Types Of Epilepsy Surgery

Surgery is not a first-line treatment for epilepsy and is typically reserved for uncontrollable cases. For instance, doctors may consider it when medications fail to work adequately or when other treatment options have been exhausted. 

Additionally, patients will not be considered for surgery without a clear diagnosis. Hence, those who suffer from seizures but have not been diagnosed with epilepsy may not be eligible. Therefore, the only way to know if you are a good candidate for surgery is to speak to your doctor and ask for a referral to a specialist. 

Epilepsy Overview

Epilepsy is a brain disorder characterized by frequent seizures. These seizures start when the electrical signals between brain cells are disrupted, causing abnormal electrical activity. 

A seizure presents symptoms such as muscle spasms, loss of muscle tone, shaking or tremors, loss of awareness, or abnormal sensations. Different types of seizures have various symptoms. That's because the symptoms are predominantly determined by the brain region in which abnormal electrical activity occurs. 

In some cases, people have seizures despite having no history of epilepsy. These are usually one-off occurrences. However, experts¹ suggest that two unprovoked seizures are an indication of epilepsy. 

Treatments for epilepsy

Medications

First-line treatments for epilepsy often involve medications known as anti-epileptic drugs (AEDs). These medications are usually targeted to the type of epilepsy you have or work by slowing the abnormal electrical conduction in the brain. 

These medications only work well when taken consistently. Therefore, you must ensure you do not miss a dose. If you are worried about missing doses, you can set reminders or aim to take it at a time during the day you're likely to remember. Back-up medication in your bag or car will also help if you forget to take it at home. 

Thankfully, there is a wide range of AEDs available, and if you find that one type is not working well, you might be able to switch to another kind. AEDs are prescription drugs only and cannot be bought over the counter at a pharmacy. 

Examples of AEDs include: 

• Carbamazepine 

• Oxcarbazepine 

• Phenytoin 

• Phenobarbital 

• Lacosamide 

• Vigabatrin

• Topiramate

• Valproate

• Levetiracetam

Lifestyle modifications

Other than AEDs, lifestyle modifications may offer some improvements to your condition. However, they are more likely to support other treatments like medication or surgery. 

These include things such as:

• Improving nutrition

• Improving the quality of sleep 

• Avoiding alcohol

• Staying away from illicit drugs

• Better management of stress 

Surgery

If all other options have been exhausted or there has been no significant improvement, your doctor may suggest a surgical approach. 

Why is surgery for epilepsy considered? 

Surgery is required when epilepsy is severe and cannot be managed appropriately with medication. Therefore, surgery might be considered when all other options have been exhausted or are no longer practical. For example, surgery could be considered when two AEDs fail to control seizures adequately. 

When should you have surgery for epilepsy? 

Experts² recommend that early intervention with surgery is best. However, if your condition worsened at a later date, you would still be considered for surgery. Doctors recommend surgical intervention for certain types of seizures. In particular, resective surgery for focal seizures has shown promising results, and surgery should be considered in the early stages of mesial temporal lobe epilepsy. 

Types of surgery for epilepsy 

There is a range of surgical treatments available. But the type of seizures you experience will determine the surgery you are eligible for. 

Resections

Resections³ is one of the most common types of epilepsy surgeries. These involve the removal of a small area of the brain in the region where electrical signals are impaired. 

There are two main types of resections. These are temporal and extratemporal resections. 

Temporal refers to a lobe or area in the brain, while extratemporal relates to locations outside the temporal lobe. 

Temporal lobe resection

Seizures that occur in the temporal lobe most often start during childhood. Because of this, experts³ are now recommending early surgical intervention for patients with seizures in the temporal lobe. 

Essentially, this surgery consists of removing part of the temporal lobe. This procedure aims to reduce the frequency or severity of seizures. 

Extratemporal resection (frontal, parietal, and occipital) 

Seizures outside the temporal lobe in other areas, such as the frontal, parietal, or occipital lobes, also commonly start during childhood. Again, this surgery removes part of the frontal, parietal, or occipital lobes to reduce the frequency or severity of seizures. 

Laser interstitial thermal therapy (LITT)

Laser interstitial thermal therapy⁴ (LITT), also called laser ablation surgery, is a surgical procedure performed with the help of magnetic resonance imaging (MRI). The MRI helps the surgeon find the location in the brain which is affected, and then a laser is directed toward that area. 

