Although this study was designed and powered to test the acute effects on spontaneous CH attacks, a rather dramatic reduction of attack frequency was observed in some patients after repetitive attack stimulation.
In the chronic patients, 65% (51/78) were considered responders per protocol (achieving effective therapy in at least 50% of attacks or experiencing a 50% reduction in attack frequency or both).
Nineteen of 28 (68%) patients experienced a clinically significant improvement: seven (25%) achieved pain relief in ≥50% of treated attacks, 10 (36%), a ≥50% reduction in attack frequency, and two (7%), both.
The reduction in attack frequency affected the number of CH attacks treated during the experimental period, and thus the number of attacks treated across patients was variable.
All 9 patients achieved a 50%% or more reduction in attack frequency, and only one patient had an attack during the treatment period.
Per protocol, frequency responders experienced ≥ 50% reduction in attack frequency and acute responders treated ≥ 50% of attacks.
A secondary observational endpoint was the reduction of attack frequency, established by comparing the frequency of cCH attacks per 4 weeks at the end of the experimental period to the frequency established at baseline.
Another patient had a clinically significant reduction in attack frequency (from 120 to 25/day after a year) [41].
The results showed statistically significant reduction in attack frequency and abortive medications at week 4 and 8 after treatment.
Three weeks later he was implanted with a >50%/<85% reduction of attack number and intensity of pain.
