To establish the prevalence of post traumatic headache, persisting at 3 months following minor traumatic brain injury.

A prospective controlled study of patients admitted with a diagnosis of mild traumatic brain injury and matched orthopedic controls over 12 months during 2004.

A level two inner city Emergency Department in Sydney, Australia.

One hundred eligible sequential admissions with mild traumatic brain injury as defined by American Congress of Rehabilitation Medicine, 1993, and 100 matched minor injury controls with nondeceleration injuries.

Subjects were part of a study on prediction of postconcussive syndrome and had neuropsychological tests, balance test and pain recordings taken at the time of injury, at 1 month and at 3 months post injury.

Main measures were the reporting of headache "worse than prior to the injury" and concordant with the definition of Posttraumatic Headache according to International Headache Society Classification of Headache Disorders 2003.

15.34% of those with minor head injury continued to complain of perisistant posttraumatic headache at 3 months compared to 2.2% of the minor injury controls.

To the authors' knowledge this is the first controlled prospective study in the prevalence of posttraumatic headache following mild traumatic brain injury.