Surgical intervention is grossly underutilized in epilepsy patients who do not receive relief from drug treatment, UC San Francisco researchers reported Tuesday. By failing to offer the treatment to most patients, doctors are condemning them to continued disabling seizures and perhaps to even an earlier death, the researchers say. Whereas hundreds of thousands of the 2 million Americans who suffer from epilepsy could benefit from the surgical procedures, only a few hundred receive them each year, according to Dr. Edward Chang, of the UCSF Epilepsy Center.
Epilepsy, which affects as much as 4% of the world's population, according to some estimates, results from a misfiring of brain cells. That misfiring causes seizures or convulsions that can range from simple staring spells to violent shaking and blackouts. It can be genetic in origin or caused by injury to the brain.
The disorder is typically treated with anticonvulsants, such as lamotrigine, carbamazapine or valproate. Such drugs are effective in controlling seizures in perhaps as many as 60% of cases. But when the patient fails treatment with at least two different drugs, their epilepsy is said to be medically refractory and they are candidates for surgery. Such surgery removes the area of the brain that is misfiring and causing the seizures. Physicians typically insert electrodes into the brain to identify the source of the electrical disturbance, then remove a small amount of tissue that is involved. The most common type of procedure is called a lobectomy.
The efficacy of such surgery was definitively shown in a 2001 clinical trial conducted by researchers at the University of Western Ontario. Eighty patients who had failed treatment with at least two drugs were randomly assigned to receive either surgery or additional drugs. The team reported in the New England Journal of Medicine that 58% of the patients with temporal lobe epilepsy who received surgery were seizure-free one year after treatment, compared with only 8% of those who received only continuing medication therapy. That trial led to a recommendation by the American Academy of Neurology that patients with intractable epilepsy be referred to a comprehensive epilepsy center for evaluation and surgery.
But those recommendations appear to have fallen on deaf ears. Chang and his colleagues used national databases to examine U.S. hospitalizations and surgeries for epilepsy between 1990 and 2010, a period bracketing the Canadian study. They reported in the journal Neurology that the yearly number of epilepsy surgeries remained relatively constant over the entire period, fluctuating between about 300 and 450 cases per year, even while the number of hospitalizations for refractory epilepsy doubled from about 4,000 to about 8,000 per year. As a consequence, the proportion of patients treated surgically declined from 6.9% in 1990-94 to 4.3% in 2004-08. White patients were more likely to undergo surgery than racial minorities, and privately insured patients were more likely than those with Medicaid or Medicare.
One driving force for the decline, the researchers found, was that a larger percentage of patients is now being evaluated at community hospitals rather than specialized epilepsy centers. "The success of epilepsy surgery totally depends upon the accurate localization of the seizure-onset region," Chang said, and the ability to identify the sources is usually lacking at community hospitals. Patients who are not responding to drugs should thus be referred to specialized centers, which exist throughout the country, he said.