The U.S. Food and Drug Administration has granted an emergency use authorization for treating suspected COVID-19 patients with a non-invasive vagus nerve stimulator. The handheld device, made by electroCore, in Basking Ridge, N.J., sends a train of electric pulses through the skin to a nerve in the neck. Research has shown this pulse train causes airways in the lungs to open and may also have a more general anti-inflammatory effect.
According to FDA’s authorization, the gammaCore Sapphire CV device can be used either at home or in a clinic or hospital to “acutely treat adult patients with known or suspected COVID-19 who are experiencing exacerbation of asthma-related [shortness of breath] and reduced airflow, and for whom approved drug therapies are not tolerated or provide insufficient symptom relief.”
The vagus nerves run along either side of the neck and connect structures deep in the brain with the body’s internal organs. (See “The Vagus Nerve: A Back Door For Brain Hacking,” June 2015.) Medical device makers have been taking advantage of this brain-organ highway to treat epilepsy, depression, postpartum bleeding, and more. ElectroCore’s device is already approved for both acute and long-term treatment of migraine and cluster headaches.
However, the company was founded on the back of research into the vagus nerve stimulations’ effect on airways, says Dr. Peter Staats, electroCore’s chief medical officer. “Early on, when we were studying airway activity, we asked patients if they experienced anything else,” he recalls. “An early patient said ‘My headache went away.’” Once the company was established, headache became the initial focus. Conveniently, the same set of stimuli used for migraine and headache—two minutes of 25 pulses per second of a 5000 Hz signal—also work for the lungs. “We’ve kind of come full circle,” says Staats.
With respect to the lungs and COVID-19, the device appears to have a two-pronged effect. The first, opening up the end terminals of the lung’s airways, is mediated by signals going up the nerve into the brain, says Staat. The second, a separate anti-inflammatory effect, appears to be caused by signals traveling down the nerve into the body. The working theory is that this second signal has an effect on cytokine production. Cytokines are a broad class of small proteins that cells use to signal to each other, some of which play a role in inflammation. Their overproduction can cause a “cytokine storm syndrome” that’s been seen in some COVID-19 patients, where an immune response spins out of control and can shut down the lungs and other organs.
Under the FDA authorization, the device is only approved for use during the COVID-19 national emergency. However, researchers have several ongoing clinical trials and FDA has invited the company to seek more permanent approval, according to electroCore CEO Dan Goldberg. And he expects the company to continue exploring the use of noninvasive vagus nerve stimulation (nVNS) for other maladies, he says. “Under the pandemic circumstances we’re laser focused, but we continue to believe that nVNS is a broad platform for a variety of clinical indications,” he says.
Samuel K. Moore is the senior editor at IEEE Spectrum in charge of semiconductors coverage. An IEEE member, he has a bachelor's degree in biomedical engineering from Brown University and a master's degree in journalism from New York University.