Traumatic Brain Injury Participants Research Articles

Diagnostic Utility of Glial Fibrillary Acidic Protein Beyond 12 Hours After Traumatic Brain Injury: A TRACK-TBI Study.

Blood levels of glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase-L1 (UCH-L1) within 12h of suspected traumatic brain injury (TBI) have been approved by the Food and Drug administration to aid in determining the need for a brain computed tomography (CT) scan. The current study aimed to determine whether this context of use can be expanded beyond 12h post-TBI in patients presenting with Glasgow Coma Scale (GCS) 13-15. The prospective, 18-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study enrolled TBI participants aged ≥17 years who presented to a United States Level 1 trauma center and received a clinically indicated brain CT scan within 24h post-injury, a blood draw within 24h and at 14 days for biomarker analysis. Data from participants with emergency department arrival GCS 13-15 and biomarker values at days 1 and 14 were extracted for the primary analysis. A subgroup of hospitalized participants with serial biomarkers at days 1, 3, 5, and 14 were analyzed, including plasma GFAP and UCH-L1, and serum neuron-specific enolase (NSE) and S100 calcium-binding protein B (S100B). The primary analysis compared biomarker values dichotomized by head CT results (CT+/CT-). Area under receiver-operating characteristic curve (AUC) was used to determine diagnostic accuracy. The overall cohort included 1142 participants with initial GCS 13-15, with mean age 39.8 years, 65% male, and 73% Caucasian. The GFAP provided good discrimination in the overall cohort at days 1 (AUC = 0.82) and 14 (AUC = 0.72), and in the hospitalized subgroup at days 1 (AUC = 0.84), 3 (AUC = 0.88), 5 (AUC = 0.82), and 14 (AUC = 0.74). The UCH-L1, NSE, and S100B did not perform well (AUC = 0.51-0.57 across time points). This study demonstrates the utility of GFAP to aid in decision-making for diagnostic brain CT imaging beyond the 12h time frame in patients with TBI who have a GCS 13-15.

Cortisol dynamics, quality of life and fatigue following traumatic brain injury in childhood.

Traumatic brain injury (TBI) is a leading cause of acquired neurological morbidity. The prevalence of post-traumatic hypopituitarism (PTHP) and associated morbidity after childhood TBI is unclear. Our study investigated long term HPA (hypothalamus-pituitary-adrenal) axis function, in a prospective childhood TBI and control cohort, using measures of cortisol/cortisone secretion (physiological, stimulated), HPA axis feedback and exploring associations with fatigue, depression and Quality of Life (QoL) outcomes. All TBI participants had data concerning severity and mechanism of TBI. All groups had clinical assessment, pituitary/brain MRI, questionnaire measures of QoL, fatigue, depression and salivary cortisone profiles including dexamethasone suppression test. In addition participants with Moderate/Severe TBI had ethical approval for baseline endocrine blood tests, overnight 12-hour venous sampling of cortisol and growth hormone, and stimulated HPA axis evaluation with an insulin tolerance test (ITT). Seventy-two participants with moderate/severe (n=31, age 19.8±4.2 years) or mild TBI (n=24, age 17.8±5.1 years) and matched controls (n=17, age 18.5±5.5 years) took part. Time post TBI was 6.8-10.8 years. Baseline endocrine tests confirmed normal thyroid and posterior pituitary function. One female with moderate/severe TBI had hypogonadism. Pituitary neuroimaging was normal in all participants. In 2/25 ITT and 9/22 overnight serum profiles peak cortisol was <500nmol/l. The two participants with suboptimal ITT cortisol response (392 and 483nmol/L) also had low peak spontaneous serum levels (227 and 447nmol/L respectively). Salivary cortisone profiles showed preservation of HPA axis circadian rhythm and suppression with dexamethasone in all but one TBI participant. TBI participants had higher morning salivary cortisone levels compared to controls. Fatigue was reported by 20/46 TBI participants but only 1/14 controls. Fatigue was not associated with stimulated (ITT) or spontaneous (overnight profile) cortisol, however one TBI participant with severe fatigue had a suboptimal ITT cortisol response. Specific QoL attributes of health state (cognition, memory) were impaired in TBI participants compared to controls. Although not as prevalent as previously reported, HPA axis dysfunction does occur in survivors of childhood TBI confirming the need for endocrine surveillance. However, in most of our paediatric TBI survivors assessed 7-11 years post-TBI, HPA function and circadian rhythmicity was preserved or had recovered. Chronic fatigue is a common concern post TBI but in the majority not associated with frank HPA axis dysfunction. Morning salivary cortisone levels were higher in TBI survivors, (who have a high prevalence of fatigue) compared to healthy controls, despite the recognised association of chronic fatigue with cortisol hyposecretion.

