New drug-free treatment in clinical trials
ElectroCore has developed a portable vagus nerve stimulator, gammaCore, that is currently being tested for the prevention and treatment of both episodic and chronic migraine. The U.S. studies are either complete or ongoing with pending results. European studies are still recruiting participants.
The vagus is the longest of 12 cranial nerves. It extends from the brain stem, down the front of the neck, through the heart, esophagus, and lungs, into the abdomen. It is responsible for variety of involuntary processes such as heart rate and digestion.
Vagus nerve stimulator implants were approved in 1997 to treat epilepsy. In the following years, patients also report a decrease in migraine attacks as a result of the implants. A 2003 study involved 6 chronic migraine patients who underwent this same procedure. The results were mixed with 2 patients improving, 1 unable to tolerate the device, and results from the other 3 were not reported. Another study in 2009 included 4 patients. Two did not benefit at all while the other 2 patients experienced a reduction down to 2-3 per month within 6 months of use. All of these patients were diagnosed with medication overuse headache and underwent detoxification protocols before VNS implantation.
In March 2014, Dr. Goadsby and a team of researchers published a study of the gammaCore portable VNS for acute treatment of migraine. They enrolled 30 patients. Some mild side effects were reported (neck twitching, raspy voice, redness at application site) but none were serious enough to discontinue use of the device. Patients were instructed to treat moderate to severe pain or after 20 minutes of mild pain. Two 90-second doses at 15 minute intervals were applied to the right cervical branch of the vagus nerve (right side of neck). 21% were pain-free after 2 hours from the first treatment.
Several other studies testing effectiveness for acute treatment and prevention of both episodic and chronic migraine took place earlier this year in the U.S. European studies are currently recruiting participants. Effectiveness in the treatment and prevention of cluster headaches was also tested in separate studies. Results of these studies are still pending.
I missed the opportunity to participate in a nearby study led by Dr. Cady in Springfield, MO this past spring. I was just a few weeks away from making the road trip when the nurse called to tell me that I was disqualified due to a benign right bundle branch heart block. Even though I have no symptoms and the cardiologist gave me a clean bill of health, it was still enough to keep me from participating. I’ve been searching for a more portable, non-drug acute treatment of cluster headache attacks. Oxygen works, but it isn’t very portable, especially when traveling. This seemed like a great opportunity. Obviously I was disappointed. Perhaps if the device passed safety testing and is in use long enough, we will all get the chance to try it one day.
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