Longitudinal health outcomes in caregivers of military members with traumatic brain injury.

PURPOSE/OBJECTIVE: To examine longitudinal change in health-related quality of life (HRQOL) in caregivers of service members/veterans with traumatic brain injury and factors associated with clinically elevated symptoms. RESEARCH METHOD/DESIGN: Caregivers (N = 220) completed nine HRQOL outcome measures and 10 risk factor measures at a baseline evaluation and follow-up evaluation 3 years later. Caregiver's responses on the nine HRQOL outcome measures were classified into four clinical change categories based on the presence/absence of clinically elevated T-scores (≥ 60 T) at baseline and follow-up: (a) Persistent (baseline ≥ 60T + follow-up ≥ 60 T), (b) Developed (baseline < 60 T + follow-up ≥ 60 T), (c) Improved (baseline ≥ 60 T + follow-up < 60 T), and (d) Asymptomatic (baseline < 60 T + follow-up < 60 T). A clinical change composite score was calculated by summing the number of Persistent or Developed HRQOL outcome measures and used to create three clinical change groups: (a) No Symptoms (n = 69, zero measures), (b) Some Symptoms (n = 88, one to three measures), and (c) Numerous Symptoms (n = 63, four to nine measures). RESULTS: Of the nine HRQOL outcome measures, Bodily Pain, Perceived Stress, Sleep-Related Impairment, and Fatigue were most frequently classified as Persistent or Developed from baseline to follow-up in the entire sample. A linear relationship was found between the vast majority of risk factors across the three clinical change groups at baseline and follow-up (Numerous > Some > None). The risk factors were correlated with the number of elevated HRQOL symptoms at baseline and follow-up. Most Asymptomatic or Persistent caregivers did not have meaningful change (≥ 1 SD) in HRQOL scores. A sizable proportion of Developed or Improved caregivers had either meaningful or no change in HRQOL scores. CONCLUSIONS/IMPLICATIONS: There is a need for ongoing clinical services for military caregivers. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

An Initial Psychometric Analysis of the Brain Gauge Tactile-Based Test Battery and Its Potential for Clinical Use Assessing Patients With Acute Mild Traumatic Brain Injury.

OBJECTIVE: A new brief computerized test battery that uses tactile stimulation, Brain Gauge (BG), has been proposed as a cognitive assessment aid and its developers have reported an almost perfect ability to distinguish acute mild traumatic brain injury (mTBI) patients from healthy controls. This investigation attempted to replicate those results and serve as an initial psychometrically and clinically focused analysis of BG. METHODS: BG scores from 73 military service members (SM) assessed within 7 days after having a clinically diagnosed mTBI were compared to 100 healthy SMs. Mean scores were compared, score distributions were examined, and univariate and multivariate base rate analyses of low scores were performed. RESULTS: SMs with mTBI had statistically significantly worse performance on both BG Reaction Time (RT) tests and the Sequential Amplitude Discrimination test as reflected by higher mean RT and RT variability and higher minimum detectable amplitude difference. SMs with mTBI also had a significantly lower whole-battery composite (i.e., Cortical Metric Symptom Score). Larger proportions of SMs with mTBI had lower overall performance than controls. However, at most only 26.9% of those with mTBI performed at potentially clinically meaningful cutoffs that were defined as various numbers of low scores that were prevalent in no more than 10% of the control group, which is equivalent to specificity ≥90% and sensitivity ≤26.9% for mTBI. CONCLUSION: Our analysis did not replicate the high level of classification accuracy reported by BG's developers. Pending further psychometric development, BG may have limited clinical utility for assessing mTBI patients.

Military TBI-What civilian primary care providers should know.

