title: Chronic Daily Headache and Medication Overuse Headache in First-Visit Headache Patients in Korea: A Multicenter Clinic-Based Study.
abstract: OBJECTIVE
  Chronic daily headache (CDH) is defined as a headache disorder in which headaches occur on a daily or near-daily basis (at least 15 days/month) for more than 3 months. Chronic migraine (CM) and medication overuse headache (MOH) are very disabling headaches that remain underdiagnosed. The aim of this study was to establish the frequency of CDH and its various subtypes, and examine the associations with MOH among first-visit headache patients presenting at neurology outpatient clinics in Korea.
  
  
  METHODS
  Eleven neurologists enrolled first-visit patients with complaints of headaches into outpatient clinics for further assessment. Headache disorders were classified according to the International Classification of Headache Disorder (third edition beta version) by each investigator.
  
  
  RESULTS
  Primary CDH was present in 248 (15.2%) of the 1,627 included patients, comprising CM (143, 8.8%), chronic tension-type headache (CTTH) (98, 6%), and definite new daily persistent headache (NDPH) (7, 0.4%). MOH was associated with headache in 81 patients (5%). The association with MOH was stronger among CM patients (34.5%) than patients with CTTH (13.3%) or NDPH (14.3%) (p=0.001). The frequency of CDH did not differ between secondary and tertiary referral hospitals.
  
  
  CONCLUSIONS
  The frequencies of CDH and MOH diagnoses were 15.2% and 5%, respectively in first-visit headache patients presented at secondary or tertiary referral hospitals in Korea. CM was the most common subtype of CDH and was most frequently associated with MOH.
authors.affiliation: Department of Neurology, National Police Hospital, Seoul, Korea.
authors.forename: Myoung Jin
authors.initials: MJ
authors.lastname: Cha
authors.affiliation: Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Heui Soo
authors.initials: HS
authors.lastname: Moon
authors.affiliation: Department of Neurology, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Korea.
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Sohn
authors.affiliation: Department of Neurology, Bundang Jesaeng General Hospital, Daejin Medical Center, Seongnam, Korea.
authors.forename: Byung Su
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Department of Neurology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Tae Jin
authors.initials: TJ
authors.lastname: Song
authors.affiliation: Department of Neurology, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Jae Moon
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Neurology, Uijeongbu St. Mary's Hospital, The Catholic University of Korea College of Medicine, Uijeongbu, Korea.
authors.forename: Jeong Wook
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Neurology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Kwang Yeol
authors.initials: KY
authors.lastname: Park
authors.affiliation: Department of Neurology, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Soo Kyoung
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Department of Neurology, Eulji University School of Medicine, Seoul, Korea.
authors.forename: Byung Kun
authors.initials: BK
authors.lastname: Kim
authors.affiliation: Department of Neurology, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea. dowonc@naver.com.
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Cho
keywords: chronic daily headache; epidemiology; headache; medication overuse headache; migraine; tension-type headache