Paroxysmal head pain with backward radiation: will epicrania fugax go in the opposite direction? J Headache Pain.

Cuadrado ML, Gómez-Vicente L, Porta-Etessam J, Marcos-de-Vega MA, Parejo-Carbonell B, Matías-Guiu J. Paroxysmal head pain with backward radiation: will epicrania fugax go in the opposite direction? J Headache Pain. 2010 Feb;11(1):75-8. doi: 10.1007/s10194-009-0172-9. PubMed PMID: 19936614; PubMed Central PMCID: PMC3452184.