In June 2019, the Department of Veterans Affairs (VA) launched the VA Mission Act, which expanded veterans' health-care access to the private sector. Since civilian primary care providers may see more veterans in their practice, it will be important to understand the unique experiences, comorbidities, and culture of this population in order to provide optimal care. Military service members (SMs) are at an increased risk for traumatic brain injury (TBI), and comorbidities, such as post traumatic stress disorder (PTSD), increasing the likelihood of prolonged symptoms. Military training and repetitive low-level blast exposure may cause symptoms similar to TBI or increase long-term negative effects in SMs. Military culture often has a strong influence in this population. Those who serve in the military identify with military values and have a strong team mentality, which places emphasis on the mission above all else, not accepting defeat, and not ever leaving a fellow SM behind. These values can impact the way a SM/veteran seeks care and/or communicates with his or her health-care provider. Taking a detailed history to understand how these factors apply, as well as screening for mental health comorbidities, are recommended. Understanding the military cultural influences can assist in promoting a stronger therapeutic alliance and encourage more open communication. Ultimately, it is the trusting and respectful relationship between the SM/veteran and the provider that will determine the most effective treatment and result in the most effective resolution of TBI and comorbid symptoms.

An Investigation of the Accuracy of Reaction Time Measurements on ANAM4 TBI-MIL Across Three Computer Platforms.

STUDY DESIGN: Using two observational methods and a within-subjects, counterbalanced design, this study aimed to determine if a computer's hardware and software settings significantly affected reaction time (RT) on the Automated Neuropsychological Assessment Metrics (Version 4) Traumatic Brain Injury Military (ANAM4 TBI-MIL). METHODS: Three computer platforms were investigated: Platform 1-older computers recommended for ANAM4 TBI-MIL administration, Platform 2-newer computers with settings downgraded to run like the older computers, and Platform 3-newer computers with default settings. Two observational methods were used to compare measured RT to observed RT on all three platforms: 1, a high-speed video analysis to compare the timing of stimulus onset and response to the measured RT and 2, comparing a preset RT delivered by a robotic key actuator activated by optic detector to the measured RT. Additionally, healthy active duty service members (n = 169) were administered a brief version of the ANAM4 TBI-MIL battery on each of the three platforms. RESULTS: RT differences were observed with both the high-speed video and robotic arm analyses across all three computer platforms, with the smallest discrepancies between observed and measured RT on Platform 1, followed by Platform 2, then Platform 3. When simple reaction time (SRT) raw and standardized scores obtained from the participants were compared across platforms, statistically significant and clinically meaningful differences were seen, especially between Platforms 1 and 3. CONCLUSIONS: A computer's configurations have a meaningful impact on ANAM SRT scores. The difference in an individual's performance across platforms could be misinterpreted as clinically meaningful change.

Developing an Executive Functioning Composite Score for Research and Clinical Trials.

OBJECTIVE: Executive functioning encompasses interactive cognitive processes such as planning, organization, set-shifting, inhibition, self-monitoring, working memory, and initiating and sustaining motor and mental activity. Researchers therefore typically assess executive functioning with multiple tests, each yielding multiple scores. A single composite score of executive functioning, which summarizes deficits across a battery of tests, would be useful in research and clinical trials. This study examines multiple candidate composite scores of executive functioning using tests from the Delis-Kaplan Executive Function System (D-KEFS). METHOD: Participants were 875 adults between the ages of 20 and 89 years from the D-KEFS standardization sample. Seven Total Achievement scores were used from three tests (i.e., Trail Making, Verbal Fluency, and Color-Word Interference) to form eight composite scores that were compared based on their psychometric properties and association with intelligence (IQ). RESULTS: The distributions of most composite scores were mildly to severely skewed, and some had a pronounced ceiling effect. The composite scores all showed a medium positive correlation with IQ. The composite scores were highly intercorrelated in the total sample and in four IQ subgroups (i.e., IQ <89, 90-99, 100-109, 110+), with some being so highly correlated that they appear redundant. CONCLUSIONS: This study is part of a larger research program developing a cognition endpoint for research and clinical trials with sound psychometric properties and utility across discrepant test batteries. Future research is needed to examine the reliability and ecological validity of these composite scores.

Comparing Composite Scores for the ANAM4 TBI-MIL for Research in Mild Traumatic Brain Injury.

