Associations Between Traumatic Brain Injury History and Future Headache Severity in Veterans: A Longitudinal Study.

ABSTRACT

OBJECTIVE: To determine whether traumatic brain injury (TBI) history is associated with worse headache severity outcomes. DESIGN: Prospective cohort study. SETTING: Department of Veterans Affairs (VA) outpatient clinics. PARTICIPANTS: Veterans (N=2566) who completed a mail follow-up survey an average of 3 years after a comprehensive TBI evaluation (CTBIE). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The presence or absence of TBI, and TBI severity were evaluated by a trained clinician and classified according to VA/Department of Defense clinical practice guidelines. Headache severity was evaluated at both the baseline CTBIE assessment and 3-year follow-up using a 5-level headache score ranging from 0 ("none") to 4 ("very severe") based on headache-associated activity interference in the past 30 days. We examined associations of mild and moderate/severe TBI history, as compared to no TBI history, with headache severity in cross-sectional and longitudinal analyses, with and without adjustment for potential confounders. RESULTS: Mean headache severity scores were 2.4 at baseline and 2.3 at 3-year follow-up. Mild TBI was associated with greater headache severity in multivariate-adjusted cross-sectional analyses (ß [SE]=.61 [.07], P<.001), as compared with no TBI, but not in longitudinal analyses (ß [SE]=.09 [.07], P=.20). Moderate/severe TBI was significantly associated with greater headache severity in both cross-sectional (ß [SE]=.66 [.09], P<.001) and longitudinal analyses (ß [SE]=.18 [.09], P=.04). CONCLUSIONS: Headache outcomes are poor in veterans who receive VA TBI evaluations, irrespective of past TBI exposure, but significantly worse in those with a history of moderate/severe TBI. No association was found between mild TBI and future headache severity in veterans. Veterans with headache presenting for TBI evaluations, and particularly those with moderate/severe TBI, may benefit from further evaluation and treatment of headache.