Headache Prevalence at 4-11 Years after Deployment-Related Traumatic Brain Injury in Veterans of Iraq and Afghanistan Wars and Comparison to Controls: A Matched Case-Controlled Study

Abstract

Objective: Evaluate the extent and severity of headache following deployment-related TBI (D-TBI) in veterans of the Iraq (OIF) and Afghanistan (OEF) wars over a follow-up period of 4-11 years with comparison to age, sex, race, and time of deployment matched controls. Background: TBI has been recognized as the "signature Injury" of the OEF/OIF campaigns occurring in 14-20% of deployed soldiers. Currently, there are very few data on the longer term follow-up of soldiers with D-TBI. This study deals with prevalence and severity of headache and headache burden at 4-11 years following D-TBI for OEF/OIF veterans with comparison to controls without D-TBI. Methods: This is a matched case controlled-study. All subjects were recruited from Operation New Dawn (OND), a voluntary program for OEF/OIF Veterans at the Oklahoma VAMC designed to assist with re-integrating into civilian life. On entry into OND a medical questionnaire was administered that included a brief screen for D-TBI, and those with a possible D-TBI were referred to a TBI clinic, For this study, the first 500 TBI clinic patients who were found to have had a D-TBI (TBIS) were matched by age, sex, race, and time of deployment to control subjects (CS), drawn from the 4411 OND program members with no D-TBI, creating a pool of 500 TBIS/CS pairs. From this pool, 55 pairs (11%) were randomly selected for this study. Data were collected from both TBIS and CS by telephone interview with questionnaires regarding the DTBI, headache, depression, and PTSD. TBI severity was measured by duration of loss of consciousness (LOC) as: [a] Very Mild (VMTBI, dazed only, no LOC), [b] Mild (MTBI, LOC 1-30 minutes), and [c] Moderate-Severe (MSTBI, LOC > 30 minutes). Intensity for individual headaches was measured by disability produced by the headache as: [a] Disabling (must be in bed), [b] Severe (50-90% decrease in activity), or [c] Mild-Moderate (>50% of usual activity possible). Statistical analysis employed Fisher's exact test and odds ratio. Results: The 55 TBIS/CS pairs were segregated by severity of TBI for the TBIS. For the TBIS there were no significant differences among these three subgroups as to mechanism producing the TBI (blast injury or direct head trauma). Comparing TBIS vs CS for phenotypic classification of headaches, for TBIS - 89% had migraine, 2% probable migraine, 9% had tension, and 0% had no headaches, while for CS - 36% had migraine, 15% probable migraine, 27% tension, and 22% no headache (P