Advances in Pediatric Neurology & Neurosurgery

It is not unusual for patients with epilepsy to express reluctance to have neurosurgery, even though the burden of seizures may have tremendous adverse effects on their function and quality of life. Parents in particular may be very hesitant to proceed with this treatment when it is proposed for refractory pediatric epilepsy, for fear of how it will affect the neurological functioning of their child. NewYork-Presbyterian/Columbia clinicians recently participated in a multicenter study that showed that most children who undergo temporal lobe resection for epilepsy do not experience memory decline, and in some cases, memory performance actually improves. The study’s findings were published online in the journal Neurology in March 2023.

About 30% of children with temporal lobe epilepsy are eligible for resection. Surgery is considered when antiseizure medications have failed and the child’s epilepsy is unilateral.

Marla J. Hamberger, PhD

"You can imagine what it is like for parents to have to make the decision to have their child undergo brain surgery. But ironically, it’s better for the child to have epilepsy surgery earlier than later," explains study co-author Marla J. Hamberger, PhD, a neuropsychologist and Director of Neuropsychology in the Division of Epilepsy and Sleep at NewYork-Presbyterian/Columbia. "The younger the child, the more plasticity there is in the brain to reorganize and support normal functioning."

Language, for example, is already settled in the left hemisphere by adulthood. But if you perform epilepsy surgery in the left cerebral hemisphere before the age of five, there is a chance that language could develop on the other side of the brain, Dr. Hamberger noted.

“The younger the child, the more plasticity they have in their brain to reorganize and support normal functioning.” — Dr. Marla J. Hamberger

Prior studies that have examined the link between pediatric temporal lobe resection for epilepsy and memory performance were small or used criteria that were not empirically driven. In this investigation, researchers led a retrospective study analyzing a cohort of 126 children ages 6-16 with epilepsy who underwent temporal lobe resection and had completed pre- and postoperative neuropsychological assessments. Change scores on Children's Memory Scale (CMS) delayed memory subtests were classified as decline, no change, or improvement.

For most children, the surgery caused no memory changes. Up to 69% demonstrated no significant changes in memory performance; up to 14% experienced memory improvement; and up to 33% had postoperative declines in memory performance.

“If a child is not responding to medication and continues to have seizures, they're likely to experience cognitive decline in the long run. Surgery is an opportunity for a cure.” — Dr. Marla J. Hamberger

Patients were more likely to have memory decline if their surgery was on the dominant side of the brain, particularly the left side (the dominant side for language in up to 99% of people); a greater extent of brain tissue removed; and a higher CMS score before surgery (since the resected brain tissue is highly functional). High IQ was inversely correlated with memory decline, since high IQ indicates that the brain is better able to compensate. That is, increased cognitive reserve leads to a lower risk of memory decline.

"This data can help clinicians and parents make informed decisions about epilepsy surgery,” says Dr. Hamberger. “If a child has refractory temporal lobe epilepsy, it is worth pursuing a workup because we can use the data from this study as well as our clinical judgment to determine a child's risk for postoperative memory decline. If a child continues to have seizures and is not responding to medication, they're likely to experience decline even without surgery, including impairment of their academic performance, social skills, and independence. Surgery is an opportunity for a cure."