With seizures that aren't well controlled, people with epilepsy may not be able to work, drive, finish their education, or enjoy many of the activities that others take for granted. Today's medications can be tremendously helpful for many people with the condition. But others require more intervention. New surgical techniques, developed at Yale, can often make all the difference.
“Epilepsy is the only chronic neurological disease that can be cured in the operating room,” says neurologist Dennis Spencer, MD, director of the Yale Medicine Epilepsy Surgery Program. Dr. Spencer pioneered the first techniques for epilepsy surgery 30 years ago and continues to perform procedures today.
What is epilepsy?
Epilepsy, a neurological disorder, is caused by abnormal overactive electrical activity in the brain. Symptoms may include episodes of sensory disturbance, loss of consciousness, and/or more generalized seizures. For patients whose seizures aren't well controlled by drugs, particularly if they've tried two or more medications, identifying and ablating or stimulating the focus in the brain may be the best treatment option.
What is epilepsy surgery?
Surgical treatment of epilepsy was pioneered in the 1970s. Researchers found that some cases of epilepsy originate in the hippocampus. The hippocampus is located in the temporal lobe, and is responsible for turning short-term memories into long-term memories. The researchers learned that people with this type of epilepsy can often be cured by removing that part of the brain.
Dr. Spencer developed the most commonly used technique for removing parts of the temporal lobe (anteriomedial temporal lobe resection). The same technique is still in use today, with decades of research confirming its efficacy. "We are now able to look at those patients over 30 years and find that the outcomes are very good," says Dr. Spencer. "Patients who are appropriate for temporal lobe resection have a 75 percent chance of controlling their seizures."
How do doctors decide which patients can be helped by epilepsy surgery?
To be considered, patients must have tried two or more anti-seizure medications without success. Doctors will then conduct a medical assessment to determine whether surgery may be helpful for a particular person's epilepsy. "The purpose of our medical evaluation is to find an area of the brain that is removable, without causing harm and that has a chance of curing the patient," says Dr. Spencer.
The evaluation begins with a full medical history, including a review of all previous medications and seizure frequency. A magnetic resonance imaging (MRI) scan looks for visible evidence that surgery is indicated. Candidates most likely to be helped by epilepsy surgery are those with a clear “lesion,” or image abnormality, that can be seen on the scan.
Next the patient spends time in a seizure monitoring unit. Here seizures are observed while the brain’s electrical impulses are recorded with electroencephalogram (EEG) monitoring equipment.
A neuropsychological test will be done to determine whether there are cognitive deficits typical for the area of the brain where the seizure activity is situated. For example, abnormalities in the dominant temporal lobe tend to affect a patient’s verbal memory.
If all these tests confirm that the patient may be a good candidate for surgery, they will then be presented to the multidisciplinary surgery review board for consideration. The surgery review board has 30 members, including neurosurgeons, neurologists, neuroradiologists, neuropsychologists, nurses, and technicians. To move ahead with surgery, all must be in agreement that a particular patient is a good candidate for the procedure.
How does epilepsy surgery work?
Epilepsy surgery involves many procedures.
Ideally, an MRI scan reveals an abnormality such as hippocampal injury, a vascular abnormality, or a developmental tumor that can be removed, leading to seizure control.
If no MRI abnormality is identified or if the scan shows a developmental malformation, then the patient is offered an operation to place electrodes into the brain in order to identify the seizure onset region. If this study is successful in localizing the focus, surgery may be carried out.
If the seizure onset is in an important functional part of the brain, such as language, motor movement, or sensation, then a stimulating electrode may be placed. It is then connected to an implanted computer chip that stimulates the seizure when it is detected in an attempt to "short circuit" the seizure.
More recently, laser ablation is being offered when the seizure onset area is discrete and might be controlled with a less invasive procedure that can destroy the seizure focus without open surgery. In this case, the patient can go home the next day.
While each patient’s surgery may be slightly different, all open surgical procedures for epilepsy follow the same basic plan, which is resection, or removal, of the portion of the brain that is associated with seizure onset and which will not cause a cognitive or neurological loss.
What is the recovery process for people who've had epilepsy surgery?
Patients may have different recovery times and experiences, depending on the procedure.
Following surgery on the temporal lobe, for example, patients may experience headache and nausea from the anesthesia; this typically goes away after a few days. Most patients are able to walk within a day of surgery and are usually discharged after five days. Sutures will be removed in seven to 10 days.
After patients return home, they'll continue to be monitored to see whether seizure activity returns. Patients who've had epilepsy surgery cannot drive for 12 months after the surgery.
And, says Dr. Spencer, even those whose seizures aren't totally cured by the surgery usually experience a significant reduction in their frequency and severity.
"Most patients are surprised at how much their lives are changed once the seizures have stopped," Dr. Spencer says. “Their quality-of-life index goes up and use of medication is often decreased."
What makes Yale Medicine's approach to epilepsy surgery unique?
Yale Medicine’s Epilepsy Surgery Program has led the world in developing new treatments. Many surgical techniques now in wide use across the country and internationally were first performed here. Yale Medicine also offers many promising clinical trials for epilepsy medication. The center continues to advance the study of epilepsy as one of the world’s leading research institutions.
Meanwhile, the staff at the center is also committed to collaborating in order to provide each patient with a personally tailored, comprehensive care plan. The goal is always to provide each person with the highest quality of life that the latest science and the most skilled surgeons can deliver.
"Epilepsy surgery can change somebody’s life," says Dr. Spencer. “That’s what drives us to do this.”