Noninvasive, Hand-held Device Promising for Migraine
A small, open-label pilot study conducted by investigators at the University of Southern California San Francisco (UCSF) showed nVNS reduced pain and increased pain-free status in a group of migraine patients with, and without, aura.
According to principal investigator Peter Goadsby, MB, BS, although the findings are preliminary, they offer the hope of an effective treatment without many of the adverse effects associated with current migraine treatments, which include triptans, ergotamine, antiepileptics, and antidepressants.
In addition, he noted, over the past 5 to 7 years there has been a trend toward developing neuromodulation treatments with implantable devices. He added that if it proves effective, this hand-held, portable, and noninvasive modality would be a step up.
"The nice thing about external devices is if they don't work [the patient] can give them back and you don't have to do anything complex. One of the problems we have with internal devices at the moment is that they are expensive to do, they're relatively invasive and things can go wrong — not big things, but still.
"If you give me a device that can help 20% of my patients then will be a happy man, particularly if I don't do any harm to any of them," Dr. Goadsby told delegates here at the American Academy of Neurology (AAN) 65th Annual Meeting.
Dr. Goadsby, who is director of UCSF's Headache Center, said the move to develop noninvasive neuromodulation approaches came from a number of clinical observations, the seminal one being the case of a young man who was treated with a VNS implant for intractable epilepsy.
The treatment failed to control his seizures, but clinicians noted that he became migraine free. The report was published in 2002 in Cephalagia.
For the pilot study the investigators recruited 30 patients — 25 females and 5 males — with a median age of 39 who had episodic migraine with and without aura.
Patients were asked to treat 3 attacks over the 6-week study period. The treatment consisted two 90-second doses at 15-minute intervals delivered to the right cervical branch of the vagus nerve. Patients were asked to self-treat once pain became moderate severe or after 20 minutes of mild pain.
Essentially, said Dr. Goadsby, the device was placed on the right side of the neck, and a thumbwheel allowed patients to turn the electrical stimulator up or down.
Three of the study participants experienced no attacks, so the final analysis was based on 27 patients and 84 treated attacks.
Data for the first attack among patients with moderate and severe pain showed that 4 of 19 patients (21%) were pain free at 2 hours and 8 of 19 (42%) had pain relief that decreased to nil or mild at 2 hours.
Results for those with mild pain at first attack showed 5 of 8 (63%) were pain free at 2 hours.
When researchers examined the effect of the device on all migraine attacks, they found that 12 of 55 (22%) patients with moderate to severe migraine and 10 of 26 (38%) with mild migraine were pain free at 2 hours.
Mild, Infrequent Adverse Effects
Adverse events were infrequent and mild and included neck twitching (n = 3), raspy voice (n = 1), and neck redness (n = 1).
Dr. Goadsby noted that the sensation patients experience from the device is not pleasant but also not unpleasant.
These findings, he said, warrant further investigation in randomized, placebo-controlled trials and added that a sham device is being developed.
Future studies of the device will examine whether there are treatment differences between the right and left sides of the neck, as well as the treatment durability.
Noninvasive neuromodulation, said Dr. Goadsby, has much to offer migraineurs.
"If we can develop noninvasive treatments for even a small group of patients that would be a helluva step forward," he said.
Warrants Further Study
Commenting on the study for Medscape Medical News, Tobias Kurth, MD, director of research, Institut national de la santé et de la recherche médicale (INSERM), University of Bordeaux, Talence, France, and associate epidemiologist, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, agreed that the data are "convincing enough to warrant further study."
"If this turns out to be an effective treatment it would add to the treatment options for migraine with a device that is almost free of side effects," said Dr. Kurth.
He noted that about 30% of migraineurs do not respond to therapy and so novel treatment approaches are urgently needed.
Dr. Kurth added that although invasive neurostimulation for severe migraine has demonstrated some benefit, he remains unconvinced that it is a good treatment option for even in this severely affected population.
On the basis of the data at this point, he said, in his opinion it should be considered a "last resort" treatment in severely affected patients for whom nothing else has worked.
On the other hand, by eliminating the need for surgery and its related risks and adverse effects, nVNS may have potential as a viable treatment option for at least a proportion of patients with migraine, he added.
"It will not be for everybody for sure but even if it works for a small fraction of patients for whom no other medication seems to work this would be a huge success," said Dr. Kurth.
Dr. Goadsby reports he has received $2000 in direct compensation related to the presentation from the device manufacturer. Funding from the study came from multiple sources, most prominently from the Sandler Family Trust and the Department of Defense. Dr. Goadsby also reports the device manufacturer had no role in the study's data collection or analysis. Dr. Kurth has disclosed no relevant financial relationships.
American Academy of Neurology (AAN) 65th Annual Meeting. Abstract S40.004. Presented March 20, 2013.
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