[Two cases of cavernous sinus dural arteriovenous fistula presenting headache as the one and only initial symptom].

We report 2 cases with cavernous sinus dural arteriovenous fistula (C-dAVF) presenting with headache as an initial symptom. A 70-year-old woman complained of acute persistent headache in the right temporal region. Another 74-year-old woman suffered from sudden and severe headache, developing from right-sided temporal throbbing to bilateral headache. Her condition was also complicated with cranial nerve deficits. These two patients were finally diagnosed as having C-dAVF based on the results of magnetic resonance angiography and cerebral angiography. It was difficult to make rapid diagnosis of C-dAVF in our patients, because they presented with headache alone but no typical symptoms of C-dAVF, such as proptosis, conjunctival injection or orbital bruit. C-dAVF should be considered as an important differential diagnosis in patients with headache.