Louis M. French

Symptom Complaints Following Combat-Related Traumatic Brain Injury: Relationship to Traumatic Brain Injury Severity and Posttraumatic Stress Disorder

Patients with a history of mild (n = 134) or moderate-to-severe (n = 91) TBI were asked to complete the Neurobehavioral Symptom Inventory (NSI) and the Posttraumatic Stress Disorder Checklist. Consistent with prior research, significantly more postconcussion symptoms were endorsed by the mild group. After controlling for age, time since injury, and mechanism of injury, TBI severity continued to be significantly related to postconcussion complaints on the NSI. However, after controlling for these same variables, along with posttraumatic stress disorder symptom severity, there no longer were differences between the TBI severity groups. That is, patients with mild TBI did not endorse significantly more complaints (adjusted mean = 22.4) than the moderate-to-severe group (adjusted mean = 21.8). These findings suggest that much of the symptom complaints in mildly injured patients may be due to emotional distress.

Official Position of the Military TBI Task Force on the Role of Neuropsychology and Rehabilitation Psychology in the Evaluation, Management, and Research of Military Veterans with Traumatic Brain Injury

This Position Statement is a summary of the literature and learning regarding current issues raised by the occurrence, treatment, and study of traumatic brain injury in military service members and veterans. The Report has been approved by the American Academy of Clinical Neuropsychology (AACN), Divisions 40 (Neuropsychology) and 22 (Rehabilitation Psychology) of the American Psychological Association (APA), and the National Academy of Neuropsychology (NAN), with the goal of providing information of relevance on an important public policy matter within their respective areas of expertise. The Report is not intended to establish guidelines or standards for the professional practice of psychology, nor has it been adopted as official policy by the American Psychological Association or any other division or subunit of APA.

Case report of a soldier with primary blast brain injury.

Primary blast injury of the central nervous system is described in a service-member exposed to a large ordinance explosion. Neuroimaging abnormalities are described together with normalization of the fractional anisotrophy on diffusion tensor imaging after follow-up imaging studies.

Peripheral Total Tau in Military Personnel Who Sustain Traumatic Brain Injuries During Deployment.

IMPORTANCE Approximately one-third of military personnel who deploy for combat operations sustain 1 or more traumatic brain injuries (TBIs), which increases the risk for chronic symptoms of postconcussive disorder, posttraumatic stress disorder, and depression and for the development of chronic traumatic encephalopathy. Elevated concentrations of tau are observed in blood shortly following a TBI, but, to our knowledge, the role of tau elevations in blood in the onset and maintenance of chronic symptoms after TBI has not been investigated. OBJECTIVES To assess peripheral tau levels in military personnel exposed to TBI and to examine the relationship between chronic neurological symptoms and tau elevations. DESIGN, SETTING, AND PARTICIPANTS Observational assessment from September 2012 to August 2014 of US military personnel at the Madigan Army Medical Center who had been deployed within the previous 18 months. Plasma total tau concentrations were measured using a novel ultrasensitive single-molecule enzyme-linked immunosorbent assay. Classification of participants with and without self-reported TBI was made using the Warrior Administered Retrospective Casualty Assessment Tool. Self-reported symptoms of postconcussive disorder, posttraumatic stress disorder, and depression were determined by the Neurobehavioral Symptom Inventory, the Posttraumatic Stress Disorder Checklist Military Version, and the Quick Inventory of Depressive Symptomatology, respectively. Group differences in tau concentrations were determined through analysis of variance models, and area under the receiver operating characteristic curve determined the sensitivity and specificity of tau concentrations in predicting TBI and chronic symptoms. Seventy participants with self-reported TBI on the Warrior Administered Retrospective Casualty Assessment Tool and 28 control participants with no TBI exposure were included. MAIN OUTCOMES AND MEASURES Concentration of total tau in peripheral blood. RESULTS Concentrations of plasma tau were significantly elevated in the 70 participants with self-reported TBI compared with the 28 controls (mean [SD], 1.13 [0.78] vs 0.63 [0.48] pg/mL, respectively; F1,97 = 4.97; P = .03). Within the self-reported TBI cases, plasma total tau concentrations were significantly associated with having a medical record of TBI compared with self-reported TBI only (mean [SD], 1.57 [0.92] vs 0.85 [0.52] pg/mL, respectively; F1,69 = 6.15; P = .02) as well as reporting the occurrence of 3 of more TBIs during deployment compared with fewer than 3 TBIs (mean [SD], 1.52 [0.82] vs 0.82 [0.60] pg/mL, respectively; F1,69 = 8.57; P = .008). The severity of total postconcussive symptoms correlated with total tau concentrations in the self-reported TBI group (r = 0.37; P = .003). CONCLUSIONS AND RELEVANCE Military personnel who report multiple TBIs have long-term elevations in total tau concentration. The total tau concentration relates to symptoms of postconcussive disorder.

