Epilepsy Surgery

What is epilepsy surgery?

Epilepsy surgery is brain surgery to stop or reduce the number of seizures you have and/or their severity. Seizures are bursts of abnormal electrical activity between your brain’s nerve cells. They can cause changes in your:

• Awareness.
• Behavior.
• Emotions.
• Muscle control.
• Sensations.

It’s a big decision to have epilepsy surgery. It’s important to note that undergoing surgery doesn’t cure epilepsy. There’s no guarantee that you’ll be seizure-free when you wake up from the procedure. But it may significantly improve your quality of life. Everyone’s outcome is different.

Your healthcare provider will let you know if this is a safe option for you and what you can expect.

When do you need epilepsy surgery?

Surgery isn’t the first option for epilepsy treatment. Your healthcare provider may consider surgery if:

• A non-epileptic condition causes seizures (for example, brain tumor or arteriovenous malformation).
• Anti-seizure medication(s) don’t regulate seizures.
• The side effects of anti-seizure medications outweigh the benefits.
• Other treatment methods, like changing your eating habits (ketogenic diet), aren’t effective.
• Seizures are frequent and making it difficult to function on a daily basis.

Your surgeon may choose not to operate on an area of your brain if it’s responsible for vital or important functions, such as memory, movement, thinking, etc. They may pursue other epilepsy treatments instead.

What are the types of epilepsy surgery?

There are many types of surgical procedures for epilepsy that vary based on the location of the seizures and/or the underlying cause. Common types of epilepsy surgery include:

• Surgical resection: Removing the part of your brain where the seizures start or removing the abnormal brain tissue that’s causing the seizures. Examples include lesionectomy, lobectomy, multilobar resection and hemispherectomy.
• Surgical disconnection: Disconnecting parts of your brain or areas where nerve cells communicate to stop the spread of seizures. Examples include corpus callosotomy and multiple subpial transection.
• Laser interstitial thermal therapy: Using MRI scans to guide a small laser probe. This technique is used to destroy nerve cells at the seizure site. It’s less invasive than other types of open surgery.
• Neuromodulation (implanted devices): Implanting a device and electrodes that send electrical signals to block or disrupt seizure activity at its source. Examples include vagus nerve stimulation, responsive neurostimulation and deep brain stimulation.
• Implantation of electrodes: Your provider may need to collect data by recording signals directly from your brain. They’ll do this by carefully implanting electrodes into (or on the surface of) your brain. This information helps your surgeon decide upon a good surgical strategy that’s tailored toward the treatment of your seizures. Examples include stereoelectroencephalography and subdural grid implantation.

How should I prepare for epilepsy surgery?

You’ll meet with your neurosurgeon before the date of surgery. Your surgeon will explain the procedure and answer any questions you may have. They’ll discuss the indications, steps, benefits and risks of surgery. They’ll also review what you may expect during your recovery. At the end of this appointment, you’ll sign an informed consent document, which serves as permission to do the surgery.

Your surgeon will also provide instructions specific to your surgery so you know exactly how you can prepare for the procedure and the recovery period afterward. These instructions may include:

• Details about pre-surgical testing.
• Changes to medications that you currently take (you may need to stop taking a medication, or in some cases, start a new medication before surgery).
• Stop or reduce the frequency of smoking.
• Make preparations with loved ones to help you as you recover.

What tests do I need before epilepsy surgery?

Healthcare providers perform pre-surgical testing before epilepsy surgery. The goals of pre-surgical testing are to:

• Locate where the seizures begin in your brain.
• Identify if your surgeon can safely remove an area of brain tissue, or safely disconnect different brain areas.
• Determine what vital functions are controlled near the brain area where the seizures start (such as speech/language, memory and movement).
• Help predict the outcome (reduction in seizure numbers or severity) after surgery.

There are usually two levels of pre-surgical testing. Phase I involves nonsurgical tests. Phase II testing requires surgery.

Phase I tests include:

• Electroencephalogram (EEG): This is a measurement of electrical activity in your brain. In some cases, you may need an in-hospital video EEG, where a provider monitors your brain activity during a seizure. A single-photon emission computed tomography (SPECT) scan may assist a video EEG.
• Positron emission tomography (PET): This scan measures function in all areas of your brain. It can identify where a seizure begins even when you’re not actively having one.
• Neuropsychological evaluation: Neuropsychological tests assess your verbal skills, memory function and other learning skills. This test serves as a baseline for measuring and comparing any changes before and after surgery.
• Functional MRI: A functional MRI measures brain activity while performing cognitive tasks, like memorizing or reading. This helps your neurosurgeon know which areas of your brain control these functions.
• Wada test: This test helps identify which side of your brain is dominant for different functions.

