Does Military Traumatic Brain Injury Increase the Risk for Developing Early-Onset Dementia and Mild Cognitive Impairment?
Abstract
Traumatic brain injury (TBI) is a common battlefield injury that, in the military, typically results from exposure to improvised explosive devices (IEDs), falls, vehicular crashes, other combat-related activities, training, or sports. Over 383,000 U.S. military Service members sustained a TBI of any severity between the year 2000 and the first quarter of 2018. Approximately 15% of TBIs are due to combat-related activities in Iraq and Afghanistan, resulting in TBI being labeled a “signature injury” of the recent conflicts. Due to the preponderance of TBIs sustained during active duty military service, it is of critical importance to examine the sequelae of these Service-induced injuries. While TBIs range in severity, even most mild TBIs (mTBI), also known as concussions, have been linked to numerous clinical symptoms. Past studies suggest a link between single and repetitive concussion and sleep disturbance, headaches, and memory impairments. A greater number of total lifetime concussions has been linked to several neurological disorders, such as increased insomnia, depression, emotional distress, and concussion symptom severity. Some studies have even shown that a history of multiple TBIs is associated with suicide. Because of the high prevalence of mTBI/concussion history in Veterans and active duty military Service members, and the possibility that these injuries may cause suffering, disability, and have an adverse impact on quality of life, it is imperative that effects of mTBI/concussion be better understood. What remains understudied to date is the link between TBIs sustained during active duty military service and subsequent development of other neurological impairments, such as mild cognitive impairment (MCI) and dementia (including Alzheimer’s disease [AD] and related conditions). It is plausible that both single and repeated concussions and more severe TBIs may be associated mid-life, early-onset neurodegenerative disease. However, no research has examined this link to date. In the present proposal, we outline a two-phase epidemiological study in which we leverage archival medical records to identify Veterans both with and without a history of TBI of varying severity and subsequent diagnoses of MCI, AD, and related dementias between the ages of 45-64 (early onset dementia [EOD]). Our primary hypothesis is that having a mTBI/concussion, moderate, severe, or penetrating TBI is associated with an increased risk for EOD, including AD, and early onset of MCI. Specifically, we propose to analyze archival medical and career records for Veterans age 45-64 currently seeking care within the Veterans Affairs (VA) healthcare system and link this with their active duty medical records from 1980-present. We will identify which of these Veterans have a history of TBI and categorize these TBIs by number and severity. We will then examine incidence and prevalence of EOD, including AD, and early onset MCI for those both with and without a history of TBI sustained during military service. The studies proposed for this 3-year period are currently not being examined or will be able to be examined by any other ongoing studies funded by the Department of Defense, VA, and Department of Health and Human Services. The findings of this research program will better inform therapy for Veterans, military Service members, and civilians with a history of brain injury of any severity.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 19, 2019
- Source ID
- W81XWH1910868
Entities
People
- Jack Tsao
Organizations
- United States Army
- University of Tennessee Health Science Center