A diagnosis of epilepsy involves a combination of observation and diagnostic tests. The doctor will listen to a description of the seizures a person has, and perhaps monitor the patient using video for a few hours or days to try and observe a seizure firsthand before scheduling diagnostic tests. The specific types of tests scheduled will depend on what kind of seizures the person is having, whether they are partial or full seizures, and where in the brain the seizures likely originate.
Electroencephalogram
An electroencephalogram, or EEG, monitors the brainwaves of a patient by using electrodes attached to the head. The goal of an EEG in an epileptic is to look for specific brain patterns that indicate the type of seizure and part of the brain affected. The spikes and waves on an EEG recording are often different for an epileptic, even when the patient is not currently having a seizure. According to the Epilepsy Foundation, the EEG may even be able to help the doctor determine which specific epilepsy medication will work best for the particular type of epilepsy noted. An EEG takes about 35 to 40 minutes if done while awake or longer if performed while sleeping, according to the Epilepsy Foundation.
CT Scan
A CT, or CAT, scan is formally known as computerized tomography, and involves X-rays of the brain in cross section that can be assembled on a computer for analysis. A CT scan may show damaged areas of the brain that are causing epileptic seizures. Sometimes, a CT scan is performed using a contrast medium, an injected dye that makes the resulting pictures clearer.
Functional MRI
Functional magnetic resonance imaging, or fMRI, is the diagnostic imaging method of choice for most doctors diagnosing epilepsy, according to Epilepsy.com. Functional MRI uses a magnetic field and radio wave pulses to image the brain. This information is analyzed using a computer, and the result is more accurate and detailed than a CT scan. Functional MRI looks at brain structure to assist the doctor in finding any physical causes behind the epileptic seizures.
Other Neuroimaging Tests
If an fMRI or CT scan fail to find the source of the seizures in an epileptic patient, other tests may be ordered. Positron emission tomography, also known as a PET scan, involves injecting a radioactive material to look at the metabolism of oxygen and glucose in the brain. Single-photon emission computed tomography, or SPECT, looks at the brain's blood flow in 3D after injection of a radioactive dye. Magnetoencephalography, which observes electrical activity in the brain, and magnetic resonance spectroscopy, which studies brain metabolism of certain nutrients, are other diagnostic tests that can be used to pinpoint the causes of epilepsy.
