Faculty Bibliography

OBJECTIVES/OBJECTIVE:To identify personal, clinical, and environmental factors associated with 4 previously identified distinct multidimensional participation profiles of individuals following traumatic brain injury (TBI). SETTING/METHODS:Community. PARTICIPANTS/METHODS:Participants (n = 408) enrolled in the TBI Model Systems (TBIMS) Participation Module, all 1 year or more postinjury. DESIGN/METHODS:Secondary data analysis of cross-sectional data from participants in a multicenter TBIMS module study on participation conducted between May 2006 and September 2007. Participants provided responses to questionnaires via a telephone interview at their study follow-up (1, 2, 5, 10, or 15 years postinjury). MAIN MEASURES/METHODS:Participants provided responses to personal (eg, demographic), clinical (eg, function), environmental (eg, neighborhood type), and participation measures to create multidimensional participation profiles. Data from measures collected at the time of injury (preinjury questionnaire, injury characteristics) were also included. The primary outcome was assignment to one of 4 multidimensional participation profile groups based on participation frequency, importance, satisfaction, and enfranchisement. The measures used to develop the profiles were: Participation Assessment with Recombined Tools-Objective, Importance, and Satisfaction scores, each across 3 domains (Productivity, Social Relationships, Out and About in the Community) and the Enfranchisement Scale (contributing to one's community, feeling valued by the community, choice and control). RESULTS:Results of the multinomial regression analysis, with 4 distinct participation profile groups as the outcome, indicated that education, current employment, current illicit drug use, current driving status, community type, and Functional Independence Measure Cognitive at follow-up significantly distinguished participation profile groups. Findings suggest a trend toward differences in participation profile groups by race/Hispanic ethnicity. CONCLUSIONS:Understanding personal, clinical, and environmental factors associated with distinct participation outcome profiles following TBI may provide more personalized and nuanced guidance to inform rehabilitation intervention planning and/or ongoing clinical monitoring.

BACKGROUND AND PURPOSE/OBJECTIVE:Several recent works using resting-state fMRI suggest possible alterations of resting-state functional connectivity after mild traumatic brain injury. However, the literature is plagued by various analysis approaches and small study cohorts, resulting in an inconsistent array of reported findings. In this study, we aimed to investigate differences in whole-brain resting-state functional connectivity between adult patients with mild traumatic brain injury within 1 month of injury and healthy control subjects using several comprehensive resting-state functional connectivity measurement methods and analyses. MATERIALS AND METHODS/METHODS:A total of 123 subjects (72 patients with mild traumatic brain injury and 51 healthy controls) were included. A standard fMRI preprocessing pipeline was used. ROI/seed-based analyses were conducted using 4 standard brain parcellation methods, and the independent component analysis method was applied to measure resting-state functional connectivity. The fractional amplitude of low-frequency fluctuations was also measured. Group comparisons were performed on all measurements with appropriate whole-brain multilevel statistical analysis and correction. RESULTS:There were no significant differences in age, sex, education, and hand preference between groups as well as no significant correlation between all measurements and these potential confounders. We found that each resting-state functional connectivity measurement revealed various regions or connections that were different between groups. However, after we corrected for multiple comparisons, the results showed no statistically significant differences between groups in terms of resting-state functional connectivity across methods and analyses. CONCLUSIONS:Although previous studies point to multiple regions and networks as possible mild traumatic brain injury biomarkers, this study shows that the effect of mild injury on brain resting-state functional connectivity has not survived after rigorous statistical correction. A further study using subject-level connectivity analyses may be necessary due to both subtle and variable effects of mild traumatic brain injury on brain functional connectivity across individuals.

BACKGROUND AND PURPOSE/OBJECTIVE:Because the corpus callosum connects the left and right hemispheres and a variety of WM bundles across the brain in complex ways, damage to the neighboring WM microstructure may specifically disrupt interhemispheric communication through the corpus callosum following mild traumatic brain injury. Here we use a mediation framework to investigate how callosal interhemispheric communication is affected by WM microstructure in mild traumatic brain injury. MATERIALS AND METHODS/METHODS:Multishell diffusion MR imaging was performed on 23 patients with mild traumatic brain injury within 1 month of injury and 17 healthy controls, deriving 11 diffusion metrics, including DTI, diffusional kurtosis imaging, and compartment-specific standard model parameters. Interhemispheric processing speed was assessed using the interhemispheric speed of processing task (IHSPT) by measuring the latency between word presentation to the 2 hemivisual fields and oral word articulation. Mediation analysis was performed to assess the indirect effect of neighboring WM microstructures on the relationship between the corpus callosum and IHSPT performance. In addition, we conducted a univariate correlation analysis to investigate the direct association between callosal microstructures and IHSPT performance as well as a multivariate regression analysis to jointly evaluate both callosal and neighboring WM microstructures in association with IHSPT scores for each group. RESULTS:Several significant mediators in the relationships between callosal microstructure and IHSPT performance were found in healthy controls. However, patients with mild traumatic brain injury appeared to lose such normal associations when microstructural changes occurred compared with healthy controls. CONCLUSIONS:This study investigates the effects of neighboring WM microstructure on callosal interhemispheric communication in healthy controls and patients with mild traumatic brain injury, highlighting that neighboring noncallosal WM microstructures are involved in callosal interhemispheric communication and information transfer. Further longitudinal studies may provide insight into the temporal dynamics of interhemispheric recovery following mild traumatic brain injury.

