ABSTRACT
Headache disorders are a leading reason for neurologic consultation in the United States; they account for about one in five outpatient visits (1,2). Managing the headache patient, particularly the patient with chronic daily headaches, is difficult (3,4). When a patient fails to respond as expected to an appropriate therapy or announces at the first consultation that he or she has already tried everything and nothing works, it is important to identify the reason(s) for failure of that treatment.
