Epilepsy Surgery

Epilepsy surgery is a treatment option that can reduce how often you have seizures and how severe your seizures are and possibly cure epilepsy. Patients may achieve total freedom from seizures.

A neurologist usually recommends surgical epilepsy treatment if you've tried two or more medications to treat epilepsy and still don’t have control over your symptoms. This is called intractable epilepsy or drug-resistant epilepsy.

Patients with drug-resistant epilepsy are often unlikely to respond to further medication so surgical evaluation can be an important step in helping you get your epilepsy under control.

There are three main types of epilepsy surgery — resection, ablation and neuromodulation.

Resection and ablation involve removing or interrupting parts of the brain that cause seizures. These procedures offer patients a high rate of seizure freedom.

Neuromodulation uses electrical stimulation to the brain or other parts of the nervous system to greatly reduce how often and severely seizures happen and, in some cases, can also result in seizure freedom.

For some patients, other procedures such as corpus callosotomy or hemispherotomy can disconnect parts of the brain causing seizures. These patients can also have significant benefits.

The goals of epilepsy surgery are the following:

• Stopping seizures completely when possible
• Preserving your important brain functions, like language, memory and motor skills
• If complete freedom from seizures is not possible, greatly reducing the severity and/or frequency of seizures
• Maintaining your independence
• Improving your quality of life
• Informing and involving you in every step of the decision making process

If you're a candidate for surgery, you’ll undergo a comprehensive evaluation. This includes a process called brain mapping. It allows your specialist to find your seizure focus and plan your surgery.

Brain mapping can involve advanced brain imaging, such as MRI or SPECT, electroencephalography (EEG) and/or a neuropsychological assessment.

In cases where more detail is needed, a specialist can perform advanced brain mapping of the regions of your brain involved in your seizures and nearby, normally functioning structures. They do so with a minimally invasive brain surgery called stereoelectroencephalography (SEEG).

SEEG involves placing small electrodes — about the size of spaghetti — through the skull into the brain using robotic guidance and then recording directly from brain structures.

After the procedure, patients typically stay in the hospital for one week to monitor for seizures and map normal brain function. Your epilepsy team will use a combination of recording and other advanced techniques such as stimulation and radiofrequency ablation to map and understand your epilepsy.

Patients benefit from advanced technology and techniques through the Rush Epilepsy Center and the Rush Center for Brain Mapping. These include robot-guided electrode placement, minimally-invasive resective neurosurgery, laser ablation and neuromodulation in the thalamus, as well asclinical trials that can offer treatments that are not yet widely available.

Symptoms and Signs That You May Need Epilepsy Surgery

If you have epilepsy symptoms, your neurologist may try treatments like medication and lifestyle changes to manage your condition. These can often help reduce seizure symptoms, like episodes of muscle spasming, stiffness, losing consciousness, convulsions or confusion.

But there are cases where these treatments aren’t enough, and surgery is recommended.

Some signs you may be a candidate for epilepsy surgery include the following:

• Your seizures are not under control after trying two or more antiseizure medications
• Imaging shows there is a lesion or mass in your brain that is related to your seizures
• Imaging shows that your seizures start in one specific area of your brain
• Your seizures significantly impair your daily life, cause injury or lead to prolonged loss of consciousness

How Epilepsy Surgery Testing and Brain Mapping are Performed at Rush

The first phase of finding out whether you will benefit from epilepsy surgery starts with diagnosis. This includes a neuropsychological evaluation to assess your brain functions, like memory and language. It will likely also include an MRI to provide imaging of your brain and occasionally other imaging like a SPECT or PET scan.

Depending on what your specialist finds, they may prescribe treatment or decide that your epilepsy may need evaluation for surgical treatment.

When your specialist recommends that your epilepsy be treated with surgery, they will move to the next phase of diagnosis and evaluation. This first involves a discussion between your epilepsy neurologist and the neurosurgeon at an epilepsy patient management conference.

Your case will be reviewed by a team that includes specialists in neurology, neurosurgery, imaging and neuropsychology, among others. They’ll work together to create a custom surgery plan tailored to your epilepsy and your unique brain.

After this discussion, your neurologist will have an in-depth conversation with you about further steps you may need. Then, if you are a candidate for surgery, you will meet with the epilepsy neurosurgeon.

At each meeting, your team will explain every test and procedure carefully and will leave plenty of time for your questions and discussions. Once your brain mapping plan is determined and you agree to proceed, the process will begin.

One goal of brain mapping is to find which area of your brain is causing seizures. Another is to find out which parts of your brain control important functions. All of the data gathered about your brain helps your neurosurgeon plan to preserve important brain functions while disrupting the seizure focus to relieve your symptoms.

