Safety and efficacy of sphenopalatine ganglion stimulation for chronic cluster headache: a double-blind, randomised controlled trial.
Goadsby PJ, Sahai-Srivastava S, Kezirian EJ, Calhoun AH, Matthews DC, McAllister PJ, Costantino PD, Friedman DI, Zuniga JR, Mechtler LL, Popat SR, Rezai AR, Dodick DW. Safety and efficacy of sphenopalatine ganglion stimulation for chronic cluster headache: a double-blind, randomised controlled trial. Lancet Neurol. 2019 12; 18(12):1081-1090.