Medications can control seizures in most people with epilepsy, but they don’t work for everyone. About 30% of people taking the drugs can’t tolerate the side effects. In some cases, brain surgery may be an option.
An operation on the brain can control seizures and improve your quality of life. Surgery has three main goals:
- Remove the area of the brain that causes seizures.
- Disrupt the nerve pathways that seizure impulses take through your brain.
- Implant a device to treat epilepsy.
Who Gets Epilepsy Surgery?
Surgery is only an option if:
- Your doctor can clearly identify the area of the brain where the seizures start, called the seizure focus.
- The area to be removed doesn’t control a critical function like language, sensation, or movement.
If you meet those standards, it works best when:
- Your seizures are disabling.
- Medication doesn’t control your seizures.
- Drug side effects are severe and affect your quality of life.
People with other serious medical problems, like cancer or heart disease, usually aren’t considered for this treatment.
What Are the Options?
The type of surgery used depends on the type of seizures you have and where in your brain they start.
Lobe resection. The largest part of your brain, the cerebrum, is divided into four paired sections called lobes -- the frontal, parietal, occipital, and temporal lobes. Temporal lobe epilepsy, in which the seizure focus is within your temporal lobe, is the most common type in teens and adults. In a temporal lobe resection, brain tissue in this area is cut away to remove the seizure focus. Extratemporal resection involves removing brain tissue from areas outside of the temporal lobe.
Lesionectomy. This surgery removes brain lesions -- areas of injury or defect like a tumor or malformed blood vessel -- that cause seizures. Seizures usually stop once the lesion is removed.
Corpus callosotomy. The corpus callosum is a band of nerve fibers connecting the two halves (called hemispheres) of your brain. In this operation, which is sometimes called split-brain surgery, your doctor cuts the corpus callosum. This stops communication between the hemispheres and prevents the spread of seizures from one side of your brain to the other. It works best for people with extreme forms of uncontrollable epilepsy who have intense seizures that can lead to violent falls and serious injury.
Functional hemispherectomy. In a hemispherectomy, the doctor removes an entire hemisphere -- or half of your brain. In a functional hemispherectomy, the doctor leaves the hemisphere in place but disconnects it from the rest of your brain. He only removes a limited area of brain tissue. This surgery is mostly for children younger than 13 who have one hemisphere that doesn’t work the way it should.
Multiple subpial transection (MST). This procedure can help control seizures that begin in areas of your brain that can’t be safely removed. The surgeon makes a series of shallow cuts (he’ll call them transections) in your brain tissue. These cuts interrupt the flow of seizure impulses but don’t disturb normal brain activity. That leaves your abilities intact.
Vagus nerve stimulation (VNS). A device put under your skin sends an electronic jolt to the vagus nerve, which controls activity between your brain and major internal organs. It lowers seizure activity in some people with partial seizures.
Responsive neurostimulation device (RNS). Doctors put a small neurostimulator in your skull, just under your scalp. They link it to one or two wires (called electrodes) that they place either in the part of your brain where the seizures start or on your brain’s surface. The device detects abnormal electrical activity in the area and sends an electric current. It can stop the process that leads to a seizure.
How Well Does It Work?
It depends on the type of surgery. Some people are completely free of seizures after surgery. Others still have seizures, but less often. You’ll need to keep taking anti-seizure medication for a year or more afterward. Once your doctor knows your seizures are under control, you may be able to cut back on meds or stop taking them.
Are There Risks?
Before you have surgery, your doctor will discuss the pros and cons with you. Some risks are:
- Infection and bleeding, as well as the chance of an allergic reaction to the anesthesia. These are common with any operation.
- Making existing problems worse or creating new trouble with the way your brain works. You could lose vision, speech, memory, or movement.
- A return of seizures.
What Is a Reoperation?
If you have a seizure right after surgery, your doctor may suggest a second surgery (called a reoperation). This doesn’t mean the operation didn’t work. It usually means your surgeon didn’t remove all the brain tissue that causes seizures.