This procedure is minimally invasive because it does not require opening the skull to access the brain. Another good aspect of this surgery is that most cases are eligible for this type of procedure. 

Neurostimulation

Neurostimulation⁵ is another non-invasive surgical procedure that does not require the removal of brain tissue. There are three different types.

These include:

• Vagus nerve stimulation (VNS)

• Responsive neurostimulation (RNS)

• Deep brain stimulation (DBS)

Vagus nerve stimulation (VNS)

VNS was one of the first procedures approved for neurostimulation. This procedure requires the implantation of a device that generates an electrical stimulation to disrupt abnormal electrical activity. 

The device contains an electrode and is usually implanted near the left clavicle so it is close to the left vagus nerve. 

Responsive neurostimulation (RNS)

RNS is a device that is implanted directly into the brain. The device monitors the brain's electrical activity and delivers electrical stimulation when required to stop a seizure as it occurs. 

Deep brain stimulation (DBS)

The FDA approved DBS for the treatment of seizures in 2018. It has also been approved in other places like Europe and Canada. Again, another electrical device is implanted, but in this instance, it interacts with the thalamus in the brain. 

Corpus callosotomy

Corpus callosotomy⁶ is a procedure typically reserved for those with severe epilepsy related to generalized seizures. These are seizures that affect both sides (hemispheres) of the brain and result in drop attacks (sudden loss of muscle tone), causing a person to suddenly fall over. 

This procedure splits the connection between the left and right sides of the brain. Splitting this connection can reduce the frequency of seizures. However, some seizures may still occur.

Multiple subpial transections

Multiple subpial resections⁷ are surgical procedures that are opted for when seizures affect areas of the brain that cannot be safely removed. For example, this includes areas of the brain with essential functions such as speech or movement. 

For this procedure, the skull is cut open to access the brain, and the surgeon makes a series of shallow cuts referred to as transactions. The transactions interrupt the brain fibers involved in seizure activity pathways. As a result, it prevents electrical seizure activity from spreading or initiating. 

Hemispherectomy

A hemispherectomy⁸ is a rare procedure reserved for extremely severe cases of epilepsy in children. This procedure is rarely performed because it's risky with many complications. 

There are different types of hemispherectomies. These include:

• Anatomic hemispherectomy

• Functional hemispherectomy

• Hemispherotomy

Anatomic hemispherectomy

During an anatomic hemispherectomy, the frontal, parietal, temporal, and occipital lobes are removed from one side (hemisphere) of the brain. This type of surgery is high-risk, and it's unlikely that any surgeon would perform this procedure today for epilepsy. 

Functional hemispherectomy

A functional hemispherectomy is less risky than an anatomic hemispherectomy. That's because it involves removing a much smaller portion of the brain. 

There is still a considerable amount of risk associated with this procedure, and as a result, it's only reserved for a very small group of people. 

Hemispherotomy

A hemispherotomy sounds are similar to a hemispherectomy. However, it's a type of hemispherectomy that removes considerably less tissue from the brain. 

Removing smaller pieces of tissue instead of one large portion significantly decreases the risks and complications associated with this procedure. But again, this type of surgery is uncommon, and surgeons will consider other surgical options first. 

Surgical risks and complications 

While most surgical procedures for epilepsy are a success, each has some risks and complications. Surgeons typically avoid high-risk surgeries and only perform them when all other options have been exhausted. 

The most common risks of epilepsy surgery are: 

• Bleeding

• Post-operative infections

• Brain injuries

• Slow healing at the site of the surgical wound 

Other complications and risks depend on the surgery being performed. For example, patients who have part of their temporal lobe removed may notice these complications:

• Memory loss

• Trouble retaining new information 

• Partial loss of peripheral vision 

• Double vision 

• Problems with mood regulation 

• Speech difficulties 

• Loss of motor function 

Other types of epilepsy surgeries could also result in these complications. But the good news is that these are often temporary and may resolve themselves after you have healed from the surgery. 

Additionally, it's unlikely that you will experience every complication listed. It's also worth noting that while problems such as mood regulation are possible, many people notice that their mood improves after the surgery. 

If you are worried about the risks and complications of your surgery, you should discuss these with your specialist or surgeon before proceeding with the surgery. 

The lowdown 

There are several surgical treatments available for epilepsy. The type of surgery you may require depends on the type of seizures you experience. Surgery is typically available for those who cannot adequately manage their condition with first-line medications.

To determine whether you are eligible for surgery, you should discuss this option with a specialist.