Implantation of a sphenopalatine ganglion stimulation device for chronic cluster headache

4.1 In a randomised sham‑controlled crossover study of 32 patients who randomly had full stimulation, sub‑perception stimulation or sham stimulation during each cluster headache attack, a reduction in pain at 15 minutes after neurostimulation was reported in 67% (127/190) of attacks treated by full stimulation and 7% (15/192) of attacks treated by sham stimulation (p<0.001). A reduction in pain at 15 minutes after neurostimulation was reported in 7% (14/184) of attacks treated by sub‑perception stimulation (p=0.96 compared against sham stimulation). Complete resolution of pain at 15 minutes after neurostimulation was reported in 34% (65/190) of attacks treated by full stimulation and 2% (3/192) of attacks treated by sham stimulation (p<0.001). Complete resolution of pain at 15 minutes after neurostimulation was reported in 2% (3/184) of attacks treated by sub‑perception stimulation (p=0.97 compared against sham stimulation).

4.2 In the randomised sham‑controlled crossover study of 32 patients, a reduction in pain at 90 minutes after neurostimulation was reported in 60% of cluster headache attacks treated by full stimulation and 13% of attacks treated by sham stimulation (p<0.001).

4.3 In the randomised sham‑controlled crossover study of 32 patients, the mean attack frequency reduced from 17.4 attacks per week to 12.5 attacks per week at 2‑month follow‑up, for the 28 patients who completed the experimental period (p=0.005).The frequency of headaches reduced by a minimum of 50% in 43% (12/28) of patients.

4.4 In the randomised sham‑controlled crossover study of 32 patients, mean Headache Impact Test scores (scores range from 36 to 78 with lower scores indicating better quality of life) improved by 6.8±10.2 points (from 66 to 59) at 2‑month follow‑up, for the 28 patients who completed the experimental period (p=0.002). Mean SF‑36 physical function scores (scores range from 0 to 100 with higher scores indicating better outcomes) improved from 38.0 to 43.5 at 2‑month follow‑up (p=0.005). Mean SF‑36 mental function scores improved from 34.5 to 39.0 (p=0.02).

4.5 Specialist advisers listed key efficacy outcomes as acute treatment of headaches, reduction in attack frequency, reduction in acute medication use and improved quality of life as measured by the Headache Impact Test.