RESUMEN
OBJECTIVE: To analyze the incidence and characteristics of the first 1000 headaches in an outpatient clinic. BACKGROUND: Headache is a common cause of medical consultation, both in primary care and in specialist neurology outpatient clinics. The International Classification of Headache Disorders, 2nd Edition (ICHD-II), enables headaches to be classified in a precise and reproducible manner. METHODS: In January 2008, an outpatient headache clinic was set up in Hospital Clínico Universitario, a tertiary hospital in Valladolid, Spain. Headaches were classified prospectively in accordance with ICHD-II criteria. In each case we recorded age and sex, duration of headache, ancillary tests required, and previous symptomatic or prophylactic therapies. RESULTS: In January 2010, the registry included 1000 headaches in 682 patients. The women/men ratio was 2.46/1 and the mean age of the patients was 43.19 ± 17.1 years (range: 14-94 years). Patients were referred from primary care (53.4%), general neurology clinics (36.6%), and other specialist clinics (9%). The headaches were grouped (ICHD-II classification) as follows: group 1 (Migraine), 51.4%; group 2 (Tension-type headache), 16%; group 3 (Trigeminal autonomic cephalalgias), 2.6%; group 4 (Other primary headaches) and group 13 (Cranial neuralgias), 3.4%. The diagnostic criteria of chronic migraine were satisfied in 8.5% of migraines. Regarding secondary headaches, 1.1% of all cases were included in group 5 (Headaches attributed to trauma) and 8.3% in group 8 (Headaches attributed to a substance or its withdrawal). Only 3.4% of headaches were classified in group 14 (Unspecified or not elsewhere classified), and 5.2% were included in the groups listed in the ICHD-II research appendix. CONCLUSION: This registry outlines the characteristics of patients seen in an outpatient headache clinic in a tertiary hospital; our results are similar to those previously reported for this type of outpatient clinic. Migraine was the most common diagnosis. Most headaches can be classified using ICHD-II criteria.