Researchers followed more than 600 patients for as long as 19 years after seizure-control surgery. They found that 52% were not having seizures (except for simple partial seizures) after five years; 47% remained seizure free after 10 years. Simple partial seizures are a type of seizure confined to a limited area of the brain, not associated with loss of consciousness.
Once considered a last resort for patients with few other treatment options, surgery is now a relatively safe and common therapeutic strategy for seizure control.
"These days if a patient has failed two or three medications we might consider surgery because it has become much safer and more effective over the last few decades," says Ashesh Mehta, MD, who is director of epilepsy surgery at the North Shore-LIJ Health System Comprehensive Epilepsy Care Institute in New Hyde Park, N.Y.
About 2 million Americans have epilepsy, a term used to describe several different brain disorders that cause frequent seizures.
According to Mehta, who did not take part in the new study, about two-thirds of adult epilepsy patients achieve good seizure control with drug treatments.
"The rest have seizures that do not respond to drugs, and these are the patients who could benefit the most from surgical treatment," he says.
In the newly published study, researchers from University College London and King's College London followed 615 epilepsy patients for an average of eight years after surgery in an effort to better understand long-term outcome patterns.
They reported their findings in the Oct. 15 issue of The Lancet.
The average patient had experienced seizures for about two decades before having surgery. All of the surgeries were conducted at London's National Hospital for Neurology and Neurosurgery from early 1990 to late 2008.
Early recurrence of seizures following surgery was the strongest predictor of poor long-term seizure control. But four out of five patients had at least one year with no seizures or with only minor seizures.
Avoiding Epilepsy Relapse
"The longer a person stayed seizure free, the less likely they were to relapse," researcher John S. Duncan, MD, and colleagues write.
About 40% of patients had long-term complete freedom from seizures after surgery. An additional 11% experienced only simple, partial seizures.
None of the patients experienced a worsening of seizures following surgery.
Although 82% of patients had at least one year with no seizures or minor seizures following surgery, the researchers noted that this did not indicate a cure.
Many patients remained on anti-seizure drugs, although 28% of patients who were seizure free at the last follow-up were off all medications.
The researchers conclude that patients whose seizures are not controlled with drugs may benefit from surgery earlier in the course of their disease.
"Surgery is successful for many individuals in whom anti-epileptic drugs have not been effective, but further improvements need to be made to pre-surgical assessment to further increase rates of success," they write.