Vagus nerve stimulation - A new option for the treatment of chronic pain syndromes?

Electrical stimulation of the vagal nerve (VNS) has become an established m ethod for treating medically refractory epilepsies. From animal experiments it is well known that depending on the stimulation intensity VNS can elici t both inhibition and facilitation of nociception. Recent physiologic inves tigations demonstrated a similar influence of VNS on pain perception in pat ients treated by chronic VNS. However, in humans, a more marked effect was shown for the pain inhibition which is probably mediated by neurobiochemica l mechanisms. These findings are discussed in consideration of the physiolo gic mechanisms underlying the modulation of pain and seizures by VNS known from animal studies. First reports of attenuation of chronic pain by VNS in dicate that the method might be an option for pain treatment in the future.