OBJECTIVE: The Automated Neuropsychological Assessment Metrics (Version 4) Traumatic Brain Injury Military (ANAM4 TBI-MIL) is commonly administered among U.S. service members both pre-deployment and following TBI. The current study used the ANAM4 TBI-MIL to develop a cognition summary score for TBI research and clinical trials, comparing eight composite scores based on their distributions and sensitivity/specificity when differentiating between service members with and without mild TBI (MTBI). METHOD: Male service members with MTBI (n = 56; Mdn = 11 days-since-injury) or no self-reported TBI history (n = 733) completed eight ANAM4 TBI-MIL tests. Their throughput scores (correct responses/minute) were used to calculate eight composite scores: the overall test battery mean (OTBM); global deficit score (GDS); neuropsychological deficit score-weighted (NDS-W); low score composite (LSC); number of scores <50th, ≤16th percentile, or ≤5th percentile; and the ANAM Composite Score (ACS). RESULTS: The OTBM and ACS were normally distributed. Other composites had skewed, zero-inflated distributions (62.9% had GDS = 0). All composites differed significantly between participants with and without MTBI (p < .001), with deficit scores showing the largest effect sizes (d = 1.32-1.47). The Area Under the Curve (AUC) was lowest for number of scores ≤5th percentile (AUC = 0.653) and highest for the LSC, OTBM, ACS, and NDS-W (AUC = 0.709-0.713). CONCLUSIONS: The ANAM4 TBI-MIL has no well-validated composite score. The current study examined multiple candidate composite scores, finding that deficit scores showed larger group differences than the OTBM, but similar AUC values. The deficit scores were highly correlated. Future studies are needed to determine whether these scores show less redundancy among participants with more severe TBIs.

Using Rates of Low Scores to Assess Agreement between Brief Computerized Neuropsychological Assessment Batteries: A Clinically-based Approach for Psychometric Comparisons.

OBJECTIVE: To assess agreement between four brief computerized neurocognitive assessment tools (CNTs), ANAM, CogState, CNS Vital Signs, and ImPACT, by comparing rates of low scores. METHODS: Four hundred and six US Army service members (SMs) with and without acute mild traumatic brain injury completed two randomly assigned CNTs with order of administration also randomly assigned. We performed a base rate analysis for each CNT to determine the proportions of SMs in the control and mTBI groups who had various numbers of scores that were 1.0+, 1.5+, and 2.0+ standard deviations below the normative mean. We used these results to identify a hierarchy of low score levels ranging from poorest to least poor performance. We then compared the agreement between every low score level from each CNT pair administered to the SMs. RESULTS: More SMs in the mTBI group had low scores on all CNTs than SMs in the control group. As performance worsened, the association with mTBI became stronger for all CNTs. Most if not all SMs who performed at the worst level on any given CNT also had low scores on the other CNTs they completed but not necessarily at an equally low level. CONCLUSION: These results suggest that all of the CNTs we examined are broadly similar but still retain some psychometric differences that need to be better understood. Furthermore, the base rates of low scores we present could themselves be useful to clinicians and researchers as a guide for interpreting results from the CNTs.

A Clinical Evidence-Based Approach to Examine the Effects of mTBI and PTSD Symptoms on ANAM Performance in Recently Deployed Active Duty Soldiers: Results From the Warrior Strong Study.

OBJECTIVE: Service members are frequently diagnosed with comorbid mild traumatic brain injury (mTBI) and posttraumatic stress disorder after returning from Afghanistan and Iraq. Little is known about how mTBI in the postacute and chronic phases combined with current posttraumatic stress disorder symptoms (PTS) affects performance on the Automated Neuropsychological Assessment Metrics, Version 4, Traumatic Brain Injury-Military (ANAM4) battery used by the US military. We examined postdeployment ANAM4 performance using conventional statistical methods, as well as rates of poor performance, below established cutoffs (<10th and ≤2nd percentile). METHODS: A total of 868 soldiers were assessed for history of mTBI during the most recent deployment, as well as, lifetime mTBI, current PTS, and current pain-related symptoms. The ANAM4 was also administered. RESULTS: Soldiers with PTS and/or mTBI performed worse on ANAM4 relative to controls with those with both conditions performing worst. However, a nontrivial minority (∼10%-30%) of individuals with mTBI, PTS, or both had scores that were at or below the second percentile. CONCLUSION: Our results illustrate that a combination of mTBI and PTS is associated with worse ANAM4 performance than either condition alone. Furthermore, only a minority of soldiers with any, or both, of the conditions had ANAM deficits. The long-lasting impacts and unique contribution of each condition have yet to be determined.

