Noninvasive Therapy for Chronic Migraine Shows Promise

PHILADELPHIA—Noninvasive vagus nerve stimulation (nVNS) is a promising alternative or adjunctive therapy for patients with migraine, according to new research presented at the American Headache Society 61st Annual Scientific Meeting.

Paul Durham, PhD, a distinguished professor and director of Cell Biology and the Center for Biomedical and Life Sciences at Missouri State University, presented these findings.

For their study, Dr Durham and colleagues aimed to compare the effectiveness of VNS with morphine to inhibit trigeminal nocifensive response in a model of rats with chronic migraine.

After being injected bilaterally with complete Freund’s adjuvant (CFA), the rats endured one night of REM sleep deprivation.

Eight days after REM sleep deprivation, rats that were sensitized were exposed to California bay leaf tree extract in order to induce a chronic migraine state.

Three days after the rats were exposed to the extract, they were treated with either nVNS (1-ms pulse of 5 kHz sine waves, repeated at 25 Hz, for 2 minutes and repeated after 5 minutes) or morphine (10-20 mg/kg, subcutaneously) twice daily for 7 days.

Results showed that California bay leaf tree extract induced a sensitized state for more than 21 days. Although morphine significantly reduced trigeminal nociceptor sensitization, nociception returned within 24 hours of administration. nVNS showed similar results.

“nVNS is similarly effective as morphine in inhibiting trigeminal nociception in a model of chronic migraine,” the researchers concluded. “Our findings have provided evidence that nVNS inhibits trigeminal activation even in chronic, severe models, and may be used as an adjunct or replacement for opioid therapies.”

—Amanda Balbi

Reference:

Durham P. Noninvasive vagus nerve stimulation and morphine transiently inhibit trigeminal pain signaling in a chronic migraine model. Paper presented at: American Headache Society 61st Annual Scientific Meeting; July 11-14, 2019; Philadelphia, PA.