Heterogeneity Is a Hallmark of Traumatic Brain Injury, Not a Limitation: A New Perspective on Study Design in Rehabilitation Research

Naming Ability in the Chronic Phase of Moderate-Severe Traumatic Brain Injury

INTRODUCTION

Naming difficulties are commonly reported in the acute and subacute stages of recovery of traumatic brain injury (TBI) and across severity levels. Previous studies, however, have used samples of mixed chronicity (acute and chronic) and severity (mild and severe) and then aggregated data across individuals from these distinct groups. Thus, we have little knowledge about the persistence of naming difficulties into the chronic stage of recovery in individuals with moderate-severe TBI.

PURPOSE

To increase the rigor and reproducibility of naming research in TBI, the present study sought to determine the presence and profile of naming disruptions into the chronic stage of moderate-severe TBI using a confrontation naming assessment.

METHOD

Thirty-three individuals aged 24-55 years in the chronic epoch of moderate-severe TBI and 33 demographically matched noninjured comparison (NC) participants completed the Philadelphia Naming Test (PNT). A mixed-effects logistic regression model predicting the probability of a correct response as a function of group was fit to the data.

RESULTS

Participants with TBI performed well on the PNT (all participants with TBI had over 90% accuracy). However, participants with TBI were statistically less likely to correctly name an item relative to demographically matched NC participants.

CONCLUSIONS

This study provides empirical evidence that naming difficulties persist into the chronic epoch of moderate-severe TBI. Despite high accuracy on the PNT, nearly 60% of these individuals with TBI reported continued difficulty with word finding in their daily lives. This discrepancy leaves open the possibility that, at this stage of injury, word-finding issues may be more reliably evoked and studied when the assessment is embedded within cognitively demanding and ecologically valid contexts (i.e., discourse, conversation). Further investigation of naming deficits in chronic moderate-severe TBI using a more naturalistic assessment is warranted.

Reduced on-line speech gesture integration during multimodal language processing in adults with moderate-severe traumatic brain injury: Evidence from eye-tracking

BACKGROUND

Language is multimodal and situated in rich visual contexts. Language is also incremental, unfolding moment-to-moment in real time, yet few studies have examined how spoken language interacts with gesture and visual context during multimodal language processing. Gesture is a rich communication cue that is integrally related to speech and often depicts concrete referents from the visual world. Using eye-tracking in an adapted visual world paradigm, we examined how participants with and without moderate-severe traumatic brain injury (TBI) use gesture to resolve temporary referential ambiguity.

METHODS

Participants viewed a screen with four objects and one video. The speaker in the video produced sentences (e.g., "The girl will eat the very good sandwich"), paired with either a meaningful gesture (e.g., sandwich-holding gesture) or a meaningless grooming movement (e.g., arm scratch) at the verb "will eat." We measured participants' gaze to the target object (e.g., sandwich), a semantic competitor (e.g., apple), and two unrelated distractors (e.g., piano, guitar) during the critical window between movement onset in the gesture modality and onset of the spoken referent in speech.

RESULTS

Both participants with and without TBI were more likely to fixate the target when the speaker produced a gesture compared to a grooming movement; however, relative to non-injured participants, the effect was significantly attenuated in the TBI group.

DISCUSSION

We demonstrated evidence of reduced speech-gesture integration in participants with TBI relative to non-injured peers. This study advances our understanding of the communicative abilities of adults with TBI and could lead to a more mechanistic account of the communication difficulties adults with TBI experience in rich communication contexts that require the processing and integration of multiple co-occurring cues. This work has the potential to increase the ecological validity of language assessment and provide insights into the cognitive and neural mechanisms that support multimodal language processing.

A Systematic Review of Traumatic Brain Injury in Modern Rodent Models: Current Status and Future Prospects

According to the Centers for Disease Control and Prevention (CDC), the national public health agency of the United States, traumatic brain injury is among the leading causes of mortality and disability worldwide. The consequences of TBI include diffuse brain atrophy, local post-traumatic atrophy, arachnoiditis, pachymeningitis, meningocerebral cicatrices, cranial nerve lesions, and cranial defects. In 2019, the economic cost of injuries in the USA alone was USD 4.2 trillion, which included USD 327 billion for medical care, USD 69 billion for work loss, and USD 3.8 trillion for the value of statistical life and quality of life losses. More than half of this cost (USD 2.4 trillion) was among working-age adults (25-64 years old). Currently, the development of new diagnostic approaches and the improvement of treatment techniques require further experimental studies focused on modeling TBI of varying severity.

