Should I have surgery?

The majority of people with epilepsy do not need to have surgery. In most cases, seizures can be well-controlled with anti-epileptic medications. However, researchers estimate that 30-40 percent of patients with epilepsy struggle with seizures that cannot be controlled with medications. If your seizures are difficult to control, you have “refractory” seizures. If they are focal or partial, you may be a candidate for surgery. Seizures are considered refractory after you have been treated with at least two drugs in separate intervals and in combination for at least two years without success. You also may benefit from surgery if doctors have been able to determine that your seizures are caused by specific abnormalities, such as tumors or vascular lesions.

Before surgery is an option, several factors must be considered. Generally, prospective surgical candidates include patients who have had:

• poor control of their seizures with more than one medication;
• a clear diagnosis of seizure type and syndrome;
• testing to rule out certain metabolic, degenerative and structural causes;
• patient and family education to ensure they understand the advantages and disadvantages of the surgical procedure or procedures recommended, including medication effects and side effects, as well as alternative treatments.

What is involved in the preoperative evaluation?

The purpose of the preoperative evaluation is to determine whether surgery can be performed safely without damaging vital functions. This requires a detailed presurgical evaluation to identify seizure type, seizure frequency, and the site of seizure onset, psychological and social functioning and the degree of disability in order to select the most appropriate treatment from a variety of surgical options. This type of evaluation is best carried out in a multi-disciplinary epilepsy center experienced in the investigation and treatment of epilepsy, such as the Bromfield Epilepsy Center.

If you undergo a preoperative evaluation, a variety of specialists will be involved in your care, including neurologists, neurosurgeons, psychologists, nurses, social workers, EEG technologists, occupational therapists and psychiatrists.

The surgical evaluation process can take from several weeks to several months, depending on individual needs. During this process, our entire team considers both the medical and emotional needs of the patients and their families.

While each preoperative evaluation is different depending on the individual patient's needs, generally speaking, the overall goal is to classify the different kinds of seizures, as well as the frequency, severity and duration of each type.

The primary components of the pre-surgical evaluation include:

• a detailed clinical history and physical examination.
• a high resolution MRI scan of the brain.
• functional imaging: This is an attempt to see changes in brain metabolism using the uptake of glucose with a radioactive atom in it, called "positron emission tomography" (PET scan). A PET scan is used to identify areas of hypometabolism (decreased glucose uptake), which may be associated with a seizure focus identified by other studies. Single photon emission computer tomography (SPECT scan), which looks at blood flow, may also be used.
• Continuous video EEG monitoring - an inpatient hospital stay for three to seven days for 24-hour video and EEG surveillance. The goal is to allow the patient to have their usual seizures in order to localize where the seizures come from. During the admission, the patient's medications may be reduced so that a seizure is more likely to occur.
• Neuropsychological Testing - a neuropsychological assessment can provide essential data that is helpful to identifying areas of altered brain function/thinking that may be related to where the seizures originate. Language function, memory (both verbal and visual) and visuospatial capability are examined. These tests last several hours and require some patience. By examining the pattern of test results, the neuropsychologist is able to identify the patient's specific areas of decreased function in the brain.
• Assessment of Psychosocial Functioning: Psychological, social and psychiatric assessment plays an important role. With this evaluation, the expectations of surgery and the post-operative adjustment are explored.
• The various parts of the evaluation gradually form a reasonably clear picture of you and your seizures. If, after an inpatient stay and video EEG monitoring, a seizure focus is suspected, but the start of the seizures is unclear, some form of surgically implanted electrodes may be indicated.

What specialists will be involved in my care?

The Edward B. Bromfield Epilepsy team strives to meet the multifaceted medical, psychological and social needs of individuals and families in order to make the experience of having epilepsy surgery as successful as possible. Our multidisciplinary team includes neurologists, neurosurgeons, neuropsychologists, neuropsychiatrists, epilepsy nurses, neuro-clinical social workers and EEG laboratory technicians, all defined below.

Neurologist: A physician who specializes in the nervous system, specifically, epilepsy and the brain. After examination and treatment, he/she may recommend brain surgery for difficult-to-control seizures if there is a strong indication that the electrical discharge is coming from a focal area such as the left or right temporal lobe.

Neurosurgeon: A surgeon specializing in the brain who has expertise in epilepsy surgery. He/she works closely with the neurologist.

Neuropsychologist: A psychologist specializing in brain and behavior, focusing on the impact of memory, insight and cognition through interview and neuropsychological testing.

Neuropsychiatrist: A psychiatrist specializing in neurological issues and the psychiatric impact of epilepsy.

Clinical Nurse Specialist: A nurse specializing in psychosocial manifestations, pre- and post-surgical care, medication treatment of epilepsy and patient education.

Neuro-Clinical Social Worker: A social worker specializing in the psychosocial issues of epilepsy, pre- and post-surgical care, resources, community programs, and patient education.

EEG Laboratory Technicians: Technicians specializing in brain wave monitoring use for procedures, and required to capture seizures for further diagnosis.

What surgical procedures are used to treat epilepsy?

The goal of epilepsy surgery is to identify an abnormal area of brain tissue from which the seizures originate and remove it without causing any significant impairment. The brain is divided into two sides, called "hemispheres." Each side of the brain is then divided into lobes. The major lobes are the temporal lobes (sides of the brain), frontal lobes (front of the brain), parietal lobes (middle of the brain) and occipital lobes (back of the brain). An operation to remove all or part of these lobes is called a lobectomy. A lobectomy may be performed when a person has seizures that start in the same lobe every time. The following are different types of surgical procedures commonly used to treat epilepsy:

Temporal lobectomy. This is the most successful type of epilepsy surgery, especially in the non-dominant side of the brain. Success rates of 60-80 percent have been reported, with or without anti-epilepsy drug (AED) therapy.

Extra temporal resection. In this procedure, dysfunctional brain tissue is surgically removed from areas outside the temporal lobes. It is generally less successful unless a clear-cut tumor, vascular malformation or other lesion is present. It can be particularly difficult to localize seizures in the frontal lobes since this represents such a large portion of the brain.

Corpus Callosotomy. The corpus callosotomy interrupts the spread of seizures by cutting the nerve fibers that connect one side of the brain (hemisphere) to the other. This nerve bridge is called the corpus callosum. The corpus callosotomy is indicated in some patients with drop attacks. In this procedure, the corpus callosum is sectioned or disconnected, usually at the front of the nerve bridge. The goal of this surgery is to prevent the spread of seizure discharges to both sides of the brain. This procedure does not stop seizure activity, but it lessens the risk of injury because it may limit the frequency and severity of seizures, especially those that cause falls.

Hemispherectomy. Hemispherectomy is most commonly performed in children with severe epilepsy. This procedure is often called a functional hemispherectomy, since most of the tissue is not really removed but disconnected. The surgery is a combination of removal and disconnection of one hemisphere, including the temporal lobe.