In addition to the previously described MRI, SPECT and PET scans, neuropsychological assessment and EEG monitoring, some patients will require a more invasive evaluation. Approximately 40-60% of the patients considered for surgical treatment will need intracranial monitoring with implanted electrodes to localize the epileptogenic area responsible for seizure onset.
Intracranial monitoring consists of depth electrodes (thin wires placed deep in the brain to detect seizure activity that cannot be detected by electrodes placed on the surface of the head) or subdural or epidural strips or grids (small plastic strips or sheets containing electrodes placed on the surface of the brain underneath the skull).
During intracranial monitoring a team of research neuropsychologists may also perform brain mapping through electrical stimulation of the implanted intracranial electrodes. They are able to pinpoint the functional areas of the brain which are then safeguarded during surgery.
You will have a pre-operative visit prior to the scheduled surgery date. At this time you will meet with an Anesthesiologist who will be with you during surgery. Instructions regarding surgery will also be provided at this appointment. You will have a visit with the neurosurgeon for any additional questions you may have prior to surgery, history and physical exam, and to provide permission to perform the surgery.
What to expect
- The morning of the procedure you will arrive from home.
- You will be taken to the operating room where you will have anesthesia, then the neurosurgeon will place the electrodes.
- Once the surgery is completed (approximately 6-8 hours) you will go to the Neurological Intensive Care Unit. Pediatric patients will be taken to the Pediatric Intensive Care Unit. You will spend the first night in the intensive care unit.
- The day after surgery, you will have an MRI, a CT scan, and a SPECT Cerebral Blood Flow study.
- After the above scans have been completed you will be taken to a specialized room that has audio-visual monitoring. Your electrodes will be connected to a specialized machine that will record your brain wave activity, and your behavior will be recorded with a camera in the room. This phase is similar to Phase I.
- You will have a large, bulky tight dressing on your head. Your face and eyes may be slightly swollen.
- After sufficient seizure activity is recorded, the electrodes will be removed. You will return to the operating room for the removal of the electrodes.
- You will be discharged to home a few days after the second operation.