Frequently asked questions about NEMOS® and t-VNS®

Where is NEMOS® available?

* All countries of the European Union and Switzerland

Why NEMOS® ?

* Vigilance data cerbomed GmbH

How does NEMOS® work?

t-VNS® treatment uses the transcutaneous vagus nerve stimulator NEMOS®.

NEMOS® consists of a stimulation unit and a dedicated ear electrode. The stimulation unit, having approximately the size of a common mobile phone, sends out the electrical impulses. It is connected with the ear electrode, which patients wear like an earphone. The impulses are transferred via ear electrode through the skin to a the auricular branch of the vagus nerve.

How often should NEMOS® be used?

Patients treat themselves with t-VNS® in sessions lasting approximately 4 hours per day.

How does t-VNS® work?

Transcutaneous Vagus Nerve Stimulation (t-VNS®) uses the fact that the auricular branch of the vagus nerve (ABVN) supplies the skin of the concha in the human ear3.

This allows for transcutaneous electrical stimulation of the nerve fibers in this area. Intensity, pulse duration and frequency of the t-VNS® stimulation have been optimized to induce signals in thick-myelinated Aß fibres of the ABVN. Like those of the cervical branch of the vagus nerve, these project directly to the nucleus of the solitary tract (NTS) in the brainstem.4,5

The NTS is the starting point to activate a complex cerebral network, corresponding closely to that targeted by invasive VNS, and associated with the anticonvulsive effect.1,2,6


  1. Beekwilder JP, Beems T: Overview of the clinical applications of vagus nerve stimulation. J Clin Neurophysiol 2010;27:130-138.
  2. Amar AP, Levy ML, Liu CY, Apuzzo MLJ: Vagus Nerve Stimulation; in Krames ES, Peckham PH, Rezai AR, (eds): Neuromodulation. London, Academic Press, 2009, pp 625-637.
  3. Peuker ET, Filler TJ: The nerve supply of the human auricle. Clin Anat 2002;15:35-37.
  4. Nomura S, Mizuno N: Central distribution of primary afferent fibers in the Arnold’s nerve (the auricular branch of the vagus nerve): a transganglionic HRP study in the cat. Brain Res 1984;292:199-205.
  5. Gao XY, Rong P, Ben H, Liu K, Zhu B, Zhang S: Morphological and electrophysiological characterization of auricular branch of vagus nerve: Projections to the NTS in mediating cardiovascular inhibition evoked by the acupuncture-like stimulation; 2010, p 694.22.
  6. Vonck K, Boon P, Van RD: Anatomical and physiological basis and mechanism of action of neurostimulation for epilepsy. Acta Neurochir Suppl 2007;97:321-328.

Which side effects may occur?

When using t-VNS®® treatment, local side effects caused by the stimulation, such as itching, paraesthesia in the area of the outer auricle, pain, redness, pressure marks and skin lesion may occur at the point of stimulation.

The stimulation of the vagus nerve may affect the autonomic nervous system. This may manifest in the form of symptoms such as headaches, nausea or vertigo.

As with any other treatment based on drugs or neurostimulation, t-VNS®® treatment may lead to an increase in seizures. This involves increases in one or more of the following: seizure frequency (series of seizures up to and including, albeit rarely, status epilepticus), severity and duration. A change in the character of seizures is also possible – they may, for example, begin to occur during the day rather than at night.

These side effects will generally subside soon after Stimulation is stopped.

Which contraindications do exist?

The NEMOS®® device should not be used in the following cases:

How effective is therapy with NEMOS® ?

Like most pharmaceutical and neuromodulatory treatments for epilepsies, t-VNS® is not an acute therapy. Even if you respond to therapy with NEMOS®, the effect may occur with a latency of some weeks to a few months. Like in all other therapies there can never be a guarantee of success for a treatment using NEMOS®. It is possible that some patients will not respond sufficiently to the therapy. Such patients can return the device within 5 days of the end of the 6 month trial, and will not be charged for the remaining cost of the device in their contract. See the Returns Policy.