Altered grey matter structural covariance in chronic moderate–severe traumatic brain injury

Traumatic brain injury (TBI) alters brain network connectivity. Structural covariance networks (SCNs) reflect morphological covariation between brain regions. SCNs may elucidate how altered brain network topology in TBI influences long-term outcomes. Here, we assessed whether SCN organisation is altered in individuals with chronic moderate–severe TBI (≥ 10 years post-injury) and associations with cognitive performance. This case–control study included fifty individuals with chronic moderate–severe TBI compared to 75 healthy controls recruited from an ongoing longitudinal head injury outcome study. SCNs were constructed using grey matter volume measurements from T1-weighted MRI images. Global and regional SCN organisation in relation to group membership and cognitive ability was examined using regression analyses. Globally, TBI participants had reduced small-worldness, longer characteristic path length, higher clustering, and higher modularity globally (p < 0.05). Regionally, TBI participants had greater betweenness centrality (p < 0.05) in frontal and central areas of the cortex. No significant associations were observed between global network measures and cognitive ability in participants with TBI (p > 0.05). Chronic moderate–severe TBI was associated with a shift towards a more segregated global network topology and altered organisation in frontal and central brain regions. There was no evidence that SCNs are associated with cognition.

11 The Moderating Effect of Depression on Workload Perception in Traumatic Brain Injury

Objective:Individuals who have experienced traumatic brain injury (TBI) are at an elevated risk for worsened physical and psychological outcomes. Increased rates of anxiety and depression, along with cognitive issues, are common post-TBI. While there is some evidence that anxiety and depression may affect objective cognitive performance, less is known about their effect on other factors that are associated with the individual’s capacity to complete the task, such as perceived workload of the cognitive task. Workload represents an individual’s perception of task difficulty and serves as a proxy for the magnitude of mental demands a given task places on an individual. Preliminary findings in the literature suggest that individuals with TBI commonly report greater workload when completing cognitive tasks compared to neurotypical peers, but the influence of anxiety and depression on survivors’ workload remains unclear. Considering the elevated rates of psychological and cognitive problems in individuals with TBI, the present study examined the moderating role of anxiety and depression on TBI survivor workload perception of a stress-inducing working memory task.Participants and Methods:Ten participants with moderate to severe TBI and eight neurologically healthy controls performed the Paced Auditory Serial Addition Task (PASAT). After completing the PASAT, participants reported their subjective workload using the NASA task load index (NASA-TLX). Participants also completed measures of psychological functioning, including the Chicago Multiscale Depression Inventory (CMDI) and the State-Trait Anxiety Inventory (STAI). Relationships between workload and depression and trait anxiety were examined using linear regression.Results:Linear regression was employed for both the TBI and the healthy control groups to assess the influence of trait anxiety and depression on perceived workload. There was no significant difference between the TBI and HC NASA perceived workload scores. Within the TBI group, there was a significant anxiety by depression interaction (b = -.015, p &lt; .001). Simple slopes analyses revealed that for TBI participants reporting low depression, perceived workload increased with increased anxiety (b = .093, p &lt; .001). For TBI participants reporting high depression, perceived workload decreased as anxiety increased (b = -.38, p = .03). While there was also significant anxiety by depression interaction in the healthy control group (b = .033, p = .04), simple slopes analyses revealed that there were no significant associations for healthy controls.Conclusions:These results demonstrate that in TBI, level of depression moderates the relationship between anxiety and workload perception. The pattern observed in the TBI group was unique from controls. The present findings suggest that post-TBI, higher depression may temper the influence of anxiety on stressful cognitive task performance and workload rating. The tempering effect of high depression in TBI may represent a biased reporting style or impaired assessment of task difficulty, which may ultimately affect the individual’s capacity to accomplish a task well.

Reduced Sensitivity to Background Reward Underlies Apathy After Traumatic Brain Injury: Insights From an Ecological Foraging Framework.

