SCIENCE / MEDICINE : Surgery Could Help More Epileptics, Panel Advises

Up to 5,000 epilepsy patients each year could benefit from surgery for their condition, a figure which is 10 times the number of those who currently undergo the procedure, a federal advisory panel said last week.

Despite recent medical advances in epilepsy therapy, there are still may people who suffer from seizures that cannot be controlled by conventional anticonvulsant drugs. Many of these could be helped by surgery, said the panel, which was convened by the National Institutes of Health.

Epilepsy is a brain disorder characterized by seizures that result from a malfunction in the brain’s electrical system. The surgery involves removing the portion of abnormal brain tissue responsible for causing the seizures.

“The operation has become safer and surgeons have become more adept” at identifying the precise location where the tissue should be removed, said Dr. Lewis P. Rowland, panel moderator and chairman of the department of neurology at Columbia Presbyterian Medical Center in New York.

But he and other panel members emphasized that the surgery should be confined to those patients who do not respond to conventional drugs.

Also, they stressed, the surgery should only be performed in epilepsy centers “with multidisciplinary teams of specialists equipped to handle the complex preoperative, surgical and postoperative stages.”

About 10% of all Americans will have at least one seizure at some time, according to the panel, and 150,000 people each year will experience their first seizure.

Of the 150,000 each year who suffer their first seizure, about 10% to 20% will prove to have “medically intractable epilepsy,” or epilepsy that does not respond to drugs, the panel said.

About 70% of those with recurrent seizures can be controlled with anticonvulsant drugs, the panel said.

The panel concluded that epilepsy patients whose seizures originate from one region in the brain are the most likely to be helped by surgery. However, they said, some patients with multiple seizure sites might also benefit.

Although the surgery is accepted procedure, controlled clinical trials have never been performed. Also, there has been some disagreement among investigators about how to evaluate patients for surgery, which procedures should be done and which methods are best to assess surgical outcome.

For example, there is no precise definition of “intractable epilepsy,” Among the considerations are frequency of seizures, severity of the attacks and impact on the quality of life.

“If a patient falls during seizures that occur only a few times a year, repeated injuries and trips to emergency rooms can make life miserable,” the panel said. “Even one seizure a year may disqualify a person from having a driver’s license.”

The panel said that repeated seizures can also have adverse effects on the brain, leading to “progressive cerebral degeneration and more severe clinical handicap.” Also, the group said, chronic use of drugs may cause toxic side effects and may also have adverse effects on learning, scholastic achievement, development and job performance.

The largest group of surgical candidates includes those who suffer what are known as partial seizures in which the patient experiences some loss of consciousness.

Surgical success rates for these patients range from 55% to 70%, where success is defined as no seizures, with the risk of death and complications less than 5%, the panel said.

“Deaths are very uncommon and injuries are also very uncommon,” said Dr. Edward R. Laws Jr., chairman of the department of neurosurgery at George Washington University Medical Center. “It is practical now to do this kind of surgery with great precision and a reasonable degree of safety.”