OBJECTIVE:To synthesize evidence for the effectiveness of self-management interventions for chronic health conditions that have symptom overlap with traumatic brain injury (TBI) in order to extract recommendations for self-management intervention in persons with TBI. DESIGN/METHODS:An umbrella review of existing systematic reviews and/or meta-analyses of randomized controlled trials or nonrandomized studies targeting self-management of chronic conditions and specific outcomes relevant to persons with TBI. METHOD/METHODS:A comprehensive literature search of 5 databases was conducted using PRISMA guidelines. Two independent reviewers conducted screening and data extraction using the Covidence web-based review platform. Quality assessment was conducted using criteria adapted from the Assessing the Methodological Quality of Systematic Reviews-2 (AMSTAR-2). RESULTS:A total of 26 reviews met the inclusion criteria, covering a range of chronic conditions and a range of outcomes. Seven reviews were of moderate or high quality and focused on self-management in persons with stroke, chronic pain, and psychiatric disorders with psychotic features. Self-management interventions were found to have positive effects on quality of life, self-efficacy, hope, reduction of disability, pain, relapse and rehospitalization rates, psychiatric symptoms, and occupational and social functioning. CONCLUSIONS:Findings are encouraging with regard to the effectiveness of self-management interventions in patients with symptoms similar to those of TBI. However, reviews did not address adaptation of self-management interventions for those with cognitive deficits or for populations with greater vulnerabilities, such as low education and older adults. Adaptations for TBI and its intersection with these special groups may be needed.

BACKGROUND/UNASSIGNED:To elucidate the sociodemographic and study factors involved in enrollment in the Traumatic Brain Injury Model System (TBIMS) database, this study examined the effect of a variety of variables on enrollment at a local TBIMS center. METHODS/UNASSIGNED:A sample of 654 individuals from the local TBIMS center was studied examining enrollment by age, gender, race, ethnicity, homelessness status at date of injury, history of homelessness, health insurance status, presence of social support, primary language, consenting in hospital or after discharge, and the need for an interpreter. Binary logistic regression was conducted to identify variables that predict center-based enrollment into TBIMS. RESULTS/UNASSIGNED: < 0.01). Here, OR denotes the odds ratio estimate from a logistic regression model and P denotes the corresponding p-value. CONCLUSIONS/UNASSIGNED:These results can be useful in driving enrollment strategies at this center for other similar TBI research, and to contribute a representative TBI sample to the national database.

With greater survival rates after catastrophic injury, more women with traumatic brain injury (TBI) are living longer than ever. However, knowledge about this transition in these women is largely unexamined and there are no scales that have been developed to assess the experience of symptoms. To address this gap, we developed and tested a new scale of menopause symptoms in midlife women with TBI. We selected candidate items from two existing measures based on feedback from focus group discussions with seven women with TBI. Twenty candidate items were tested in cognitive interviews with six women with TBI/1 non-TBI. Then, these were field tested with 221 participants (TBI, n = 68; non-TBI, n = 153) recruited from registries. Rasch analysis and convergent validity testing were used to evaluate the new scale. Results of the Rasch analysis indicate that overall, the scale fits well the Rasch model with evidence for unidimensionality. Differential item functioning indicated that the scale performed equally well for women with and without TBI and distinguished pre- and post-menopausal states. Convergent validity was found in the expected directions. These findings support further development of the new scale to understand the experience of menopause symptoms among women with TBI.

