“…25,26,[30][31][32] Some authors state that 14% of patients will transform from episodic to chronic migraine headaches. 21 Transformed migraines are not addressed in the ICHD-2. 19,[21][22][23] Migraines can be chronic, more than 8 migraines per month for 3 months according to ICHD-2 criteria, 27,30 without being transformed.…”