A TBI is any temporary or permanent neurologic dysfunction after a blow to the head.10,17 TBI is classified based on severity and mechanism (direct blow to the head or exposure to blast waves). Mild TBI (mTBI) is commonly referred to as a concussion and usually is not associated with loss of consciousness or altered mental status. Brain imaging results are also normal with mTBI. Severe TBI, on the other hand, is associated with prolonged loss of consciousness, altered mental status, and abnormal brain imaging results (TABLE 2).17
A unique obstacle to accurate evaluation in the field. It is important to emphasize that mTBI is a clinical diagnosis, and its detection requires honest patient communication. This can be problematic with motivated soldiers who are anxious to continue the mission and fear that any admission of symptoms might delay a return to their unit. As with a concussed athlete eager to return to the field of play, the clinical diagnosis of mTBI requires a high index of clinical suspicion and constant vigilance by the health care provider. Despite being the most common combat- related injury, mTBI is often overlooked due to the absence of obvious physical injuries.4 Recent data suggest that 28% to 60% of ser- vice members evacuated from combat have a TBI. Most of these injuries (77%) are mTBI.18-20 Improved personal protective equipment (including Kevlar helmets and body armor) and the high number of blast-related injuries are likely responsible for the high incidence of mTBI among OEF/OIF veterans.8,21,22 The prevalence of mTBI among service members not evacuated is estimated to be 20% to 30%.20
Symptoms can persist. Most patients with mTBI completely recover within 30 days of the injury. Unfortunately, 10% to 15% of mTBI patients develop chronic problems lasting months to years.4 Residual symptoms most commonly include headache, irritability, depression, sleep disturbance, impaired reasoning, memory problems, and difficulty concentrating. These symptoms are not unique to mTBI and overlap with comorbid combat diagnoses like PTSD, depression, and sleep deprivation.10 The following tools can help physicians determine whether mTBI is present.
Checking for possible mtBi. In the field, patients with possible mTBI can be screened rapidly using the Military Acute Concussion Evaluation (MACE, found at www.dvbic.org), a modification of the validated and widely used Sideline Assessment of Concussion (SAC) tool. More challenging is evaluating potential mTBI patients who present weeks or months after a traumatic event, for which there are no simple confirmatory tests. In this event, conduct a thorough neurological evaluation that includes vestibular, vision, postural, and neurocognitive assessments. For patients with persistent symptoms or possible anatomic brain abnormalities, magnetic resonance imaging (MRI) is the imaging modality of choice. Patients with complications or a questionable diagnosis are best managed in consultation with a neurologist.
Initial treatment of mtBi is symptom-based. When practical, try nonpharmacologic interventions first (TABLE 3).10 In particular, have the patient avoid further high-risk exposures that could lead to second impact syndrome (an issue increasingly recognized in contact sports). Also critical are physical and cognitive rest and the restoration of sleep until the patient is completely asymptomatic.
If the patient exhibits irritability and depression, selective serotonin reuptake inhibitors (SSRIs) are first-line treatment. Avoid narcotics and sedative-hypnotic sleep medications if treating comorbidities such as pain and sleep deprivation. The VA/DoD guideline on managing concussion and mTBI provides additional detailed, evidence-based treatment recommendations.17
Reliving the horror again and again: PTSD
PTSD is a persistent and, at times, debilitating clinical syndrome that develops after exposure to a psychologically traumatic event. It’s the second most common illness among OEF/OIF combat veterans, with an estimated prevalence of 3% to 20%, a finding consistent with prior wars.6,23-25 In the case of combat veterans, the inciting event usually involves an actual or perceived risk of death or serious injury. The individual’s response to the event involves intense fear, helplessness, or horror. The traumatic event is persistently re-experienced through intrusive and disturbing recollections or dreams that cause intense psychological distress. This, in turn, leads to a state of persistent sympathetic arousal. As symptoms are often triggered by specific cues, individuals with PTSD actively seek to avoid thoughts, situations, or stimuli associated with the event.23,26
Symptoms commonly associated with PTSD include difficulty falling or staying asleep, recurrent nightmares, hypervigilance, and an exaggerated startle response. Individuals with PTSD also have a poorer sense of well-being, a higher rate of work absenteeism, and significantly more somatic complaints than age-matched peers.27 For symptoms to be attributable to PTSD, their onset must follow a recent inciting event and must also cause clinically significant distress or impairment in social, occupational, or other areas of daily living. Common comorbid illnesses include mTBI, depression, and substance abuse. As with mTBI, the presence of multiple comorbidities in patients with PTSD can complicate evaluation, diagnosis, and treatment.