[1]  Piagkou M, Demesticha T, Troupis T, Vlasis TK, Skandalakis P, Makri A, et al. The pterygopalatine ganglion and its role in various pain syndromes: from anatomy to clinical practice. Pain Pract. 2012;12(5):399–412.

[2]  Vinson DR. Treatment patterns of isolated benign headache in US emergency depart- ments. Ann Emerg Med. 2002;39(3):215–22.

[3]  Sluder G. The role of the sphenopalatine ganglion in nasal headaches. N Y State J Med. 1908;27(1):8–13.

[4]  DagenaisR,ZedPJ.IntranasalLidocaineforAcuteManagementofPrimaryHeadaches: A Systematic Review. Pharmacotherapy. 2018;38(10):1038–50.

[5]  Schaffer JT, Hunter BR, Ball KM, Weaver CS. Noninvasive sphenopalatine ganglion block for acute headache in the emergency department: A randomized placebo- controlled trial. Ann Emerg Med. 2015;65(5):503–10.

[6]  Blanda M, Rench T, Gerson LW, Weigand JV. Intranasal lidocaine for the treatment of migraine headache: a randomized, controlled trial. Acad Emerg Med. 2001;8(4): 337–42.

[7]  Avcu N, Doğan NO, Pekdemir M, Yaka E, Yılmaz S, Alyeşil C, et al. Intranasal Lidocaine in Acute Treatment of Migraine: A Randomized Controlled Trial. Ann Emerg Med. 2017;69(6):743–51.