Surgery for Epilepsy can be done for some people who have seizures that are not controlled by antiepileptic medications. The two main goals of Epilepsy surgery are:
Although some people do become seizure free after this surgery, not everyone does so. No surgery is without risk. To ensure that patients have the best chance for a good outcome, it is necessary to go through many vigorous and comprehensive tests.
The candidates for focal resective epilepsy surgery are people who:
If your seizure is coming from a small, single area of the brain which can be safely removed, focal resection may be performed to significantly reduce the seizure frequency and severity. Typical cases for this type of surgery are tumor resection, lesion resection, temporal lobe resection, carvenorma (abnormal blood vessel) resection, etc. To ensure that patients have the best chance for a good outcome, it is necesary to go through many vigorous and comprehensive tests.
A surgical procedure that disconnects the anterior cerebral hemisphere in order to prevent the seizure from spreading.
An FDA approved neurostimulation therapy for refractory epilepsy. It is an adjunctive treatment for certain types of intractable epilepsy. It is designed to prevent seizures by sending regular, mild pulses of electrical energy to the brain via the vagus nerve in the neck. These pulses are supplied by a device comparable to a pacemaker.
https://www.epilepsy.com/learn/treating-seizures-and-epilepsy/devices/vagus-nerve-stimulation-vns
Another FDA approved neurostimulation therapy for an adult with a drug resistant focal epilepsy. It is designed to detect the seizure in the brain up to 2 focal areas by monitoring brain activity continuously from electrodes placed directly in the brain. It only delivers the stimulation automatically upon the detection of seizure or pre-seizure activity through the electrodes in order to stop or prevent the seizure.
The latest FA approved neurostimulation therapy for an adult with refractory focal epilepsy. It is designed to reduct the seizures by sending regular, mild pulses of electrical energy to the deep part of the brain (Thalamus) via electrodes directly placed on both sides of the Thalamus. This therapy is also used to treat other neurological conditions such as Parkinson's Disease, Essential Tremor, Dystonia, and Obsessive-Compulsive Disorder.
https://www.epilepsy.com/learn/treating-seizures-and-epilepsy/devices/deep-brain-stimulation-dbs
There are some other investigational neurostimulation therapies but are currently not available for epilepsy treatment, such as Transcranial Magnetic Stimulation (TMS) or Electroconvulsive Therapy (ECT).
In order to decide if epilepsy surgery can help you to control your seizures, we need to do a number of tests. These tests help us locate where in the brain seizures may be starting. They also tell us if any part of the brain is abnormal in other ways. Each person is evaluated individually before we decide which tests you will need.
An EEG shows the brain's electrical activity and is the most common test used to help diagnose epilepsy. It can help pin point where your seizures are coming from. The technologist will place electrodes on your scalp in order to record brain activity. These will be secured to your scalp with removable adhesive, they must adhere to the skin so we can get an accurate reading.
Instrucciones de EEG (electroencefalograma)
Instrucciones para un EEG (electroencefalograma) Ambulatorio
We need to determine first whether or not your typical spells/events are truly epileptic seizures and if they are the right types of seizures for the epilepsy surgery.
Welcome to the Epilepsy Monitoring Unit (EMU)
Bienvenido a la Unidad de Monitoreo de Epilepsia (Siglas en inglés: EMU)
If we think you should be evaluated for possible surgery to help control your seizures, we bring you into the hospital for another EMU evaluation with additional tests. Ultimately, we need to capture 3-5 seizures to ensure all of your seizures are coming from one focus. Also, an ictal SPECT study may be done during this admission.
SPECT is a special type of brain scan. SPECT stands for Single Photon Emission Computed Tomography. A small amount of a radioactive isotope is given intravenously when the seizure occurs. This isotope goes to the part of the brain where the seizure is occurring. Inter-ictal SPECT is often obtained for the baseline. This is a very safe test. This type of radioactivity only lasts a couple of hours in the body before it is eliminated. There are no special precautions after the injection.
High resolution MRI is performed to evaluate any structural abnormalities or lesions which may be responsible for seizure foci.
This is also a special brain scan. PET stands for Positron Emission Tomography. It is similar to SPECT scan. It is also very safe and usually can be done as an outpatient study. It will show if there is any functional abnormality in the brain where there may be the seizure focus. It creates a map of your brain and how it is using oxygen and sugar. This helps our providers determine where your seizures are coming from.
It will be performed by our neuropsychologist in the office. These tests show us how the different areas of the brain work. The tests include thinking, problem solving, reading, visual identification, naming, other language function, memory, and movement. These tests help identify areas where the patients may have problems. Usually the problem areas are the areas where your seizures are happening. These tests take several hours. Please get a good night’s sleep and have a meal before coming.
