An electric stimulation device, gammaCore has received clearance from the U.S. Food and Drug Administration (FDA) as an acute treatment of pain associated with migraine in adult patients. gammaCore is a hand-held device that stimulates the vagus nerve in the neck through the skin and was developed following and based on my 2005 publication describing the use of implantable vagus nerve stimulator for refractory chronic cluster and migraine headaches. This adds to the approval gammaCore received for the acute treatment of pain associated with episodic cluster headache in adult patients in April 2017. The clearance is limited to pain of migraine, rather than migraine attacks, meaning that the device relieves pain and may not relieve other migraine symptoms, such as nausea and sensitivity to light and noise.

The FDA clearance of gammaCore for the acute treatment of pain associated with migraine was supported by the results of the multicenter, randomized, double-blind, sham-controlled trial that demonstrated that “treatment with gammaCore for the acute treatment of pain associated with migraine was superior to sham, and also enabled patients to reach pain freedom more frequently by 30, 60, and 120 minutes compared with sham treatment”. Just like with all other studies with gammaCore, the therapy was found to be well tolerated by patients.

gammaCore is also available outside of the U.S., including in Canada and the European Economic Area. The manufacturer offers a free trial of the device, which cannot be purchased, but only rented. Some insurance plans may pay for the rental.

Here are a few disclaimers and warnings from the manufacturer:

The safety and effectiveness of gammaCore (non-invasive vagus nerve stimulator) has not been established in the acute treatment of chronic Cluster Headache.
This device has not been shown to be effective for the prophylactic treatment of chronic or episodic cluster headache.
The long-term effects of the chronic use of the device have not been evaluated.
Safety and efficacy of gammaCore has not been evaluated in the following patients, and therefore is NOT indicated for:
Patients with an active implantable medical device, such as a pacemaker, hearing aid implant, or any implanted electronic device
Patients diagnosed with narrowing of the arteries (carotid atherosclerosis)
Patients who have had surgery to cut the vagus nerve in the neck (cervical vagotomy)
Pediatric patients
Pregnant women
Patients with clinically significant hypertension, hypotension, bradycardia, or tachycardia

Patients should not use gammaCore if they:
Have a metallic device such as a stent, bone plate, or bone screw implanted at or near their neck
Are using another device at the same time (eg, TENS Unit, muscle stimulator) or any portable electronic device (eg, mobile phone)

A new electric device is being tested for the treatment of migraine by an Israeli company, Theranica. Transcutaneous electric nerve stimulation (TENS) has been successfully used for the treatment of musculoskeletal disorders for decades. The theory behind it is the so-called gate theory of pain. It is thought that by stimulating larger nerve fibers we can block pain messages sent by smaller pain-sensing nerve fibers.

Cefaly is a TENS device which became available in 2014 and it provides electrical stimulation of the supraorbital nerves in the forehead. Only small studies have been conducted, so it is not clear how well Cefaly relieves migraines. As far as our experience, we at the NY Headache Center usually treat more severely affected patients, so it is possible that the results are better in people with less severe migraines.

The new wireless patch that is being developed by Theranica is applied to the upper arm. The results of the first study of this patch were published in Neurology, the medical journal of the American Academy of Neurology.

The study author, is a well-known neurologist and pain researcher, Dr. David Yarnitsky of Technion Faculty of Medicine in Haifa, Israel. He was quoted saying, “People with migraine are looking for non-drug treatments, and this new device is easy to use, has no side effects and can be conveniently used in work or social settings.”

The patch device is controlled by a smartphone app. It was studied in 71 patients with episodic migraine who had two to eight attacks per month and who were not on any preventive medications for migraines. The device was applied soon after the start of a migraine and kept in place for 20 minutes.

The devices were programmed to randomly give either a very weak stimulation to serve as placebo or different levels of stronger electrical stimulation.

A total of 299 migraine attacks were treated by these 71 patients. Two hours after the start of real treatment, pain was reduced by at least 50% in 64 percent of patients, compared to 26 percent of patients who received the sham stimulation.

Starting treatment early produced better results, which is similar to what we see with all migraine medications as well. None of the participants found the treatment to be painful.

The device is very safe and we hope that the ongoing trial that Theranica is conducting in the US will confirm its efficacy. It is not yet available in this or any other country.

Vagus nerve stimulation (VNS) with an electrode implanted in the neck is an FDA-approved treatment for depression and epilepsy, when these conditions do not respond to medications. Since antidepressant and anti-epilepsy medications help migraines, I had six patients (four with migraines and two with cluster headaches) treated with VNS. Two of the four chronic migraine patients and both cluster patients had good relief – results that were published in the journal Cephalagia in 2005. This publication led to the development of gammaCore, a device to stimulate the vagus nerve through the skin, without the need for surgical implantation of an electrode. The New York Headache Center participated in one of the earliest studies of this device and the results were encouraging.

An article published in the current issue of Neurology presents the results of another study of gammaCore. In this first double-blind study 59 adults with chronic migraines (15 or more headache days each month) were given either real VNS or sham treatment for two months. After two months they were all given the real treatment for 6 months. The main goal of the study was to examine the safety and tolerability of this treatment, but the researchers also looked at the efficacy by measuring the change in the number of headache days per 28 days and acute medication use.

Both sham and real treatment were well tolerated with most adverse events being mild or moderate and transient. The number of headache days were reduced by 1.4 days in the real and 0.2 days in the sham group. Twenty-seven participants completed the open-label 6-month phase, which suggests that this treatment might work for half of the patients. However, larger sham-controlled studies are needed to prove that this treatment really works. GammaCore is also being tested for the treatment of cluster headaches. Although it has not been definitively proven to be effective, it is already being sold in some European countries.