Assessing and treating veterans with traumatic brain injury

Conflicts in Iraq and Afghanistan have resulted in greater proportions of service members with traumatic brain injury than in prior conflicts. These brain injuries range from the mild (concussion) to severe, and have enormous implications for clinical practice with these soldiers. The highly stressful and dangerous context in which these injuries are sustained set them apart in significant ways from brain injuries seen in civilian settings. The associated emotional toll of the environment and comorbid injuries, often resulting from blast exposure, complicates the clinical picture. In this article, the authors describe the complex presentations in this population of traumatically brain injured combat veterans and illustrate with case vignettes.

Neuropsychological Outcome from Blast versus Non-blast: Mild Traumatic Brain Injury in U.S. Military Service Members

The purpose of this study was to compare the neuropsychological outcome from blast-related versus non-blast related mild traumatic brain injury (MTBI). Participants were 56 U.S. military service members who sustained an MTBI, divided into two groups based on mechanism of injury: (a) non-blast related (Non-blast; n = 21), and (b) blast plus secondary blunt trauma (Blast Plus; n = 35). All participants had sustained their injury in theatre whilst deployed during Operation Iraqi Freedom or Operation Enduring Freedom. Patients had been seen for neuropsychological evaluation at Walter Reed Army Medical Center on average 4.4 months (SD = 4.1) post-injury. Measures included 14 clinical scales from the Personality Assessment Inventory (PAI) and 12 common neurocognitive measures. For the PAI, there were no significant differences between groups on all scales (p > .05). However, medium effect sizes were found for the Depression (d = .49) and Stress (d = .47) scales (i.e., Blast Plus > Non-blast). On the neurocognitive measures, after controlling for the influence of psychological distress (i.e., Depression, Stress), there were no differences between the Non-blast and Blast Plus groups on all measures. These findings provide little evidence to suggest that blast exposure plus secondary blunt trauma results in worse cognitive or psychological recovery than blunt trauma alone. (JINS, 2012, 18, 595-605).

Subjective cognitive complaints and neuropsychological test performance following military-related traumatic brain injury

This study examined the relation between neuropsychological test performance and self-reported cognitive complaints following traumatic brain injury (TBI). Participants were 109 servicemembers from the U.S. military who completed a neuropsychological evaluation within the first 2 yr following mild-severe TBI. Measures included the Personality Assessment Inventory (PAI), Posttraumatic Stress Disorder Checklist (PCL-C), Neurobehavioral Symptom Inventory (NSI), and 17 select measures from a larger neurocognitive test battery that corresponded to three self-reported cognitive complaints from the NSI (i.e., memory, attention/concentration, and processing speed/organization). Self-reported cognitive complaints were significantly correlated with psychological distress (PCL-C total: r = 0.50-0.58; half the PAI clinical scales: r = 0.40-0.58). In contrast, self-reported cognitive complaints were not significantly correlated with overall neurocognitive functioning (with the exception of five measures). There was a low rate of agreement between neurocognitive test scores and self-reported cognitive complaints. For the large minority of the sample (38.5%-45.9%), self-reported cognitive complaints were reported in the presence of neurocognitive test scores that fell within normal limits. In sum, self-reported cognitive complaints were not associated with neurocognitive test performance, but rather were associated with psychological distress. These results provide information to contextualize cognitive complaints following TBI.

