NeuroLogic
Summer 2016

Epileptologist Joon Kang and neurosurgeon William Anderson are among the handful of practitioners in the nation using laser interstitial thermal therapy to treat epilepsy. The minimally invasive procedure, performed by surgeons using MRI guidance, involves threading a wire holding a laser applicator through a small skin incision and a small hole in the skull into the brain.

Patients who don’t respond to multiple medications for epilepsy often face a painful catch-22—either continue to suffer from debilitating and dangerous seizures while hoping to be one of the rare minority who will eventually benefit from further medications, or undergo surgery to remove the seizure focus, a procedure that typically involves an open craniotomy and comes with inherent risks, including the chance of deficits to speech, memory, vision, motor or sensory function.

“It’s not surprising that only about 5 percent of patients with intractable epilepsy undergo surgery annually,” says Johns Hopkins epileptologist Joon Kang. “This procedure is probably underutilized because patients are afraid of mortality or permanent morbidity from complications.”

However, a third option now available at Johns Hopkins could make epilepsy surgery more palatable to the thousands of patients who could benefit from it: a procedure known as laser interstitial thermal therapy, or LITT. Johns Hopkins is currently the only hospital in Maryland and the Washington, D.C., area that offers this operation, joining a handful of other medical institutions across the country.

LITT, which has been approved by the U.S. Food and Drug Administration for other conditions since 2007 but has only been used for epilepsy in the past four years, involves threading a wire holding a laser applicator through a small skin incision and small hole in the skull into the brain. Using MRI guidance to precisely locate the seizure focus, surgeons, including Johns Hopkins neurosurgeon William Anderson, heat the affected tissue with the laser to temperatures that permanently destroy it. The risk of damage to nearby tissues is low because the surrounding cerebrospinal fluid wicks heat away.

“It’s an extremely targeted approach,” Anderson says.

This focused procedure has a number of benefits, he adds. Because it’s minimally invasive, patients avoid the large, visible scar, potentially deformed skull, severe postoperative pain and long recovery times that typically accompany the traditional open surgery. LITT’s surgical wound is typically closed by a stitch or two, and most patients spend just a single night in the hospital. They’re able to return to their normal activities within a week, compared to the four to six weeks most patients need to recover from a craniotomy. And because the procedure is so targeted, Anderson says, the risk of functional and cognitive deficits drops significantly.

Compared to the open procedure, LITT has a slightly lower success rate, caution Kang and Anderson—about 50 to 60 percent become free of disabling seizures, compared to 60 to 70 percent of patients undergoing traditional surgery. However, they say, experience amassed by centers offering LITT is gradually improving this procedure. Additionally, patients who have LITT can still undergo an open procedure if the minimally invasive one isn’t successful.

“We’re very excited to be able to offer this new procedure,” Anderson says. “It’s a paradigm shift in how we treat epileptic patients.”