Effect of Transcutaneous Vagal Nerve Stimulation on Reducing Visually Induced Motion Sickness in Healthy Volunteers

Effect of Transcutaneous Vagal Nerve Stimulation on Reducing Visually Induced Motion Sickness in Healthy Volunteers

Effect of Transcutaneous Vagal Nerve Stimulation on Reducing Visually Induced Motion Sickness in Healthy Volunteers

Nausea is a common and distressing experience that often precedes vomiting. Amongst symptoms emanating from the gastrointestinal (GI) tract nausea can be considered somewhat unique, as on one hand it represents a normal, highly conserved, physiological response to an ingested toxin yet on the other it may indicate pathology. Nausea may also arise as a consequence of pharmaco- and chemotherapeutic interventions. Nausea negatively impacts on quality of life, adherence to treatment and is a cause for discontinuation of the development of novel compounds. Experimentally, nausea can be induced in humans using a visually induced motion stimulus. Previously we have developed a 10-minute motion video of the landscape rotating as seen from the perspective of a subject standing on Westminster Bridge, London. The tilted and rotating view visual display makes the subject perceive that they are spinning round and round on a spot tilted away from centre of gravity due to circular vection. This motion video induced nausea in approximately 50% of healthy participants and caused a reduction in cardiac vagal tone, a validated measure of the parasympathetic nervous system branch on the autonomic nervous system. We therefore are evaluating the role of external transcutaneous vagal nerve stimulation in visually induced motion sickness.

Placebo vagal nerve stimulation - stimulator attached to the ear but rotated 180 degrees so that it is not stimulating the vagus nerve.

Inclusion Criteria: Healthy subjects, aged 18-65, from staff, students and local population of Queen Mary, University of London. Inclusion will be determined on the basis of availability, with no prior selection bias included. They should be able to attend the Wingate Institute for at least 2 x 1 hour sessions. Subjects who score >15 on MSSQ (suggesting that they are sensitive to visually induced nausea). Exclusion Criteria: Subjects unable to provide informed consent. Subjects with any systemic disease or medications that may influence the autonomic nervous system (e.g. beta-agonists or Parkinson's disease). Subjects who score <15 on MSSQ (suggesting that they are insensitive to visually induced nausea). Pregnant females to prevent any confounding effects on pregnancy related nausea.

Farmer AD, Al Omran Y, Aziz Q, Andrews PL. The role of the parasympathetic nervous system in visually induced motion sickness: systematic review and meta-analysis. Exp Brain Res. 2014 Aug;232(8):2665-73. doi: 10.1007/s00221-014-3964-3. Epub 2014 May 4.