According to the Chronic Effects of Neurotrauma Consortium (CENC), nearly 20 percent of the 2.5 million service members and veterans who deployed to Iraq and Afghanistan sustained at least one mild traumatic brain injury (mild TBI).

A U.S. Department of Veterans Affairs/Department of Defense study aims to track mild TBI (mTBI) over a decades-long period. The federally-funded study is enrolling service members and veterans who fought in Iraq or Afghanistan. Researchers hope to follow participants for 20 years or more to better understand the long-term neurologic effects of mild TBI and other deployment-related conditions.

The researchers published the first stages of the study in the journal Brain Injury. Of the approximately 700 participants enrolled so far, 80 percent have a history of at least one mild TBI, while the others have no TBIs, for comparison purposes. The focus is strictly on mild TBI; those with more severe brain injuries are excluded.

Leading the study is Dr. William Walker, a TBI expert at the Richmond VA Medical Center and Virginia Commonwealth University, where CENC is based. He says the long-term observational study is one of the most comprehensive TBI projects to date. He states that the study will focus on lifetime concussive events. The research team will conduct diagnostic interviews of participants concerning not only possible mild TBIs that occurred in combat zones, but also those that occurred earlier in life, or following military service. In addition, the study will involve brain scans, eye-movement tracking, computerized balance tests, neuropsychological tests, blood tests, and others exams. Study participants will undergo approximately eight hours of tests, once every five years. In the intervening years, there will be a 45-minute phone assessment.

TBIs can have long-term effects on cognitive ability, memory, mood, and focus. Other symptoms may include headaches, vision, and hearing problems. Walker notes that some mild TBIs resolve in weeks or months with no long-term effects, and there is growing debate about how frequently the brain does not fully heal.

One goal of the CENC is to research how the circumstances of the injury make a difference in long-term outcomes. Of particular focus is whether mild TBI increases the risk for early dementia. Walker hopes the long period of the study will enable researchers to look at neurodegenerative conditions that develop later in life, such as Alzheimer’s or chronic traumatic encephalopathy (CTE).