Types of epilepsy surgery and what they involve

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Epilepsy surgery is a name for several types of brain surgery that aim to reduce epileptic seizures. Some procedures could potentially completely stop seizures for many years.

The specific effectiveness of surgery varies depending on the type of seizures that a person has and the specific surgical procedure. According to the Epilepsy Society, 70% of people who have temporal lobe surgery become seizure-free, with 50% remaining seizure-free after 10 years. However, doctors will only recommend epilepsy surgery for those whom they expect to benefit from it.

Even if surgery does not totally stop seizures, it can produce long-term reductions in seizure frequency for some people. A 2018 study from the United Kingdom found that in people with refractory epilepsy, almost 75% of participants were having half as many seizures 5 years after their surgery. After 10 years, 70% were still having half as many seizures.

However, epilepsy surgeries have risks. For this reason, doctors typically only consider people for surgery if they have not responded to AEDs.

To be eligible for epilepsy surgery, a person must:

• have a type of epilepsy that responds well to surgery
• have tried several AEDs first, with little success
• be in reasonably good health

A neurologist can determine whether someone is a suitable candidate for epilepsy surgery by performing tests to determine:

• where in the brain the seizures originate
• the areas of the brain to which the seizures spread
• whether surgery would affect important brain functions

If the neurologist can find a specific location, and that location is operable, a person may be able to undergo surgery.

All epilepsy surgeries carry some risks. These include:

• infection
• bleeding
• adverse reactions to anesthesia
• scarring

There may also be a risk of changes in brain function. Depending on the type of surgery, these can include changes to vision, thinking skills, personality, and mood. The risks can vary among individuals, and in some people, they may only be temporary and improve after the swelling from surgery goes down.

It is important to weigh up the risks and benefits of the surgery with a medical team before making a decision.

The most common types of epilepsy surgery include:

Temporal lobe resection

A temporal lobe resection removes a portion of the temporal lobe of the brain. The goal of surgery is to reduce or eliminate the abnormal electrical activity in the brain that causes temporal lobe epilepsy. It is the most common type of epilepsy surgery.

Success rates for this type of surgery are generally high. According to a 2016 longitudinal study, temporal lobe resection may control seizures — meaning that it eliminates or significantly reduces them — in 80% of people who have this procedure.

Risks

The temporal lobe plays an important role in memory, so one of the risks of this surgery is memory problems. If this occurs, finding words or recognizing faces may be difficult, although these abilities may improve with time.

Older studies have found that in people having a resection in the dominant hemisphere of their brain, 44% experience some level of decline in their verbal memory. However, some studies also find that memory improves after the surgery.

A 2017 study of 216 patients who chose this surgery found that the mortality rate 30 days after surgery was 1.6%.

Resection of other areas of the brain

Doctors may also remove other areas of the brain, including portions of the occipital, frontal, or parietal lobe. This treatment works best when doctors discover lesions on these regions of the brain or find that unusual electrical activity in these regions is causing seizures.

Risks

The risks and side effects depend on the area of the brain on which a person has surgery, as each brain region plays a different role in basic functions. For example, surgery on the occipital lobe may affect vision.

A 2018 study involving 42 people undergoing occipital lobe resection for treating epilepsy found that 57.6% had good visual function following surgery. Lateral occipital lobe resection was more likely to harm vision. The same study also found that 78.6% of participants had good seizure control, with either no seizures or only auras.

Corpus callosotomy

A corpus callosotomy is a palliative procedure, which means that it eases symptoms but does not eliminate them. During the surgery, a surgeon cuts the corpus callosum, which connects the left and right hemispheres of the brain. This prevents seizures from spreading from one side of the brain to the other.

Doctors usually recommend this procedure for people who experience tonic or atonic drop seizures, which can cause severe injuries. It can also be a treatment option for people with West syndrome or Lennox-Gastaut syndrome.

Risks

One of the risks of this surgery is “disconnection syndrome,” which occurs when the two halves of the brain have difficulty communicating. As a result, a person may not be able to name smells that enter through the right nostril, for example, or they may struggle to name objects that they see only on the left side. Disconnection syndrome can affect a person’s ability to drive or complete other complex tasks.

This effect is often temporary, but it can sometimes be permanent. Language or memory problems are other potential complications.

Lesionectomy

A lesionectomy involves removing any lesions, tumors, or abnormal blood vessels in the brain that are causing seizures. When surgery is successful, a person may become seizure-free.

