Seizures are caused by excessive electrical activity in the brain, although the cause is not always known.

Many patients with epileptic seizures can benefit from surgical treatment. For such patients, the surgeon often must work with a neurologist to determine the precise location in the brain from which the seizures are originating. In order to make such a determination, the surgeon often must temporarily implant a grid of sensitive electrodes on the surface of the brain, which can be connected to a monitoring device. These electrodes record the brain's activity during a seizure and can help locate the abnormal spot where the seizure starts.

If successful, this information is used to plan the second stage of the surgery, in which the abnormal area of the brain where the seizures originate is removed, along with the electrodes themselves.