Epilepsy Neurosurgery
Of the thousands of patients diagnosed with new onset epilepsy this year, a third will fail to achieve control of their seizures with medication. After trying two medications and failing, only 5% will succeed with another medication.
Yet those with medically intractable epilepsy will, on average, live through another 14 years of seizures, risks of complications, and diminished quality of life before being evaluated for a procedure that could offer very good odds for a permanent cure.
“In patients with a well localized focal onset in the temporal lobe, we have an 85% chance of achieving freedom from seizures,” said neurosurgeon Kristen Riley, MD. “In extra-temporal neocortical focal epilepsy, 50% of patients become seizure free. We usually see an improvement in symptoms even in those who aren’t completely free of seizures.”
With 200 procedures performed annually at UAB and Children’s Hospital, Birmingham is a world leader in epilepsy surgery, and among the top busiest centers in the United States. The largest comprehensive epilepsy center in the Southeast, UAB’s level four epilepsy center is also the highest level recognized by the National Association of Epilepsy Centers.
The position of focal onset is predictive of whether surgery can help. Determining which patients are good candidates for surgery requires detective work and imaging.
“It’s a phenomenal team effort,” Riley said. “We look for a concordance of data that can include high resolution MRI, EEG, FMRI, PET and magnetic source imaging using magnetoencephalography (MEG). With these technologies, we can locate seizure foci we couldn’t identify in the past. They give us information that helps to guide the procedure.”
In cortical dysplaysia, when the MRI is normal, or if the focus is outside the temporal lobe or near areas that are highly vascular or control essential functions, invasive monitoring may be required.
“In those cases, we place electrodes around the temporal lobe and monitor the patient so we can inject a radioactive tracer at the beginning of a seizure,” Riley said.
About 90% of the patients who have invasive monitoring are able to have the surgery. The other 10% either have a focus that can’t be well enough defined, or it’s located in an area that could cause a serious deficit in sensory function, movement or memory.
“Even when there is some overlap, we occasionally see cases where not doing surgery is more dangerous than doing it,” Riley said. “I had one patient with progressive seizures so severe she could no longer work or care for herself or her child. She had declining motor and cognitive symptoms, so our backs were against the wall. After surgery, she was seizure free, and with rehab and speech therapy she is 95% of the way back to normal function. She is able to work again, be a mother to her child, and live a normal life.”
Although the costs of evaluation testing and surgery are not inexpensive, Riley points out that uncontrolled epilepsy is costing far more.
“It’s billions of dollars a year, not only in medical costs, but also in lost wages, lost opportunities and diminished quality of life,” Riley said. “Patients are at risk of complications of epilepsy—even sudden death during seizures. They are also constantly at risk of accidents.
“One of my patients almost died when he broke his neck in a fall, and he went through a painful recovery. If he’d had surgery a few years earlier, that fall most likely wouldn’t have happened.
“Patients shouldn’t have to go through a dozen years or more or uncontrolled seizures before being evaluated. If seizures aren’t controlled after trying two or three medications, it’s time to start thinking about referring patients to see if surgery might restore them to a normal life.”
On the horizon, Riley sees another possible treatment for epilepsy that could offer new benefits to patients.
“In the ROSE (Radiosurgery or Open Surgery for Epilepsy) trial, we’re testing radiosurgery to eliminate the focal areas that trigger seizures. It’s a randomized trial comparing the efficacy of the gamma knife to traditional surgery in patients with well defined foci in the temporal lobe,” Riley said.
“If radiosurgery proves as effective as we hope, soon many patients will be able to choose a less invasive option with faster recovery and live their lives seizure free.”
