Epilepsy surgery
Courtesy of Christopher Demers, MD

Surgical resection to remove the seizure trigger zones or “foci” of the brain is considered for patients who don’t respond to medication, have seizures that can be localized to a particular location in the brain (focal epilepsy), and who can function well with that section of brain excised.

Resective surgery can completely eliminate seizures in the majority of patients who undergo this treatment. Epilepsy surgery requires a collaborative approach that draws upon the expertise of medical professionals from a number of disciplines. Their assessment, using the wealth of data provided by sophisticated diagnostic testing, helps to accurately identify patients for whom surgery promises to be an effective treatment. Essential for the success of surgical treatment of epilepsy is the careful analysis of test results of possible surgical candidates to ensure that the epileptogenic zone has been clearly established. The more accurate the diagnostic phase of treatment for patients with focal epilepsy, the more successful the surgical outcome.

Surgery is considered when seizures consistently originate in only one lobe (temporal, parietal, frontal or occipital) and in an area that can be safely removed without damaging vital functions.

  • Lobectomies are surgeries that result in the removal of part of a lobe, with temporal lobe resection being the most common type of lobectomy. Extratemporal resection refers to the removal of part of the parietal, frontal or occipital lobes. Many patients become seizure free when the affected portion of the lobe is removed. Other more complex, but less common, types of surgery may be helpful for some patients.

  • Lesionectomies are surgeries to remove lesions, which can be tumors, abnormal blood vessels, hematomas or scars, in the brain. Lesions can cause or exacerbate seizures, and are responsible for seizures in approximately 20 to 30 percent of medically refractory patients. Because surrounding brain tissue may also be affected by the lesion, surgery may also include removal of a small amount of tissue surrounding the lesion.

  • Multiple subpial transections is a type of surgery that may be performed when the part of the brain in which the seizures originate is too important to be removed. The surgeon may use surgical incisions to interrupt neural circuits to prevent seizures from spreading into other regions of the brain.

  • Corpus callosotomy is a type of surgery that may be performed when a patient suffers from a particularly debilitating type of seizure, namely atonic seizures or “drop attacks.” These seizures may be prevented or dramatically reduced by surgery that partially or completely severs the corpus callosum, a band of nerve fibers located deep in the brain that connects the two hemispheres. The surgery in effect severs the connection, preventing seizures from spreading from one side of the brain to the other.

  • Functional hemispherectomy is the most extensive surgery, used only for a very rare and devastating form of epilepsy. In this procedure, the most seizure prone and damaged half of the brain is functionally disconnected. Especially in younger patients, the remaining half of the brain can often successfully assume the functions of the detached half. After surgery, patients initially continue to take anti-seizure medications. If seizure-free for one to two years, they may be weaned in stages from their anticonvulsant medication, with many patients remaining seizure-free with less or no medication. However, some may have to continue some medication to optimize control.