Epilepsy Diagnosis and Evaluation

The initial evaluation includes a review of your medical history, a neurological exam, imaging tests, and electroencephalography (EEG).

Routine EEG (Electroencephalography)
Records brain waves using electrodes placed on the scalp. While lying still on a bed, you may be asked to perform some simple tasks or look at a flashing light. In most cases, brain waves are recorded when you are both awake and asleep. You shouldn't experience any pain or discomfort during this one- to two-hour test.

Ambulatory EEG
As with a routine EEG, electrodes are placed on the scalp, but you will go home with the electrodes and a miniature, portable recorder for one to four days. Brain activity is recorded continuously over this time. You will be asked to push a button when any seizures occur and to maintain a detailed log of your activities to help doctors learn more about your seizures.

MRI (Magnetic Resonance Imaging)
Creates high-quality images of the brain to identify abnormalities that may indicate a potential seizures focus (the area in your brain where seizures begin).

Video EEG and the Epilepsy Monitoring Unit
Records brain waves and video during and between seizures. Before and during this test, anti-seizure medications are often reduced or stopped to increase the chances of recording a seizure. For three to five days you will be admitted to the hospital and closely monitored in our specialized epilepsy monitoring unit (EMU) by a large team that includes doctors, nurses, technologists, and other staff. Video EEG can also be performed using electrodes that have been surgically placed on or in the brain. This allows for more precise mapping of brain function and targeting seizure origins.

Genetic Testing
Recent research shows that epilepsy can have a genetic component. A blood test can help inform doctors whether your epilepsy is genetic, which can affect your treatment plan. 

If your initial evaluation results indicate that you may be a candidate for epilepsy surgery, you will need to undergo some additional testing.

Functional MRI (Magnetic Resonance Imaging)
Similar to a standard MRI, this scan also detects brain areas involved in particular functions, such as language, vision, and movement. 

PET (Positron Emission Tomography)
Investigates chemical activity and shows brain metabolism. Before the scan, a radioactive dye is administered via an IV. This highlights areas of the brain where seizures begin.

SPECT (Single-Photon Emission Computed Tomography)
Shows blood flow and brain function. Like PET, this test requires IV injection of a radioactive dye (in this case, administered at the start of a seizure), which is only active in the body for a brief period.

High-Density EEG and ESI (Electrical Source Imaging)
Similar to a routine EEG, except that many more electrodes are placed on the scalp to give doctors even more information. The resulting data are analyzed with sophisticated computerized programs to determine not only where the seizures start but also how they spread.

Neuropsychological Testing
Neuropsychologists perform interviews and ask you to complete questionnaires and timed cognitive tasks over four to six hours. Understanding your strengths and weaknesses helps doctors determine which parts of your brain might not be functioning normally because of your epilepsy. This can be helpful in improving your cognitive function and determining your eligibility for various epilepsy surgical procedures.

Robot-Assisted Stereoelectroencephalography (SEEG)
In some people, SEEG is used to pinpoint where a seizure starts. While you are under general anesthesia, a neurosurgeon will guide a robotic arm to make tiny holes in your skull and place small electrodes into your brain. This surgery takes about two hours. You’ll recover outside of the operating room and remain in the hospital for seven to ten days. 

During this time, the electrodes will monitor your brain activity to identify where seizures begin. After enough information is collected, the electrodes are surgically removed, and you will discharged from the hospital on the following day. Compared with a craniotomy (which requires a larger opening in the skull), the robotic-assisted procedure is quicker and better tolerated. Stereo EEG is ideal for the most challenging cases of epilepsy. 

Subdural Electrodes
Subdural strip or grid electrodes are surgically placed on the surface of the brain and are used when the seizure focus is difficult to pinpoint. Also, your epileptologist and neurosurgeon can use these electrodes to electrically activate parts of your brain for mapping. As with robot-assisted SEEG, monitoring is usually done for several days so that seizures can be recorded. 

Brain Mapping
Brain mapping identifies vital areas in your brain responsible for movement, sensation, language, and vision. This lowers the risks associated with epilepsy surgery. First, a neurosurgeon will remove a portion of your skull (a craniotomy) to implant electrodes in or on your brain while you are under general anesthesia. You will recover from this surgery for a day or two in the hospital. Once the electrodes are in place, the mapping (which takes one to two hours) can be done while you are awake or under general anesthesia, and either in the operating room or in our specialized epilepsy monitoring unit (EMU), depending on what functions your doctors are testing. In both instances, brief electrical pulses will pass through the implanted electrodes, which may cause mild responses like a muscle jerk or tingling. You may also temporarily (for seconds) be unable to perform certain tasks, like speaking. 

Wada Test
Also known as the intracarotid amytal test, this is used to determine which sides or parts of the brain are responsible for critical functions like language and memory. A surgeon will administer a short-acting anesthetic into your right or left carotid artery, effectively putting one side of your brain to sleep for five to ten minutes. During this time, doctors ask questions to test your language and memory. Then the procedure is repeated on the other side of the brain. The entire procedure lasts about two or three hours. After a brief recovery period, you should be able to go home the same day.