Introduction: Although the International Headache Society considers chronic tension headache to be a chronic headache, patients with daily chronic headache may have pain which is not only due to tension but also has migrainous features.
Objective: To evaluate the clinical differences and abuse of drugs in a group of patients with chronic daily headache who were consecutively evaluated in the Neurology Clinic.
Material and methods: We consider the patients to have daily chronic headache when they have had pain at least 6 days a week for the past 6 months. Using this criterion, we studied 112 patients, of whom 90 (80.4%) were women and 22 (19.6%) men. Results. Sixty nine (61.6%) had transformed migraine and 43 (38.4%) tension headache. There were no differences in their current ages but the age of onset of the headaches varied (p = 0.000,t). Unilateral pain, trigger factors and a family history were more frequent in the cases of transformed migraine. Eighty four patients (75%) abused analgesics. Although we found different pain intensities (p = 0.000, chi 2) there was no difference in the weekly consumption of analgesics (p = 0.64, t) in the mg/week of ergotamine (p = 0.96, t) nor in absence from work between the two types of headache.
Conclusions: In spite of clinical differences between transformed migraine and tension headache, which may help diagnosis, in our series abuse of analgesics (including ergotamine) was a common characteristic.