Persistence of headache and its relation to other major sequelae following traumatic brain injury at 2-8years after deployment-related traumatic brain injury in veterans of Afghanistan and Iraq wars.

Abstract

This study deals with headache in relation to other major sequelae of traumatic brain injury (TBI) in veterans of Iraq and Afghanistan wars over 8years after experiencing a deployment-related TBI (DTBI). TBI occurred in 14%-23% of veterans deployed to the Iraq or Afghanistan campaigns. This study evaluates sequelae of TBI (STBI) over 1-8years after a DTBI. This is a secondary, cross-sectional analysis of previously collected data, which was taken from review of medical records of the first 500 veterans with a DTBI seen in the TBI clinic of the Oklahoma City Veterans Health Center. This report deals with five of the most common STBIs and represents the presence and severity of, or absence of, the particular symptom at the time of a patient's initial visit to the clinic. All subjects were evaluated between June 1, 2008, and April 30, 2011. The STBI used here include: headache, dizziness, balance, coordination difficulties, and difficulty with decisions. In the TBI clinic, the burden of these symptoms was evaluated with a Likert Scale of none, mild, moderate, severe, or very severe. For this report, the scale was compressed into three categories: none, mild/moderate, and severe/very severe. Data were complete for age at TBI and mechanism of TBI in 500 subjects, for symptom severity in 497 subjects, for TBI severity in 491 subjects, and for presence of prior TBI in 496 subjects. For the 497 subjects with complete symptom severity data, headache was seen in 476 (95.8%) and absent in 21 (4.2%). Regarding headache severity, 236 (47.5%) reported mild/moderate and 240 (48.3%) reported severe/very severe headache burden. For other sequelae, including severity of dizziness, balance, and coordination problems, these symptoms were absent in 85 (17.1%), 85 (17.1%), and 106 (21.3%) patients, respectively; of mild/moderate severity in 356 (71.6%), 355 (71.4%), and 321 (64.6%) patients; and of severe/very severe intensity in 56 (11.3%), 57 (11.5%), and 70 (14.1%) patients. Difficulty with decisions, which was used as an indication of cognitive difficulty, was noted in 429 (86.3%) of the subjects, of which 252 (50.7%) noted mild/moderate and 177 (35.6%) severe/very severe intensity. To evaluate changes over time, the subjects were divided into 2-year cohorts of 1-2, 3-4, 5-6, and 7-8years since DTBI. Comparing symptom burden within these four 2-year cohorts, there was no statistically significant change in symptom burden analyzing by time interval from DTBI to TBI clinic evaluation. For analysis by severity of the DTBI in 491 subjects with complete data, categories were constructed based on alteration of consciousness (AOC) or duration of loss of consciousness (LOC) as follows: AOC (264/491 [53.8%]); LOC <1min (95/491 [19.4%]); LOC, 1-30min (115/491 [23.4%]); and LOC >30min (17/491 [3.5%]). The proportion of subjects with severe/very severe symptom intensity increased as the severity of the DTBI increased (from p=0.043 to p=0.001). Additional evaluations included groupings by age at DTBI (20-29, 30-39, and ≥40years), by presence or absence of a TBI prior to the DTBI, and by causation of the DTBI (blast or direct head trauma). No significant differences were observed with any of these comparisons. For veterans experiencing a DTBI, these TBI-related sequelae persist with little improvement over time up to 8years. A trend toward symptoms becoming worse as DTBI severity increased was observed. Headache was the most frequent sequela of TBI, occurring in 96% of the patients with almost half of these reporting severe/very severe intensity of headache burden. The basis for the prolonged persistence of these STBI is not known.