Epilepsy Tests & Diagnosis

The South Texas Comprehensive Epilepsy Center (STCEC) offers the most advanced diagnostic testing and evaluation of pediatric and adult brain disorders available in South and Central Texas. As San Antonio’s only Level IV-designated epilepsy center, and the largest program in Texas, University’s STCEC gives you access to the highest level of expertise and sophisticated diagnostic technology available in the area.

Sophisticated Diagnostics for the Best Epilepsy Treatment

Our epilepsy specialists use their expertise and a wide range of technologically advanced diagnostic tests and procedures to accurately diagnose seizure disorders, including epilepsy, and determine the best course of treatment to control seizures. If your seizures can’t be controlled with medication, our specialists have access to sophisticated diagnostics to determine if surgery is an appropriate treatment option.

Our 14-bed Epilepsy Monitoring Unit (EMU) is the largest inpatient monitoring unit for children and adults in San Antonio. Nurses and diagnostic specialists with expertise in epilepsy and seizure disorders use advanced diagnostic tools to continuously monitor brain activity during seizures. This specialized testing helps pinpoint the type of seizure and where it’s occurring in the brain, equipping doctors with the information they need to accurately diagnose and control your seizures.

Comprehensive Epilepsy Tests Offered

At the South Texas Comprehensive Epilepsy Center, we perform the following imaging tests:


The Single Photon Emission Computed Tomography (SPECT) scan provides information about blood flow to the brain. Blood flow to an area of the brain increases during a seizure and can decrease before or after a seizure. This scan produces images using a radioactive tracer and a special camera.

Electroencephalography (EEG)

An EEG measures and records the brain’s electrical activity. Special sensors (electrodes) are attached to the head and hooked by wires to a computer that records the brain’s electrical activity. An EEG technician conducts the test, which can be done in a hospital or in a doctor’s office, and a neurologist reads the results. Approximately 3,500 studies are performed each year.

Electrocorticography (ECoG)

An ECoG uses sensors that are surgically implanted on the brain to record brain activity. ECoG is considered the “gold standard” for detecting an epilepsy episode.

Functional Brain MRI (fMRI)

fMRI is a type of MRI that produces images of the brain in action. The scan captures images of the brain while you perform specific tasks that involve thinking, speaking and moving, allowing your doctor to see which part of the brain is at work.

Magnetic Resonance Imaging (MRI)

An MRI is a scan that can detect growths, such as a tumor, or scarring, that can cause a seizure.

Neuropsychological Testing

This assessment measures your memory and ability to learn and comprehend. The testing can help identify areas of the brain that aren’t functioning normally. Neuropsychological testing is used before and after surgery to evaluate potential risks of the surgery based on where the seizures occur in the brain.

Positron Emission Tomography (PET)

A PET scan shows blood flow and how the brain uses sugar (glucose), measuring changes in the brain’s metabolism and chemistry.


This testing is 24-hour EEG monitoring of the brain during seizures, and videotaping of the symptoms of the seizures. The testing is performed in our inpatient Epilepsy Monitoring Unit over several days. The results help doctors determine whether all of the seizures originate in one part of the brain, and pinpoint where the seizures begin. The test also records brain activity between seizures.


The WADA test looks at language and memory on one side of the brain at a time. A doctor injects medication through a catheter to put one side of the brain to sleep. Your doctor will ask you to identify pictures and objects while one side of your brain is asleep and after the drug has worn off. The process is repeated on the other side of your brain.

The WADA pinpoints where speech, thinking and memory functions are in the brain. The test helps determine if surgery is an option to control seizures and if so, plan the surgery to avoid further problems with speech and memory.