Primary Blast Traumatic Brain Injury in the Military (part two): Diagnosis, Detection & Treatment

Primary Blast Traumatic Brain Injury in the Military:

Diagnosis/Detection & Treatment (Part Two of Series)

Jeremy Jinkerson

ID 21465382 © Skypixel | Dreamstime.com

ID 21465382 © Skypixel | Dreamstime.com

Properly detecting and diagnosing blast-related military-related mild TBI (mTBI) is problematic for at least two reasons. First, individuals may be unaware that they have suffered concussions following exposure to blast events, and second, both mTBI’s etiology and symptomology are highly correlated with PTSD. Namely, they both follow blast events and both involve insomnia, memory problems, concentration difficulties, depression, anxiety, irritability, and noise intolerance (Sherer & Sander, 2014). As such, accurate detection and diagnosis of mTBI is paramount. In most VA centers, the primary means of blast-related mTBI diagnosis remains the multi-disciplinary clinical and medical interview, which is conducted in polytrauma treatment centers. When an individual presents with exposure to blast events conjoint with cognitive symptoms, mTBI may be diagnosed (Taber, Warden, & Hurley, 2006). For a more optimal diagnostic situation, interviewers attempt to identify symptoms and symptomatic progressions that are known to be consistent with mTBI responses. Furthermore, it is helpful to partially base mTBI diagnosis on symptoms unique to mTBI (not associated with PTSD), including headache, dizziness, fatigue, and intolerance to light. If symptoms, even cognitive symptoms, developed several weeks after the blast exposure, this suggests psychiatric rather than physical trauma origin (Jak, 2013). Likewise, if the individual presents with symptoms unique to PTSD (i.e., re-experiencing psychologically traumatic events, nightmares, emotional numbing, and anxious avoidance), PTSD is more likely. Diagnosis in this fashion, however, cannot actually confirm the presence of an mTBI, and it may often be insufficient to rule out PTSD (Tepe, Cernich, & Kelly, 2013). Indeed, one VA polytrauma strategy is to ensure that co-morbid conditions are treated prior to diagnosing mTBI. If an individual is sleeping well, does not exhibit signs of depression, and does not present with significant PTSD, it is much more likely that cognitive deficits are secondary to mTBI (pending exposure to head injury, including primary blast exposure) (Veazey-Morris, 2013). Although this strategy is clinically useful and may be necessary at times, it certainly has drawbacks. Namely, some individuals may not be properly diagnosed with mTBI when they have experienced blast-related brain injuries and present with post-concussive symptoms.

Neuropsychological tests provide one possible means of identifying differences between individuals with mTBI and other individuals (including those with PTSD). In sports-related concussion injuries, the civilian injuries that most closely approximate military mTBI, tests have successfully differentiated between injured athletes and non-injured athletes. Neuropsychological deficits have been identified in planning, set-switching, learning and memory, attention, processing speech, vigilance, psychomotor speed, visuospatial/constructional ability, sensorimotor function, and language (Lew et al., 2007). That is, sports-related concussions produce a variety of neuropsychological impairments, and military/combat-related mTBI may produce similar measurable discrepancies. In sports-related injuries, however, such performance deficits generally normalizes within one week of the injury. Given that military mTBI subjective symptoms endure for substantially longer periods of time, the sports-related concussion may provide an insufficient comparison profile. Sports-related injuries may, however, demonstrate functional areas that are likely to be impaired by blast-related injuries. Indeed, the neuropsychological impairments identified in sports concussions do match common cognitive complaints of people with blast exposure (Dikmen et al., 2010; Jak, 2014). As such, if diffuse neuropsychological disadvantage is observed in individuals with blast exposure histories, outside of alternative explanations, neurotrauma may be inferred.

Another possible means of identifying whether individuals have mTBI is neuroimaging. The primary neuropathology associated with blast injury, however, is diffuse axonal injury. Diffuse injury is very difficult to identify across neuroimaging techniques, meaning that neuroimaging is presently an insufficient means of detecting and/or diagnosing primary blast-related mTBI. Using diffusion tensor imaging (DTI), an advanced version of MRI, however, such identification may be possible due to greater sensitivity to axonal injury. In an investigation of DTI with 63 combat veterans who had experienced primary blast and secondary or tertiary damage, DTI was successfully able to identify the diffuse axonal injury (MacDonald et al., 2011). This outcome is promising regarding the eventual use of DTI in identifying diffuse axonal injury generally and its inclusion as a diagnostic tool in situations allowing for increased resources (i.e., forensic cases). It is also promising for the plausibility of identifying axonal injury in veterans with primary blast exposure only; however, it is not possible to generalize to that population until replication is achieved in veteran groups without secondary/tertiary exposure. In a more recent study, Raji and colleagues (2015) found differences in SPECT between individuals with mTBI and PTSD; SPECT may represent a promising avenue of mTBI detection.

