The research combined linked records from the Airborne Hazards and Open Burn Pit Registry, Department of Defense electronic health records and Veterans Health Administration electronic health records. The parent analytical sample contained 247,583 participants with self-reported burn-pit exposure data. Investigators used stratified random sampling to select 1,980 registry participants who had used Veterans Health Administration care within the preceding 18 months. A total of 772 people responded to the online survey, and 335 completed all items required to classify a headache phenotype. The study was explanatory and sequential: quantitative survey findings were examined first, followed by semi-structured interviews intended to contextualize symptoms and care trajectories. Investigators conducted the interviews remotely from January through May 2025.

Headache phenotypes were assigned using questionnaire items operationalizing the International Classification of Headache Disorders, third edition, alongside coding guidance from the American Migraine Prevalence and Prevention study. Post-traumatic headache was given priority when a participant met more than one classification, and migraine, cluster headache and other headache were then assigned within that group. This hierarchy meant that each respondent was counted in one primary phenotype even though headache disorders can overlap. Among 112 exposed veterans classified as having post-traumatic headache, 67.0% also screened positive for migraine, 21.4% for other headache and 11.6% for cluster headache. The small comparison group without reported burn-pit exposure contained 24 respondents, including seven with post-traumatic headache, eight with migraine and nine with other headache; no cluster headache was identified in that group.

Validated patient-reported measures quantified the consequences of headache. The six-item Headache Impact Test, with scores ranging from 36 to 78, assessed effects on social and role functioning, pain, vitality, cognition and psychological distress. The seven-item Insomnia Severity Index, ranging from 0 to 28, measured insomnia symptoms and functional impact. Researchers also included a three-item measure of pain intensity and interference, a two-item pain self-efficacy scale, two-item screens for depression and anxiety, and the Veterans Health Administration’s ACORN social-determinants assessment. Exposed veterans scored an average of 61.47 on the Headache Impact Test, compared with 58.21 among veterans with headache but no reported burn-pit exposure, a difference of 3.26 points with a 95% confidence interval of 0.04 to 6.48. Their mean Insomnia Severity Index score was 15.47, compared with 11.88 in the unexposed group, a difference of 3.60 points with a 95% confidence interval of 1.15 to 6.04.

The remaining comparisons were not statistically significant at the study’s two-tailed threshold of p below 0.05. These included pain intensity and interference, pain self-efficacy, depression, anxiety and headache frequency. The authors cautioned that the 24-person comparison group sharply limited statistical power, so the findings do not establish that these outcomes were identical between groups. Sensitivity analyses assigning 38 respondents with missing exposure information first to the exposed and then to the unexposed category generally supported the principal results: insomnia remained significantly different under both assumptions, whereas some headache-impact findings varied with exposure classification. The observational design also could not control fully for other deployment-related conditions, and no baseline survey of headache before deployment was available for all participants.

Phenotype-level comparisons among exposed veterans indicated greater overall burden in the migraine and post-traumatic headache groups than in the other-headache group. Significant differences appeared across the outcome measures, with post-hoc comparisons mainly separating those two phenotypes from other headache. Migraine and post-traumatic headache did not differ significantly from each other on the measured outcomes, a result the authors partly attributed to the predominance of migraine within the post-traumatic group. The interview sample showed a parallel distribution: after 12 participants were removed because of possible secondary headaches, post-traumatic headache remained most common at 45.9%, followed by migraine at 29.7%, other headache at 21.6% and cluster headache at 2.7%. These findings characterize the sample rather than establishing the prevalence of each disorder in the wider exposed-veteran population.

Qualitative accounts placed many headaches within a deployment-related timeline. Most interviewees reported no headache before military operations or described only occasional, relatively minor symptoms. Many said their first substantial headaches began during deployment or shortly after returning, often after repeated tours or while stationed near open burn pits. Some described worsening headaches accompanied by respiratory symptoms, altered vision, tinnitus, sleep apnea, traumatic brain injury, post-traumatic stress disorder or chronic sinusitis. Interviewees with migraine or post-traumatic headache described daily pain, nausea, vomiting, sensitivity to light and sound, and restrictions on work and other activities. These accounts support temporal association but do not independently prove that burn-pit smoke caused an individual headache disorder.

The care pathways varied widely. During deployment, the most frequently described approach was foundational self-care centered on over-the-counter ibuprofen, rest or continuing duty while symptomatic. Interviewees said field settings often lacked diagnostic equipment, prescription-strength options and preventive headache care. After deployment, some entered care through primary care, while others used emergency departments, traumatic brain injury clinics or neurology referrals. Veterans Health Administration patients received varying combinations of primary care, specialty headache care and advanced treatments such as botulinum toxin injections, nerve blocks and trials of headache medication. Some also used community clinicians, and a few reported sustained multidisciplinary care. Interviewees said that learning about specialist options, repeatedly requesting referrals and navigating transitions between Department of Defense and Veterans Health Administration systems often required substantial personal advocacy.

Social conditions added to the burden. Among 297 exposed veterans with headache who completed the ACORN assessment, 202, or 68.0%, reported social isolation or loneliness, making it the most common unmet social need. Food insecurity was reported by 15.2%, household utility concerns by 16.2%, legal issues by 9.1%, housing concerns by 6.1%, transportation needs by 5.7% and digital needs by 5.1%. The authors noted that the stepped-care framework used for evaluation organizes care by severity, from self-management through primary care, specialty consultation and advanced headache services, but social determinants are not consistently embedded as a required parallel component. Their results therefore motivate assessment of social needs at each tier, not a conclusion that isolation caused the observed headache burden. The survey was cross-sectional, and the interviews, although informative, were voluntary and may underrepresent veterans with the most severe disabilities.

Burn-pit smoke can contain combustion-derived pollutants, and experimental literature discussed by the authors raises a potential route from inhaled exposures to headache biology. Fine particles and volatile compounds may reach the respiratory system and circulation, while experimental models of particulate exposure have been associated with lung and brain inflammation and altered nuclear factor-kappa B signaling in rodents. Other experiments have linked combustion irritants with trigeminal sensory pathways and CGRP-dependent signaling, mechanisms relevant to migraine. These biological models offer plausible explanations for the migraine-heavy pattern, but the present veteran study did not measure biomarkers, establish the chemical dose received by individual participants or directly test neuroinflammation. Accordingly, the evidence supports a high-burden, heterogeneous headache phenotype associated with self-reported exposure, alongside uneven access to coordinated care; it does not yet demonstrate whether exposure caused the disorders, whether preventive treatment during deployment could alter their course, or whether newer navigation and screening systems would improve outcomes. Those questions require longitudinal follow-up and prospective evaluation.

Subject of Research: Headache phenotypes, health outcomes and care trajectories among veterans reporting open burn-pit exposure

Article Title: Veteran deployed burn pits exposure: headache phenotypes, trajectories, and outcomes: a mixed-methods evaluation

Article References: Laferriere, C., Rogers, D. G., Rattray, N. A., Goldman, R. E., Baird, S. A., Burrone, L., Spontak, K., Sico, J. J., & Damush, T. M. (2026). Veteran deployed burn pits exposure: headache phenotypes, trajectories, and outcomes: a mixed-methods evaluation. Frontiers in Neurology, 17, Article 1899580. https://doi.org/10.3389/fneur.2026.1899580

Image Credits: AI Generated

DOI: 10.3389/fneur.2026.1899580

Keywords: open burn pits, military veterans, migraine, post-traumatic headache, insomnia, headache disability, social isolation, military health, mixed-methods research, Veteran, deployed, burn