The influence of sex and pre-traumatic headache on the incidence and severity of headache after head injury.

Pre- and post-traumatic headache of 168 individuals aged 18-60 years was registered 9-12 months after a head trauma. Headache before the trauma was reported by 39.9%, women being in the majority. After the trauma 64.3% were suffering from headache. Post-traumatic headache was reported by 64 patients (38.1%), of whom 22 patients experienced an increase of already existing headache and 42 patients complained of new headache. Patients suffering from headache before the trauma were not more at risk of having post-traumatic headache than patients who did not suffer from headache before the trauma. Patients who experienced an increase of already-existing pre-traumatic headache used more analgesics than patients first suffering from headache after the trauma. Post-traumatic headache was reported by more women than men (p less than 0.02), the corresponding relative risk being 1.6. Both the use of analgesics and the frequency of headache showed a significant increase for patients with post-traumatic headache when compared with a "control group" of 41 patients with unchanged headache and when compared with all patients with headache before the trauma. There was no significant difference in the location of pain between the groups analysed.