Altered reward processing is increasingly recognised as a crucial mechanism underpinning apathy in many brain disorders. However despite its clinical relevance, little is known about the mechanisms of apathy following moderate-to-severe traumatic brain injury (TBI). In real-life situations, reward representations encompass both foreground (gains from current activity) and background (potential gains from the broader environment) elements. This latter variable provides a crucial set-point for switching behaviour in many naturalistic settings. We hypothesised apathy post-TBI would be associated with disrupted background reward sensitivity. We administered a computer-based foraging task to 45 people with moderate-to-severe TBI (20 with apathy, 39 males) and 37 matched controls. Participants decided when to leave locations (patches) where foreground reward rates depleted at differing rates, to pursue greater rewards from other patches in the environment, which had either a high or low background reward rate. Primary analysis was performed using linear mixed effects models, with patch leaving time the dependent variable. Findings showed a significant interaction between apathy and background reward sensitivity, driven by apathetic TBI participants not altering patch-leaving decisions as environmental reward rate changed. In contrast, although TBI was associated with reduced sensitivity to changing foreground rewards, this did not vary as a function of apathy. These results provide the first evidence directly linking disrupted background reward processing to apathy in any brain disorder. They identify a novel mechanism for apathy following moderate-to-severe TBI, and point towards novel interventions to improve this debilitating complication of head injury.

Examining the validity of the Delis-Kaplan Executive Function System (D-KEFS) in traumatic brain injury.

This study examines the validity of the Delis-Kaplan Executive Function System (D-KEFS) in a traumatic brain injury (TBI) population compared to participants with orthopaedic injuries and normative controls. The utility of the D-KEFS was examined using a between groups design. One hundred patients with mild uncomplicated to severe TBI were recruited from a consecutive cohort of patients admitted as inpatients to a UK Major Trauma Centre and compared to 823 participants from the D-KEFS normative sample and 26 participants with orthopaedic injuries. Data were filtered for performance validity. Sample discrimination was calculated from D-KEFS subtest scores and derived index scores. Sensitivity to TBI severity was established. The TBI participants performed significantly lower on the D-KEFS Trail Making Test, Colour Word Interference, Colour Word Switching, Letter Fluency and Verbal Fluency Category Switching Total Words Correct. The D-KEFS index scores discriminated between TBI, orthopaedic and normative participants with large and moderate effect sizes, respectively. The D-KEFS demonstrated a dose-response relationship with TBI severity. These effects were robust to differences in premorbid intellectual functioning; however, D-KEFS performance was sensitive to performance on tests of mental processing speed. The use of a D-KEFS index score provides a robust and reliable discrimination of TBI patients from healthy control participants. This discrimination is not accounted for by premorbid intellect or the non-specific effects of trauma. The clinical and conceptual implications of these findings are considered.

Wayfinding and path integration deficits detected using a virtual reality mobile app in patients with traumatic brain injury.

The ability to navigate is supported by a wide network of brain areas which are particularly vulnerable to disruption brain injury, including traumatic brain injury (TBI). Wayfinding and the ability to orient back to the direction you have recently come (path integration) may likely be impacted in daily life but have so far not been tested with patients with TBI. Here, we assessed spatial navigation in thirty-eight participants, fifteen of whom had a history of TBI, and twenty-three control participants. Self-estimated spatial navigation ability was assessed using the Santa Barbara Sense of Direction (SBSOD) scale. No significant difference between TBI patients and a control group was identified. Rather, results indicated that both participant groups demonstrated 'good' self-inferred spatial navigational ability on the SBSOD scale. Objective navigation ability was tested via the virtual mobile app test Sea Hero Quest (SHQ), which has been shown to predict real-world navigation difficulties and assesses (a) wayfinding across several environments and (b) path integration. Compared to a sub-sample of 13 control participants, a matched subsample of 10 TBI patients demonstrated generally poorer performance on all wayfinding environments tested. Further analysis revealed that TBI participants consistently spent a shorter duration viewing a map prior to navigating to goals. Patients showed mixed performance on the path integration task, with poor performance evident when proximal cues were absent. Our results provide preliminary evidence that TBI impacts both wayfinding and, to some extent, path integration. The findings suggest long-lasting clinical difficulties experienced in TBI patients affect both wayfinding and to some degree path integration ability.