A Multisite Study of the Relationships between Blast Exposures and Symptom Reporting in a Post-Deployment Active Duty Military Population with Mild Traumatic Brain Injury

Explosive devices have been the most frequent cause of traumatic brain injury (TBI) among deployed contemporary U.S. service members. The purpose of this study was to examine the influence of previous cumulative blast exposures (that did or did not result in TBI) on later post-concussion and post-traumatic symptom reporting after sustaining a mild TBI (MTBI). Participants were 573 service members who sustained MTBI divided into four groups by number of blast exposures (1, 2, 3, and 4-10) and a nonblast control group. Post-concussion symptoms were measured using the Neurobehavioral Symptom Inventory (NSI) and post-traumatic stress disorder (PTSD) symptoms using the Post-traumatic Checklist-Civilian version (PCL-C). Results show groups significantly differed on total NSI scores (p<0.001), where symptom endorsement increased as number of reported blast exposures increased. Total NSI scores were significantly higher for the 3- and 4-10 blast groups compared with the 1- and 2-blast groups with effect sizes ranging from small to moderate (d=0.31 to 0.63). After controlling for PTSD symptoms using the PCL-C total score, NSI total score differences remained between the 4-10-blast group and the 1- and 2-blast groups, but were less pronounced (d=0.35 and d=0.24, respectively). Analyses of NSI subscale scores using PCL-C scores as a covariate revealed significant between-blast group differences on cognitive, sensory, and somatic, but not affective symptoms. Regression analyses revealed that cumulative blast exposures accounted for a small but significant amount of the variance in total NSI scores (4.8%; p=0.009) and total PCL-C scores (2.3%; p<0.001). Among service members exposed to blast, post-concussion symptom reporting increased as a function of cumulative blast exposures. Future research will need to determine the relationship between cumulative blast exposures, symptom reporting, and neuropathological changes.

Factors influencing postconcussion and posttraumatic stress symptom reporting following military-related concurrent polytrauma and traumatic brain injury.

The purpose of this study was to identify factors that are predictive of, or associated with, high endorsement of postconcussion and posttraumatic stress symptoms following military-related traumatic brain injury (TBI). Participants were 1,600 U.S. service members (age: M = 27.1, SD = 7.1; 95.4% male) who had sustained a mild-to-moderate TBI and who had been evaluated by the Defense and Veterans Brain Injury Center at one of six military medical centers. Twenty-two factors were examined that included demographic, injury circumstances/severity, treatment/evaluation, and psychological/physical variables. Four factors were statistically and meaningfully associated with clinically elevated postconcussion symptoms: (i) low bodily injury severity, (ii) posttraumatic stress, (iii) depression, and (iv) military operation where wounded (p < .001, 43.2% variance). The combination of depression and posttraumatic stress symptoms accounted for the vast majority of unique variance (41.5%) and were strongly associated with, and predictive of, clinically elevated postconcussion symptoms [range: odds ratios (OR) = 4.24-7.75; relative risk (RR) = 2.28-2.51]. Five factors were statistically and meaningfully associated with clinically elevated posttraumatic stress symptoms: (i) low bodily injury severity, (ii) depression, (iii) a longer time from injury to evaluation, (iv) military operation where wounded, and (v) current auditory deficits (p < .001; 65.6% variance accounted for). Depression alone accounted for the vast majority of unique variance (60.0%) and was strongly associated with, and predictive of, clinically elevated posttraumatic stress symptoms (OR = 38.78; RR = 4.63). There was a very clear, strong, and clinically meaningful association between depression, posttraumatic stress, and postconcussion symptoms in this sample. Brain injury severity, however, was not associated with symptom reporting following TBI.

Functional MRI in the investigation of blast-related traumatic brain injury

This review focuses on the application of functional magnetic resonance imaging (fMRI) to the investigation of blast-related traumatic brain injury (bTBI). Relatively little is known about the exact mechanisms of neurophysiological injury and pathological and functional sequelae of bTBI. Furthermore, in mild bTBI, standard anatomical imaging techniques (MRI and computed tomography) generally fail to show focal lesions and most of the symptoms present as subjective clinical functional deficits. Therefore, an objective test of brain functionality has great potential to aid in patient diagnosis and provide a sensitive measurement to monitor disease progression and treatment. The goal of this review is to highlight the relevant body of blast-related TBI literature and present suggestions and considerations in the development of fMRI studies for the investigation of bTBI. The review begins with a summary of recent bTBI publications followed by discussions of various elements of blast-related injury. Brief reviews of some fMRI techniques that focus on mental processes commonly disrupted by bTBI, including working memory, selective attention, and emotional processing, are presented in addition to a short review of resting state fMRI. Potential strengths and weaknesses of these approaches as regards bTBI are discussed. Finally, this review presents considerations that must be made when designing fMRI studies for bTBI populations, given the heterogeneous nature of bTBI and its high rate of comorbidity with other physical and psychological injuries.