Device Offers Cluster Headache Relief
Mean duration of illness was 10 years. At baseline, mean attack frequency was 16.8 per week and the mean HIT-6 headache disability score was 66.2 (SD 6.2), indicating severe disability. About two-thirds were taking verapamil for prophylaxis. For acute attacks, half of patients reported using oxygen therapy and all used triptans. Patients were allowed to use these acute treatments in addition to the stimulation at their discretion.
In 27% of attacks treated with the full stimulation, patients reported being completely pain-free within 15 minutes, Jensen said. In another 28%, patients said their pain was reduced to levels they considered mild.
For attacks in which the stimulators were not activated or in which the stimulation was at levels too low for patients to feel, only 6% to 7% reported complete or partial pain relief, Jensen’s group stated.
Evaluations 90 minutes after patient-recorded attack onset indicated that complete pain relief had occurred in about 38% of attacks treated with full stimulation. Overall, 50% of treated attacks resulted in complete or partial relief within 90 minutes, compared with 13% of attacks treated with sham or imperceptible stimulation (P-value not reported).
The mean attack frequency declined to 11.1 per week at the end of the treatment period. Among 16 patients classed as frequency responders, showing at least a 50% decline in frequency, the mean decline was 89%, resulting a mean frequency of 1 per week.
Cluster headaches (also used in singular: headache), also nicknamed suicide headaches, occur several times a day, they come on unexpectedly, do not last long, and are generally very painful. The pain is usually intense, and sometimes only on one side of the head. Frequently, the sufferer also feels pain around the eye.
A cluster-headache sufferer can wake up during the night because of the pain. Often, this occurs at the same time each night. The eye on the painful side of the head may be reddened and watery. The individual’s nose may be runny or blocked on the side of the nose where the pain is.
In northern countries cluster headaches tend to occur more frequently during the autumn (fall) and spring. Alcohol or extreme variations in temperature can trigger an episode during a cluster period – generally, the change in temperature refers to a rapid rise in body temperature.
Cluster headache attacks occur cyclically, hence the name. A bout of regular attacks – cluster periods – can last from a few days, weeks, to even months. This is followed by remission periods during which no headaches are felt.
Jensen and colleagues reported that 21% of patients were considered acute-phase responders for severity, for whom at least half of attacks resulted in complete or partial pain relief within 15 minutes. Another 42% showed at least a 50% reduction in attack frequency, and 8% were responders in both categories.
One-Year Follow-Up
After the initial treatment period of 3 to 8 weeks, patients then could choose to receive full stimulation on an open-label basis until 1 year after initial device implantation, at which point they were asked to complete a questionnaire about their overall experience.
Among the 28 patients completing the questionnaire, satisfaction was common, with 71% rating the overall system as good or very good, 71% calling it useful in treating their headaches, and 96% saying they would recommend it to other patients.
More than 90% indicated that the stimulation sensation was tolerable, 86% said the implanted component was comfortable or imperceptible when not activated, and 82% found the implantation procedure tolerable.
Most notably, Jensen said, about 11% of patients stopped using medications for their headaches and 29% reduced them. Only 14% said they had increased their use of prophylactic or rescue medications.
Peter Goadsby, MD, PhD, of the University of California San Francisco, and president of the International Headache Society, told MedPage Today that the technology appeared to be a promising option for patients with frequent cluster headaches not controlled with conventional therapies.
Goadsby had led much of the basic research confirming that the SPG was a viable target for electrostimulation in cluster headache, and has consulted for Autonomic Technologies but did not participate in the current clinical study.
He said that SPG stimulation would probably not replace verapamil or other standard medical therapies as first-line treatment for cluster headache, and wouldn’t be appropriate at all for the majority of patients whose headaches occur only once or twice a year.
Rather, Goadsby said, it would likely rival occipital nerve stimulation as a second-line therapy and would push deep brain stimulation, currently a last-resort treatment, further back in the algorithm.
But he also noted that the studies to date with the SPG stimulator have been too small and too short to establish long-term safety and tolerability.
Additional Studies
Autonomic Technologies’ device is currently approved in the European Union but not in the U.S. The firm is now conducting another randomized, controlled trial in Europe called M-1 with a projected 30 patients, and has promised to conduct one in the U.S. to support an FDA marketing application.
Also underway is a three-patient trial to determine if SPG stimulation can treat migraines. It was conceived by Stewart Tepper, MD, of the Cleveland Clinic, with support from Autonomic Technologies. But instead of using the firm’s own stimulator, it is testing a different pulse generator manufactured by Medtronic for spinal cord stimulation, implanted in the shoulder with leads placed in the SPG.
Results from Cleveland Clinic and M-1 trials are expected in 2015.
The study was funded by Autonomic Technologies.
Jensen reported relationships with Pfizer, Berlin-Chemie, Allergan, Merck, Autonomic Technologies, Medotech, Neurocore, and Linde Gas.
Goadsby reported relationships with Autonomic Technologies, Allergan, Colucid, MAP, Merck, eNeura, Boston Scientific, Eli Lilly, Medtronic, Bristol-Myers Squibb, Pfizer, Nevrocorp, Impax, Zogenix, Dr. Reddy, Amgen, and Electrocore.
Schytz reported relationships with Pfizer, Merck, Minster Research, Autonomic Technologies, and several foundations.
###
By John Gever, Deputy Managing Editor, MedPage Today
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco