conditions

• Vagus Nerve Autonomic Disorder
• Heart Rate
• Pain
• Equilibrium; Disorder, Labyrinth
• Microbial Colonization

Interventions

Type	Name	Description
OTHER	mechanical Vagus Nerve Stimulation (Low Intensity)	The stimulation consists of a combination of normal neck movements, performed in a comfortable supine position, which can selectively stimulate the VN. In particular. The participant will be stimulated supine on a comfortable massage/treatment bed with the experimenter standing at the cranial short side of the bed. All the neck movements will be gently performed with a combination of upper cervical flexion and contralateral lateral flexion to load the intracranial portion of the vagus nerve. The ipsilateral neck rotation will be combined to load the cervical tract of the nerve. Keeping the participant's head in the final movements combination the upper abdomen will be gently moved caudally to load the thoracic tract and intermittent gentle impulses 1 each second will be administered. The stimulation will be provided for 2 consecutive minutes for each side, only once for the experiment duration.
OTHER	mechanical Vagus Nerve Stimulation (Intermediate Intensity)	The stimulation consists of a combination of normal neck movements, performed in a comfortable supine position, which can selectively stimulate the VN. In particular. The participant will be stimulated supine on a comfortable massage/treatment bed with the experimenter standing at the cranial short side of the bed. All the neck movements will be gently performed with a combination of upper cervical flexion and contralateral lateral flexion to load the intracranial portion of the vagus nerve. The ipsilateral neck rotation will be combined to load the cervical tract of the nerve. Keeping the participant's head in the final movements combination the upper abdomen will be gently moved caudally to load the thoracic tract and intermittent gentle impulses 1 each second will be administered. The stimulation will be provided for 3 sessions of 2 minutes, with 2 minutes of rest for each side. stimulation will be provided only once for the experiment duration.
OTHER	mechanical Vagus Nerve Stimulation (High Intensity)	The stimulation consists of a combination of normal neck movements, performed in a comfortable supine position, which can selectively stimulate the VN. In particular. The participant will be stimulated supine on a comfortable massage/treatment bed with the experimenter standing at the cranial short side of the bed. All the neck movements will be gently performed with a combination of upper cervical flexion and contralateral lateral flexion to load the intracranial portion of the vagus nerve. The ipsilateral neck rotation will be combined to load the cervical tract of the nerve. Keeping the participant's head in the final movements combination the upper abdomen will be gently moved caudally to load the thoracic tract and intermittent gentle impulses 1 each second will be administered. The stimulation will be provided for 8 consecutive minutes for each side, only once for the experiment duration.
OTHER	Sham mechanical Vagus Nerve Stimulation	Participants will be treated with a fake vagus stimulation by letting the operator hold the neck of the participant in one hand and placing the other hand on the abdomen without any stretch on the vagus nerve

Timeline

• Start date: 2024-12-02
• Primary completion: 2025-07-25
• Completion: 2025-09-30
• First posted: 2024-08-07
• Last updated: 2024-12-05

Locations

1 site across 1 country: Austria