Extratemporal cortical resection for Epilepsy

Overview

Approximately 20 percent of people with epilepsy cannot adequately control their seizures with anti-epileptic drugs (AEDs). Other people experience serious side effects from AEDs that impact their quality of life. Some of these people may be candidates for surgery.

Extratemporal cortical resection is one type of brain surgery used to treat people with epilepsy. The goal of extratemporal cortical resection surgery is to remove the seizure focus while preserving vital functions such as speech, sensation, movement, and memory.

The largest part of the brain, the cerebrum, is divided into left and right halves known as hemispheres. Each hemisphere has four lobes: Frontal, temporal, occipital, and parietal. The temporal lobe is the most common location for seizures to start. However, in some people, the seizure focus is located in other areas of the brain. In an extratemporal cortical resection, one or more seizure focuses are surgically removed from lobes of the brain other than the temporal lobe. Extratemporal cortical resections are most frequently performed on the frontal lobe. Extratemporal cortical resection surgery may involve more than one lobe.

Not everyone with intractable epilepsy is a good candidate for extratemporal cortical resection. Extratemporal cortical resection is a surgical option for people who experience seizures that originate outside the temporal lobe. In addition, it must be possible to remove the seizure focus or focuses without disrupting important brain functions such as memory, communication, and hearing. In order to qualify for extratemporal cortical resection, you must have tried several different AEDs for significant periods of time. Finally, you and your doctors must agree that the benefits you might gain by undergoing the surgery outweigh the risks of performing the procedure.

What does it involve?
In order to decide whether you are a good candidate for extratemporal cortical resection, your neurologist will perform extensive testing. The pre-surgical evaluation tests may include seizure monitoring, magnetic resonance imaging (MRI) scans, positron emission tomography (PET) scans, magnetoencephalography (MEG) tests, Wada tests, and electroencephalography (EEG) monitoring. The EEG monitoring may be performed externally or invasively, using electrodes that are placed inside your skull. Pre-surgical evaluation is very thorough in order to ensure you will receive the maximum possible benefit from the surgery and avoid disruptions of normal brain function. You and your doctor should decide together whether an extratemporal cortical resection may be right for you. Do not be afraid to ask questions about any aspect of the surgery or recovery.

You will be given instructions to stop eating a few hours or possibly the night before surgery. When you arrive at the hospital, vital signs will be taken, and blood will be drawn for testing. A portion of your head may be shaved. When it is time for the surgery, you will receive an intravenous (IV) line and anesthetic medication.

During the extratemporal cortical resection, the neurosurgeon will make an incision in your scalp and retract a flap of skin. The neurosurgeon will then remove a section of your skull in a procedure known as a craniotomy. Next, the neurosurgeon will retract a section of the dura mater, the tough outer covering of the brain. Viewing your brain through a surgical microscope, the neurosurgeon will insert instruments. For a portion of the surgery, you may be put into a sedated, twilight state, just conscious enough to respond to questions. Doctors or nurses may ask you to count, describe images, or other tasks in order to help the neurosurgeon pinpoint which sections of your brain are responsible for which functions. The neurosurgeon will cut away one or more seizure focuses. When the neurosurgeon is finished performing the extratemporal cortical resection, they will close the dura mater, fix the skull back in place, and finally close your scalp with staples or stitches.

You can expect to stay in the hospital for two to four days after receiving extratemporal cortical resection surgery. Once you return home, it will take four to six weeks to recover completely from surgery and resume work, school, or other normal activities. Your hair will hide the scar when it grows back.

You will likely continue taking your AEDs after surgery until your neurologist establishes how effective the surgery was in controlling your seizures. You may eventually be able to reduce or stop taking your medications. You should never suddenly stop taking an AED. Always consult your neurologist for a plan to taper off gradually in order to avoid withdrawal.

Intended Outcomes
Extratemporal cortical resection may help eliminate or reduce seizures, and it may reduce the number or amount of medications you need to take to control your epilepsy.
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Results
As many as 65 percent of people are either free of seizures or have their seizures dramatically reduced after receiving an extratemporal cortical resection. In general, extratemporal cortical resection is more likely to be successful if the surgery involves only one seizure focus.

Constraints
Temporal lobe resection surgery may not be successful in reducing or eliminating your seizures.

Any surgery carries risks including blood clots, blood loss, infection, breathing problems, reactions to medication, and heart attack or stroke during the surgery. Extratemporal cortical resection carries rare but serious risks including paralysis, personality change, loss of some functions relating to memory, speech, or vision, and weakness or numbness in the limbs.

Extratemporal cortical resection surgery can cause pain and swelling, and you will most likely need pain medication for some weeks during recovery. Other temporary side effects may include fatigue, depression, headaches, numbness in your scalp, nausea, and trouble remembering or speaking some words.

Possible complications of extratemporal cortical resection include swelling in the brain and damage to healthy brain tissue. Even if seizures are eliminated, you may continue to experience auras, the sensations that signal the beginning of a seizure.

Some people become anxious if they experience a seizure after surgery. A seizure after surgery does not indicate that the surgery was unsuccessful. It may be necessary to examine seizure triggers or adjust medication in order to reestablish control.

Even if surgery is successful at completely controlling seizures, some people have trouble adjusting to life without seizures. Although it is a positive change in many ways, it can create stress and put pressure on interpersonal relationships. Seek support or therapy if you find yourself becoming depressed or anxious due to changes in life after surgery