Sphenopalatine ganglion (SPG) stimulation may serve as an effective acute therapy for patients with chronic cluster headache after first-line therapies have failed, according to data published in Cephalalgia.
The study, a long-term follow-up of the Pathway CH-1 study, sought to characterize the long-term outcomes of microstimulator use on acute and frequency response to stimulation, headache disability, and use of preventative medication over 24 months.
Of the 43 patients with medically refractory chronic cluster headache who participated in the Pathway CH-1 study, 33 were enrolled in the long-term follow-up study. Participants recorded their response to stimulation in an electronic headache diary. Pain scores were reported using the Categorical Pain Scale (0-4), with headache pain reported prior to stimulation and headache pain and acute medication use reported either 15 minutes following start of stimulation (first 12 months) or immediately after cessation (12-24 months).
Professor Dr Tim P Jurgens, of Universitats-Klinikum Hamburg-Eppendorf in Hamburg, Germany, and colleagues reported on 5956 cluster headache attacks treated with stimulation, of which 65% achieved effective therapy and 50% became pain-free. The average duration of stimulation was 11.2 ± 8.4 minutes (range 0.1–61.5 minutes). Patients reported not using acute medication in 79% of attacks, including those attacks that achieved effective therapy and those in which no pain reduction was recorded. Forty-five percent of participants were found to be acute responders by achieving effective therapy in at least 50% of their cluster headache attacks. Nearly 50% of all acute responders experienced a very strong response to stimulation therapy, with effective therapy occurring in at least 75% of their attacks. In all, 73% of patients were able to effectively treat 30% of their cluster headache with the stimulation therapy.
Compared to baseline, 35% (11/31) of patients reported at least a 50% reduction in headache frequency at 24-month follow-up. Two of these responders reported no cluster headaches at 24 months, while 64% of responders reduced or stopped their preventative medication. Among the total study population, 65% of those who did not see a reduction in frequency reported improvements in preventative medication and experienced clinical improvements.
Headache disability as measured by the HIT-6 headache disability survey was clinically and significantly reduced by 4.8 points compared to baseline in 29 patients who completed the survey. Fifty-five percent of these patients were considered HIT-6 responders (reduction of at least 2.3 points). Frequency responders experienced a reduction of 12.6 ± 6.7 points; patients with acute and frequency response experienced a reduction of 11.2 ± 8.8 points; acute responders experienced a reduction of 1.9 ± 4.8 points; and non-responders experienced an increase of 0.4 ± 6.9 points. Of those who responded to the satisfaction survey (18/26), 69% indicated that they found SPG stimulation to be useful for the treatment of their headaches.
“Previously published data from the sham-controlled experimental period in the Pathway CH-1 study showed a 68% therapeutic responder rate (acute and/ or frequency) for SPG stimulation,” the authors wrote. “Compared to these results with similar proportions of acute and frequency responders, the present study shows a maintained effectiveness in the majority of patients over time, indicating that the acute and/or attack frequency reduction benefit is robust, stable, and is likely not attributable to the implant procedure itself.”