Diagnosing Childhood Seizures and Epilepsy

This initial evaluation includes a review of your child’s medical history, medical records, and medications, a neurological exam, and one or more of the following tests. 

Magnetic Resonance Imaging (MRI)
MRI uses magnets to create a high-quality image of the brain and detect abnormalities that may reveal the seizure focus.

Routine Electroencephalography (EEG)
Electrodes are placed on the scalp to record brain waves. While lying still on a bed, your child may be asked to perform simple tasks or watch a flashing light. In most cases, brain waves are recorded when your child is awake and asleep.

Ambulatory EEG
This test records brain waves for a longer than a routine EEG to increase the chances of recording an irregularity. Your child will go home wearing electrodes on their scalp and a miniature, portable recorder for one to four days. Brain activity is recorded continuously. You will be asked to push a button when any seizures occur and to maintain a detailed log of your child's activities. This helps doctors learn more about your child’s seizures.

Video EEG and the Epilepsy Monitoring Unit
This technology records brain waves and captures video during actual seizures, which can help doctors with diagnosis and surgical evaluation. Before and during the test, anti-seizure medications are often reduced or stopped to increase the chances of recording a seizure. Your child will be admitted to the hospital for three to five days and closely monitored in our specialized epilepsy monitoring unit (EMU). 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.

Neurogenetic Testing
A blood test can help determine whether your child’s epilepsy is genetic, which can affect the treatment plan. 

If your child’s medical evaluation indicates they may be a candidate for epilepsy surgery, additional testing or surgical procedures may be performed to pinpoint the seizure focus. 

Functional MRI
This test is similar to a standard MRI, but it also detects brain areas involved in specific functions as well as changes in blood flow in the brain. 

DTI (Diffusion Tensor Imaging)
This specialized MRI focuses on brain anatomy. Duke’s ultra-high-resolution scanner enables doctors to examine complex microstructures in the brain and identify small abnormalities that aren’t visible on conventional MRI scans.

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

SPECT (Single-Photon Emission Computed Tomography)
This test highlights blood flow and brain function. Like PET, it 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)
This is similar to a routine EEG, except 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
Pediatric neuropsychologists who have extensive experience working with children perform interviews and ask your child to complete puzzles, questionnaires, and timed tasks. Understanding your child's strengths and weaknesses helps doctors determine which parts of their brain might not be functioning normally. This can be helpful for improving your child’s cognitive function and determining whether they are eligible for epilepsy surgery.

Wada Test
Also known as the intracarotid amytal test, this is used to determine vital brain functions on the left versus right side of the brain. An expert will administer a short-acting anesthetic into your child’s right or left carotid artery, effectively putting one side of the brain to sleep for ten minutes or less. During this time, doctors ask questions to test language, speech, and memory. Then the procedure is repeated on the other side of the brain. 

Electrode Placement and Inpatient Monitoring
Electrode placement procedures are performed in an operating room while your child is under general anesthesia. There are two ways to place electrodes:

• Subdural Grid Electrode Placement: Subdural strip or grid electrodes are surgically placed on the surface of the brain through an opening in the skull (called a craniotomy).
   
• Robot-Assisted Stereoelectroencephalography (SEEG): In this less-invasive approach, neurosurgeons guide a robotic arm to make tiny holes in the skull through which small electrodes are placed. Compared with a craniotomy, the robotic-assisted procedure is quicker and better tolerated. Stereo EEG is ideal for the most challenging cases of epilepsy. In conjunction with SEEG, doctors may be able to produce a 3D model of your child’s brain to better understand where electrodes are in relation to each other and in relation to important brain structures. 

After these procedures, your child will remain in our specialized epilepsy monitoring unit (EMU) for about a week while the electrodes monitor their brain activity. 

Brain Mapping
Brain mapping identifies vital areas in your child’s brain responsible for movement, sensation, language, and vision. This lowers the risks associated with epilepsy surgery.

After electrodes are placed using either subdural electrodes or SEEG, your child’s doctors will stimulate portions of the brain using electrical currents. Then they will look for mild responses like a muscle jerk or tingling. Your child may also temporarily (for seconds) be unable to perform certain tasks, like speaking. 

An expert may also stimulate your child’s hand to record activity on the electrodes placed in the brain. This mapping process is called evoke potential.

Brain mapping can be done while your child is awake or under general anesthesia either in the operating room or in the EMU, depending on which functions doctors are testing.

Electrode Removal and Next Steps
After a seizure focus is determined, the electrodes are surgically removed. Then your child’s care team will use that information to decide on the best treatment option.

Highly Experienced Center
At Duke, hundreds of patients are monitored annually with video EEG. This includes diagnostic and presurgical evaluations. Our staff is highly experienced and accustomed to working with children with seizure disorders and epilepsy.

Advanced Monitoring Techniques
Our neurodiagnostic laboratory technologists who perform EEG and long-term monitoring are accredited by ABRET Neurodiagnostic Credentialing and Accreditation. This recognizes that the highest standards are followed during these evaluations.

Advanced Imaging
Duke epilepsy experts have developed new ways to visualize your child’s brain before epilepsy surgery, which helps to make brain surgery safer and more precise. 

• We work with team of dedicated pediatric neuroradiologists who specialize in caring for children with epilepsy. 
• We offer advanced imaging techniques and procedures, including the high-resolution 3 Tesla MRI (which uses a stronger magnet to create more detailed images of organs and soft tissues compared with other types of MRI), and functional MRI, PET, and SPECT scans.
• We use machine-learning algorithms and artificial intelligence to locate small abnormalities that are not detectable with conventional methods. These include augmented reality and 3D printing to help surgeons to better visualize the brain.