The success rate for lesionectomies depends on the type and location of the lesions, among other factors. However, studies suggest that success rates are generally good. An older 2013 study of 68 people with non-mesial temporal sclerosis lesions found that 63.2% were seizure-free a year after surgery.

Risks

As a lesionectomy often involves removing only a lesion, it comes with a lower risk of damaging parts of the brain that deal with important functions, such as memory. However, the risk can depend on the location of the growths.

For some types of lesions, there is a risk that growths will come back after a lesionectomy. If seizures begin occurring again after the surgery, doctors will monitor the person closely to see whether this has happened.

Hemispherectomy or hemispherotomy

In rare cases, a doctor may perform a hemispherectomy, which involves the removal of an entire hemisphere, or half, of the brain. A related surgery, known as a hemispherotomy, is similar to a corpus callosotomy and involves disconnecting the brain’s hemispheres but not removing either of them. These procedures are rare.

A hemispherectomy can often eliminate seizures, with estimated success rates ranging from 54–90%.

Risks

This procedure is not common, so it is more difficult for scientists to study its risks and side effects. Some people experience changes in motor skills, but the rates vary from study to study.

One of the most common complications of removing tissue from the brain is hydrocephalus, which is the accumulation of fluid in the brain. Doctors can sometimes treat this by installing a shunt to remove the liquid.

Multiple subpial transection

A multiple subpial transection removes several small areas of the brain where seizure activity occurs.

In some people, seizure activity happens in areas of the brain that are vital for basic functions, which makes removing these regions unsafe. Multiple subpial transection works around this issue.

The brain fibers that play a role in most basic functions lie vertically on the brain, but those involved in epilepsy are horizontal. Multiple subpial transection cuts into the horizontal fibers. Cutting into horizontal fibers will not stop seizures from occurring, but it can stop them from spreading.

This surgery is relatively rare, and doctors usually only perform it on children whose seizures begin in infancy. A 2018 Cochrane review concluded that there is not enough evidence to confirm whether the surgery is safe or effective.

Neurostimulation device implantation

In addition to removing parts of the brain, surgeons can implant devices to treat epilepsy. These devices stimulate the brain in different ways to stop the signals that trigger seizures.

Neurostimulation can be suitable for people whose seizures originate in a part of the brain that surgeons cannot remove. Some of the options include:

• Vagus nerve stimulation: This type stimulates the vagus nerve on a set schedule.
• Responsive neurostimulation: This neurostimulation can detect the onset of seizures and stop them as they occur.
• Deep brain stimulation: Healthcare professionals use this in conjunction with a device similar to a pacemaker.

Recovery from epilepsy surgery differs from person to person. It can depend on how healthy a person is before the surgery, how effective the surgery is, and whether the person develops any complications.

It will usually be necessary to stay in the hospital for several days following surgery. It is normal to feel groggy or experience headaches, as well as nausea. In most cases, people can return to work or school within 4–6 weeks.

However, this does not necessarily mean that they have fully recovered from the procedure. A person may still need AEDs, and their surgical wounds may still need time to heal. If a person has side effects, they may need occupational, speech, or physical therapy to regain full function.

It may take months for epilepsy surgery to become fully effective and for doctors to assess how well it has worked.

The amount a person pays for epilepsy surgery depends on:

• whether they have insurance and how much their insurance covers
• the rate their insurer has negotiated with the hospital or surgeon
• whether they get care from any out-of-network providers
• the size of their copay, deductibles, and out-of-pocket maximums
• how long they stay in the hospital
• which specific medications they need

A 2015 study of 78 children with epilepsy who had surgery found that the median cost of epilepsy surgery hospitalization was $118,400. However, this study is several years old, and it did not take into account what portion of the fee people’s health insurance covered.

A 2020 study of people with temporal lobe epilepsy found that epilepsy surgery was more cost effective than long-term medical management.

Epilepsy surgery can be a good option for people whose epilepsy originates in a specific place in the brain and does not respond to medication. Various procedures may help, and a neurologist can advise on the best options to suit a person’s circumstances.

Any brain surgery carries the risk of infection, bleeding, and scarring. Epilepsy surgeries can also cause temporary changes to certain cognitive functions, which sometimes become permanent. It is important to weigh up the benefits and risks with a medical team before undergoing a surgical procedure.