The multi-disciplinary interview, neuropsychological testing, and neuroimaging models all pose difficulties because of the comorbidity and neuropsychological overlap between mTBI and PTSD. Specifically, physical trauma (including blast exposure and other brain injuries) increase the likelihood of developing PTSD (Hoge et al., 2008). In addition to the overlap between mTBI and PTSD in terms of psychiatric symptoms, there is overlap among cognitive symptoms. PTSD is associated with measured deficiencies in attention, memory, and executive functions (Vasterling & Brailey, 2005). Unfortunately, this makes the neuropsychological picture confusing, such that cognitive deficits themselves are insufficient to rule out PTSD and rule in mTBI. Even with regard to neuroimaging, functional differences observed in veterans with mTBI are mirrored in veterans with PTSD. Specific implicated areas include the anterior cingulate, medial frontal gyri, amygdala, and hippocampus (Bogdanova & Verfaellie, 2012). Collectively, detection and diagnosis of mTBI versus PTSD is a complex process that may involve interview, multidisciplinary evaluation, records review, neuropsychological examination, and neuroimaging. The areas most likely to assist in diagnosing mTBI at this time are the chronological proximity of cognitive symptoms to the blast event and whether psychological explanations are sufficient for psychiatric symptoms.

Treating blast-related mTBI may not be much different than treating mTBI generally; however, given that blast injury mTBI is a signature injury of the OEF and OIF conflicts, specific concerns related to the veteran experience must be made in treatment. First, the injuries were suffered in deployed environments, which are highly stressful situations where sleep dysregulation is normative. Second, blast injuries were necessarily contracted during life-threatening events. As such, posttraumatic stress may be the rule rather than the exception for many individuals who have contracted mTBI. For those recovering from psychological trauma, both sleep disruption and cognitive impairment can be complicating factors, so the individual with blast injury-related mTBI may be expected to have multiple co-morbidities. Specifically, the individual may present with sleep dysregulation (due to reinforced effects of upset circadian rhythm from the deployed environment), PTSD (conjoint with hyperarousal and re-experiencing which may further upset sleep and executive functioning), somatic symptoms, cognitive symptoms (either unique to mTBI or complicated by PTSD), and depression (existentially related to the loss of function and identity that mTBI often represents) (Taber, Warden, & Hurley, 2006).

In treating blast-related mTBI, it is important to first take a thorough history, correctly diagnose the condition, and identify functionally impaired domains. Further, it is preferable for treatment to be provided by a multidisciplinary team, including occupational therapists, physical therapists, speech-language pathologists, rehabilitation psychologists, and physicians (Holland, Hogg, & Farmer, 1997). On that team, it is the psychologist’s role to act as consultant to other providers who treat impaired domains identified through the multi-disciplinary assessment. The psychologist may also treat sleep disorders, substance abuse, posttraumatic stress, and depression directly, using therapies including Cognitive-Behavioral Therapy for Insomnia (CBT-I), Seeking Safety, Prolonged Exposure for PTSD (PE), CBT, and/or Acceptance and Commitment Therapy (ACT) (Veazey-Morris, 2013). If depression is related to existential issues, depression may alternatively be treated through existential therapy or other meaning-making interventions. Pain may be managed medically and/or treated behaviorally with treatments such as Cognitive Behavior Therapy for Chronic Pain (CBT-CP) or Mindfulness-Based Stress Reduction. After the veteran’s sleep, arousal, pain, substance use, and mood are regulated, the veteran can be engaged in an active return to work, school, and/or play. Throughout the treatment process, education is provided to the veteran and family members to help the veteran achieve the most possible in all functional domains, including academic and career achievement (Holland & Shigaki, 1998). Although blast-related mTBI cases are routine enough to present with consistently identifiable variables, there is high individuality among clinical cases. Therefore, it is important, as always, to tailor care to the individual.

Finally, because of the controversy surrounding primary blast-related mTBI, there may be resistance from patients, family members, or other providers regarding the possibility of mTBI. It is the psychologist’s role to provide accurate, up-to-date information on military mTBI. Demonstrating knowledge in this area and genuine concern may increase patient and family motivation to treatment, as we seek to heal the invisible wounds of war.

References

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