For years, Khris and Robin Dysart just thought their baby Keagan loved to giggle. But as the boy grew older, he began doing so at inappropriate times, and with a laugh that sounded robotic and mirthless rather than happy. Keagan’s teachers began chastising him for disrupting school, and his behavior made it hard to study or make friends.
After specialists in the US and Canada gave the Dysarts conflicting diagnoses, Robin finally typed “laughing episode” into Google and learned about gelastic seizures (named for Gelos, the Greek god of laughter). They are caused, scientists now know, by a rare form of epilepsy triggered by a congenital hypothalamic hamartoma, a non-cancerous tumor attached to the brain’s hypothalamus. While neither as dramatic nor as common as classic grand mal seizures, the Dysarts’ son’s seizures were preventing him from living a normal life.
“Keagan was having dozens of seizures a day,” says neurologist Dr. Angus Wilfong, the medical director of the Comprehensive Epilepsy Center at Texas Children’s Hospital. “Without stopping them he’d never drive, he’d never complete school, he’d never live independently.”
Because the tumor was at the center of Keagan’s brain, the traditional way to eliminate it would have been to perform a hemispherectomy, in which the surgeon removes or detaches half of the patient’s brain in order to reach the tumor and remove it. Hemispherectomy patients often suffer partial paralysis, or hearing and memory loss.
“It speaks to how bad epilepsy is that people would sacrifice being paralyzed on one side of the body just to stop the seizures,” says Wilfong, a Canada native with a passing resemblance to Mad Men’s Roger Sterling. “You can still drive a car with a paralyzed arm, but you can’t drive a car with a seizure.” (In Texas, epileptic patients can only get a driver’s license if a doctor certifies that they have been seizure-free for at least six months.)
Epilepsy is one of the most common neurological disorders, and yet it carries a lingering stigma. The oldest written description of an epileptic seizure comes from a Mesopotamian text written around 2,000 BCE, in which the sufferer is diagnosed as being possessed by the moon god and given an exorcism. Ancient Romans believed it was a curse, while early Christians saw it as evidence of demonic possession. Until the 1970s, epileptics in the United Kingdom were legally prohibited from marrying, while in the US it was legal to deny them access to restaurants, theaters, and other public places.
Fortunately for Keagan, Wilfong, along with neurosurgeon Dr. Daniel Curry and the rest of the epilepsy team at Texas Children’s Hospital, had recently pioneered a game-changing surgical technique that eliminated the need for open-brain surgery. Using a laser originally developed by Houston-based Visualase to treat brain cancer, the team cut a hole a quarter-inch in diameter in Keagan’s head, inserting a tiny laser catheter. Using real-time MRI scanning, Dr. Curry guided the laser to the spot of the tumor, then gradually turned up the heat until it had been destroyed.
That very afternoon, Keagan woke up from anesthesia an ordinary kid, and he hasn’t had a single seizure in the four years since the surgery. The procedure has a 90 percent success rate and hardly a single documented side effect. Unsurprisingly, the Texas Children’s Hospital’s epilepsy center—already one of the best in the country—has become the world’s top destination for patients with hypothalamic hamartoma; Wilfong and his team perform the operation almost every week. Neurosurgeons from around the country travel to Houston to train with him, and Visualase is currently applying for permission to sell its product to hospitals in the European Union. Wilfong believes that the new procedure will likely make hemispherectomies all but obsolete.
“It’s one of the most rewarding things I’ve done in my career, because it’s not just helping my patients here and now,” he says. “It’s something that will spread around the world.”