Laser ablation: Finding the 'sweet spot' to stop seizures

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More than 50 million people worldwide have epilepsy. For some, medication controls the onset of seizures. Others need major surgery.

For still others, laser ablation is the solution, but there have been no guidelines for doctors to determine how much ablation is just enough to be effective.

Now, neurosurgeons are getting closer to having answers.

Scott Geryk is an avid cyclist, but a recent epileptic seizure knocked him off his bike and onto a busy roadway.

"I had an aura that rapidly changed to a seizure, and I crashed the bike and ended up all bloody on the face," he recalled.

After that, Geryk stayed off his bike and in the house. At first, medications worked.

"He put me on it and, poof, the auras, the seizures stopped," he said.

But the meds stopped working. Brain surgery was an option, but it's invasive with a long recovery.

Instead, Geryk and his doctor chose laser surgery. During the procedure, Dr. Chengyuan Wu used a tiny catheter to zap lesions thought to cause seizures and leave healthy tissue intact.

"The actual ablation again is only three or four minutes, total," Wu said.

Wu recently co-led a study designed to pinpoint the precise ablation spot in the brain to significantly reduce seizures. In the operating room, he uses MRI guidance to insert the probe.

"Then, it's just activating the probe, creating the ablation. That's done in the control room of the MRI scanner," Wu said.

Wu and colleagues studied the MRI scans of 234 patients in the study and found when they ablated sections in the central part of the brain, patients had the best outcomes.

What has the laser surgery meant for Geryk?

"It's back to what it was before the accident. I can drive, I can bike and do everything that I could do before," he said.

The overall rate of patients who were seizure-free after laser ablation across the 11 study centers was 58%. But Wu says when looking only at the procedures that targeted the optimal locations, that rate was significantly higher – surgical success rates are around 80%.

MEDICAL BREAKTHROUGHS
RESEARCH SUMMARY
TOPIC: LASER ABLATION: FINDING THE "SWEET SPOT" TO STOP SEIZURES
REPORT: MB #4631

BACKGROUND: Epilepsy is a neurological disorder in which brain activity becomes abnormal, causing seizures or periods of unusual behavior, sensations, and sometimes loss of awareness. Anyone can develop epilepsy. Epilepsy affects both males and females of all races, ethnic backgrounds and ages. Seizure symptoms can vary widely. Some people with epilepsy simply stare blankly for a few seconds during a seizure, while others repeatedly twitch their arms or legs. Having a single seizure doesn't mean you have epilepsy. At least two unprovoked seizures are generally required for an epilepsy diagnosis. (Source: https://www.mayoclinic.org/diseases-conditions/epilepsy/symptoms-causes/syc-20350093)

DIAGNOSING: There are a variety of options that are used to treat epilepsy. Most commonly are AEDs (anti-epileptic drugs) that work by controlling the electrical activity in the brain that causes seizures. Up to 70 percent of people could have their seizures fully controlled with the right AEDs. Other options include a ketogenic diet, vagus nerve stimulation, brain surgery or neurosurgery, deep brain stimulation, and cannabis oil for epilepsy. (Source: https://www.epilepsysociety.org.uk/treatment#.XWasCOhKhPY)

NEW TECHNOLOGY: Chengyuan Wu, MD at Jefferson University Neurological Surgery talked about using laser ablation to treat epilepsy, "In the early experience with this, again, we would only choose patients with that scar tissue, that mesial temporal sclerosis because that was a hallmark of saying, 'hey that's where this is coming from.' You know, X marks the spot. But what's interesting in this study and some of the other studies is that the presence of that scar tissue does not predict seizure outcome. So as long as we're confident that the seizures are coming from that area, whether you have scar tissue or not does not necessarily mean that you will have a better outcome or not, right? So the thing that is really more important is making sure the seizures are coming from that location and in hitting that location." (Source: Chengyuan Wu, MD)