Veterans of the 9/11 era with a history of traumatic brain injury (TBI), stroke, and other neurologic conditions are at increased risk of developing multiple sclerosis (MS), according to study results presented at the 2023 American Academy of Neurology (AAN) Annual Meeting, held from April 22 to 27, 2023, in Boston, Massachusetts.
Since 2013, the prevalence of MS has increased and been linked to environmental factors, such as smoking history, obesity, and Epstein-Barr Virus. Moreover, there is limited data that suggests a link between MS and multiple concussions and TBI. For the study, researchers assessed the associations of TBI history and a subsequent diagnosis of MS among post-9/11 era veterans.
The researchers used the International Classification of Diseases (ICD)-9 and ICD-10 codes to identify patients with MS. Information on TBI exposure was obtained from the Department of Defense Trauma Registry, self-reports from veterans, veterans with a history of posttraumatic amnesia, and ICD-9 and ICD-10 codes. TBI was classified as no TBI, mild TBI, moderate/severe TBI, or penetrating TBI.
The researchers used the first date TBI had been diagnosed as the index date. The main outcome examined was the time from TBI index day to MS diagnosis. Comorbid health conditions associated with MS (depression, anxiety, hypertension, hypercholesterolemia, and chronic lung disease) were included as covariates, along with age, sex, race/ethnicity, and health behaviors such as smoking, substance use disorders, overdoses, and obesity.
A total of 2,291,789 veterans met the inclusion criteria and were included in the analysis. Among these veterans, 16.6% had a history of TBI.
The researchers found that the time to MS diagnosis was the fastest for women (hazard ratio [HR], 2.4; 95% CI, 2.2-2.6). In terms of association with medical conditions, the time to MS was fastest for veterans with a history of stroke (HR, 2.1; 95% CI, 1.8-2.5), other neurological conditions (HR, 2.2; 95% CI, 1.8-2.6), and the severity of the TBI (penetrating TBI [HR, 1.96; 95% CI, 1.5-2.6) vs moderate/severe TBI [HR, 1.5; 95% CI, 1.2-1.8] vs mild TBI [HR, 1.5; 95% CI, 1.3-1.6]).
The researchers concluded that “neurological conditions including TBI were the strongest clinical predictors of MS emergence in this younger veteran cohort,” noting that these findings “should be considered in caring for post-9/11 veterans with neurological conditions.”
This article originally appeared on Neurology Advisor.
Pugh MJ, Amuan M, Ocier K, Graham G, Adamson A. Association between TBI exposure and multiple sclerosis among post-9/11 era veterans. Abstract presented at: 2023 AAN Annual Meeting; April 22-27, 2023; Boston, MA. Abstract P1.027.