In the words of Brian L. Edlow, MD, co-director of Mass General Neuroscience and associate director of the Center for Neurotechnology and Neurorecovery at Massachusetts General Hospital, members of the United States Special Operations Forces (SOF) community are “some of the most resilient human beings on the planet.” However, due to the nature of their missions and training, these elite members of the U.S. military repeatedly experience explosive blasts. That exposure has the potential to cause brain injuries, yet there is no diagnostic test to detect them. Without a test, SOF personnel may experience a variety of symptoms that can be misdiagnosed, and they can then be returned to operational duties when their brains are still recovering — and still vulnerable.
“Those who defend our country and conduct the most dangerous missions to protect our way of life deserve the best medical care. We as a society owe it to them, and until we advance this field, we won’t live up to our responsibility.”
To fill that gap, Dr. Edlow, who is also a Chen Institute Mass General Research Scholar, and his team embarked on a pioneering study to understand the effects of repeated blast exposure on SOF brain health and inform the development of a diagnostic test, since typical MRI scans cannot detect these injuries. Called ReBlast, the two-year study surveyed 30 active-duty SOF personnel about their blast exposures and conducted cutting-edge imaging tests at Mass General’s Athinoula A. Martinos Center for Biomedical Imaging. The University of South Florida’s Institute of Applied Engineering coordinated and managed the study, which U.S. Special Operations Command (USSOCOM) funded.
What Dr. Edlow found was that these Operators reported extraordinary levels of blast exposure — much more than he and his team originally anticipated. And, the higher an individual’s level of reported blast exposure, the more likely they were to have changes in the brain’s structure, function and inflammatory response. In addition, the more blast exposure someone reported, the more likely they were to report a decreased quality of life, which can include trouble sleeping and difficulties with family relationships.
“Those who defend our country and conduct the most dangerous missions to protect our way of life deserve the best medical care,” Dr. Edlow says. “We as a society owe it to them, and until we advance this field, we won’t live up to our responsibility.”
Two Decades of Data
Dr. Edlow first joined Mass General in 2014, when he launched a neuroimaging laboratory to detect, predict and promote recovery of consciousness in comatose patients with severe traumatic brain injuries (TBI). That civilian-based work led him to a collaboration with Daniel P. Perl, MD, who had established a state-of-the-art neuropathology laboratory at the Department of Defense’s Uniformed Services University of the Health Sciences, dedicated to research on the acute and long-term effects of TBI and post-traumatic stress disorder (PTSD) among military personnel. When Dr. Perl’s research revealed scarring within the brains of SOF Operators, which he and Dr. Edlow believed to be a signature of blast injury, the two obtained the military’s support to move forward with the ReBlast study.
The 30 active-duty SOF personnel in the study, which ran from 2021 to 2023, came from all branches of the military, with the U.S. Army most heavily represented. Many joined the armed forces after the terrorist attacks of Sept. 11, 2001, with an average age of 37 and a mean service duration of 17 years. After serving two decades in the global war on terror, they were, as Dr. Edlow puts it, “the most frequently deployed, heavily combat-exposed Operators in the history of our country.”
In addition to 12 hours of cognitive, psychological and physical assessments, these Operators underwent a comprehensive battery of brain imaging tests at the Martinos Center. Those tests included MRIs and PET scans on state-of-the-art equipment to study various neuroimaging biomarkers, such as brain network connectivity, inflammation and abnormal collections of tau protein. The study’s findings — that higher reported blast exposure was associated with structural, functional and neuroimmune brain alterations as well as lower health-related quality of life — showed an urgent individual and societal need for a reliable test to diagnose brain injuries associated with repeated blast exposure.
“Without a diagnostic test, these brave men and women have no idea what’s causing their symptoms. On top of the cognitive, psychological or physical symptoms, the lack of a diagnosis may contribute to despair, depression, and in the most tragic cases, even suicide,” Dr. Edlow says. “There’s a whole set of downstream consequences on the quality of life of these American heroes and their families.
“It potentially affects the national security of our country,” he adds. “These are our most elite warfighters. If their combat readiness is compromised because they have undiagnosed blast injuries, they may not perform at an optimal level, and these highly trained and highly skilled people might have to retire early. It also affects recruitment. People understand that repeated blasts aren’t good for you. Until we figure out a diagnostic test, are fewer elite warfighters going to volunteer to serve on SOF teams?”
Diagnosis as the Foundation
Now that Dr. Edlow and his team have identified potential diagnostic biomarkers of repeated blast brain injury, they plan to expand the study’s sample size, perform longitudinal studies to follow Operators over longer periods and account for how other exposures during training and combat might impact their brains. In the meantime, USSOCOM and the Department of Defense are already taking steps to minimize exposure, Dr. Edlow says, and the Home Base Program of Mass General and the Boston Red Sox, along with other organizations, are providing world-class care to help people recover from blast-related injuries.
“Even if we don’t fully understand what we’re treating, people are getting better,” Dr. Edlow says. “But, until we figure out how to detect this scarring within the brain, there won’t be a treatment to prevent the inflammation that leads to it. Diagnosis is the foundation for future progress in prevention and treatment.”
Due to the data security regulations and confidentiality agreements surrounding research studies of active-duty SOF personnel, Dr. Edlow’s study does not fit into standard grant mechanisms. He and his team consider philanthropy an essential ingredient to their work, and they have been grateful for the support of the Navy SEAL Foundation, which recently recognized the team’s work on the ReBlast study with its Distinguished Science Award.
“The Operators we’ve met, they have no regrets,” Dr. Edlow says. “They wouldn’t change a thing in their service, and they’re not complaining. They did this for us, and they deserve our time, attention and effort.”
To learn more about Dr. Edlow and his team and to support their work, click here or contact us.