Some brain mapping tests for epilepsy surgery are noninvasive, while others are minimally invasive. Brain mapping tests offered at Rush include the following:

• Routine EEG: This involves placing electrodes on the scalp that record electrical activity in your brain for a short period of time, typically 30 to 90 minutes.
• Continuous video EEG (VEEG): Like a routine EEG, scalp electrodes record brain activity. But video and audio of your seizures are also recorded, usually over several hours or days. You may be monitored in the hospital or, in some cases, from home.
• High-density EEG (HEEG): An HEEG is also like an EEG but uses many more electrodes combined with high-quality MRI. This gives doctors a better sense of where the seizures come from. If they also need to do an intracranial EEG, an HEEG gives them more targeted planning and guidance.
• SISCOM (SPECT): Epileptologists use this brain mapping tool to visualize activity in your brain during a seizure. They use advanced MRIs to compare blood flow in your brain during a seizure to blood flow in your brain’s resting state. This helps find your seizure focus.
• Stereotactic EEG (SEEG): This is a minimally-invasive brain surgery to temporarily implant electrodes that record directly from the brain during seizures and normal function. The neurosurgeon will use a robotic guidance system to implant the electrodes and relies on stereotactic guidance. This means they combine at least two forms of imaging to provide a more three-dimensional map of your brain. Most patients stay in the hospital for about a week for monitoring, then they can go home. But in rare cases, patients have surgical treatment for epilepsy during the same hospital stay. Before patients are discharged, their epileptologist and neurosurgeon will have a detailed conversation with them about the findings of the SEEG and what the next steps and options are. Most patients will follow up in 2-3 weeks to schedule their next surgery.

Types of Surgery for Epilepsy Performed at Rush

Surgical procedures that can treat epilepsy include the following:

• Focal resection, or removal of the seizure focus, involves surgically removing the part of the brain causing seizures. One of the most common focal resections performed is temporal lobectomy. In temporal lobectomy, neurosurgeons remove parts of the temporal lobe to treat epilepsy. At Rush, we specialize in using brain mapping techniques, including SEEG, to minimize the amount of brain tissue removed to preserve your normal functions while treating your epilepsy. Because of this, we often perform selective resections.
• Ablation involves using heat or energy to disrupt the seizure focus in the brain. Some types of ablation include the following:
  • Laser interstitial thermal therapy (LITT) involves heating the tip of a laser catheter to burn the lesion area of the brain that is causing seizures. LITT can significantly improve seizures using only a small hole in the scalp that is easily stitched.
    People with mesial temporal sclerosis are often ideal candidates for LITT.
  • Radiofrequency ablation (RFA) involves using a special device to create a radiofrequency lesion in the brain at the seizure focus guided by already implanted SEEG electrodes. This can often be performed in the same setting as your SEEG. It usually does not provide a cure, but it can give important information about the location of your epilepsy.
• Neuromodulation involves surgically implanting devices that respond to abnormal electrical activity in the brain. There are several types of neuromodulation, including the following:
  • Responsive neurostimulation (RNS): Neurosurgeons implant a neurostimulator device, also called a NeuroPace, that both records brain electrical activity and can stimulate to stop or reduce seizures. This device is implanted in the skull and the electrodes are implanted inside the brain. It requires regular data uploads to make sure your epilepsy team can review the recordings of your brain. RNS can be used for bilateral, non-resectable and potentially even generalized epilepsy.
  • Deep brain stimulation (DBS): DBS can be used to stimulate deep areas in the brain at critical nodes for epilepsy including the anterior nucleus of the thalamus, pulvinar nucleus of the thalamus and centromedian nucleus of the thalamus. This procedure involves implanting permanent electrodes in these regions of the brain and then connecting them to a battery in your chest. If necessary, your team can map your brain during implantation to ensure the best electrode placement.
  • Vagus nerve stimulation (VNS): This device treats epilepsy by stimulating the vagus nerve in the neck. The surgery involves placing an electrode on the nerve and then connecting it to a battery in the chest. This can also greatly reduce seizures. At Rush, we often use heart rate detection with our VNS, which can optimize how and when the VNS device stimulates to treat seizures.
• Disconnection surgery involves disconnecting but not removing parts of the brain to prevent the spread of seizures, or generalization, or disconnect areas of the brain that are causing seizures. Examples of this include the following:
  • Corpus callosotomy: This procedure involves cutting the corpus callosum, which connects the left and right sides of the brain. This stops seizures from spreading from one side of the brain to the other. It is most often used for people with intractable drop seizures. Although not a cure, it can reduce how often you have seizures. It may be performed as an open surgery or as a minimally invasive procedure using lasers.
  • Hemispherotomy: For patients with severe drug-resistant epilepsy and dysfunction of an entire hemisphere — for example, they’re unable to use one side of the body — a neurosurgeon can disconnect one hemisphere of the brain entirely. This is usually performed for severe conditions such as hemimegalencephaly, Rasmussen’s encephalitis and large strokes. For selected patients, this can be the most effective procedure for stopping their epilepsy.