Application of ICHD-II and revised diagnostic criteria to patients with chronic daily headache.

The objective of this study was to evaluate how the criteria of the second edition of the International Classification of Headache Disorders (ICHD-II) and the revised criteria fit a sample of patients with chronic daily headache (CDH). One hundred and five patients with CDH in a tertiary headache centre were included. Headache was assessed using a semi-structured interview. Patients were classified according to the ICHD-II and to the new appendix criteria of the ICHD. Using the ICHDII, 91% of patients received a combination of diagnoses and 76% received only a probable diagnosis: 47% had probable chronic migraine (CM) with probable medication overuse headache (MOH), 28% had probable chronic tension-type headache (CTTH) with probable MOH, 20% had CTTH and 3.8% had CM. Using the new appendix criteria, 88.5% of patients required one diagnosis. Seventy-six percent of patients were classified as MOH, 17% had CTTH and 6.7% had CM. The classification of CDH remains controversial. Alternative criteria for CM with and without medication overuse are discussed.