Abstracts

To investigate the preliminary safety and efficacy of Trigeminal Nerve Stimulation (TNS) in patients with refractory epilepsy., Nine subjects with refractory complex partial and generalized tonic clonic seizures were enrolled in a pilot prospective feasibility trial of TNS. After a four-week prospective baseline, subjects underwent stimulation of the infraorbital or supraorbital branches of the trigeminal nerve. Stimulation was delivered using an FDA approved external neurostimulator (EMS 400) at 120 Hz, pulse duration of 250 microseconds, and a duty cycle of up to 30 seconds on and 30 seconds off. 1.25-inch disposable, hypoallergenic, self-adhesive stimulating electrodes were used. Initially, infraorbital stimulation was utilized (subjects 1-4). Right-sided stimulation alternating every other day with left-sided stimulation. For infraorbital stimulation, electrodes were applied over the cheek, with the positive electrode placed over the infraorbital foramen, and the negative electrode placed postero-lateral, in line with the nasolabial fold. For supraorbital stimulation, (subjects 5-9) a single electrode was placed immediately above the supraorbital foramen on each side, which allowed continuous bilateral simultaneous stimulation with the use of only two electrodes., TNS was well tolerated. Subjects reported the hypoallergenic adhesive electrodes were easy to apply and maintain. Tingling or pressure in the forehead or canine teeth were reported, but these side effects were minimized or eliminated by a reduction in current. Two subjects of the original nine exited the study before completion of the first one-month follow-up visit, due to changes in antiepileptic drugs requiring study exit. Seven subjects continued in the study for the minimum three-month study duration. At three-months, four of seven (57%) responded with a 50% or better reduction in seizure frequency., TNS was safe and well tolerated. Preliminary efficacy data is promising. Further study of TNS is indicated., (Supported by Investigator initiated study, supported by Advanced Bionics, Inc.)