How to Test for Epilepsy
At your first appointment, your doctor will review your epilepsy symptoms and medical history. He or she will use different tests to pinpoint the cause and location of your seizures.
Initial testing for epilepsy at your appointment may include:
- a neurological exam where the doctor tests things like motor skills, mental function, and behavior or
- blood tests to check for things like infection or genetic conditions that could be associated with your seizures.
Epilepsy Testing Methods
Once these initial tests are complete, your doctor may recommend one or more of the following tests:
Electroencephalogram (EEG)
Electroencephalograms are the most common diagnostic test for epilepsy. During the test, you will have electrodes attached to your scalp -- either directly or with a cap. These electrodes will watch and record the electrical activity inside your brain. If you have epilepsy, your EEG test results may show abnormalities in your brain wave patterns. These abnormalities may occur even when you're not experiencing a seizure.
We use many different types of EEG tests such as:
- Routine EEG—This test is conducted in a doctor's office or an epilepsy monitoring unit in the hospital. You may be awake or asleep during the test. Your doctor may use video monitoring to record any seizures you experience to help identify the types of seizures you are having and rule out other conditions.
- Ambulatory EEG—This test is performed at home over the course of several days. Your doctor will provide you with instructions on how to wear the monitoring device to record your brain and seizure activity.
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Imaging Scans
If your doctor suspects that your seizures may be caused by irregularities in your brain tissues, he or she may recommend an imaging test. Brain tissue irregularities could be from things like tumors, lesions, or scars. Common imaging tests include:
- Computerized tomography (CT) scans—X-rays that provide your doctor with a series of brain images that can reveal things like cysts, tumors, or abnormal bleeding.
- Magnetic resonance imaging (MRI)—This scan uses magnets and radio waves to create a detailed map of your brain that doctors use to find lesions or other abnormalities.
- Functional MRI (fMRI) — These detailed tests locate areas of the brain used during speech, memory, movement, and other critical functions. Doctors use this information to more accurately pinpoint the areas of the brain affected by the seizure.
- Positron emission tomography (PET) scan — Your veins will be injected with a small dose of radioactive material that creates a visual of your brain activity and may reveal abnormalities. PET scans are often used for patients with multiple brain conditions. They can show changes in your brain chemistry and metabolism.
- Single-photo emission computerized tomography (SPECT) scan — If your doctor is unable to pinpoint the location of seizures in your brain using an MRI or EEG tests, he or she will recommend a SPECT scan. These must be done during a seizure. The test takes place in a monitoring unit where you wait for the seizure to occur. The test occurs in two phases: the first takes place during the seizure and the second occurs after the seizure is over. At each stage, we will inject imaging agents to help visualize the blood flow in your brain.
Neuropsychological Testing for Epilepsy
Your doctor needs to correctly diagnose the cause of your seizures to effectively treat you. He or she will use imaging and other tests in combination with neuropsychological testing to get a more complete picture of where the seizures are occurring inside your brain. These vary by patient and include:
- speech skills,
- cognitive assessments, or
- memory tests.
For example, a patient who has trouble with memory tests could show that the abnormality causing the seizures is in a specific part of the brain.
Wada Testing
Wada testing is sometimes performed after video-EEG monitoring to determine which parts of your brain control language and memory. Our specialists will look at images to see if your language and memory functions are on the same side of the brain as your seizure focus. If so, functional MRI or other brain mapping may be necessary before surgery.
These tests are performed by a:
- neuroradiologist,
- epileptologist, and
- neuropsychologist.
During the tests, our doctors will put one side of your brain to “sleep” for a short period of time using medication, then test your speech and memory function. After your brain “wakes up”, we will put the other side to sleep and perform additional speech and memory tests. Once both sides are awake, you will be asked to recall what you saw during the tests, and we will identify which side of your brain controls your memory and speech.
Long-Term Monitoring
In some cases, our doctors will not be able to determine the cause of your seizures from the initial imaging tests or EEG (electroencephalogram). Your doctor may admit you to a long-term monitoring unit. Outpatient EEGs only capture abnormal brain wave activity about half the time, but long-term monitoring will capture that information in about 95 percent of patients.
The units are inside the hospital and staffed by:
- an attending neurologist, who specializes in diagnosing and managing epilepsy,
- nurses, and
- EEG technologists.
In a long-term monitoring unit, your doctor will observe and record information before, during, and after a seizure occurs. This helps characterize the following:
- what type of seizure you are having,
- identify the specific location where your seizure begins, and
- rule out any other health conditions that may have similar symptoms to epilepsy.
If you are taking anti-epilepsy medications, the neurologist will tell you to reduce or stop the medication before the test. This may increase the frequency or intensity of your seizures.
What to Expect In the Monitoring Unit
Inside the monitoring unit, we may also request that you stay awake all night to trigger a seizure. You will be monitored 24 hours a day by video, EEG, attending nurses, and other staff members to ensure your safety.
These stays can sometimes get boring. Feel free to bring the following to keep you busy:
- books,
- work,
- movies, or
- personal electronic devices.
Please keep in mind that you will not be able to leave your room because you will be attached to a monitoring unit and need to be on video. However, you will be able to move freely around your room during your stay.
You will spend three to seven consecutive days in the long-term monitoring unit. Your neurologist will gather this information to determine the best treatment plan for your seizures. It will be based on the type and location of seizures you are experiencing.
Risks & Benefits
Before you begin a long-term monitoring test, talk to your doctor about the potential risks. These are the same as risks associated with having a seizure and could include:
- injuries to the muscles, bones, nerves, and head, or
- slight risk of death. However, this risk is minimal because the test is conducted under constant supervision in a controlled hospital setting.
In most cases, the benefits of getting a proper diagnosis and treatment plan outweigh the potential risks.
Intracranial Monitoring
If the doctor is still unable to find the location of seizures, or you don't respond to medication, we may recommend intracranial monitoring—an invasive surgery where doctors place electrodes inside your brain to monitor brain activity over several days or weeks.
How to Make an Appointment to Get Tested for Epilepsy
You will need a referral from your primary care physician or another provider to be seen in our Epilepsy Clinic. You may call 801-585-7575 to schedule an initial appointment after you are referred. Our team will help coordinate your care to see an epileptologist (a neurologist who specializes in epilepsy) for evaluation and schedule any necessary testing as part of your treatment plan.
We will also work with your insurance carrier to determine what epilepsy tests and treatment are covered under your plan, and obtain pre-authorization for procedures that are covered by your insurance. If you have questions about your insurance coverage, contact your insurance carrier directly.
