Novel laser hemispherotomy ends debilitating seizures and restores lives

Patient Zachary Kurek with his mother

When Zachary Kurek, 11, had a laser functional hemispherotomy for intractable epilepsy in 2021, he was only the second known person in the world to undergo the procedure. Since then, two more children have had the minimally invasive surgery at the University of Chicago Medicine Comer Children’s Hospital, all of whom are now seizure-free.

“Replacing open hemispherectomy, which has potentially significant complication rates, with laser interstitial thermal therapy is a major breakthrough for children with hemispheric epilepsy,” said pediatric neurosurgeon Peter Warnke, MD, UChicago Medicine’s Director of Stereotactic and Functional Neurosurgery. Using interstitial lasers to disconnect the brain’s two hemispheres may have been uncharted territory when Warnke performed the eight-hour surgery on Zachary. But the procedure offered assurance of greater safety than open surgery. Performed in the MRI scanner, laser interstitial thermal therapy (LITT) provides continuous vision and real-time monitoring of the brain temperature and imaging of the cell damage produced, said Warnke. “We are making hemispherotomy more accessible to families who would not otherwise consider epilepsy surgery.”

Zachary had a left perinatal infarct that caused him to lose most of the function of the left cerebral hemisphere and brought about seizures starting at age 1. Despite trials of four antiseizure medications, he continued to have multiple seizures a day, resulting in countless bruises, a few broken bones and teeth, insomnia, depression, and the inability to lead a normal life.

Like Zachary, all the patients who have undergone LITT for refractory hemispheric epilepsy have had a prior vascular disruption of one hemisphere, causing extensive tissue damage. “Instead of surgically removing all the abnormal tissue, we believed it would be feasible to disconnect the pathways from the epileptogenic tissue to prevent spread to the contralateral hemisphere,” said Douglas R. Nordli, Jr., MD, Co-Director of the Comprehensive Epilepsy Center and Chief of the Section of Pediatric Neurology. “The concept is radical, the outcomes amazing.”

The MRI-guided laser probe is passed through catheters inserted into small holes drilled into the skull. Three or four passes with the laser are generally enough to ablate the epileptogenic tissue with pinpoint precision and seal off connections between the brain hemispheres. Warnke is now assisted by a robot that inserts the laser fibers in the brain with greater speed, shortening the surgery time.

The average length of stay for children who have had LITT for hemispheric epilepsy is three days—compared with an average 12 days for open hemispherectomy. “One of my patients was awake, sitting in his bed and eating a sandwich several hours after the procedure,” said Nordli.

Professor of Pediatrics Douglas R. Nordli, Jr., MD

Over the past decade, LITT has also been used to treat other causes of focal epilepsy, such as tumors, cortical dysplasia and scarring in the hippocampus. “It’s a very elegant tool to have to combat refractory or intractable epilepsy,” said Nordli. UChicago Medicine, which is a level 4 pediatric epilepsy center, has performed more than 300 laser surgeries to treat epilepsy in children and adults.

Only 5% to 10% of children with refractory epilepsy are candidates for surgery, according to Nordli’s research. Fortunately, research in pediatric epilepsy at Comer Children’s has provided the four epileptologists with novel therapies to offer their patients. For example, pediatric neurologist and epileptologist Chalongchai Phitsanuwong, MD, has successfully treated neonates and recently broke new ground by treating premature neonates with a ketogenic diet to control their epilepsy.