Before any epilepsy surgery, you will start a long and thorough evaluation

Story by: Norton Healthcare on December 12, 2017

If your doctor recommends you start a presurgical evaluation because medication hasn’t controlled your epilepsy, you’ll embark on a thorough process to identify treatment options based on the unique details of your seizures and their impact on your life.

Your physician likely will order many tests for you.

The purpose of these tests is to gather as much information as possible to pinpoint the area in the brain where your seizures are starting. This area is called the seizure focus.

After the testing, your care team (epileptologists, neurosurgeon, neuropsychologist, radiologists and others) will discuss your case and find the best treatment to help stop your seizures.

The team may decide that more testing is needed. Some patients require many conferences and tests before a final recommendation can be made.

It’s a marathon, not a sprint

For some people, testing to find the best treatment could take up to a year or longer to complete.

Here are some tests you may have:

• Video EEG monitoring – Electroencephalography (EEG) is a test that measures the electrical activity in your brain. It is performed at our epilepsy monitoring unit (EMU) at Norton Brownsboro Hospital.
• 3T MRI –A high-resolution magnetic resonance image (MRI) looks for structural changes in your brain that may cause seizures. This is an outpatient test.
• PET – Positron emission tomography (PET) is another  imaging test. A small, safe radiotracer dye is injected into your bloodstream. It highlights areas of increased or decreased energy consumption, which may show the seizure. This is an outpatient test.
• SPECT – Single-photon emission computed tomography (SPECT) is a test that shows blood flow in your brain during and between seizures. A small amount of dye is injected into your bloodstream at the moment a seizure starts. This test requires an inpatient stay at our epilepsy monitoring unit (EMU) at Norton Brownsboro Hospital.
• Functional MRI – This outpatient test measures your brain activity by looking at changes associated with blood flow. It shows which parts of your brain are involved in important activities, such as language and memory.
• Neurocognitive evaluation – This test measures your thinking, learning, memory, language, attention and problem-solving. It is helpful in determining where seizures start in your brain and the safety of the surgery that might be recommended for you. Wada test – This test, named for Juhn Wada, M.D., the neurologist who developed it, determines which side of your brain is most responsible for functions such as speech and memory. It helps determine the safety of surgery that might be recommended for you. The test is done in the operating room, but nearly all patients go home the same day.
• MEG – Magnetoencephalography (MEG) is a test to find where seizures start in your brain. It is not performed in Louisville, so you may need to travel.
• Intracranial EEG – In this test, electrodes are surgically placed inside the skull, giving doctors a much more accurate look at brainwaves than using electrodes on the outside of the head. This test requires an inpatient stay.

Types of surgical treatment

Once the tests have been completed and the information reviewed, your epilepsy team will recommend one or more surgical treatment options for you to consider. These procedures involve removing, destroying or disrupting the seizure-onset zone — the area of brain where your seizures are starting.

Here are some surgical treatment options:

• Resection – Surgical removal of the seizure onset.   The chance of this surgery stopping seizures far outweighs the risk of permanent injury.
• Laser ablation – A minimally invasive procedure that uses heat delivered through a small laser probe to destroy the seizure onset through a very small incision. This procedure is done partly in the operating room and partly in the MRI scanner.
• Responsive neurostimulation (RNS) – A surgical procedure to implant a permanent stimulation device in the brain. Electrodes are placed in or around the brain areas that cause seizures. These electrodes monitor the brain at all times and disrupt the seizure-onset zone with small amounts of electricity just before the  seizures start. Doctors review data remotely, and the device is adjusted during office visits.
• Vagus nerve stimulator (VNS) – A “pacemaker” for the brain; a battery is implanted in the chest region with a wire connecting to a nerve in the neck. The stimulator gives off small impulses of electricity every few minutes to try to reset or reduce the brain’s activity and prevent seizures. Some stimulators do “autostimulation,” providing impulses as a seizure is starting in order to stop it. Some patients use a hand-held magnet to activate the VNS if they feel a seizure starting, which can sometimes stop that seizure.