Fixel-based analysis of the diffusion properties of the patients with brain injury and chronic health symptoms

The diffusion properties from diffusion tensor imaging (DTI) are sensitive to white matter (WM) abnormalities and could serve as indicators of diffuse axonal damages incurred during a traumatic brain injury (TBI). Analyses of diffusion metrics in the regions of interest (ROIs) were used to compare the differences in the 18 major fiber tracts in 46 participants, between TBI participants with (n = 17) or without (n = 16) chronic symptoms (CS) and a control group (CG, n = 13). In addition to the widely used diffusion metrics, such as fractional anisotropy (FA), mean (MD), axial (AD) and radial (RD) diffusivities, apparent fiber density (AFD), complexity (CX) and fixel number (FN) derived from Mrtrix3 software package were used to characterize WM tracts and compare between participant groups in the ROIs defined by the fixel numbers. Significant differences were found in FA, AFD, MD, RD and CX in ROIs with different FNs in the corpus callosum forceps minor, left and right inferior longitudinal fasciculus, and left and right uncinate fasciculus for both TBI groups compared to controls. Diffusion properties in ROIs with different FNs can serve as detailed biomarkers of WM abnormalities, especially for individuals with chronic TBI related symptoms.

The impact of traumatic brain injury on inhibitory control processes assessed using a delayed antisaccade task

It has been well established that traumatic brain injury (TBI) can affect cognitive function such as attention, working memory and executive functions. In the present study, we further investigated TBI-related changes in cognitive functions by investigating the ability to reorient visuospatial attention using a modified antisaccade task. Performing an antisaccade requires disengaging attention, inhibiting a reflexive saccade, and then engaging attention to execute a voluntary saccade in a direction opposite to a peripheral target. Particularly we quantified the time (latency), and accuracy (directional and disinhibition errors) of 26 TBI and 33 normal participants in making an antisaccade after a variable period of delay (0, 0.0625, 0.125, 0.250, 0.500 or 1.0 s). Changing the delay period allowed to systematically quantify the temporal and spatial characteristics of preparing and initiating an antisaccade and whether this process is affected by TBI. TBI participants took longer (approximately 33–66 ms for variable delays) to generate correct delayed antisaccades and showed increased directional errors (2–11 % for variable delays) and increased disinhibition prosaccade errors (2–6 % for variable delays) compared to controls. However, both groups made similar disinhibition antisaccade errors. These findings indicate that TBI participants required a longer time to process information, and a possible poorer response inhibition and poor spatial information processing due to head injury.

Differentiating Use of Facial Expression between Individuals with and without Traumatic Brain Injury Using Affectiva Software: A Pilot Study.

This study investigated the feasibility of using an automated facial coding engine, Affectiva (integrated in iMotions, version 8.2), for evaluating facial expression after traumatic brain injury (TBI). An observational cross-sectional study was conducted based on facial expression data from videos of participants with TBI and control participants. The aims were to compare TBI and control groups, and identify confounding factors affecting the data analysis. Video samples of two narrative tasks (personal event and story retell) from ten participants with severe TBI and ten control participants without TBI were analyzed using Affectiva. Automated data on participants' engagement, smile and brow furrow were compared statistically between and within groups. Qualitative notes for each sample were also recorded. Affectiva detected a higher percentage of time of engagement for TBI participants than for control participants on both tasks. There was also a higher percentage of time of smiling for TBI participants in one task. Within groups, there were no significant differences between the two narrative tasks. Affectiva provides standardized data about facial expression and may be sensitive to detecting change in the use of facial expression after TBI. This study also identified factors to avoid during videorecording to ensure high quality samples for future research.

Measuring pragmatic competence of discourse output among Chinese-speaking individuals with traumatic brain injury.

Discourse analysis is one of the clinical methods commonly used to assess the language ability of individuals with traumatic brain injury (TBI). However, the majority of published analytic frameworks are not geared for highlighting the pragmatic aspect of discourse deficits in acquired language disorders, except for those designed for quantifying conversational samples. This study aimed to examine how pragmatic competence is impaired and reflected in spoken monologues in Chinese speakers with TBI. Discourse samples of five tasks (personal narrative, storytelling, procedural, single- and sequential picture description) were elicited from ten TBI survivors and their controls. Each discourse sample was measured using 16 indices (e.g., number of informative words, percentage of local/global coherence errors, repeated words or phrases) that corresponded to the four Gricean maxims. Twenty-five naïve Chinese speakers were also recruited to perform perceptual rating of the quality of all 50 TBI audio files (five discourse samples per TBI participant), in terms of erroneous/inaccurate information, adequacy of amount of information given, as well as degree of organization and clarity. The maxim of quantity best predicted TBI's pragmatic impairments. Naïve listeners' perception of pragmatics deficits correlated to measures on total and informative words, as well as number and length of terminable units. Clinically, personal narrative and storytelling tasks could better elicit violations in pragmatics. Applying Gricean maxims in monologic oral narratives could capture the hallmark underlying pragmatic problems in TBI. This may help provide an additional approach of clinically assessing social communications in and subsequent management of TBI.

