Dr Naoufel Ouerchefani Functional neurosurgeon - Pain doctorPain and abnormal movement surgeon

Vagus nerve stimulation

The vagal nerve

Vagal nerve stimulation consists in stimulating that nerve thanks to a small electrode which is implanted near the neck, and hooked up to a small neurostimulation device: “a battery”.

Vagal nerve stimulation (VNS) consists in stimulating that major nerve of the autonomous nervous system with electrical impulses. Vagal nerve stimulation has been used for more than 20 years to treat drug-resistant epilepsy, and it has seen its therapeutic field expand as discoveries are made about that crucial nerve.

General idea

It is divided into two parts, left and right: it starts off around the brain, goes down the brainstem into the neck, penetrates the thorax and takes the nerves out of many organs: the heart, the stomach, the digestive system, the lungs, the genital organs.

That nerve plays a crucial role in the transmission of information from the brain to the body, and vice versa with the afferent fibers (going from the periphery to the brain) and the efferent fibers (going from the brain to the periphery). Therefore, with the vagal nerve, the brain controls thusly how organs function which can, by themselves, send information to the brain about how they are doing, how they are working.

Vagal nerve stimulation consists in stimulating that nerve thanks to a small electrode implanted at neck level and hooked up to a small neurostimulation device – “a device”.

Recommendations

Epilepsy

Epilepsy which either isn’t or is badly contained by medicated treatments is the first and most important reason for getting vagal nerve stimulation. Vagal nerve stimulation will be made available, if, like one epileptic patient out of three, your epilepsy is drug-resistant, and that surgery is not possible, like in the case of an extended or multi-pronged epileptogenic outbreak, or fails.

Patient selection is made by the neurologists.

Vagal nerve stimulation consists of regularly, every 5 minutes, for example – sending brief and light electric pulses, via the vagal nerve, towards the cerebral areas associated with epilepsy – so as to help in controlling the electric disturbances which cause these seizures. That technique’s aim is not to cure epilepsy, but to reduce the frequency, the intensity, and the strength of these seizures. Studies also show improvements of mood, memory, and an increased vigilance. VNS (Vagal Nerve Stimulation) enables, as time goes by, a reduction in anti-epilepsy treatments and as such a reduction in their secondary effects.

That technique works both before seizures, and at the moment they happen, thanks to two additional devices:

  • The magnet: you – or your loved ones – will have a magnet, given to you by your neurologist. You should start passing it in front of the stimulator, when you have a seizure, in order to kickstart a stronger and longer stimulation – and make the seizure stop.
  • An internal detection system: cardiac frequency picks up during a seizure. The generator can pick out that increased heart rate and kick start an additional stimulation. You do not have to intervene in that case.

Please note that VNS is a long-term stimulation: its efficiency is more notable over time.

Depression

Vagal nerve stimulation can only be offered in the case of some severe, chronic, drug-resistant depressions.

Clinical trials

The vagal nerve also has some anti-inflammatory properties, and some pilot-studies are currently taking place over use of its stimulation against certain chronic, inflammatory pathologies – inflammatory bowel disease (IBD), CROHN’s disease, rheumatoid arthritis, etcetera.