Epilepsy is hard to live with. Having epilepsy can cause many emotional problems for you and your family. Depression is more common in patients with epilepsy. Also, many of anti-epileptic medications can cause emotional problems, such as depression and suicidal thought. Epilepsy surgery can produce many changes in your life. Patients who undergo the surgical evaluation see our psychiatrist for an evaluation so that we can be sure they will get all the emotional support.
This test is performed by our contracted specialists at the Mind Clinic. This is located just north of the hospital. This test provides us even more information as to where your seizures are coming from by measuring magnetic fields created by the brains electrical currents You will need a MRI prior to this test, this was ordered previously as part of your original work up.
The WADA test is named after Dr. Juhn Wada. The test is conducted while the patient is awake. This test looks at the language and memory function on each side of the brain. Each side of the brain will be evaluated one at a time. A barbiturate or other anesthetic medication is introduced into one of the internal carotid arteries via angiogram. The drug is injected into one hemisphere at a time in order to shut down temporarily any language and/or memory function in that hemisphere. The patient is engaged in a series of language and memory related tests to understand which hemisphere support these functions. This requires three doctors who specialize in this test to perform it (neuroradiologist/epileptologist/neuropsychologist). This test can range anywhere from 30-60min and can be completed in conjunction with the functional MRI (This is done at Sandoval Regional Medical Center ONLY).
It is a specialized MRI to understand how the different areas of your brain work. It measures the hemodynamic response (change in blood flow) related to neural activity in the brain with various activities. This test may be ordered so we can detect small changes in blood flow that happen with brain activity and which part of the brain is handling critical functions. This study can see abnormalities within the brain that cannot be seen on other tests. This can only be done at Sandoval Regional Medical Center. They have a special team who are experts in this study.
This test is a record of magnetic fields, measured outside the head, produced by electrical activity within the brain. The magnetic fields are produced by the same underlying electrical changes that give rise to the electroencephalogram (EEG). This technique is also used for mapping brain activity. It is performed by our contracted specialists at the Mind Clinic. This is located just north of the hospital. This test provides us even more information as to where your seizures are coming from by measuring magnetic fields created by the brains electrical currents. You will need an MRI prior to this test. This MRI was ordered previously as part of your original work up.
It is an evaluation of continuous video-EEG monitoring with intracranial electrodes instead of scalp electrodes. Some patients who are evaluated for epilepsy surgery with Phase I scalp video-EEG monitoring need to have more intensive video-EEG monitoring. This time we do an operation and put special electrodes into or onto the brain. Then we record seizures just as we did during the previous diagnostic and Phase I evaluation. This helps us to pinpoint more precisely the area where your seizures are starting within only a few millimeter radiuses. It also helps us learn if the seizures are coming from more than one area of the brain. During this invasive evaluation, we may perform the brain mapping with electrocorticography and stimulation which can tell us if the seizure focus has any important function such as controlling language, movement, or vision.
Two main types of intracranial EEG monitoring are Stereo Electroencephalogram, called sEEG and subdural/depth EEG.
This is a test we use if we need to further narrow down where your seizures are coming from. This is a surgery but rest assured our team are experts at this. The sEEG is a minimally invasive procedure that uses electrodes (similar to the ones placed on top of your head) in certain areas of your brain. These are then monitored to pin point exactly where your seizures are coming from. When the source of the seizures are found, another brain surgery is planned to help get them under control. This is usually something that happens eight weeks after the sEEG.
This is another test we use if we need to further narrow down where your seizures are coming from. This is a surgery that our team has an extensive experience. The subdural EEG is an invasive procedure, requiring craniotomy to place electrodes directly on your brain. Sometimes, a combination of subdural electrodes and depth electrodes similar to sEEG will be placed together. This procedure may occur before or after sEEG. When the source of seizures are found and that area is safe to be removed, resection to safely remove the seizure focus may occur while subdural EEGs are removed. If not, another surgery with neurostimulation is planned.
If the patient is thought to have potential benefit from the surgery with previous tests, the next step is the actual epilepsy surgery. It takes a long time and lots of testing before we can reach this point. We are very careful because we want to offer patients the best possible chance for controlling the seizures. We also want to be as sure as possible that we can do the operation safely and not cause any harm. The chance for a good result depends on many things. The evaluation allows us to tell our patients how possible a good outcome is for them.
Surgery is not the end of the process. The recovery (Phase IV) is also an important time. We keep all our patients on antiepileptic medications for at least one to two years. We can never be absolutely sure that we have removed all the brain tissue that can cause seizures. However, the medications are usually able to work to control the seizures. The medications also help protect the brain as it heals. Many people never have another seizure after their operation. Some people have a few seizures immediately after the operation and then gain full control. Others will have fewer or less severe seizures. A few people see no improvement in their seizure control. There are no guarantees for this operation, but we try our best to give our patients the best chance possible. Whatever the outcome, we will continue to provide the care for our patients.
