Epilepsy Treatment Devices

In some cases, epilepsy treatment devices are used when medications have failed to control seizures. These computerized electrical devices are implanted into the chest or skull, and help control seizures by focally stimulating the electrochemical activity of the brain. The most common of these is called the “vagus nerve stimulator (VNS).” The responsive neurostimulator system and the deep brain stimulator are two other promising epilepsy treatment devices.

Vagus Nerve Stimulation

The vagus nerve is the longest of 12 cranial nerves. It connects the brain to the body’s other organs. Vagus nerve stimulation controls seizures via mild electrical pulses to the brain through the vagus nerve. These electrical pulses come from a small, flat round battery that is surgically implanted into the chest wall. It’s connected to the vagus nerve in the neck by tiny wires (electrodes).

The VNS device is programmed to send electrical pulses to the vagus nerve at regular intervals. If the individual feels a seizure coming on, he can pass a special magnet over the implanted device and it will give off extra stimulation to help to prevent it. Vagus nerve stimulation therapy has mild (usually temporary) side effects, including:

  • Change in voice during stimulation
  • Coughing
  • Hoarseness
  • Shortness of breath
  • Sore throat.

The VNS device is known as the “pacemaker for the brain” and is currently approved for individuals over the age of 12 with partial seizures who have not responded to medication. According to the Epilepsy Foundation of America®, approximately one-third of people treated with VNS therapy reported a significant improvement in the frequency of their seizures. One-third reported some improvement and the final third saw no change at all.

Responsive Neurostimulator System

The responsive neurostimulator system (RNS) is a seizure-detection system. A small, flat computerized electrical device is implanted just under the scalp. Electrodes are inserted into the brain’s epilepsy focus (area of the brain responsible for seizures) and connected to the RNS device. These electrodes send signals to the RNS device that is programmed to detect the electrochemical brain activity that causes seizures. When such activity is detected, the RNS device sends an electrical stimulus over to the epilepsy focus to prevent the seizure.

The responsive neurostimulator system is still undergoing clinical trials, but many of these trials have proven to be successful in controlling seizures in individuals with epilepsy.

Deep Brain Stimulator

Like the VNS device, a deep brain stimulator (DBS) device is implanted in the collarbone or chest. The DBS device sends signals to the brain via an insulated wire that connects the device to an electrode implanted deep into the brain. The electrode then sends a stimulus to the thalamus (the part of the brain typically responsible for producing the most seizures).

Deep brain stimulator therapy has been used for some time to treat the debilitating effects of Parkinson’s disease. In March 2010, the U.S. Food and Drug Administration voted to approve deep brain stimulator therapy for adults with partial seizures that have not been controlled by medication.

Resources

Donner, E. J. (2006). Vagus nerve stimulation for epilepsy. Retrieved March 29, 2010, from http://www.aboutkidshealth.ca/Epilepsy/Vagus-Nerve-Stimulation-for-Epilepsy.aspx?articleID=6638