Temporary ambiguity and memory for the context of spoken language in adults with moderate-severe traumatic brain injury

Language is processed incrementally, with addressees considering multiple candidate interpretations as speech unfolds, supporting the retention of these candidate interpretations in memory. For example, after interpreting the utterance, "Click on the striped bag", listeners exhibit better memory for non-mentioned items in the context that were temporarily consistent with what was said (e.g., dotted bag), vs. not consistent (e.g., dotted tie), reflecting the encoding of linguistic context in memory. Here, we examine the impact of moderate-severe traumatic brain injury (TBI) on memory for the contexts of language use. Participants with moderate-severe TBI (N=71) and non-injured comparison participants (NC, N=85) interpreted temporarily ambiguous utterances in rich contexts. A subsequent memory test demonstrated that participants with TBI exhibited impaired memory for context items and an attenuated memory advantage for mentioned items compared to NC participants. Nonetheless, participants with TBI showed similar, although attenuated, patterns in memory for temporarily-activated items as NC participants.

Comprehension of Miranda warnings in adults with chronic, moderate-severe traumatic brain injury

INTRODUCTION

To compare comprehension of Miranda rights in adults with traumatic brain injury (TBI) versus adults without TBI as measured by response accuracy on the Miranda Right Comprehension Instruments.

METHODS

Data were collected virtually via teleconferencing from July 2022 to February 2023. Participants included 25 adults with moderate-severe TBI (12 females, 13 males) and 25 adults without TBI (12 females, 13 males), ages 20-55 years. In this observational study, both groups (with and without TBI) completed the Miranda Right Comprehension Instruments (MRCI), which includes four instruments including Comprehension of Miranda Rights, Comprehension of Miranda Rights-Recognition, Function of Rights in Interrogation, Comprehension of Miranda Vocabulary instruments. Response accuracy on the MRCI was compared across groups.

RESULTS

The TBI group was significantly less accurate when responding to questions on the MRCI compared to the NC group.

CONCLUSION

Individuals with chronic moderate-severe TBI underperform their non-injured peers on the Miranda Rights Comprehension Instruments, a tool used in legal settings when there is doubt about an individual's understanding of their Miranda rights. TBI is a risk factor for disruptions in comprehension of language in legal contexts that may, in part, contribute to the increased interaction with the criminal justice system and incarceration for individuals with TBI. Implications for policy, advocating, and intervention are discussed.

HISTOLOGICAL COMPARISON OF REPEATED MILD WEIGHT DROP AND LATERAL FLUID PERCUSSION INJURY MODELS OF TRAUMATIC BRAIN INJURY IN FEMALE AND MALE RATS

ABSTRACT

In preclinical traumatic brain injury (TBI) research, the animal model should be selected based on the research question and outcome measures of interest. Direct side-by-side comparisons of different injury models are essential for informing such decisions. Here, we used immunohistochemistry to compare the outcomes from two common models of TBI, lateral fluid percussion (LFP) and repeated mild weight drop (rmWD) in adult female and male Wistar rats. Specifically, we measured the effects of LFP and rmWD on markers of cerebrovascular and tight junction disruption, neuroinflammation, mature neurons, and perineuronal nets in the cortical site of injury, cortex adjacent to injury, dentate gyrus, and the CA 2/3 area of the hippocampus. Animals were randomized into the LFP or rmWD group. On day 1, the LFP group received a craniotomy, and on day 4, injury (or sham procedure; randomly assigned). The rmWD animals underwent either injury or isoflurane only (randomly assigned) on each of those 4 days. Seven days after injury, brains were harvested for analysis. Overall, our observations revealed that the most significant disruptions were evident in response to LFP, followed by craniotomy only, whereas rmWD animals showed the least residual changes compared with isoflurane-only controls, supporting consideration of rmWD as a mild injury. LFP led to longer-lasting disruptions, perhaps more representative of moderate TBI. We also report that craniotomy and LFP produced greater disruptions in females relative to males. These findings will assist the field in the selection of animal models based on target severity of postinjury outcomes and support the inclusion of both sexes and appropriate control groups.