A Comparison of Four Computerized Neurocognitive Assessment Tools to a Traditional Neuropsychological Test Battery in Service Members with and without Mild Traumatic Brain Injury.

OBJECTIVE: Computerized neurocognitive assessment tools (NCATS) are often used as a screening tool to identify cognitive deficits after mild traumatic brain injury (mTBI). However, differing methodology across studies renders it difficult to identify a consensus regarding the validity of NCATs. Thus, studies where multiple NCATs are administered in the same sample using the same methodology are warranted. METHOD: We investigated the validity of four NCATs: the ANAM4, CNS-VS, CogState, and ImPACT. Two NCATs were randomly assigned and a battery of traditional neuropsychological (NP) tests administered to healthy control active duty service members (n = 272) and to service members within 7 days of an mTBI (n = 231). Analyses included correlations between NCAT and the NP test scores to investigate convergent and discriminant validity, and regression analyses to identify the unique variance in NCAT and NP scores attributed to group status. Effect sizes (Cohen's f2) were calculated to guide interpretation of data. RESULTS: Only 37 (0.6%) of the 5,655 correlations calculated between NCATs and NP tests are large (i.e. r ≥ 0.50). The majority of correlations are small (i.e. 0.30 > r ≥ 0.10), with no clear patterns suggestive of convergent or discriminant validity between the NCATs and NP tests. Though there are statistically significant group differences across most NCAT and NP test scores, the unique variance accounted for by group status is minimal (i.e. semipartial R2 ≤ 0.033, 0.024, 0.062, and 0.011 for ANAM4, CNS-VS, CogState, and ImPACT, respectively), with effect sizes indicating small to no meaningful effect. CONCLUSION: Though the results are not overly promising for the validity of the four NCATs we investigated, traditional methods of investigating psychometric properties may not be appropriate for computerized tests. We offer several conceptual and methodological considerations for future studies regarding the validity of NCATs.

Which Matters More? A Retrospective Cohort Study of Headache Characteristics and Diagnosis Type in Soldiers with mTBI/Concussion.

OBJECTIVE: To describe the diagnostic types and characteristics of headaches in soldiers with mild traumatic brain injury during the wars in Afghanistan and Iraq. BACKGROUND: Persistent post-traumatic headache interferes with returns to activity or duty. The most commonly cited headache diagnosis after concussion is migraine. We hypothesize that headache diagnosis type, eg, migraine, is not sufficient to predict relationships with occupational outcomes after concussion. METHODS: The study sample consisted of all new patients referred for headache evaluation at the Brain Injury Center at Womack Army Medical Center over a 1-year time period. The design was retrospective and observational. Clinical data reported included demographics, causes of injury, headache characteristics, and headache diagnosis type. After reviewing records for retention or severance from military service, the primary occupational outcome measure was departure from service due to medical cause as determined by a Medical Evaluation Board (MEB). The primary outcome measure was to test the strength of association between leaving service for MEB and headache characteristics or diagnosis. RESULTS: A total of 95 patients (94% male) with concussion described 166 distinct headache types, the most common being migraine (60%) and trigeminal autonomic cephalalgia (24%). A total of 25% of all patients remained on active duty. A continuous headache of any type was present in 75% of patients and of these, 23% remained on active duty. Of the 51% of patients who had both a continuous and non-continuous headache, 17% remained on active duty (P < .001). Therefore, we report that a continuous headache, regardless of diagnosis type was associated with negative occupational outcomes. Regardless of headache duration, headache diagnosis type alone was not associated with soldiers' separations from service. CONCLUSIONS: Persistent post-traumatic headache is most likely to present with continuous pain. Migraine is the most common primary diagnosis type. The presence of a continuous headache was strongly associated with negative occupational outcomes. Primary headache diagnosis type was not. Headache characteristics, therefore, may be more important than diagnosis type when determining active duty status. Further prospective research is indicated.

Developing a Cognition Endpoint for Traumatic Brain Injury Clinical Trials.

