When your child has epilepsy, their care team may suggest surgery. To better understand your options, they'll suggest some testing. Phase 2 testing maps the brain to find where the seizures are starting.
Phase 2 Testing (Brain Mapping) to Pinpoint Seizures
Phase 2 testing involves stereoelectroencephalography (stereo-EEG). This is a less invasive procedure. Surgeons place thin electrodes into the brain. Doctors sometimes refer to this as brain mapping.
They place the electrodes in and around the areas where they think seizures start. The electrodes can help pinpoint where the seizure is coming from.
Surgeons may also put electrodes in parts of the brain that control speech and movement. This tells them how well the brain works.
After the epilepsy surgery team runs these tests, they'll review your child's options. These may include:
- Removing the part of the brain causing the seizures (focal cortical resection).
- Using lasers to damage areas deep in the brain causing seizures (laser ablation).
- Implating a neurostimulator under the scalp with electrodes in the brain to stop seizures.
What to Expect During Phase 2 Testing
Before surgery, the care team gives your child general anesthesia to put them to sleep.
During surgery, the surgeon puts electrodes into the brain through tiny holes in the skull. The electrodes show changes in brain activity on a monitor. This helps with seizure localization.
The care team closely watches the readout from the electrodes in the operating room. They keep watching it throughout their hospital stay.
After the surgeon implants the electrodes, the care team will closely watch your child's blood pressure, pulse, and breathing. When the child is stable enough, the care team will move them to the Epilepsy Monitoring Unit (EMU).
At the EMU, they'll watch the brain activity readouts for seizures 24 hours a day. They also record all of your child's seizures and brain activity. In most cases, your child will stay in the EMU until they've had several typical seizures.
After the care team watches the seizures, they may want to do more brain mapping. This involves sending small electrical currents through the electrodes into the brain. These currents stimulate portions of the brain.
After stimulating the brain, the doctor watches your child's movements and language for changes. This helps them pinpoint the parts of your child's brain that control these critical functions. The surgeon can then avoid these areas during surgery.
This testing allows the care team to gather details about your child's seizures and working brain areas. After phase 2 testing, they'll walk through your options.
Potential Risks of Phase 2
Every surgery has risks. The risks of phase 2 testing include infection, bleeding, and brain swelling.
Phase 2 testing may also trigger prolonged seizures or clusters of seizures. The care team will have a detailed plan to protect your child from prolonged or clustered seizures.
