Vagus nerve stimulation (VNS)

Some children, whose seizures are not being well controlled with seizure medications, may benefit from a procedure called vagus nerve stimulation (also known as vagal nerve stimulation or VNS).

VNS attempts to control seizures by sending small pulses of energy to the brain by way of the vagus nerve. The vagus nerve travels from the brain down into the body but is easily accessed in the neck. The surgery places a stimulator (computer/battery) under the muscle of the chest wall. This is connected to small wires that are placed under the skin and around the vagus nerve. The device is programmed to send weak electrical signals that travel to the brain at regular intervals. For reasons that are not well understood, stimulation of the nerve reduces seizure frequency and severity. The stimulation can be temporarily increased by the patient or caregiver with a magnetic bracelet in cases at the time of seizure onset which can reduce the duration or severity of the event.

There are some side effects that may occur with the use of VNS. The most common side effects are discomfort in the throat or hoarseness during cycles of stimulation. The device settings can be adjusted to prevent these effects if they are occurring. The stimulator typically requires replacement every 7-10 years as the battery expires. Unfortunately the device does not have the same benefit for every patient and it is not possible to identify patients who will not respond prior to surgery. Because the risks of surgery are low, and the device is well tolerated in most, VNS can be a reasonable choice to improve seizure control in many patients.

Children’s Wisconsin has performed more than 50 VNS procedures since 2014.