Transcutaneous electrical stimulation of the trigeminal nerve

External electrical stimulation of cranial nerves V and X add to the therapeutic armamentarium for patients with pharmacoresistant epilepsy who are not suitable for or do not want surgery. Stimulation of these nerves induces activation of various brain stem nuclei and the ascending reticular activating system (ARAS) which in turn desynchronizes cortical electrical activity. The anticonvulsive effect of external electrical stimulation of the cranial nerve V (eTNS) has been demonstrated in animal studies. Three small non-randomized human studies in patients with epilepsy and one study of patients with major depression showed good anticonvulsive and antidepressive effects. One small randomized controlled phase II trial in epilepsy patients comparing treatment with active control showed a statistically significant superiority of the treatment only after 18 weeks of treatment probably due to a strong transient placebo effect in the active control group. A phase III trial is being designed. Own experiences with eTNS showed good patient tolerance and few side effects. Most patients reported favorable effects on mood. The data remain preliminary and are insufficient to report antiepileptic efficacy.