Neurocognitive and behavioral predictors of theory of mind (ToM) in patients with traumatic brain injury (TBI).

Investigating the core component of social cognition, known as the theory of mind (ToM), becomes imperative in patients with moderate-to-severe traumatic brain injury (TBI) as they may present with social cognitive deficit-related disability interfering with patients' functional and behavioral status. This study aimed to investigate the neurocognitive and behavioral predictors of the ToM in patients with traumatic brain injury (PtTBI). Thirty PtTBI and 30 healthy controls (HCs) were assessed on a set of tasks. The assessment included ToM tasks (cognitive and affective, verbal and nonverbal, and first-order and second-order) along with various neuropsychological (NP) assessments to explore their memory, executive functioning, and intelligence. Further, TBI participants also underwent behavioral and functional outcome measures using the Functional Status Examination (FSE) and the Neurobehavioral Rating Scale (NBRS). The obtained data were analyzed using descriptive statistics and regression analyses. Findings confirmed ToM deficit across all modes of ToM tasks in PtTBI and implicated the role of executive function and working memory in the expression of ToM in this group. While cognitive faux pas (FPC) and first-order false belief together could explain poor performance on NBRS, the nonverbal ToM task predicts functional outcome in PtTBI. These findings have practical implications as they promote cognitive remediation intervention focused on restoring ToM, which may improve functional limitations and resulting disability in PtTBI.

Validity and Reliability of the Persian Version of the Frontal Assessment Battery (FAB) in Patients with Traumatic Brain Injury (TBI)

Objective: This study aimed to ascertain the validity and reliability of the Frontal Assessment Battery (FAB) in patients with traumatic brain injury (TBI). Methods: This study was conducted in a methodological, cross-sectional and prospective design. The study recruited 65 patients with TBI from the university rehabilitation centers in Tehran, Iran and matched them with 65 healthy participants in terms of age and sex. Concurrent validity was evaluated using Mini-Mental State Examination (MMSE), Wisconsin Card Sorting Test (WCST), Stroop Color and Word Test (SCWT). The discriminant validity was evaluated through a comparison of the mean FAB scores between healthy participants and patients with TBI. The reliability was assessed with the analyses of internal consistency, test-retest reliability, and inter-judges reliability. Data was analyzed in SPSS V. 22 software. Results: FAB score in patients did not vary with age, sex and education. There was a significant correlation between the FAB score and MMSE (r=0.791, p&lt;0.001) and also various executive measures: the number of categories achieved (r=0.745, p&lt;0.001) and the number of perseveration errors (r=0.307, p&lt;0.05) in the WCST and all parts of the Stroop test (p&lt;0.001), except the interference score (p&gt;0.05). The FAB exhibited acceptable internal consistency (Cronbach’s α: 0.863) and also good test-retest (r=0.882, 95%CI = 0.77–0.95) and inter-judges reliability (r=0.994, 95%CI = 0.77–0.95). A cut-off of 15 for the total FAB score yielded the highest sensitivity (0.93) and specificity (0.90) to discriminate between patients with TBI and healthy participants. Conclusion: Our present study shows that the Persian version of the FAB is an easy, quick and confident tool for the screening of executive dysfunction in patients with TBI.

Insights into social communication following traumatic brain injury sustained in older adulthood.

