BACKGROUND Migraine headaches affect more than 28 million persons in the United States (Foundation). Approximately 25% of women and 9% of men experience migraine headaches (Rasmussen BK, 1991) (Lipton RB, 1993) (Ramadan NM, 2002). Individuals with migraine headaches lose an average of 4 to 6 working days each year resulting in a total annual loss nationwide of 64 to 150 million workdays. It is estimated that the direct and indirect cost of migraines is nearly $17 billion (Hu XH, 1999) (RK., 1999). Headache is responsible for approximately 2% of all visits to emergency departments (Goldstein JN, 2006).