WASHINGTON – Stereotactic laser ablation resulted in better cognitive outcomes in patients with temporal lobe epilepsy than did treatment with standard open surgical approaches, Daniel Drane, Ph.D., reported at the annual meeting of the American Epilepsy Society.
In a study comparing pre- and posttreatment cognitive outcomes in 17 people with temporal lobe epilepsy, those treated with MRI-guided laser ablation had better outcomes on episodic memory measures 6 months after surgery than did the patients treated with standard surgical treatments, said Dr. Drane of the departments of neurology and pediatrics at Emory University, Atlanta. The results suggest that "memory decline requires broader damage to mesial temporal lobe structures or that epilepsy patients are able to reorganize memory more efficiently if structural damage is more selective," he concluded.
The study compared neuropsychological data before surgery and 6 months after surgery in 7 people who were treated with hippocampal laser ablation (5 left and 2 right resections) and 10 people who underwent surgery with standard or selective surgical approaches, including selective amygdalohippocampectomy (5 left and 5 right resections). Patients in both groups were similar in age (mean 36-39 years) and were on a mean of two antiepileptic drugs. Two patients in the surgery group and three in the laser ablation group had had seizures since they were 5 years or younger.
The investigators evaluated episodic memory with measures that included tasks of visual and verbal memory.
After treatment, there was evidence of a significant decline in one or both of the memory tasks in only 1 of the 7 patients treated with laser ablation, compared with 9 of the 10 surgical patients, a statistically significant difference, Dr. Drane said. In addition, six patients who had laser ablation showed a significant improvement in one or more memory measures after treatment, compared with four standard surgery patients.
In a statement issued during the meeting, Dr. Drane said that considering "the presumed importance of the hippocampus in episodic memory, we were surprised by the absence of any decline" in the laser ablation group. The results suggest that the function of the hippocampus may not be completely understood "and that being able to perform such a precise resection may help us learn more about brain regions in a manner that was never before possible in humans," he added.
During a press briefing held during the meeting, Dr. Drane pointed out that laser ablation benefits patients with less pain and a short hospital stay lasting a median of 1 day with no time spent in the intensive care unit.
Another possible benefit of the less invasive procedure is a positive effect on mood, he said. He described a patient in her early 60s with chronic epilepsy and chronic depression who was completely seizure free after laser ablation. But the most striking result of treatment was that she was no longer depressed and was off all antidepressants for the first time since she was a teenager.
This is just one case, but mood may benefit "from not cutting so many regions," he noted.
Dr. Drane said he received funding from the National Institutes of Health to conduct the study.