Mapping Brain Function Prior to Surgery

After determining the part of the brain responsible for the seizures (see Diagnosing and Treating Epilepsy in Children), the epilepsy surgical team can map the brain via invasive and non-invasive methods to predict any major problems that may arise when a specific area is removed. The neurosurgical approach is tailored to obtain maximal seizure control and minimize any dysfunction afterward. The objective is always to improve quality of life.

The area of the brain responsible for seizures may include scar tissue, a tumor, or tissue that was improperly located in the brain during early development. The removal of this abnormal tissue may control the seizures without causing any change at all in the patient’s functioning. In other cases, however, the area of the brain that gives rise to seizures is located near important areas that control speaking, understanding, moving, remembering, or other critical human abilities. Careful testing during the brain mapping process helps protect those functions.

During brain mapping, the surgeon stimulates the brain to create a functional map of the area of interest to determine the exact function of the area being considered for surgical removal. In some cases, the surgeon will briefly interrupt the function of that part of the brain and check to see whether the patient can still speak, understand, or move. If no function is lost when interrupting the function of that part of the brain, the surgeon can safely remove that portion and stop the seizures.

In some cases, the surgeon may identify some minor loss of function that will occur if the focus of the seizure is removed.  It's critical to insure that the proposed surgery to control seizures will improve quality of life and not create significant long-term deficits for the patient. The information gathered from functional mapping of the brain is shared with the patient and his or her family to help them make an informed choice regarding surgery.