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

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.

Conditions

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

Interventions

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

Sponsors & Collaborators

• University of Vienna

  lead OTHER

Principal Investigators

• Giacomo Carta, PhD · University of Vienna

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-12-02

Primary Completion

2026-04-22

Completion

2026-04-22

Countries

• Austria

Study Locations