Data from a post hoc analysis is adding to positive literature on vagus nerve stimulation, concluding that the treatment quickly and consistently reduced pain intensity while decreasing rescue medication use among patients with episodic migraine.
Noninvasive vagus nerve stimulation (nVNS) has demonstrated safety and efficacy among patients with migraine. Results of the Prospective Study of nVNS for the Acute Treatment of Migraine (PRESTO) trial found that treatment with the self-administered device was superior to sham for the majority of end points, including pain freedom, pain relief, and more than 50% responder rates at various time points.
Now, data from the post hoc analysis are adding to the positive literature, concluding that the treatment quickly and consistently reduced pain intensity while decreasing rescue medication use.
The PRESTO study enrolled 285 patients with episodic migraine at 10 sites between January 11, 2016, and March 31, 2017, and consisted of 3 periods, each lasting 4 weeks: a run-in period in which patients received their standard medications, a double-blind period in which patients were randomly assigned to either nVNS or sham treatment, and an open-label period in which all patients received nVNS treatment.
Patients were instructed to treat up to 5 migraine attacks during the double-blind period and up to 5 additional attacks with nVNS during the open-label period. Within 20 minutes of migraine pain onset, patients self-administered the device.
The post hoc analysis evaluated the likelihood of experiencing at least a 1-point decrease in pain intensity while reducing the need for rescue medication and aimed to determine whether treatment of a migraine attack when the pain is mild affects the efficacy of nVNS.
Results of the analysis showed that for the first treated attack, the percentage of patients who recorded at least a 1-point drop in pain intensity was significantly greater in the nVNS cohort than in the sham group at 30 minutes (32.2% vs 18.5%), 60 minutes (38.8% vs 24.0%), and 120 minutes (46.8% vs 26.2%).
For all treated attacks, there were significantly more improvements of 1 point or greater seen in the nVNS cohort than in the sham cohort at 60 minutes (33.3% vs 22.2%) and 120 minutes (39.4% vs 26.4%).
Similarly, the proportion of patients who did not use rescue medication was significantly higher among patients using the nVNS device for the first attack (59.3% vs 41.9%) and for all attacks (52.3% vs 37.3%).
“Differences in pain-free rates between nVNS and sham were more pronounced in patients who initiated treatment when the attack was mild than for those who waited until the pain was moderate or severe to treat their attack,” explained the researchers. They added, “The percentage of patients who successfully aborted a mild first migraine attack was significantly higher with nVNS than with the sham at 120 minutes (50% vs 25%).”
Reflecting on the data, the researchers argue that the treatment serves as a viable and effective option for patients to relieve pain without increasing exposure to pharmacologic adverse events or medication overuse.
Grazzi L, Tassorelli C, de Tommaso M, et al; PRESTO Study Group. Practical and clinical utility of non-invasive vagus nerve stimulation (nVNS) for the acute treatment of migraine: a post hoc analysis of the randomized, sham-controlled, double-blind PRESTO trial [published online October 19, 2018]. J Head Pain. doi: 10.1186/s10194-018-0928-1.