Trigeminal nerve stimulation: A new way of treatment of refractory seizures

BACKGROUND: Refractory epilepsy is a significant problem in clinical practice. Sometimes, multiple antiepileptic drugs are required to control the attacks. To avoid various complications ensuring from these drugs, new methods of treatment such as vagus nerve stimulation (VNS) have been recommended. Trigeminal nerve stimulation (TNS) is a new method under evaluation. The purpose of this paper is to determine whether this method is effective or not. MATERIALS AND METHODS: Percutaneous simulation of supraorbital branches of the trigeminal nerve by an electrical device was planned in 18 patients over a six-month period. Participants who fulfilled the research criteria were selected randomly from epileptic patients referred to the clinic. (November 2011-December 2012). T-test was used for data analysis. RESULTS: Only eight of 18 patients stayed in the study during all 6 months. A 47.9% reduction in daily seizure frequency was seen in this group (P = 0.022). Other subjects left the study earlier. In this group, seizure frequency increased by 10.6% (P = 0.82). CONCLUSIONS: The mechanism of the antiepileptic effects of TNS is not yet clear. In animal studies, it is suggested that the trigeminal nucleus and its projection to nucleus tractus solitarius (NTS) and the locus ceruleus, are involved in seizure modulation. Although in comparison with seizure frequency prior to the study there was significant seizure reduction, according to the usual criteria for VNS i.e. 50% seizure frequency reduction, the effect of TNS per se may not yet be adequate for treatment of seizures. Trigeminal nerve stimulation may be an effective “adjuvant” method for treatment of intractable seizure.