Abstract

Background
s: Although daily and near-daily headache named chronic daily headache(CDH) is an important reason for consultation in headache clinics, the International Headache Society(IHS) headache classification has a problem in the definition and classi-fication of the CDH. This fact led Silberstein et al in 1996 to propose revised criteria for CDH. They subdivided CDH into transformed migraine(TM), chronic tension type headache(CTTH), hemicrania continua(HC), and new daily persistent headache (NDPH). The objective of the present study was to prospectively classify CDH into subtypes according to the revised criteria for CDH and evaluate the effectiveness of new classification. Methods: We used structured questionnaire and clinical interview to make diagnosis of headache. Subject who had headaches more than 15 headache days a month considered to have CDH. CDH was further classified into TM, CTTH, HC, and NDPH according to the second revision of IHS criteria proposed by Silberstein, et al. Results: During 9 months, we studied 193 consecutive outpatients with CDH. The average age of these patients was 46 years. One hundred sixty-four patients(85.0%) were women. Eighty-nine(46.1%) had CTTH. TM was diagnosed in 90(46.6%). The 3 cases(1.6%) in this series met the criteria of NDDH. However the remaining 11 cases(5.7%) were not classifiable. No one was diagnosed as having HC. Analgesic overuse was reported in 24.4% of cases. Conclusions: Although most of patients with CDH had CTTH or TM, we were still not able to classify all the CDH. Therefore, we propose that modifica- tion of this classification system is needed. Korean Journal of Headache 1(1):67-73, 2000