Extra-Temporal Seizure Focus Resection or Ablation
In some cases, neurosurgeons can remove the tissue causing seizures in other areas of the brain. Resection (removal) is possible if a child’s seizures are caused by an area of the brain that does not control speech, movement or such critical function. This type of surgery may be done with open surgery or with stereotactic laser ablation.
For some types of epilepsy, localizing the precise area where the seizures are coming from may need a stepwise approach.
If it is not clear from the EEG, MRI, PET, MEG or other studies about the exact area where seizures are arising, two steps of surgery may be needed.
If the staged Phase 2 monitoring is recommended, in the first procedure, the epilepsy team plans the surgery carefully to determine where we need to study to determine precisely where the seizures are coming from. With this type of planning to get more information, neurosurgeons may use subdural grids or stereoEEG.
One choice may be place flat electrodes (subdural grids and strip electrodes) on the brain's surface or place thin electrodes into the brain. Stereotactic EEG (sEEG) electrodes are placed with the assistance of a surgical robot. At Lurie Children's, we use the ROSA, the stereotactic robot system for our neurosurgical procedures for precise placement of electrodes. For the next few days, the child is monitored by video and EEG in the 19th floor Epilepsy Monitoring Unit, where the electrodes record for seizures and give important information to make a detailed map of the area of the brain where seizures are coming from.
Based on this important detailed map of a child's brain and the seizures recorded, the epilepsy surgery team can make a plan for the next steps. Options to address the area of the seizure focus are:
- Surgical resection (removal) of the part of the brain if it is safe to remove
- Stereotactic laser ablation of the part of the brain causing seizures if it is small and if it is safe to laser. At Lurie Children's, our team uses the Visualase stereotactic laser ablation system.
- Placement of neurostimulation devices such as a Responsive Neurostimulator (RNS) if the area of the brain where the seizures are coming from is identified but it is not safe to remove that area of the brain. Neurostimulation allows the brain tissue to stay in place. Implanting a device helps send signals to the brain with the goal of decreasing seizures. For instance, in the case of RNS, the device records and "learns" a patient's seizure activity patterns, and in time aims to deliver signals to the brain to stop seizures even before they start.
It is important to reflect that, as recently as 10 years ago, patients who are now benefitting from these types of surgeries would not have been considered for surgery. Now, we have more and more options to offer hope for seizure control and for a better quality of life.
The Comprehensive Pediatric Epilepsy and Epilepsy Surgery Program is inspired, honored and grateful to be a part of our patients' and families' journeys.