Surgery

Epilepsy is a neurological (brain) disease that causes recurring seizures. The seizures are caused by abnormal activity in the brain. Surgery is an option to treat epilepsy in some people.

Epilepsy surgery removes a part of the brain where seizures occur. Epilepsy surgery is most successful when there is a single or limited foci of seizure activity that can be targeted for resection. Evaluation for surgery may be recommended if someone has drug-resistant (refractory) epilepsy. This is epilepsy that is not controlled by medicine alone.¹

Epilepsy surgery is not an option for everyone with drug-resistant epilepsy. Some generalized epilepsy syndromes where multiple areas of the brain can trigger seizures are typically not good candidates for epilepsy surgery.¹

The goal of surgery is to stop seizures or limit their severity, with or without medicine. Some people may someday be able to stop taking their anti-seizure drugs and remain seizure-free.¹

Types of epilepsy surgery

There are several types of epilepsy surgery. Each type is right for different kinds of seizures, areas of the brain, and age of the person. These surgeries include:¹

• Resection surgery
• Laser interstitial thermal therapy (LITT)
• Deep brain stimulation
• Corpus callosotomy
• Hemispherectomy
• Functional hemispherectomy
• Multiple subpial transection

Resection surgery

Resection surgery is the most common epilepsy surgery. “Resection” is the medical term for a surgery that removes tissue. It is most often performed on the temporal lobe. This is the part of the brain behind the ears. It controls emotions, memory, language, and processing sound and sight. Extratemporal resection involves removing tissue from other parts of the brain that causes seizures such as the parietal, occipital, and frontal lobes.¹

In resection surgery, a part of the skull is removed (craniotomy) to access the brain. During resection, your surgeon removes a section of brain tissue where your seizures start. Sometimes, this is the site of a tumor, brain injury, or malformed tissue. It results in about 2 out of 3 people becoming seizure-free. Success rates are highest in resection involving the temporal lobe.¹

Laser interstitial thermal therapy (LITT)

LITT uses a laser to pinpoint and destroy a small section of brain tissue. It is less invasive than resection surgery.¹

Deep brain stimulation

With deep brain stimulation surgery, a device is implanted deep into the brain. This device then releases electrical signals on a regular schedule. These signals counteract the abnormal electrical signals that cause seizures.¹

Corpus callosotomy

The corpus callosum is the part of the brain that connects and allows communication between the right and left sides (hemispheres) of the brain. Corpus callosotomy surgery removes some or all of this part of the brain. This surgery is most often done in children who have seizures that start in 1 area of the brain and spread to the other side.¹

Hemispherectomy

Hemispherectomy removes 1 side (hemisphere) of the brain. Half of the brain is fully or partially removed. When a small part of the brain is removed it is called a functional hemispherectomy. When the entire half of the brain is removed it is called an anatomic hemispherectomy. This surgery happens most often in children who have seizures caused by multiple sites in 1 side (hemisphere) of the brain.¹

Multiple subpial transection

During multiple subpial transection surgery, a small portion of the skull is removed (craniotomy). This procedure does not remove brain tissue that causes seizures. Instead, multiple shallow cuts, termed “transections,” are made into the outer surface of the brain (cortex) in areas known to be a source of seizures. This interrupts the communication between overactive brain cells (neurons), leading to a reduction in seizures. ²

What happens before surgery

Epilepsy surgeries are performed in level 3 or 4 epilepsy care centers. Level 4 centers can perform the highest level of epilepsy care. If you normally are cared for by a primary care doctor or a general neurologist, you will be referred to one of these specialized centers for evaluation by an epileptologist and neurosurgeon.¹

Before surgery, your doctors will run a series of tests. Some of the tests will be done to find the source and type of abnormal electrical activity. This is done using EEG (electroencephalogram) and MRI (magnetic resonance imaging). If more detailed information is needed before surgery, your doctor may also order these tests:¹

• Video EEG
• Intracranial monitoring
• Positron emission tomography (PET scan)
• Single-photon emission computerized tomography (SPECT scan)
• Functional MRI
• Wada test
• Brain mapping

Your doctors also will want you to undergo neuropsychological tests. These tests will document your verbal and language skills, ability to learn, and memory. The results give your team a baseline that helps them track any changes after surgery. The results may also provide important information about the area of your brain affected by seizures.¹

What are the possible side effects of epilepsy surgery?

As with any surgery, there are risks. This is especially true when the brain is operated on. Some common risks are:¹

• Memory and language problems that affect the ability to talk, read, and understand
• Vision changes
• Depression and other mood changes
• Brain tissue injury
• Seizure recurrence
• Infection

These are not all the possible side effects of surgery. Also, not all of these surgeries carry the same risks. Your doctors will help you understand the risks linked with the type of surgery you are considering.