Vagus Nerve Stimulation (VNS) is a neuromodulation treatment option available to people living with drug-resistant epilepsy. The procedure involves implanting a device which emits regular, mild pulses of electrical energy to stimulate the vagus nerve in your neck.
The vagus nerve, also known as Cranial Nerve X, is one of 12 pairs of nerves responsible for sending signals to different parts of your body and is used to treat conditions such as inflammatory bowel disease and depression.
Seizure Control
The vagus nerve is responsible for transmitting information between your neck, chest, and stomach to the brain and plays an essential role in breathing, speech production, digestion, seizure management and seizure control. Studies indicate that stimulating this nerve with electrical pulses may reduce seizure frequency in people who do not respond well to medications or who suffer from medically intractable epilepsy.
VNS is an add-on treatment, meaning it works alongside seizure medications to significantly decrease seizures in 40-50% of people with refractory epilepsy; however, it doesn’t work on everyone.
As soon as VNS becomes an option, your neurologist will discuss its potential uses in treating your type of epilepsy. Once both parties decide it’s the best choice, surgery to place the device will need to occur and usually lasts 1-1.25 hours with general anesthesia being administered during this process.
Once an implanted device has been activated, it sends mild electrical impulses at predetermined intervals to stimulate the vagus nerve. These pulses do not cause any sensation and most people cannot perceive them; occasionally additional stimulation might need to be administered during seizures using magnets.
Follow-up visits should include testing your device to make sure it’s functioning as intended, and telling your neurologist before undertaking any tests such as an MRI that might interfere with its functionality.
Vagus nerve stimulation does not cure epilepsy; most people will still require anticonvulsant medication to control seizures. But, if your seizures are under control through these means, vagus nerve stimulation may give you more confidence to live life freely without fear of having seizures; potentially leading to either no more episodes or less severe ones when they do occur. While its exact mechanism remains unknown, pulses from VNS could affect certain regions in the brain where seizures originate.
Quality of Life
The Vagus Nerve is one of twelve Cranial (nervous) Nerves which run in pairs down either side of the head and neck to transmit information between brain cells and other parts of the body. It helps regulate digestion, heart rate and more – while electrical stimulation through VNS therapy sends signals down Vagus to reach brain and help reduce seizures by making them less severe.
VNS (vagus nerve stimulator) is an add-on therapy for people living with epilepsy who cannot control their seizures with antiseizure medicines alone, such as surgery or increasing doses. If other treatments, such as surgery or increasing dosage of seizure medicines haven’t helped, VNS might be appropriate as an additional method. A neurologist implants a pulse generator into your upper left chest through which an electrical pulse connects it to the vagus nerve in your neck; your settings for this device (about the size of stopwatch size with battery power) can be adjusted at an outpatient clinic or hospital visit by changing settings through wires connected by wires to your vagus nerve – with settings changes made through outpatient clinic or hospital visits as needed by your neurologist themselves – unlike with conventional antiseizure medicines alone.
Your neurologist will program your device to deliver electrical impulses at certain times throughout the day and night, on an ongoing schedule, directly into the vagus nerve and left vagus nerve that pass along to the right thalamus in your brain which in turn communicates messages to other areas of the body – potentially helping reduce seizures but won’t prevent future ones from occurring.
Most people with VNS devices report improved quality of life; they feel more alert and less worried about seizures; approximately half claim their seizures have become less severe as a result.
The device may also help address other health concerns, including chronic treatment-resistant depression and posttraumatic stress disorder (PTSD). It works by helping regulate people’s emotions and improving their ability to think clearly.
Before considering VNS therapy, it’s essential that you discuss it with your physician. VNS may not be suitable for people suffering from serious heart or lung conditions; additionally, pregnant women or those who have had a stroke should avoid this option.
NORSE Management
As research into VNS progresses, so too do its applications for treatment. VNS is being studied as a possible remedy for cluster headaches, fibromyalgia and multiple sclerosis – as well as showing great promise for managing new-onset refractory status epilepticus (NORSE).
NORSE is a potentially life-threatening form of epilepsy where a person experiences prolonged seizures that don’t respond to standard anti-seizure medication, leading to seizures lasting several hours without response from standard anti-seizure treatments. NORSE requires immediate medical intervention from neurocritical care teams in intensive care units in order to save lives.
Initial treatment consists of administering benzodiazepines such as lorazepam, diazepam and clonazepam; followed by standard anti-seizure medications like valproic acid, phenytoin levetiracetam or phenobarbital for seizures resistant to other therapies; vagus nerve stimulation devices may reduce spatial synchronization and cortical excitability during episodes of SE thereby decreasing risks.
To achieve this goal, a small device, approximately the size and shape of a stopwatch running on battery power is placed in your chest and connected via wire to your left vagus nerve in your neck. A neurologist programs the device for you; however, you can control it yourself using a handheld magnet. Though not known if the device completely prevents seizures from returning, studies have demonstrated it can decrease their duration and frequency significantly.
An investigation is currently under way to assess whether VNS can improve outcomes of NORSE patients, by closely observing its use within an intensive care unit setting and collecting clinical and biological data from them.
An international consortium of medical centers is also currently in the process of creating an invaluable registry of cryptogenic NORSE patients, collecting detailed demographic and clinical information as well as serum CSF samples or brain biopsies when possible. This will enable researchers to identify key factors which could improve outcomes among this population – it may even allow for prediction purposes should this treatment become available later on.
Side Effects
As part of your VNS surgery, a small incision will be made under your collarbone on the left side of your chest for the pulse generator device, and another in the center for electrode leads that connect to your vagus nerve. An implantable pulse generator acts like a pacemaker by sending electrical stimulation directly into your brain – it starts slowly at first before gradually increasing as you adjust. For optimal safety it stimulates 30 seconds every five minutes with additional bursts available by passing a magnet over its pulse generator.
VNS therapy aims to alter how your brain works to prevent seizures. Although its exact mechanism remains unknown, doctors believe the device may work by stimulating vagus nerve fibers to reach various parts of the brain that regulate seizures – disrupting unusual brain activity that leads to them. Medication may still be required, yet some individuals report more than 50% fewer seizures with VNS than without it.
Some individuals may experience temporary side effects when stimulating the vagus nerve. These side effects are typically mild and improve over time.
Other non-invasive ways of stimulating the vagus nerve can include humming, singing or chanting to activate nerves in your throat; breathing exercises and yoga may also prove effective ways to manipulate it.
Some individuals suffering from treatment-resistant depression could also benefit from vagus nerve stimulation (VNS). VNS can reduce anxiety while improving mood-related symptoms by encouraging relaxation, although more research needs to be conducted into whether VNS can indeed be used effectively for such purposes. If considering VNS as an option for you, be sure to discuss it with a mental healthcare provider as they will be best equipped to assess whether you qualify as a candidate and understand risks and benefits; additionally it’s wise to inform health care providers prior to having medical tests that might interfere with an implanted device (i.e. an MRI for instance).
