The title of this presentation is Traumatic Brain Injury in the United States Army Special Forces. I'd like to thank the AANS and the General Neurotrauma Session for the opportunity to present this in 2020, albeit virtually, and I'd like to thank the Mount Sinai Hospital and the Cleveland Clinic's Department of Neurosurgery, as well as the Green Beret Foundation, all of whom made this research possible. This research was conducted in collaboration with the U.S. Green Beret Foundation, but other than this, we have no conflicts of interest to disclose. The Department of Defense estimates that TBI comprises 22% of all combat casualties from the Iraq and Afghanistan wars, the two most recent wars fought by the U.S. military. TBI is associated with a large number of medical conditions that often become apparent long after the original insult, and these include severe cognitive dysfunction, including memory loss, mental health problems, such as anxiety and depression, sleep problems, weight problems, and much more. TBI has a debilitating impact on a soldier's life and health care outcomes overall for these patients, and TBI also represents a major financial burden to the U.S. military, the Department of Defense, the Veterans Administration, and to overall soldier and wartime preparedness. So, who are the U.S. Army Special Forces, or the Green Berets? They are the most elite fighting unit of the U.S. Army, a very small group that focuses specifically on unconventional guerrilla warfare. Special Forces soldiers represent a striking 60% of all special operations casualties, and this is primarily due to their missions in extraordinarily high-risk environments and the types of warfare that they engage in, including hostage rescue, subversion, undercover missions, and more. Since Operations Iraqi Freedom and Enduring Freedom post-911, combat-related blast injuries have been the primary focus of Army medical research. In just 2011, over 33,000 U.S. military personnel were diagnosed with TBI, and that's TBI across the spectrum from mild all the way to moderate and severe. And as such, prevention of TBI has been one of the highest priorities in military medicine for about the last two decades. So why is all of this important? While there's been extensive study of military TBI, it has never been previously investigated amongst this most elite group of U.S. soldiers, the U.S. Army Special Forces. And so our objective was to better understand TBI incidents in Special Forces, its mechanisms of injury and acquisition, and how we can learn from this and prevent it by addressing key issues pertaining to protective equipment, body armor, and headgear use. The methods of this study were multifaceted, but they primarily included a survey that we devised. So I'll start with the participant inclusion criteria. Participants had to be U.S. Army Special Forces qualified. They had to be 18-series designation. They also had to have completed the neurological portion of the questionnaire. In terms of the data collection, we devised an online survey in collaboration with the Green Beret Foundation and the Departments of Neurosurgery at Mount Sinai and Cleveland Clinic with the senior attending neurosurgeons. And our data points included questions on military background, demographics, medical and family history, and injury history. With respect to statistical analysis, we used primarily descriptive statistics, including chi-squared tests of independence and two-tailed independent sample t-tests when needed. And our statistical significance was set at P less than 0.05. For our results, we had 494 respondents who met inclusion criteria, representing about an 8.2% response rate. For our demographics, all Special Forces soldiers are male. The mean age was 51 years old. And the U.S. Army service range was from 1945 to 2019. For TBI incidents, we found that the incidence of mild TBI reported was about 42%. For moderate to severe TBI, it was 22%. And we found a statistically significant association between post-911 Special Forces soldiers and moderate to severe TBI diagnosis. On this first slide of our results, we see two graphs. On the left side is for mild TBI, on the right side for moderate to severe TBI. And both of these graphs are looking at attributed causes. So on the left side, we see that the leading causes are blasts and airborne operations. And we see the same trend for the moderate to severe TBI cohort on the right with blasts and airborne operations. The difference, though, is that for mild TBI or concussion, the percentages reported for these leading to causes were much closer at 46% and 44% as compared to the right side graph, where we're seeing a much larger differential between those who reported blasts and airborne ops as the cause of their moderate to severe TBI. So on this slide, again, we see mild TBI on the left and moderate to severe TBI cohorts on the right. And the question asked was, how many times were you diagnosed with your TBI? So for the mild TBI group, we see that the vast majority were diagnosed with a concussion two to three times. Over 47% reported that. And on the right, we see that the vast majority of soldiers who reported a moderate to severe TBI only had one at 63%. But nevertheless, a decent percentage reported having two to three at almost 24%. On this slide, again, we have mild TBI on the left and moderate to severe TBI on the right. And the question asked was, are you special forces sniper qualified? And we found a statistically significant association between the sniper qualification and having a TBI. For the mild TBI group, about 37% reported having a sniper qualification. And for the moderate to severe TBI group, over 40% reported the sniper qualification. We also found a number of statistically significant associations between comorbid conditions and both mild and moderate to severe TBI. For the mild and moderate to severe TBI cohort, there were almost universal statistically significant associations between all of the disorders listed on the left, except for erectile dysfunction, which did not have a statistical association with moderate to severe TBI. But low testosterone, tinnitus, hyperacusis, sleep apnea, PTSD, depression, and anxiety were all statistically significantly correlated in both groups. So in terms of the discussion, there's a high incidence reported of TBI among US Army Special Forces. Multiple TBIs was the norm, especially in the mild TBI cohort. The leading cause of both mild TBI and moderate to severe TBI was blast explosions and airborne operations. And we did find correlations between TBI and comorbid conditions and mental illness. There has been minimal investigation into whether repeated firing of heavy weapons can lead to TBI over time, given the significant levels of blast overpressure. We found this novel statistically significant correlation between sniper qualification and TBI. And with respect to snipers, this is the most exposed group within the US Armed Forces to repeated low-level blasts from heavy weapons firing, both in training and in combat theater. And so with the data that we've collected and the results that we've found, our theory is that there is a subconcussive neurological injury following this repetitive low-level occupational blasts, and that over time, these lead to mild TBI. And on the right-hand side here, we see photographs of actual snipers in the field. And not only can you appreciate the environments that they're in, the close contact they are with the weapon, but also just how large this weapon is, and one can imagine the low-level blasts that one feels when firing that, especially in a repetitive basis. Our conclusions. That 80% of TBIs occurred while wearing headgear might be reflective of inadequate protective equipment. This is, in fact, one of the questions that we had asked in the survey. There was no requirement to safeguard against primary blast-induced brain injury for the Army's current advanced combat helmet, nor for the integrated head protection system. It is possible that military helmets are not tailored to protect against repeated low-level blast overexposure from weapons firings, or that snipers might just not at all be wearing helmets in the field due to comfort or due to a desire to increase vision or other unknown surprises that can occur in the field. The authors of this research would like to thank the staff at the U.S. Green Beret Foundation for their immeasurable assistance in recruiting participants and their guidance on devising survey questions related to military experience and to exposures. In particular, we would like to thank Colonel William J. Davis, Lieutenant Colonel Dennis Downey, and Sergeant First Class Mark Christensen, all of the U.S. Army Special Forces, who were truly invaluable in their counsel and knowledge of global military operations, and we are so grateful to them and thankful for their service. Thanks. Thank you.

Traumatic Brain Injury

United States Army Special Forces

incidence

medical conditions

Department of Defense