Cognitive impairment is a core clinical feature of traumatic brain injury (TBI). After TBI, cognition is a key determinant of post-injury productivity, outcome, and quality of life. As a final common pathway of diverse molecular and microstructural TBI mechanisms, cognition is an ideal endpoint in clinical trials involving many candidate drugs and nonpharmacological interventions. Cognition can be reliably measured with performance-based neuropsychological tests that have greater granularity than crude rating scales, such as the Glasgow Outcome Scale-Extended, which remain the standard for clinical trials. Remarkably, however, there is no well-defined, widely accepted, and validated cognition endpoint for TBI clinical trials. A single cognition endpoint that has excellent measurement precision across a wide functional range and is sensitive to the detection of small improvements (and declines) in cognitive functioning would enhance the power and precision of TBI clinical trials and accelerate drug development research. We outline methodologies for deriving a cognition composite score and a research program for validation. Finally, we discuss regulatory issues and the limitations of a cognition endpoint.

Headache in military service members with a history of mild traumatic brain injury: A cohort study of diagnosis and classification.

Introduction Headaches after concussion are highly prevalent, relatively persistent and are being treated like primary headaches, especially migraine. Methods We studied all new patients seen between August 2008 and December 2009 assessed by a civilian headache specialist at the TBI Center at Womack Army Medical Center, Fort Bragg, NC. We report sample demographics, injuries and headache characteristics, including time from injury to headache onset, detailed descriptions and International Classification of Headache Disorders second edition primary headache diagnosis type. Results A total of 95 soldiers reported 166 headaches. The most common injury cited was a blast (53.7%). Most subjects (76.8%) recalled the onset of any headache within 7 days of injury. The most commonly diagnosed headache was a continuous type with migraine features ( n = 31 (18.7%)), followed by chronic migraine (type 1.5.1, n = 14 (8.4%)), migraine with aura (type 1.2.1, n = 10 (6.0%)), hemicrania continua (type 4.7, n = 12 (7.2%)), chronic cluster (type 3.1.2, n = 6 (3.6%)) and headaches not otherwise classifiable (type 14.1, n = 5 (3.0%)) also present. The most clinically important was a continuous headache with migraine features. Conclusion We present a series of patients seen in a military treatment facility for headache diagnosis after concussion in whom we found migraine, as well as uncommon primary headache types, at frequencies that were much higher than expected.

The impact of administration order in studies of computerized neurocognitive assessment tools (NCATs).

Computerized neurocognitive assessment tools (NCATs) have become a common way to assess postconcussion symptoms. As there is increasing research directly comparing multiple NCATs to each other, it is important to consider the impact that order of test administration may have on the integrity of the results. This study investigates the impact of administration order in a study of four different NCATs; Automated Neuropsychological Assessment Metrics (ANAM4), CNS Vital Signs (CNS-VS), CogState, and Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). A total of 272 healthy active duty Service Members were enrolled into this study. All participants were randomly assigned to take two of the four NCATs with order of administration counterbalanced. Analyses attempted to investigate the effect of administration order alone (e.g., Time 1 versus Time 2), the effect of administration order combined with the impact of the specific NCAT received at Time 1, and only the impact of the Time 1 NCAT on Time 2 score variability. Specifically, independent samples t tests were used to compare Time 1 and Time 2 scores within each NCAT. Additional t tests compared Time 1 to Time 2 scores with Time 2 scores grouped by the NCAT received at Time 1. One-way analysis of variance (ANOVA) was used to compare only an NCAT's Time 2 scores grouped by the NCAT received at Time 1. Cohen's d effect sizes were calculated for all comparisons. The results from this study revealed statistically significant order effects for CogState and CNS-VS, though with effect sizes generally indicating minimum practical value, and marginal or absent order effects for ANAM4 and ImPACT with no clinically meaningful implications. Despite finding minimal order effects, clinicians should be mindful of the impact of administering multiple NCATs in a single session. Future studies should continue to be designed to minimize the potential effect of test administration order.

[Formula: see text]Interpreting change on the neurobehavioral symptom inventory and the PTSD checklist in military personnel.

