BY ED SUSMAN
SAN FRANCISCO—A tiny device implanted in the skull can effectively abort chronic cluster headache, researchers reported here at the annual meeting of the American Headache Society (AHS).
Chronic cluster headaches represent about 20 percent of all cluster headaches, and cluster headaches occur in about one in every 2,000 to 2,500 people, said study author Peter Goadsby, MD, PhD, chair of the AHS scientific program committee, professor of neurology at King's College London and University of California, San Francisco, and director of NIHR-Wellcome Trust Clinical Research Facility at King's College Hospital in London.
"Sphenopalatine ganglion stimulation offers an alternative approach to the treatment of chronic cluster headache that is effective, safe, and well tolerated," he said.
Dr. Goadsby said sphenopalatine ganglion microstimulator is battery-free and activated by a device held against the face during a cluster headache. The stimulator is about half the size of a matchstick. He said it takes about an hour to insert the device surgically.
"This is the second of two studies showing its effectiveness," Dr. Goadsby said. "In my experience, most of the patients say they have a beneficial effect that can be observed within the first month after implantation."
In the study, 45 patients with chronic cluster headaches were randomized to stimulation of the sphenopalatine ganglion and 48 patients to a sham control that delivered cutaneous electrical stimulation. All subjects were implanted with a miniaturized neuromodulator that was activated by an external handheld device that induced the current, or delivered a sham cutaneous stimulus.
Sphenopalatine ganglion treatment more than doubled the chance of pain relief at 15 minutes compared to the sham (p=0.008) and more than doubled the odds of being pain free (p=0.04), Dr. Goadsby reported.
Further, sphenopalatine ganglion stimulation-treated attacks had significantly greater odds of providing sustained pain freedom (p<.05 ).
"It appears that the more use sphenopalatine ganglion stimulation, the less frequent cluster headaches become," Dr. Goadsby said. "The more you use it, the more the effect builds up."
Findings from post hoc analysis on weekly ipsilateral cluster attack frequency also suggested that sphenopalatine ganglion treatment significantly reduced attack frequency relative to sham (p<0.05), he said.
"We have not observed a waning of effect," he said, adding: "A European study [published earlier this year in the Journal of Headache and Pain] suggests that almost all patients who achieve an effect in the first year after implantation continue to have an effect three years down the road."
Sphenopalatine ganglion stimulation was well tolerated, Dr. Goadsby said. There were four related serious adverse events involving the device and the procedure, all of which completely resolved, he reported in his poster discussion.
Dr. Goadsby noted that other nerve stimulators appeared to work in patients who experienced episodic cases of cluster headache, but they didn't work in patients with chronic cluster headaches.
Commenting on the study, Noah Rosen, MD, program director of neurology at the Donald and Barbara Zucker School of Medicine at Hofstra-Northwell Health in Great Neck, NY, said: "One of the advantages of this procedure is that it is fully reversible, although any procedure is associated with a certain amount of risk."
He told the Neurology Today Conference Reporter that he would likely have surgeons implant the devices in patients under general anesthesia.
Dr. Rosen suggested that "more work needs to be done to determine if the device will just treat symptoms or if it can be neuromodulating." The evidence is more compelling that it controls symptoms, but it is significantly more invasive a procedure than using oxygen therapy or triptans, he noted.
Dr. Rosen disclosed no commercial relatioships. Dr. Goadsby disclosed commercial relationships with Akita Biomedical, Alder, Amgen, Autonomic Technologies, Inc., Avanir Pharma, Cipla, Colucid Pharmaceuticals, Dr Reddys Laboratories, Electrocore, Novartis, Pfizer, Promius Pharma, Quest Diagnostics, Sion, Teva, Trimengina Inc, Eli Lilly, eNeura, and Allergan.
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Barloese M, Petersen A, Stude P, et al. Sphenopalatine ganglion stimulation for cluster headache, results from a large, open-label European registry. J Headache Pain 2018; 19(1): 6.