UCLA is reporting about early efforts to control epilepsy via trigeminal nerve stimulation. In the study of seven patients at the David Geffen School of Medicine, trigeminal stimulation using electrodes from Valencia, Calif.-based Advanced Bionics Corp., has resulted in four subjects reporting “50 percent or better reduction in seizure frequency.”
“Most people with chronic epilepsy who have continuing seizures are drug-resistant,” said Dr. Christopher DeGiorgio, vice chair and professor in residence of neurology at UCLA, and co-developer of TNS and lead author of the study. “In addition, anti-seizure drugs can have significant side effects on behavior, thinking and alertness. Women taking anti-seizure drugs and their unborn children are at special risk because of the effect of these drugs on fetal growth and development.
Unlike VNS [vagus nerve stimulation -ed.] , the TNS stimulator can be tested externally to gauge results before implanting the device. Patients treated in the clinical trial wore the stimulator on their belt. Wires from the stimulator were passed under clothing and connected to electrodes attached to the face by adhesive. The electrodes could be covered by a cap or hat.
In addition, while VNS stimulates only one side of the brain, TNS stimulates both sides, a theoretical advantage that will require more testing to validate and quantify.
The cost of an external TNS stimulator is about $180. The monthly retail cost of batteries and electrodes is $150 to $170.
Originally tested in animal studies by researchers at Duke University, TNS was developed and used for the first time in humans at UCLA in the recently completed pilot study outlined in Epilepsia. The research is being conducted using a grant from Advanced Bionics.
DeGiorgio is currently enrolling patients in a follow-up study that will seek to extend the findings to 25 patients. A third study will examine the impact of implanting TNS with an electrode under the skin (just beneath the eyebrow) of patients who respond to the external stimulator.