Despite standard treatment, a large percentage of emergency migraineurs continue to suffer from headaches after ED discharge. Recurrent or persistent headaches rated as moderate or severe in intensity occurred in 14-43% of subjects 24 hours after discharge in ED-based migraine clinical trials [20,23,24]. In a Canadian population, 45% of headache patients reported headache-related functional impairment within 24 hours of ED discharge [16].