Factors influencing recovery from headache after common whiplash.

OBJECTIVE--To assess the relation between pretraumatic and trauma related headache in patients suffering from whiplash. DESIGN--Follow up study of patients examined a mean (SD) of 7.4 (4.2) days after trauma and again at three and six months. SETTING--Patients referred from primary care. SUBJECTS--117 patients (mean age 30.8 (9.5) years. MAIN OUTCOME MEASURES--Prevalence of trauma related headache and the predictive relation by multiple logistic regression between different somatic and psychological variables and trauma related headache at each examination. RESULTS--Prevalence of trauma related headache decreased from 57% to 27%. History of pretraumatic headache proved a significant risk factor for presenting with trauma related headache. A significant relation between trauma related headache and the following variables was found: at seven days the initial wellbeing score, early onset of neck pain, depression scale from the personality inventory, and the initial intensity of neck pain; at three months, intensity of neck pain, and history of pretraumatic headache; and at six months neck pain, pain intensity, and history of pretraumatic headache. CONCLUSIONS--History of pretraumatic headache significantly increases the likelihood of presenting with trauma related headache but only in combination with findings indicative of clinically important injury to the cervical spine.