WASHINGTON, DC—Cognitive outcome after epilepsy surgery in children is significantly correlated with duration of epilepsy, but not with age at the time of surgery, according to research presented at the 67th Annual Meeting of the American Epilepsy Society.
“Data from this study support moving more quickly toward surgery for children of any age, as longer duration of epilepsy was a more robust predictor of cognitive outcome than most other presurgical considerations,” commented Elizabeth N. Adams, PhD, a neuropsychologist with the Minnesota Epilepsy Group in St. Paul.
The investigators analyzed data from neuropsychologic evaluations of 30 children who had undergone epilepsy surgery between 2005 and 2012. Participants had a mean age of 11.7 years at the time of surgery and a mean age of 5.3 years at seizure onset. The mean duration of epilepsy at surgery was 6.4 years, and the mean time between surgery and postoperative testing was 1.3 years. Twelve patients had surgery in the left hemisphere, six of which were classified as left hemisphere dominant for language based on language mapping with magnetic source imaging. Within the group of patients, 18 temporal lobe resections had been performed, as well as five extratemporal resections and seven multilobar resections. The mean presurgical Full-Scale IQ (FSIQ) was 85, and the mean postsurgical FSIQ was 83.
Dr. Adams’ group found that the postsurgical FSIQ was significantly associated with epilepsy duration (r = 0.54), but not with age at the time of surgery. “The same finding held true for postoperative Verbal IQ, naming, and verbal fluency,” according to Dr. Adams. Patients whose epilepsy duration was five years or less had a mean postsurgical FSIQ of 97, while those with an epilepsy duration of greater than five years had a mean postsurgical FSIQ of 72. Post hoc analyses revealed that the association between epilepsy duration and FSIQ remained after excluding factors such as the age of seizure onset, side of surgery, surgery in the language-dominant hemisphere, type of resection, Engel class outcome, number of antiepileptic drugs (AEDs) taken postsurgery, and time between surgery and testing.
“Postsurgical FSIQ was significantly associated with the number of AEDs tried prior to surgery, potentially reflecting complicated epilepsy course or chronic effects of more medications on cognition,” stated Dr. Adams. “The association between number of AEDs tried prior to surgery and postsurgical FSIQ suggests that surgical intervention earlier in the course of epilepsy treatment may mitigate these effects and improve long-term cognitive prognosis.”
—Colby Stong