Background and purpose: Chronic daily headache (CDH) is not a diagnosis but a category that includes many disorders representing primary and secondary headaches. According to the International Classification of Headache Disorders, 2nd edition (ICHD-II), CDH is defined as headache which occurs more often than 15 days per month for at least 3 months.
Material and methods: We assessed 1154 headache sufferers diagnosed in our headache outpatient clinic. Clinical history, physical and neurological examination, and laboratory tests were performed to make a diagnosis.
Results: CDH was diagnosed according to ICHD-II in 185 (16%) patients; their mean age was 41±17 years (80% were women). Chronic migraine was a cause of CDH in 49% (91/185) of patients, chronic tension-type headache in 18% (33/185), secondary headache in 25% (46/185) and unclassified pain in 8%. Medication overuse headache occurred in 15%. The most effective therapy in our patients was treatment with tricyclic antidepressants and selective serotonin reuptake inhibitors.
Conclusions: The most frequent cause of CDH in our cohort was chronic migraine. Women suffered more frequently than men. Antidepressants were the most effective preventive medications for all types of CDH, which may suggest that serotoninergic mechanisms can be an important factor in the pathophysiology of chronic pain syndromes.