Medications aren't always successful in treating seizures. And epilepsy surgery is often very invasive, sometimes involving removal of large sections of the brain in the hopes of getting rid of the origin of seizures. But for some people with epilepsy, a less invasive surgery that disrupts the electrical impulses in the brain &mdash called multiple subpial transection &mdash might be an option.

What Is Multiple Subpial Resection?

Usually in epilepsy surgery, the specific location in the brain where the seizures begin, called the focus, is removed. But when the focus may be in a difficult spot to reach without causing significant damage and impacting a function like comprehension.

In the type of epilepsy surgery known as multiple subpial resection, no part of the brain is removed. Instead, sections of nerve are disrupted with a series of cuts. This type of epilepsy surgery was developed as an alternative for people who weren't able to have the seizure focus removed using standard epilepsy surgery.

During multiple subpial resection surgery, the neurologist will make several small cuts (called transections) into the brain's cerebral cortex. These cuts do not penetrate deeply, and only reach the gray matter of the brain — perhaps one-quarter of an inch down — just enough to stop electrical impulses from traveling any further.

As a result, the brain is no longer able to push the abnormal electrical impulses that cause the seizure across all sections of the brain, so instead of spreading out, the seizures are confined only to one area because the electrical impulses are blocked.

Who Can Have Multiple Subpial Transection?

The best candidates for multiple subpial transection are those whose seizure focus is in an area of the brain that can't be reached through traditional epilepsy surgery. The focus must be in an area of the brain that, if removed by surgery, would cause significant damage to brain function and leave significant side effects.

Any epilepsy surgery, including multiple subpial transection, is recommended only for epilepsy patients who can't control their seizures with epilepsy medication or for those who experience significant side effects of these anti-seizure medications.

Risks and Success Rates for Multiple Subpial Transection

Although they're rare, there are some risks associated with multiple subpial transections including:

  • Bleeding in the brain where the cuts are made
  • Impaired speech or language function
  • Temporary improvement, meaning the seizures return at some point
  • Temporary changes in neurological function

Overall, the risk of major complications is rare with this surgery — and most side effects are minor. One of the biggest concerns is that multiple subpial transection has not been established as a permanent method of controlling seizures — seizures may return again, anywhere from 2 months up to 20 months after surgery.

But the good news is that about 70 percent of people who have the surgery do experience fewer seizures. Though more research needs to be done on risks versus benefits, it seems to be a promising option for those who aren't eligible for other types of epilepsy surgery.