There is a lack of evidence relating to cognitive-communication difficulties following traumatic brain injury (TBI) sustained in older adulthood. A prominent area in which post-TBI cognitive-communication difficulties manifest is at the level of social communication. An investigation of social communication focusing on comparison of those injured in older and younger adulthood is a practical starting point for age-related cognitive-communication outcome comparison. The overall objective of this study was to explore the social communication of individuals who sustained severe TBI in an early period of older adulthood (50-70 years) compared to younger adulthood (18-40 years), as informed by self and close other reports. This exploratory controlled group comparison study involved analysis of self-reported and close other reported La Trobe Communication Questionnaire data for 22 adults with severe TBI (11 older at injury; 11 younger at injury) and 22 control participants (11 older; 11 younger). TBI participants were matched for injury variables and participant groups were matched for sex, age and education. The close others of the older and younger adults with TBI reported them to have significantly more frequent difficulty with social communication than the close others of age-matched control groups. Older adults with TBI reported significantly more frequent difficulty with social communication than uninjured older adults. In contrast, younger adults with TBI and uninjured younger adults reported a similar frequency of difficulty with social communication. No age-based difference in the frequency of social communication difficulty was evident when comparing the self or close other reports of older and younger adults with TBI. Awareness of social communication difficulty, as indexed by comparing self and close other perceptions, showed a different pattern across the TBI groups. The older TBI group rated themselves as having significantly less frequent social communication difficulty than was perceived by their close others. In contrast, no statistically significant difference was evident between the self and close other social communication ratings of the younger TBI group. Where possible clinicians need to work with close communication partners to understand the nature and degree of social communication difficulty following severe TBI. This may be especially important when working with people who sustain TBI in older adulthood if future research shows that this population have greater difficulty with self-awareness of social communication difficulty. What is already known on the subject Cognitive-communication difficulties are a common consequence of traumatic brain injury (TBI) that can have long-term impact on everyday functioning. These challenges have primarily been investigated in individuals who sustained TBI in younger adulthood. What this paper adds to existing knowledge Individuals who sustain severe TBI in early older adulthood have a higher frequency of reported social communication difficulty to non-injured adults of a similar age, albeit they may underreport such difficulties potentially in the context of reduced self-awareness. What are the potential or actual clinical implications of this work? Social communication difficulty is an issue for people who sustain severe TBI in early older adulthood. However, a poorer overall social communication outcome in comparison to those injured in younger adulthood should not be assumed. Clinical service delivery for these challenges is most optimally delivered in a collaborative manner with the individual and their close others. Future research is required to investigate the identified trends from this study.

Effects of Computerized Biofeedback-based Balance Intervention on the Muscle Coactivation Patterns during Dynamic Postural Control in Traumatic Brain Injury.

Balance Dysfunction (BDF) is a severe conse-quence of Traumatic Brain Injury (TBI) that significantly increases the falls risk. However, the neuromuscular mecha-nisms of the BDF are not adequately researched. Therefore, in this study, our objective was to investigate the effects of a Computerized Biofeedback-based Balance Intervention (CBBI) on the muscle coactivation patterns in a group of TBI participants. This study presents the findings from 13 TBI individuals randomized into the Intervention group (TBI - INT, N=6) and Control group (TBI-CTL, N=7). Using a computerized posturography platform (Neurocom Balance Master) during baseline and follow-up assessment visits, the participant's pos-tural response to anterior-posterior balance perturbations were recorded in a multimodal setup including electroencephalogra-phy (EEG), electromyography (EMG), and the platform sway in terms of center of pressure (COP). The muscle responses were recorded from lower-limb muscles, including tibialis an-terior (TA) and gastrocnemius (GAST), whose coactivation was computed using a metric called Co-Contraction Index (CCI). Clinical outcome measures such as Berg Balance Scale (BBS), 10 Meter Walk Test (10MWT), and Timed Up-and-Go (TUG) tests were used to evaluate functional balance and mobility. The comparison of CCI values across time points (baseline and follow-up) revealed a significant decrease (p<0.01) in the TBI-INT group but not TBI-CTL. The intervention-related changes in CCI correlated with the changes in BBS score (from baseline to follow-up). These preliminary findings demonstrate that the CBBI training may help postural stability by facilitating the coactivation between muscles involved in postural control. Clinical relevance- The current knowledge of changes in the neuromuscular response to balance perturbation in TBI is limited. Our study opens the possibility of using the muscle CCI metric to evaluate the muscle response in individuals with impaired balance.

Video game training in traumatic brain injury patients: an exploratory case report study using eye tracking.