Phase II tests involve surgery to place electrodes within (or on the surface of) your brain, to collect more direct signals from the brain itself, to better locate the network(s) where the seizures are starting. These tests include:

• Electrode placement: Your provider places electrodes, or wires with electrodes, on your brain to monitor electrical activity.
• Stereoelectroencephalography (SEEG): This test involves placing electrodes at different depths in your brain to create a 3D view of the start and spread of seizure activity.
• Subdural grid implantation: Your surgeon will open an access point to the surface of your brain, allowing for flat electrodes to be carefully placed on the surface, to record seizures and also permit testing of important brain functions (for example, motor or language function).
• Functional brain mapping: Your surgeon places electrodes on your brain in different areas to create a map and identify seizure-producing areas.

You likely won’t need every test listed here. Your surgical team will decide which of these tests are appropriate for you.

What happens during epilepsy surgery?

First, your healthcare provider will shave the part of your head where they’ll perform the surgery. You don’t need to worry — your hair should grow back once you heal. An anesthesiologist will give you general anesthesia. You’ll be asleep during the surgery. Your healthcare team will closely watch your heart rate, blood oxygen level and blood pressure.

Your neurosurgeon will remove a small area of your skull and set it aside. They may perform an EEG during surgery to confirm the exact location or source of the seizures.

In some cases, your surgical team may wake you up so you can respond to your neurosurgeon’s questions. This helps guide surgery and maps out areas in your brain that control vital functions, like speech, hearing and movement. You won’t feel pain during this step of the procedure.

After brain mapping, you’ll go back to sleep. Your neurosurgeon will treat the area of brain tissue where the seizures occur, with the appropriately determined surgical approach. They’ll set your skull bone back in place and secure it with small titanium clips (which are inert, so they don’t activate metal detectors or airport scanners). Your surgeon will then close the skin covering your skull, and carefully bandage your head.

How long does epilepsy surgery take?

Epilepsy surgery takes several hours to complete. Your surgeon will give you the best time estimate, as each procedure varies based on what your surgeon needs to do.

What happens after epilepsy surgery?

After surgery, you’ll move into an area of the hospital for observation. You may need to stay in intensive care for one day, and in the hospital for three to five days for open surgery.

You can expect scalp and face swelling, as well as headaches, after the procedure. You’ll receive medications to manage these symptoms. They should go away within a few weeks. But let your provider know if the pain is severe or if you experience any additional symptoms.

What are the benefits of epilepsy surgery?

The benefits of epilepsy surgery may include, but aren’t limited to, the following:

• Fewer seizures or becoming seizure-free.
• Reducing the dosage or quantity of anti-seizure medications.
• Increasing your chance of returning to work, driving or participating in activities that seizures made unsafe.
• Reducing life-threatening complications (like unexplained death or status epilepticus).
• Improving your mental health and emotional well-being.

What are the risks or complications of epilepsy surgery?

All surgeries have risks. Typical surgical risks include:

• Reaction to anesthesia.
• Bleeding.
• Infection.
• Brain tissue damage, resulting in neurological changes (like weakness and speech impairments) or stroke.
• Hydrocephalus, referring to water build-up in the brain.
• Delayed healing at the surgical site.

In addition to these risks, brain surgery can affect vital functions like memory, speech, vision and movement. It may affect your mood as well. This is why healthcare providers perform extensive pre-surgical testing to locate where the seizures start. Your surgical team will do everything they can to make sure they preserve the function of these areas of your brain.

What is the recovery time after epilepsy surgery?

You’ll need plenty of rest as you slowly return to your normal daily activities, in about four to six weeks. You can expect to return to work or school in about one to three months. But it usually takes two years to see the full results of surgery.

You’ll continue taking your anti-seizure medications for some time after surgery. The medications help protect your brain as it heals, and they lower the chance of having seizures later on. If you don’t have any seizures after a year or more, your healthcare provider may gradually reduce your medication dosage and eventually stop it.

Unless your vital functions have been affected (like speech, memory and movement), you won’t need rehabilitation therapy.

What is the success rate of epilepsy surgery?

The success of your surgery depends on many factors, including:

• The type of seizures you experience.
• The frequency and severity of seizures.
• The area of your brain involved.
• The type of surgery.
• Your age.
• Other existing health issues you may have.

Between 40% to 50% of people who undergo vagus nerve stimulation surgery may experience a decreased number of seizures. They may only have half as many as before. More than 85% of people who’ve had temporal lobe resection experienced a large decrease in the number of seizures after surgery.

Ask your neurosurgeon about what outcome you can expect if you have epilepsy surgery.

When should I call my healthcare provider?

Your provider will let you know what symptoms to look out for when you go home after surgery. For example, contact your provider right away if you have a fever or any of the following symptoms at the incision site:

• Severe pain.
• Swelling.
• Bleeding.

It’s important that you follow up with your provider as instructed. You’ll need regular visits and imaging scans to monitor your healing.