OBJECTIVE: The purpose of this study was to examine the prevalence and stability of symptom reporting in a healthy military sample and to develop reliable change indices for two commonly used self-report measures in the military health care system. PARTICIPANTS AND METHOD: Participants were 215 U.S. active duty service members recruited from Fort Bragg, NC as normal controls as part of a larger study. Participants completed the Neurobehavioral Symptom Inventory (NSI) and Posttraumatic Checklist (PCL) twice, separated by approximately 30 days. RESULTS: Depending on the endorsement level used (i.e. ratings of 'mild' or greater vs. ratings of 'moderate' or greater), approximately 2-15% of this sample met DSM-IV symptom criteria for Postconcussional Disorder across time points, while 1-6% met DSM-IV symptom criteria for Posttraumatic Stress Disorder. Effect sizes for change from Time 1 to Time 2 on individual symptoms were small (Cohen's d = .01 to .13). The test-retest reliability for the NSI total score was r = .78 and the PCL score was r = .70. An eight-point change in symptom reporting represented reliable change on the NSI total score, with a seven-point change needed on the PCL. CONCLUSIONS: Postconcussion-like symptoms are not unique to mild TBI and are commonly reported in a healthy soldier sample. It is important for clinicians to use normative data when evaluating a service member or veteran and when evaluating the likelihood that a change in symptom reporting is reliable and clinically meaningful.

Military Deployment May Increase the Risk for Traumatic Brain Injury Following Deployment.

OBJECTIVE: To compare rates of traumatic brain injury (TBI) diagnosis before and after overseas military deployment. DESIGN: We conducted a retrospective examination of a cohort of 119 353 active duty US military service members (Army, Navy, Air Force, and Marines) whose first lifetime overseas deployment began at any time between January 1, 2011, and December 31, 2011, and lasted at least for 30 days. For this cohort, TBI diagnoses were examined during the 76 weeks prior to deployment, during deployment, and 76 weeks following the end of deployment. MAIN MEASURES: 4-week rates of TBI diagnosis. RESULTS: The risk of being diagnosed with TBI within 4 weeks after returning from deployment was 8.4 times higher than the average risk before deployment. The risk gradually decreased thereafter up to 40 weeks postdeployment. However, during the 41 to 76 weeks following deployment, risk stabilized but remained on average 1.7 times higher than before deployment. CONCLUSION: An increased rate of TBI diagnosis following deployment was identified, which may be partly due to delayed diagnosis of TBIs that occurred while service members were deployed. Also, the increased rate may partly be due to riskier behaviors of service members following deployment that results in an increased occurrence of TBIs.

Using base rates of low scores to interpret the ANAM4 TBI-MIL battery following mild traumatic brain injury.

Base rates of low ANAM4 TBI-MIL scores were calculated in a convenience sample of 733 healthy male active duty soldiers using available military reference values for the following cutoffs: ≤2nd percentile (2 SDs), ≤5th percentile, <10th percentile, and <16th percentile (1 SD). Rates of low scores were also calculated in 56 active duty male soldiers who sustained an mTBI an average of 23 days (SD = 36.1) prior. 22.0% of the healthy sample and 51.8% of the mTBI sample had two or more scores below 1 SD (i.e., 16th percentile). 18.8% of the healthy sample and 44.6% of the mTBI sample had one or more scores ≤5th percentile. Rates of low scores in the healthy sample were influenced by cutoffs and race/ethnicity. Importantly, some healthy soldiers obtain at least one low score on ANAM4. These base rate analyses can improve the methodology for interpreting ANAM4 performance in clinical practice and research.

Test-retest reliability of four computerized neurocognitive assessment tools in an active duty military population.

Computerized neurocognitive assessment tools (NCATs) are increasingly used for baseline and post-concussion assessments. To date, NCATs have not demonstrated strong test-retest reliabilities. Most studies have used non-military populations and different methodologies, complicating the determination of the utility of NCATs in military populations. The test-retest reliability of four NCATs (Automated Neuropsychological Assessment Metrics 4 [ANAM4], CNS-Vital Signs, CogState, and Immediate Post-Concussion Assessment and Cognitive Test [ImPACT]) was investigated in a healthy active duty military sample. Four hundred and nineteen Service Members were randomly assigned to take one NCAT and 215 returned after approximately 30 days for retest. Participants deemed to have inadequate effort during one or both testing sessions, according to the NCATs scoring algorithms, were removed from analyses. Each NCAT had at least one reliability score (intraclass correlation) in the "adequate" range (.70-.79), only ImPACT had one score considered "high" (.80-.89), and no scores met "very high" criteria (.90-.99). However, overall test-retest reliabilities in four NCATs in a military sample are consistent with reliabilities reported in the literature and are lower than desired for clinical decision-making.