Remediation of attentional impairments is an essential component of cognitive rehabilitation after traumatic brain injury (TBI). Evidence from healthy participants has demonstrated attentional improvement following playing an action video game. This exploratory study investigated its application in TBI participants in a multiple baselines single case experimental design (SCED). Saccadic eye movements, recognized as the visible indicators of visual attention, were assessed to evaluate the effectiveness of the game training. Three severe TBI participants were trained in an action game for 10 hours. Saccadic eye movements during a self-paced saccade and an abstract visual search task were investigated during baseline, mid training and post-training. Using Percentage of Non-overlapping Data (PND), analysis showed consistent increase in the rate of the self-paced saccades in participants 1 (PND=80%) and 2 (PND=70%). In abstract search, fixation duration showed a minimally effective decrease for participant 2 (PND= 60%) and a moderately effective reduction in participant 3 (PND= 80%). Search time showed a highly effective reduction in participant 2 (PND = 100%) and moderately effective decrease in participant 3 (PND=70%). Overall, video game training might modify allocation of attention in eye movements. More evidence is required to validate the usefulness of this novel method of the cognitive training.

Photosensitivity Is Associated with Chronic Pain following Traumatic Brain Injury.

Individuals with a history of traumatic brain injury (TBI) report increased rates of chronic pain. Photosensitivity is also a common chronic symptom following TBI and is prevalent among other types of chronic pain. The aim of this study was to better understand the relationship between chronic pain, pain-related disability, and photosensitivity in a TBI population. We quantified participants' visual photosensitivity thresholds (VPT) using an Ocular Photosensitivity Analyzer and measured pressure-pain sensitivity using pressure algometry. Participants also completed a battery of self-report measures related to chronic pain, TBI history, and mental health. A total of 395 participants completed testing, with 233 reporting a history of TBI. The TBI group was divided into 120 symptomatic TBI participants (s-TBI), and 113 asymptomatic TBI participants (a-TBI) based on their Neurobehavioral Symptom Inventory (NSI) scores. Participants in the s-TBI group scored significantly higher on self-reported chronic pain measures compared with a-TBI and no-TBI participants, including the Symptom Impact Questionnaire Revised (SIQR; p < 0.001) and the Michigan Body Map (MBM; p < 0.001). Despite differences in chronic pain complaints, groups displayed similar pressure-pain thresholds (p = 0.270). Additionally, s-TBI participants were more sensitive to light (lower VPT, p < 0.001), and VPT was correlated with SIQR scores across all participants (R = -0.452, p < 0.001). These data demonstrate that photosensitivity is associated with self-reported chronic pain and disability in individuals with chronic TBI symptomatology. Photosensitivity could therefore serve as a simple, more highly quantitative marker of high-impact chronic pain after TBI.

Occurrence Patterns of Traumatic Brain Injury Within the Emergency Department and Internal Screening Process Efficacy During the COVID-19 Pandemic: Retrospective Analysis.

BackgroundTraumatic brain injury (TBI) is one of the leading causes of death in pediatric patients. Continued recruitment of pediatric TBI participants into a biobank amidst the COVID-19 pandemic not only necessitates adaptive changes to traditional recruitment methods but also requires an evaluation of emergency department (ED) utilization by TBI-presenting patients.ObjectiveThe primary objective of this exploratory retrospective study was to evaluate pediatric TBI-related ED utilization during the pandemic. The secondary objective was to appraise the efficacy of the research team’s internal screening processes.MethodsPotential participants (ie, individuals who met all inclusion criteria and would be approached by a consenter) were screened from an ED’s electronic health record system. Data regarding their visit were recorded in a Health Insurance Portability and Accountability Act–compliant manner, which were cleaned through Google Sheets. Cleaned data were then coded as either a screening variable or a hospital utilization variable to examine the effects of the pandemic on internal operations and hospital utilization patterns. The variables were compared between select months during the pandemic in 2020 to analogous months in 2019 in the R programming language via the two-sample Student t test and the Mann-Whitney-Wilcoxon rank-sum test.ResultsThe sample (N=2321) consisted of 1245 entries from 2019 and 1076 entries from 2020. A significantly greater proportion of potential participants (P<.001) were identified in 2020 (222/633, 35.1%) than in 2019 (195/908, 21.4%). A significantly greater proportion of potential participants (P<.001) had a visit reason indicative of a TBI in 2020 (181/222, 81.5%) than in 2019 (103/195, 52.8%). A significantly greater proportion of these injuries (P=.02) occurred inside (39/181, 21.5%) in 2020 than in 2019 (11/103, 10.7%). No significant difference was found across the mechanism of injury categories reported for potential participants between 2019 and 2020. Potential participants were significantly older (P=.006) in 2019 (mean 8.93 years) than in 2020 (mean 7.31 years). Screeners spent significantly longer (P=.03) to identify potential participants in March 2020 (55 minutes) than in March 2019 (32 minutes), but spent significantly less time (P=.01) to do so in July 2020 (22 minutes) than in July 2019 (42 minutes). Screening coverage was significantly lower (P<.001) in March 2020 (241.8 hours) than in March 2019 (346.5 hours). Screening coverage was significantly greater (P<.001) in April 2020 (611.5 hours) and July 2020 (513.5 hours) than in April 2019 (470.5 hours) and July 2019 (404.3 hours), respectively.ConclusionsThere was a significant increase in the rate of incoming TBI cases to the ED during the COVID-19 pandemic, warranting continued enrollment with added safety measures. Additionally, refinement of internal processes improved the accuracy of data collection. As demonstrated in this study, researchers can leverage ongoing data collection to facilitate process improvements and evaluate the impact of unexpected global events on their research.

