The goal of epilepsy surgery is to reduce or eliminate seizures in children whose condition is not well controlled with medication. In some cases, surgery can actually cure epilepsy. In other cases surgery may reduce the frequency and severity of seizures. Since uncontrolled seizures can lead to irreversible effects on cognitive and functional development, and in some cases be life threatening, surgery for epilepsy can be life-saving.
Surgery for epilepsy is both safe and effective when performed on carefully selected patients by a pediatric neurosurgeon specializing in epilepsy surgery in children. Not all neurosurgeons have advanced training and expertise in epilepsy surgery, so it is important to choose a surgeon and team that specifically specializes in the workup and treatment of pediatric epilepsy (see Doctors Who Treat Epilepsy in Children).
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 surgical team may map the brain 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 creates a centimeter-by-centimeter functional map of the brain 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 abilities are lost even though there has been interruption in that part of the brain, the surgeon can safely remove that portion to remove the area responsible for seizures.
Sometimes this mapping is performed at the time of surgery, in other cases this mapping performed through a “two-stage” process in which electrodes are placed on the brain surface and monitored for a few days to record more specifically areas responsible for seizure activity as well as to precisely map the functions of the underlying brain in those areas.This can take several forms, either with the use of grids, strips, or with a minimally invasive technique called stereo EEG (sEEG)
In some cases, the surgeon may identify some minor loss of function that will occur if the focus of the seizure is removed. It is critical to ensure that the proposed surgery to control seizures will improve quality of life and not create any major long-term problems for the patient. The information gathered from functional mapping of the brain is shared with the patient and a decision is made together as to the safest and best options for the patient.
Types of Surgery
There are two basic types of epilepsy surgery: curative and palliative.
The goal of curative surgery is to identify the specific area of the brain where seizures are generated and then to remove that area. A variety of specialized tests are performed prior to surgery to identify both the seizure-generating area of the brain as well as the specific functions of the brain. If the site of seizure onset can be removed safely, without neurological damage, then surgery can proceed with a high probability of a cure. For example, children with temporal lobe epilepsy can often be cured with a temporal lobectomy, which is a procedure that involves the complete removal of the affected portion of the temporal lobe. In children who don’t reach a complete cure, surgery often greatly reduces the number and severity of seizures.
If the area of the brain generating the seizures is important for normal brain function, then curative surgery cannot be performed safely and palliative surgery is considered.
The goal of palliative surgery is to reduce the frequency and severity of seizures in cases where curative surgery isn’t possible. Palliative operations often involve “disconnecting” parts of the brain where seizures start or spread. For example, the brain structure called the corpus callosum is a major route of communication between the hemispheres of the brain — and a pathway along which seizures can spread. A procedure called a corpus callosotomy eliminates that pathway by severing the corpus callosum. The brain has other routes of information flow between the two hemispheres, but they don’t allow the spread of seizures. Although information flow is reduced after a corpus callosotomy, children do well and seizures are reduced.
Other options for palliative disconnection of areas responsible for seizures from the normally functioning areas of the brain are hemispherotomy and temporo-occipito-parietal disconnection (TPO). These procedure aim to disconnect areas of abnormality in order to prevent the spread of seizures from these areas to the normally functioning areas of the brain. In carefully selected cases, these disconnective procedures can have significant benefit for patients with substantial reductions in seizure frequency and severity.
In cases where no focus in either hemisphere of the brain can be identified, neurostimulation provides a good option for seizure control. These procedures include vagal nerve stimulation (VNS), responsive neural stimulation (RNS), and deep brain stimulation (DBS) are other palliative options for epilepsy surgery. In these procedures, a neurosurgeon implants a device similar to a pacemaker to deliver electrical impulses to the part of the brain where the seizures originate. These electrical impulses decrease the frequency and severity of seizures.
Surgery for epilepsy in children is an advanced procedure that should only be performed by a pediatric neurosurgeon specializing in epilepsy surgery, after evaluation by a multidisciplinary team of epilepsy specialists. Prior to surgery a child should be evaluated by a multidisciplinary team consisting of neurologists, neurosurgeons, neuroradiologists, neuropsychologists, nurse specialists, language therapists, and occupational and physical therapists. These teams are found at major medical centers and include the Comprehensive Epilepsy Center at NewYork-Presbyterian/Weill Cornell Medical Center (see Doctors Who Treat Epilepsy in Children).
Reviewed by: Caitlin Hoffman, M.D.
Last reviewed/last updated: January 2021