Dr. Gupta discussed findings from the TimeToStop study, a retrospective observational study that involved 766 pediatric epilepsy surgery patients at 15 European centers from 2000 to 2008. The study found that the chance of seizure recurrence was higher when medications were reduced earlier, “but it also found [that] even though you have a higher chance of seizure occurrence, this does not usually affect the long-term outcome,” said Dr. Gupta. “By reducing medication, if you have a child whose seizures were to recur, you’re really just unmasking the surgical failure earlier.”
In the TimeToStop study, patients’ mean IQ increased by about 4 or 5 points for every AED that was reduced after epilepsy surgery. “There is compelling evidence to suggest that these agents do cause certain cognitive or behavioral or IQ issues,” said Dr. Gupta. “If you have done a good job of selecting these children for epilepsy surgery and delivering a good seizure outcome, you probably have a very good chance that you are going to actually be able to take them off [their AEDs].”
Global Function
Understanding patients’ cognitive, behavioral, and global function outcomes “is imperative and it’s being looked at more and more,” he said. Prior studies reported qualitative outcomes such as improved communication, alertness, or social behavior, but solid and objective markers of IQ, language, memory, and behavior are needed to evaluate patients’ long-term outcomes. Following their study on seizure outcomes in 170 children who underwent hemispherectomy, the researchers assessed the functional outcome for 115 patients from that series (mean age, 12.7). At a mean follow-up of six years, 83% of the children walked without assistance, 76% did not have any new visual symptoms, and 73% had no significant behavior issues. Reading is one of the most complex issues: only 42% of patients had satisfactory reading skills. The most important finding of this study and a similar study is that “seizure freedom after surgery independently correlated with higher functional outcome in each domain,” Dr. Gupta said.
These findings can help neurologists answer families’ questions about epilepsy surgery. “It is very important and it’s actually very good to know that seizure outcome, which is the number one objective of surgery, also drives your AED outcome ... and it also drives your cognitive outcome,” Dr. Gupta said. Future well-designed studies may further improve neurologists’ ability to predict outcomes in pediatric epilepsy surgery, he concluded.
—Jake Remaly