Temporal order memory impairments in individuals with moderate-severe traumatic brain injury

ABSTRACT Introduction Temporal order memory is a core cognitive function that underlies much of our behavior. The ability to bind together information within and across events, and to reconstruct that sequence of information, critically relies upon the hippocampal relational memory system. Recent work has suggested traumatic brain injury (TBI) may particularly impact hippocampally mediated relational memory. However, it is currently unclear whether such deficits extend to temporal order memory, and whether deficits only arise at large memory loads. The present study assessed temporal order memory in individuals with chronic, moderate-severe TBI across multiple set sizes. Method Individuals with TBI and Neurotypical Comparison participants studied sequences of three to nine objects, one a time. At test, all items were re-presented in pseudorandom order, and participants indicated the temporal position (i.e., first, second, etc.) in which each object had appeared. Critically, we assessed both the frequency and the magnitude of errors (i.e., how far from its studied position was an item remembered). Results Individuals with TBI were not impaired for the smallest set size, but showed significant impairments at 5+ items. Group differences in the error frequency did not increase further with larger set sizes, but group differences in error magnitude did increase with larger memory loads. Individuals with TBI showed spared performance for the first object of each list (primacy) but were impaired on the last object (recency), though error frequency was better for last compared to middle items. Conclusions Our findings demonstrate that TBI results in impaired temporal order memory for lists as small as five items, and that impairments are exacerbated with increasing memory loads. Assessments that test only small set sizes may be insufficient to detect these deficits. Further, these data highlight the importance of additional, sensitive measures in the assessment of cognitive impairments in TBI.

Symptom Frequency and Persistence in the First Year after Traumatic Brain Injury: A TRACK-TBI Study.

Symptom endorsement after traumatic brain injury (TBI) is common acutely post-injury and is associated with other adverse outcomes. Prevalence of persistent symptoms has been debated, especially in mild TBI (mTBI). A cohort of participants ≥17 years with TBI (n = 2039), 257 orthopedic trauma controls (OTCs), and 300 friend controls (FCs) were enrolled in the TRACK-TBI study and evaluated at 2 weeks and 3, 6, and 12 months post-injury using the Rivermead Post-Concussion Symptoms Questionnaire (RPQ). TBI participants had significantly higher symptom burden than OTCs or FCs at all times, with average scores more than double. TBI cases showed significant decreases in RPQ score between each evaluation (p < 0.001), decreasing ∼1.7 points per month between 2 weeks and 3 months and 0.2 points per month after that. More than 50% of the TBI sample, including >50% of each of the mild and moderate/severe TBI subsamples, continued to endorse three or more symptoms as worse than pre-injury through 12 months post-injury. A majority of TBI participants who endorsed a symptom at 3 months or later did so at the next evaluation as well. Contrary to reviews that report symptom resolution by 3 months post-injury among those with mTBI, this study of participants treated at level 1 trauma centers and having a computed tomography ordered found that persistent symptoms are common to at least a year after TBI. Additionally, although symptom endorsement was not specific to TBI given that they were also reported by OTC and FC participants, TBI participants endorsed over twice the symptom burden compared with the other groups.