The Food and Drug Administration approved on April 18 a handheld vagus nerve stimulation device for treating episodic cluster headaches.
These “suicide headaches,” however, are only one among different chronic conditions that experts seek to address through the use of vagus nerve stimulation, which consists of sending a low electric pulse through the vagus nerve situated in the neck.
In fact, a new report stated that increasing innovation in the field has led to greater knowledge of these VNS devices. For instance, patients that have resistance toward anti-epileptic drugs are being treated using the devices, while surgeons increasingly focus on minimizing the potential side effects of using the tools.
Cluster Headaches
GammaCore, the patient-administered handheld device for stimulating the vagus nerve, was developed by New Jersey-based neuroscience and technology firm ElectroCore. It transmits a mild electrical stimulation to the nerve through the skin, leading to pain reduction.
“It does not have the side effects or dose limitations of commonly prescribed treatments or the need for invasive implantation procedures, which can be inconvenient, costly, and high-risk,” assured Dr. Stephen Silberstein, director of Jefferson University’s Headache Center in a statement.
Long available in Europe, the device is applied to the neck during a headache.
But while the FDA release was based on two trials, it is important to note that using the device could lead to mild, transient side effects. It should also be avoided by patients with active implantable medical devices; those with hypotension, hypertension, tachycardia (rapid heartbeat), or bradychardia (slow heartbeat); and children and pregnant women.
Depression
Adjunctive vagus nerve stimulation, too, was shown to improve antidepressant effects among patients with treatment-resistant depression.
“APA [American Psychiatric Association] recommends VNS as a treatment option for patients who have not responded to at least four adequate trials of depression treatments, including electroconvulsive therapy,” wrote Dr. Scott Aaronson and his colleagues.
Patients who underwent VNS demonstrated improved clinical outcomes than those who received the usual treatment, including a significantly greater f-year cumulative response rate or 67.6 percent versus 40.9 percent.
Drug Addiction
VNS therapy is used to help people overcome drug addiction, with the process consisting of helping the patient’s addicted brain adopt new behaviors and replace the ones linked to the need for drug intake.
"When a subject is addicted to a drug, extinction is a method to help them relearn behaviors - so they are able to take different actions," said lead author and assistant professor Sven Kroener.
The treatment aims to reinforce positive behavior as opposed to the drug-related one, placing the two types of behaviors in direct contradiction. When applied correctly, it could also decrease the relapse rates in drug-addicted individuals.
Rheumatoid Arthritis
Last year, a study found that rheumatoid arthritis patients who received VNS displayed “robust” responses. Researchers from the Feinstein Institute, SetPoint Medical, and the University of Amsterdam conducted a trial to see if a direct inflammatory reflex stimulation can minimize rheumatoid arthritis symptoms.
Prior studies done on animals already showed great promise and success rates. Here, the team recruited 17 patients whose vagus nerve was surgically given a stimulation device, and then measured their response and progress for 42 days.
Many of the patients whose previous rheumatoid arthritis treatments failed exhibited significant developments, according to the study.
