Neurostimulation (using devices to treat epilepsy) is an acceptable way of treating seizures in people with refractory epilepsy. It’s usually considered in people who are not appropriate for epilepsy surgery or when surgery is not helpful. With neurostimulation, the goal is not complete seizure control, but a reduction in seizures and their consequences.
Types of Neurostimulation
There are several types of neurostimulation, but only two are currently approved by the U.S. Food and Drug Administration (FDA) to treat epilepsy.
- VNS provides stimulation to the entire brain by stimulating the vagus nerve in the neck.
- The stimulation settings are preprogrammed by the health care provider and can be adjusted at clinic visits.
- The VNS stimulates the vagus nerve intermittently during the day – the exact frequency and other parameters (duration, intensity) are set by the health care provider.
- Although the FDA indication for VNS use is narrow and limited to partial epilepsy in adults, it also is used more broadly, for example in generalized epilepsies. (Partial or focal seizures start in one area or group of cells in one side of the brain. Generalized seizures affect both sides of the brain. Learn more about Types of Seizures.)
- The device is generally well tolerated with nearly 3 out of 4 people with VNS choosing to continue therapy when the battery expires.
- The most common side effects are cough, voice changes, chest pain, and nausea.
- A limitation of VNS use is inability to obtain neck MRI.
- VNS appears to improve quality of life for people living with epilepsy.
- The three-year seizure reduction is 44%.
- RNS is a more invasive device that requires surgery to place electrodes on the brain where the seizures are thought to begin.
- The approach is unique in that the device can detect when a seizure happens and give stimulation directly to that area.
- RNS requires that the area of seizure onset (focus) be known.
- Unlike VNS, RNS can be used as a recording device for months to years since it records brain activity (the electroencephalogram or EEG).
- The efficacy of RNS may be slightly higher than VNS: over 3 years, seizures may be reduced by 60%.
Where to Find VNS and RNS Therapy
Both approaches, VNS and RNS, are effective and safe treatment options for difficult-to-control seizures, and are offered (or should be) at most level 4 epilepsy centers.