Laser Ablation Holds Promise for Patients With Epilepsy

Pauline Anderson

December 03, 2012

San Diego, California — Laser thermal ablation is gaining momentum as an effective and potentially cost-effective alternative to conventional neurosurgery in patients with epilepsy, new research suggests.

Laser ablation "opens up doors" for pediatric patients with cognitive or behavioral problems or others who might not tolerate surgery, said Michael G. Chez, MD, director of Child Neurology, Sutter Neuroscience Group, Sacramento, California.

The technique is "kind of a breakthrough," added Dr. Chez, in that it's noninvasive, has a quick recovery, involves little pain, and causes relatively little tissue disruption.

Dr. Chez's research group was among several to report on a growing number of cases of laser ablation at their respective institutions during the 66th American Epilepsy Society (AES) 66th Annual Meeting.

Dr. Michael G. Chez

The Sutter researchers presented results of ablation of nonmesial temporal foci on 8 patients: 6 children and 2 young adults. The cases involved occipital, temporal, parietal, and frontal foci, some of which were in difficult-to-reach regions.

Tiny Hole

For the procedure, researchers first place plastic electrodes over the ablation region on the cranial surface for electroencephalography (EEG) monitoring. They also collect EEG data using magnetic encephalography. A surgeon then drills a tiny hole — about the diameter of a pen tip — in the skull, through which a fiberoptic probe with laser is inserted.

Placing the tube It takes only about a half hour, after which researchers perform the real-time MRI-guided procedure. The heat from the laser burns an area up to 2 cm; a water system keeps surrounding tissue cool.

After ablation, all 8 patients showed resolution (n = 7) or a diminished number (n = 1) of spikes. Five patients were pain free and ambulatory within 6 to 8 hours.

"We have had very good outcomes with no complications in children who are now 2 months to 12 months post-surgery," Dr. Chez reported. "The nice thing is that once patients recover, they go home within 24 hours and even within hours of surgery, most are up eating, talking, and walking whereas with typical craniotomy, they would be sedated, probably not walking until a day or 2 later and sometimes not eating probably for 2 or 3 days and staying in hospital for 3 to 5 days."

Once released from the hospital, the ablation patients stay on steroids for about 2 weeks to help decrease swelling, said Dr. Chez.

The researchers also noted cognitive improvements — including among those patients who started with deficits (some had autism or were hyperactive). "We have patients who couldn't remember how to use the microwave or their iPad code who now do that without any problem or prompting," said Dr. Chez.

Laser ablation has a lot of cost advantages, too, he added, including shorter hospital time and less time in the operating room.

But despite its advantages, laser ablation probably won't completely replace surgery, said Dr. Chez. "Craniotomy is still the gold standard, and we don't have any data saying this is better long-term. What we're saying is that for patients who may not tolerate a craniotomy or maybe would like to try this first," it might be an option.

Miami Experience

Another research group from the Miami Children's Hospital reported on their first cases of laser ablation for intractable epilepsy: 5 children aged 11 to 18 years, 2 of whom had not responded to prior conventional surgery. The mean length of hospital stay was 1.6 days, and there were no complications from infection, bleeding, or unintended neurological injury.

Dr. Ian Miller

Two of the patients were Engel class I (seizure free) after the procedure, and 2 were Engel class IV. The fifth patient was Engel class I after conversion to conventional resection. The results are similar to those in patients who had traditional surgery.

"It adds one more tool in the tool box," said Ian Miller, MD, director of Neuroinformatics, Miami Children's Hospital. "But where the right place is for this long term remains to be seen." They have since compiled data on 10 cases.

Dr. Sanjiv Bhatia

Time will tell which patients are best candidates for the procedure, added Sanjiv Bhatia, MD, Pediatric Neurological Surgery, Miami Children's Hospital. "We need to fine tune the indications."

None of the researchers have disclosed relevant financial relationships.

66th American Epilepsy Society (AES) 66th Annual Meeting. Abstracts 1.287 and 1.278. Presented December 2, 2012.