The study examined 175 patients with intractable epilepsy (when the condition is not relieved by medication) who had surgery that removed a small portion of the brain identified as a region involved in seizure generation, and who were seizure-free for the first year following surgery. Researchers followed up with the patients for an average of more than eight years, and found that 63 percent never relapsed (stayed seizure-free).
"Little is known about seizure recurrence in patients five, 10, or 20 years after surgery, and one year isn't enough to follow up a patient who had surgery," said study author and neurologist Susan S. Spencer, MD, of the Yale University School of Medicine, New Haven, Conn. "The number of patients who didn't relapse in this study was larger than we thought it would be."
Among the 65 patients who relapsed, 51 percent had one or fewer seizures per year. A longer seizure-free period indicated that a relapse would be less severe. The remaining patients had more than one seizure per year, and 10 of these patients, who relapsed within four years of surgery, had more than one seizure per month.
Duration of epilepsy before surgery rather than age at the onset of epilepsy was a significant factor in predicting seizure freedom, although all patients had a prolonged duration of epilepsy prior to surgery. The group who remained seizure-free had epilepsy for an average of almost 16 years prior to surgery. The group who relapsed had epilepsy for an average of more than 20 years prior to surgery.
In an editorial published in the same issue of Neurology, Edwin Trevathan, MD, MPH, Director of the Pediatric Epilepsy Center at Washington University in St. Louis,
Contact: Marilee Reu
American Academy of Neurology