Vagal Nerve Stimulation

Diagram of Vagal Nerve Stimulator

One of the most exciting developments in the field of epilepsy treatment is the Vagal Nerve Stimulator (VNS). The VNS is a device about the size of a hockey puck, which is placed in the chest in a manner similar to a pacemaker for the heart. Once implanted, the neurologist will program the VNS to deliver a series of stimulations. The VNS does not work by sensing a seizure. Instead it works by repetitively stimulating the vagus nerve for a period of time and then by pausing for a period time.

The VNS is also programmed with a special sequence that is activated when a magnet is swept over the device. For patients who can sense a seizure is about to start (the aura of a seizure), it can be useful in aborting the seizure. For patients who cannot sense the impending seizure, it can be useful for family and caretakers to shorten the seizure and allow for faster recovery of the patient.

VNS has not been shown to be a more effective treatment than any other anti-epileptic medications. Its advantage lies in its different side effects like neck pain and voice change (usually transient), not shared by drugs. When effective, it allows the decrease of other drugs, which improves the quality of life for the patient and caregivers. It also seems to shorten the duration of seizures and the recovery time after a seizure occurs. Unfortunately, VNS does not benefit everyone and there is no way to predict in advance who will benefit from its implantation.

VNS is also felt to have great potential in the area of treating depression that often accompanies Epilepsy, however this is currently under investigation by the FDA and approved only as part of ongoing research.