INTRODUCTION:There is a growing population of women with limb loss, yet limited research is available to provide evidentiary support for clinical decision-making in this demographic. As such, there is a critical gap in knowledge of evidence-based healthcare practices aimed to maximise the physical and psychosocial needs of women with limb loss. The objective of this study is to develop a comprehensive, survey-based needs assessment to determine the unique impact of limb loss on women, including physical and psychosocial needs. METHODS AND ANALYSIS:A bank of existing limb loss-specific and non-limb loss-specific surveys were arranged around domains of general health, quality of life, prosthetic use and needs, psychosocial health and behaviours and body image. These surveys were supplemented with written items to ensure coverage of relevant domains. Written items were iteratively refined with a multidisciplinary expert panel. The interpretability of items and relevance to limb loss were then internally tested on a small group of rehabilitation, engineering and research professionals. A diverse sample of 12 individuals with various levels of limb loss piloted the instrument and participated in cognitive interviews. Items from existing surveys were evaluated for relevance and inclusion in the survey, but not solicited for content feedback. Pilot testing resulted in the removal of 13 items from an existing survey due to redundancy. Additionally, 13 written items were deleted, 42 written items were revised and 17 written items were added. The survey-based needs assessment has been crafted to comprehensively assess the wide spectrum of issues facing women with limb loss. The final version of the survey-based needs assessment included 15 subsections. ETHICS AND DISSEMINATION:This study was approved by the Veterans Affairs Central Institutional Review Board. The results will be disseminated through national and international conferences, as well as through manuscripts in leading peer-reviewed journals. TRIAL REGISTRATION NUMBER:No healthcare intervention on human participants was conducted.

Traumatic brain injury (TBI) triggers progressive neurodegeneration resulting in brain atrophy that continues months-to-years following injury. However, a comprehensive characterization of the spatial and temporal evolution of TBI-related brain atrophy remains incomplete. Utilizing a sensitive and unbiased morphometry analysis pipeline optimized for detecting longitudinal changes, we analyzed a sample consisting of 37 individuals with moderate-severe TBI who had primarily high-velocity and high-impact injury mechanisms. They were scanned up to three times during the first year after injury (3 months, 6 months, and 12 months post-injury) and compared with 33 demographically matched controls who were scanned once. Individuals with TBI already showed cortical thinning in frontal and temporal regions and reduced volume in the bilateral thalami at 3 months post-injury. Longitudinally, only a subset of cortical regions in the parietal and occipital lobes showed continued atrophy from 3 to 12 months post-injury. Additionally, cortical white matter volume and nearly all deep gray matter structures exhibited progressive atrophy over this period. Finally, we found that disproportionate atrophy of cortex along sulci relative to gyri, an emerging morphometric marker of chronic TBI, was present as early as 3 month post-injury. In parallel, neurocognitive functioning largely recovered during this period despite this pervasive atrophy. Our findings demonstrate msTBI results in characteristic progressive neurodegeneration patterns that are divergent across regions and scale with the severity of injury. Future clinical research using atrophy during the first year of TBI as a biomarker of neurodegeneration should consider the spatiotemporal profile of atrophy described in this study.

Post-traumatic stress disorder (PTSD) is a mental disorder diagnosed by clinical interviews, self-report measures and neuropsychological testing. Traumatic brain injury (TBI) can have neuropsychiatric symptoms similar to PTSD. Diagnosing PTSD and TBI is challenging and more so for providers lacking specialized training facing time pressures in primary care and other general medical settings. Diagnosis relies heavily on patient self-report and patients frequently under-report or over-report their symptoms due to stigma or seeking compensation. We aimed to create objective diagnostic screening tests utilizing Clinical Laboratory Improvement Amendments (CLIA) blood tests available in most clinical settings. CLIA blood test results were ascertained in 475 male veterans with and without PTSD and TBI following warzone exposure in Iraq or Afghanistan. Using random forest (RF) methods, four classification models were derived to predict PTSD and TBI status. CLIA features were selected utilizing a stepwise forward variable selection RF procedure. The AUC, accuracy, sensitivity, and specificity were 0.730, 0.706, 0.659, and 0.715, respectively for differentiating PTSD and healthy controls (HC), 0.704, 0.677, 0.671, and 0.681 for TBI vs. HC, 0.739, 0.742, 0.635, and 0.766 for PTSD comorbid with TBI vs HC, and 0.726, 0.723, 0.636, and 0.747 for PTSD vs. TBI. Comorbid alcohol abuse, major depressive disorder, and BMI are not confounders in these RF models. Markers of glucose metabolism and inflammation are among the most significant CLIA features in our models. Routine CLIA blood tests have the potential for discriminating PTSD and TBI cases from healthy controls and from each other. These findings hold promise for the development of accessible and low-cost biomarker tests as screening measures for PTSD and TBI in primary care and specialty settings.