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Doctors will ask about the individual's history of seizures, along with other diseases, surgeries, and medications. A thorough history of recreational drug and alcohol use or abuse is equally important. It is helpful for the doctor to distinguish seizure subtypes, partial or generalized; time of day of the event, including whether the seizure occurred during wakefulness or sleep; and any known triggers, such as a flickering light, severe sleep deprivation, or dehydration.
Doctors will perform a neurological examination.
The Stanford Comprehensive Epilepsy Program offers the full range of diagnosis options and tools for localizing epilepsy seizures. A detailed evaluation by a team of experienced epilepsy experts is available to determine the cause of each patient’s seizures.
Diagnostic tests used to find the cause of your seizures typically include:
Advanced brain imaging techniques: Produce very high resolution images showing scarring or abnormal growth related to epilepsy seizures, and include 3- and 7-Tesla MRIs, PET scans, PET/MRI scans, SPECT and high-resolution functional MRIs.
Intracranial video-EEG monitoring: Determines where in the brain epilepsy seizure waves are originating. Stanford has a five-bed inpatient epilepsy unit to perform computer-enhanced video-EEG monitoring in order to capture potential epilepsy seizure episodes.
Neuropsychological testing: Evaluates the brain's reserve function. Specialized epilepsy clinical neuropsychologists identify which brain portions are not functioning well because of seizures.
The image on the left is created with a 1.5 Tesla MRI. On the right, the same patient's brain is visualized in greater detail with a high resolution 7-Tesla MRI.
Laboratory data used in the diagnostic evaluation of patients with seizure disorders may include CT scan imaging, magnetic resonance imaging (MRI), PET/MRI imaging, and electroencephalogram (EEG). A complete blood panel is usually performed. Blood tests will determine the basic functioning of the body, such as electrolyte (including sodium and potassium) levels and kidney and liver function.
Once the seizure type and seizure source in the brain are identified, your treatment team develops a customized treatment plan for you. If epilepsy seizures are ongoing in spite of treatment with medications and originate from a single source, surgery to remove the epileptic tissue may be considered by your care team with input from you.
Other tests that may be conducted
Electroencephalogram (EEG): An EEG records the electrical activity of the brain via electrodes. The electrodes are attached to the scalp. Individuals with epilepsy often have changes in the normal pattern of brain waves, even when they are not having a seizure.
To prepare for an EEG, healthcare professionals recommend that individuals avoid elaborate hair styling, metallic hair spray, or greasy hair products. The individual should refrain from caffeine for six hours before the test. The procedure itself is painless and usually lasts about 30 minutes. However, it can take as long as an hour to place the electrodes on the scalp properly.
Video-EEG monitoring may also be used in some individuals as a diagnostic tool while they are having a seizure. Video monitoring can be helpful because it allows the doctor to compare the behaviors that occur during a seizure with an EEG pattern from the same time. Knowing where the seizure originates in the brain helps the doctor in treating the condition. Individuals undergoing video-EEG may be required to stay in a hospital or clinic for several days. The individual is monitored on video constantly during this time. The EEG electrodes stay attached for the entire time, which may cause discomfort in some individuals.
Computerized tomography (CT): Computerized tomography, or CT, uses special x-ray equipment to produce images of body structure. CT machines obtain images from many different angles and join them together to show cross-sectional images of the brain and skull. CT scans can reveal abnormalities in brain structure including tumors, cysts, strokes, or tangled blood vessels. This helps the doctor rule out other potential causes of the individual's seizures.
To prepare for a CT scan of the head, individuals should remove such things as earrings, eyeglasses, dentures, and hairpins. An intravenous (IV) line may be inserted into a vein if the test requires the injection of a contrast material, which makes abnormalities easier to see. During the test, the individual will lie on a table that slides into the CT machine. Depending on the number of images needed, the scan can take between two and 20 minutes. The procedure is painless, but some individuals may experience discomfort or claustrophobia while having to sit still.
Magnetic resonance imaging (MRI): A magnetic resonance imaging (MRI) device uses radio waves and a strong magnetic field to produce detailed images of the brain. Like CT scans, MRIs can reveal brain abnormalities that could be causing seizures. Dental fillings and braces may distort the images.
During the test, the individual will lie on a padded table that slides into the MRI machine. The head will be immobilized in a brace to improve precision. The test is painless, but some individuals experience an uncomfortable feeling similar to claustrophobia inside the MRI device's close quarters. Sedative medications, such as alprazolam (Xanax®), can be given to sensitive individuals.
Positron emission tomography (PET): Positron emission tomography (PET) scans use injected radioactive material to help visualize active areas of the brain. After the radioactive material is injected into a vein, it will take 3-90 minutes for the substance to accumulate in the brain tissue. During this waiting period, the individual will be asked to rest quietly and not talk or move around much. The actual scan takes 30-45 minutes. The amount of radioactive material used in the test is very small.
Positron emission tomography/magnetic resonance imaging (PET/MRI scan): PET/MRI is a two-in-one imaging procedure that performs PET and MRI scans at the same time. This technology shows the structure and activity of the brain in one unified picture. By merging the information from both types of scans, doctors may be able to identify specific groups of brain cells that are causing seizures. Because the cause of epilepsy is different for each person, PET/MRI helps doctors personalize your care.
Single-photon emission computerized tomography (SPECT): Single-photon emission computerized tomography (SPECT) is used primarily in individuals being evaluated for epilepsy surgery when the area of seizure onset is unclear on MRIs or EEGs. SPECT imaging requires two scans, one during a seizure and one 24 hours later. Radioactive material is injected for both scans and then the two results are compared.
Conditions resembling seizure disorders: Seizure disorders must be differentiated from a variety of problems whose symptoms approximate or closely resemble those of epilepsy. These include cerebrovascular (stroke-related) disorders, migraine, narcolepsy (a neurological condition with uncontrollable sleep attacks and persistent daytime sleepiness), syncope (fainting), and anxiety.
A pseudoseizure, or a psychogenic non-epileptic seizure, may also occur. These spells are not triggered by nerve cell discharges that cause true epilepsy, although the individual may experience muscle twitching and even apparent loss of consciousness. These spells have a psychiatric component and often coexist in people who have epilepsy with true seizures. EEG monitoring can help distinguish disorders that mimic epilepsy from true seizures.
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