By Laura Freeman
Radiofrequency ablation made big news in the 1990s when it became the standard of care for correcting some types of heart arythmmias. In the years that followed, it became a tool for treating disorders in many areas of the body. Now two neurosurgeons from UAB Heersink School of Medicine are using the technology to treat drug resistant focal epilepsy for the first time in Alabama.
Nicole Bentley, MD and Kirsten Riley, MD of the department of neurology teamed up for the first case. It involved Ashley Williard a recent college graduate. Despite having seizures since early childhood, Williard was active in ballet, swimming, tennis and cheer. However, her seizures had increased in frequency to about twice a week in college, which was making her life more difficult.
"Focal epilepsy is triggered by lesions in specific areas of the brain," Bentley said. "The first step to eliminate the lesions is to locate them. This requires implanting electrodes and waiting to capture a seizure in real time as it is happening so we can precisely map out the location of lesions triggering the attack and the areas they affect."
Riley said: "The mapping procedure is known as stereo-electroencephalography. Electrodes are placed directly in the brain in areas that the epileptologist and neurosurgeon have identified as the most likely seizure onset zone. The temporal lobe is where most problems begin."
By taking advantage of the electrodes that are already in place, the RF procedure offers minimally invasive access to areas near the focal lesions without the need for a craniotomy.
"After we have identified the exact location of the lesions that are triggering seizures, we can connect RF energy to any electrodes that are near enough to the seizure onset zone to target it," Riley said.
Bentley said: "Usually we would welcome any improvements in symptoms as a step toward our ultimate goal of getting the patient to the point of being seizure-free. We would normally expect to follow up with either laser ablation or traditional surgery to fully eliminate the lesion. However, our first patient, Ashley Williard, was very lucky. She has been completely free of seizures since the procedure."
"Her lesion was extremely tiny," Riley said. "And we had the good fortunate to place the electrode directly on top of it."
Other cases using RF ablation have been successful, but have needed a typical follow-up procedure to eliminate all of the lesion that is causing problems.
"To some degree, depending on the individual anatomy, the RF procedure can be predictive of what we might expect in the follow-up procedure," Riley said. "If we see fewer seizures and milder symptoms after the ablation, we can feel more optimistic about the quality of data from the mapping and the outcome we are likely to achieve from the follow-up surgery. If there are any unexpected changes, they may offer clues that we need to be particularly vigilant in protecting an area that may influence primary functions."
For patients with focal epilepsy who are not candidates for surgery because the lesions triggering their seizures are too near eloquent structures controlling essential function, radiofrequency ablation may offer at least some hope for reducing the number and severity of seizure. That would depend on the brain's individual anatomy.
Bentley is hopeful. "Epilepsy care has come so far in recent years," she said. "Our goal for all our patients is to help them become seizure free so they can enjoy their lives to the fullest."