Vagus Nerve Stimulation
Vagus nerve stimulators come in two types: the conventional implanted devices & a non-invasive unimplanted device. The conventional VNS involves a surgery to have the stimulator implanted in the chest while a wire is threaded, under the skin, to the vagus nerve. Only the left vagus nerve is used, as the right one may carry more nerves that supply the heart.
It was originally developed for the treatment of drug resistant epilepsy, but studies have found that VNS can provide a strong pain relieving effect as well. Non-invasive VNS has shown effectiveness in the treatment of migraines, acute migraines and cluster headaches. Prolonged use showed a preventive effect for chronic migraines and chronic cluster headaches.
The implanted device is currently FDA approved for the treatment of epilepsy and treatment-resistant major depressive disorder. The non-invasive device is currently FDA approved for the treatment of episodic cluster headaches and migraine pain.