Which Matters More? A Retrospective Cohort Study of Headache Characteristics and Diagnosis Type in Soldiers with mTBI/Concussion

ObjectiveTo describe the diagnostic types and characteristics of headaches in soldiers with mild traumatic brain injury during the wars in Afghanistan and Iraq. BackgroundPersistent post-traumatic headache interferes with returns to activity or duty. The most commonly cited headache diagnosis after concussion is migraine. We hypothesize that headache diagnosis type, eg, migraine, is not sufficient to predict relationships with occupational outcomes after concussion. MethodsThe study sample consisted of all new patients referred for headache evaluation at the Brain Injury Center at Womack Army Medical Center over a 1-year time period. The design was retrospective and observational. Clinical data reported included demographics, causes of injury, headache characteristics, and headache diagnosis type. After reviewing records for retention or severance from military service, the primary occupational outcome measure was departure from service due to medical cause as determined by a Medical Evaluation Board (MEB). The primary outcome measure was to test the strength of association between leaving service for MEB and headache characteristics or diagnosis. ResultsA total of 95 patients (94% male) with concussion described 166 distinct headache types, the most common being migraine (60%) and trigeminal autonomic cephalalgia (24%). A total of 25% of all patients remained on active duty. A continuous headache of any type was present in 75% of patients and of these, 23% remained on active duty. Of the 51% of patients who had both a continuous and non-continuous headache, 17% remained on active duty (P<.001). Therefore, we report that a continuous headache, regardless of diagnosis type was associated with negative occupational outcomes. Regardless of headache duration, headache diagnosis type alone was not associated with soldiers' separations from service. ConclusionsPersistent post-traumatic headache is most likely to present with continuous pain. Migraine is the most common primary diagnosis type. The presence of a continuous headache was strongly associated with negative occupational outcomes. Primary headache diagnosis type was not. Headache characteristics, therefore, may be more important than diagnosis type when determining active duty status. Further prospective research is indicated.