CT Scan of Soldier. Photo Courtesy of U.S. Army. Photo by U.S. Air Force Tech. Sgt. Cecilio M. Ricardo Jr.

Introduction

During the course of the current conflicts in Afghanistan and Iraq, traumatic brain injury (TBI) has emerged as a significant cause of morbidity. Although penetrating TBI is typically identified and cared for immediately, mild TBI (mTBI) may be missed, particularly in the presence of other more obvious injuries. Due to numerous deployments and the nature of enemy tactics, troops are at risk for sustaining more than one mild brain injury or concussion in a short timeframe. The sports literature, which is highly relevant to the combat blast injury model, has published consensus documents on the assessment and management of sports related concussion (McCrory, 2005). However, due to tactical, logistical and resource considerations, it is challenging to directly apply these findings in a combat setting.

In an effort to gather best practice evidence with regards to assessment and management of mild traumatic brain injury in military settings, the Defense and Veterans Brain Injury Center (DVBIC) assembled 32 key military and civilian experts. The two day meeting was convened on 9 and 10 November 2006 in Washington DC. The purpose of this meeting was to create a literature-based clinical practice guideline (CPG). We acknowledge that more work is needed to fully support all the recommendations but recognize an acute need for guidance during this time of combat operations. To meet this need, a six week timeframe from the initiation of the meeting to the release of the CPG was created.

There are four main areas of focus within the CPG: (1) an operational definition of mTBI, (2) assessment of mTBI, (3) management of mTBI and (4) operational considerations which directly impact the feasibility of evaluating and treating mTBI within the context of the current theatres of operation.

Operational Tenets

Assessment and management of mTBI in operational settings provides a unique set of tactical challenges that must be considered when balancing patient care and mission goals. Mission completion may supersede individual service member welfare in certain operational environments. However, if a service member must be removed, the decision to evacuate that individual is best determined by the medical team caring for the service member in context with the operational risk and cost as determined by the command. There also exists a potential psychological cost when a service member is prematurely removed from duty. Conversely, returning a neurocognitively impaired individual to full duty may jeopardize operational success. Due to the limited availability of neuroimaging and neurosurgical treatment, the small risk of deterioration in patients who present with mTBI must also be considered.

Screening for mTBI

Anyone exposed to or involved in a blast, fall, vehicle crash, or direct impact who becomes dazed, confused or loses consciousness, even momentarily, should be further evaluated for a brain injury.

Operational Definition of mTBI

Mild TBI in military operational settings is defined as an injury to the brain resulting from an external force and/or acceleration/deceleration mechanism from an event such as a blast, fall, direct impact, or motor vehicle accident which causes an alteration in mental status typically resulting in the temporally related onset of symptoms such as: headache, nausea, vomiting, dizziness/balance problems, fatigue, insomnia/sleep disturbances, drowsiness, sensitivity to light/ noise, blurred vision, difficulty remembering, and/or difficulty concentrating.

This operational definition of mTBI is the result of deliberation by top experts in the field of operational medicine and traumatic brain injury. Drawing from widely-accepted definitions such as the American College of Rehabilitation Medicine (ACRM) (Kay et al, 1993), Centers for Disease Control (CDC) and Prevention (2003), World Health Organization (WHO) (Von Holst et al, 2004), National Athletic Trainers’ Association position statement on management of sport-related concussion (2004) and the Prague sports concussion guidelines (McCrory et al, 2005), this definition incorporates common criterion. These established definitions endorse biomechanical forces as the cause of concussion that results in an alteration of consciousness to include: loss of consciousness (LOC), post-traumatic or retrograde amnesia (PTA or RGA) or being dazed/confused. An important aspect of this definition is that LOC is not a required characteristic of concussion, that is, a service member does not have to have a loss of consciousness to have sustained a concussion. The group acknowledged the continued usefulness of these parameters and adopted them with a few changes. Variations from the established definitions include adding combat-related mechanisms such as blast as well as a comprehensive list of TBI related symptoms.

After a concussive injury, a patient usually experiences symptoms. Common symptoms as listed above in the operational definition should be assessed and documented in medical records as they can impede occupational functioning and combat effectiveness. In addition to cognitive symptoms, a patient may experience emotional or personality changes as a result of the traumatic brain injury (Ryan & Warden, 2003). Irritability, anxiety and depression are the most common issues and usually resolve over time but should be documented because they may have operational implications. By self-report or by observations by others, a person may “not act like themselves.” Clinicians and command should be aware that this may be a trigger statement to prompt an evaluation for concussion. Many times a patient will experience a combination of physical, cognitive and behavioral symptoms. Although an area of continued discussion, the majority of TBI experts agreed that symptoms associated with mTBI occur frequently but the presence of these symptoms is not mandatory in order to establish the diagnosis of mTBI.