Self-reported mild TBI and postconcussive symptoms in a peacetime active duty military population: effect of multiple TBI history versus single mild TBI.

OBJECTIVE: To investigate the potential cumulative impact of mild traumatic brain injury (MTBI) on postconcussive symptoms. PARTICIPANTS: A total of 224 active duty soldiers reporting MTBI within 1 year of testing. For 101, this MTBI was their only reported traumatic brain injury (TBI); 123 had sustained at least 1 additional MTBI during their lifetime. A No TBI control group (n = 224) was included for comparison. MAIN MEASURE: Self-report symptoms data via questionnaire. Within time since injury subgroups (≤3 months; Post-3 months), symptom endorsement (no symptoms, 1 or 2 symptoms, 3+ symptoms) among soldiers with 1 MTBI was compared with that of soldiers with 2 or more MTBIs. Injured soldiers' symptom endorsement was compared with that of soldiers who had not sustained a TBI. RESULTS: Among the recently injured (≤3 months), those with 2 or more MTBIs endorsed significantly more symptoms than those with 1 MTBI: 67% of soldiers with 2 or more MTBIs reported 3+ symptoms, versus 29% of One MTBI soldiers. Among Post-3 month soldiers, there were no significant differences between MTBI groups. Overall, soldiers with MTBI endorsed significantly more symptoms than those without TBI. CONCLUSION: Past experience of MTBI may be a risk factor for increased symptom difficulty for several months postinjury. Clinicians should ascertain lifetime history of brain injury when evaluating patients for MTBI.

Hospitalization associated with traumatic brain injury in the active duty US Army: 2000-2006.

OBJECTIVE: to determine the potential impacts of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) on the incidence of TBI-related hospitalization in the active duty US Army. METHODS: All active duty Army personnel hospitalized with a TBI diagnosis during fiscal years 2000 through 2006 were identified in an administrative database. Annual crude incidence rates were calculated. Two-year adjusted incidence rates were calculated to compare TBI-related hospitalization rates in the Army to rates in the age-comparable segment of the US civilian population. RESULTS: The overall incidence of TBI-related hospitalization in the active duty Army increased 105% from FY2000 to FY2006. There was a 60-fold increase in the hospitalization rate for TBIs attributed to weapons. The increases in TBI hospitalizations coincided with the occurrence of OEF/OIF. During OEF/OIF, the Army's hospitalization rates for moderate and severe TBIs were lower than civilian rates; however, the Army's hospitalization rate for mild TBIs was higher than civilian rates. CONCLUSION: OEF/OIF appear to have had a substantial impact on TBI-related hospitalization rates in the active duty US Army but differences between Army and civilian rates were not as excessive as expected.

Neuropsychological test performance in soldiers with blast-related mild TBI.

This exploratory study was conducted to increase understanding of neuropsychological test performance in those with blast-related mild traumatic brain injury (mTBI). The two variables of interest for their impact on test performance were presence of mTBI symptoms and history of posttraumatic stress disorder (PTSD). Forty-five soldiers postblast mTBI, 27 with enduring mTBI symptoms and 18 without, completed a series of neuropsychological tests. Seventeen of the 45 met criteria for PTSD. The Paced Auditory Serial Addition Test (Frencham, Fox, & Mayberry, 2005; Spreen & Strauss, 1998) was the primary outcome measure. Two-sided, 2-sample t tests were used to compare scores between groups of interest. Presence of mTBI symptoms did not impact test performance. In addition, no significant differences between soldiers with and without PTSD were identified. Standard neuropsychological assessment may not increase understanding about impairment associated with mTBI symptoms. Further research in this area is indicated.