Discovery of generalizable TBI phenotypes using multivariate time-series clustering

Traumatic Brain Injury (TBI) presents a broad spectrum of clinical presentations and outcomes due to its inherent heterogeneity, leading to diverse recovery trajectories and varied therapeutic responses. While many studies have delved into TBI phenotyping for distinct patient populations, identifying TBI phenotypes that consistently generalize across various settings and populations remains a critical research gap. Our research addresses this by employing multivariate time-series clustering to unveil TBI's dynamic intricates. Utilizing a self-supervised learning-based approach to clustering multivariate time-Series data with missing values (SLAC-Time), we analyzed both the research-centric TRACK-TBI and the real-world MIMIC-IV datasets. Remarkably, the optimal hyperparameters of SLAC-Time and the ideal number of clusters remained consistent across these datasets, underscoring SLAC-Time's stability across heterogeneous datasets. Our analysis revealed three generalizable TBI phenotypes (α, β, and γ), each exhibiting distinct non-temporal features during emergency department visits, and temporal feature profiles throughout ICU stays. Specifically, phenotype α represents mild TBI with a remarkably consistent clinical presentation. In contrast, phenotype β signifies severe TBI with diverse clinical manifestations, and phenotype γ represents a moderate TBI profile in terms of severity and clinical diversity. Age is a significant determinant of TBI outcomes, with older cohorts recording higher mortality rates. Importantly, while certain features varied by age, the core characteristics of TBI manifestations tied to each phenotype remain consistent across diverse populations.

Narrative Discourse Performance in Traumatic Brain Injury: Does Story Comprehension Predict Story Retelling?

PURPOSE

Little is known about the relationship between discourse comprehension and production in traumatic brain injury (TBI), especially for spoken language. This study examined to what extent narrative discourse comprehension accounts for narrative discourse production outcomes (story grammar, story completeness). A secondary aim was to provisionally test an assumption of a discourse model, the structure building framework (SBF), that discourse comprehension and production share cognitive processes by investigating the strength of the relationship between them.

METHOD

Twenty-one individuals with TBI completed story comprehension and story retelling tasks. Discourse measures included the Discourse Comprehension Test, a picture story comprehension task, story grammar, and story completeness. Correlational and multiple regression analyses were performed using comprehension measures as predictors for production measures.

RESULTS

There were significant moderate-to-large correlations between all comprehension and production measures. Comprehension measures approached but did not reach significance for predicting story grammar performance but strongly predicted story completeness outcomes.

CONCLUSIONS

The story comprehension measures likely tapped content aspects of discourse more so than organization. Results provided support for a link between content-focused discourse comprehension measures and discourse production outcomes, which may have clinical implications for approaches to discourse intervention. Findings were interpreted as providing preliminary support for the SBF's claim that discourse production deploys the same processes involved in discourse comprehension.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.26338045.

Stem cell therapies for neurological disorders: current progress, challenges, and future perspectives

Stem cell-based therapies have emerged as a promising approach for treating various neurological disorders by harnessing the regenerative potential of stem cells to restore damaged neural tissue and circuitry. This comprehensive review provides an in-depth analysis of the current state of stem cell applications in primary neurological conditions, including Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), stroke, spinal cord injury (SCI), and other related disorders. The review begins with a detailed introduction to stem cell biology, discussing the types, sources, and mechanisms of action of stem cells in neurological therapies. It then critically examines the preclinical evidence from animal models and early human trials investigating the safety, feasibility, and efficacy of different stem cell types, such as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), neural stem cells (NSCs), and induced pluripotent stem cells (iPSCs). While ESCs have been studied extensively in preclinical models, clinical trials have primarily focused on adult stem cells such as MSCs and NSCs, as well as iPSCs and their derivatives. We critically assess the current state of research for each cell type, highlighting their potential applications and limitations in different neurological conditions. The review synthesizes key findings from recent, high-quality studies for each neurological condition, discussing cell manufacturing, delivery methods, and therapeutic outcomes. While the potential of stem cells to replace lost neurons and directly reconstruct neural circuits is highlighted, the review emphasizes the critical role of paracrine and immunomodulatory mechanisms in mediating the therapeutic effects of stem cells in most neurological disorders. The article also explores the challenges and limitations associated with translating stem cell therapies into clinical practice, including issues related to cell sourcing, scalability, safety, and regulatory considerations. Furthermore, it discusses future directions and opportunities for advancing stem cell-based treatments, such as gene editing, biomaterials, personalized iPSC-derived therapies, and novel delivery strategies. The review concludes by emphasizing the transformative potential of stem cell therapies in revolutionizing the treatment of neurological disorders while acknowledging the need for rigorous clinical trials, standardized protocols, and multidisciplinary collaboration to realize their full therapeutic promise.

COOK technology to support meal preparation following a severe traumatic brain injury: a usability mixed-methods single-case study in a real-world environment

INTRODUCTION

Following a traumatic brain injury (TBI), meal preparation may become challenging as it involves multiple cognitive abilities and sub-tasks. To support this population, the Cognitive Orthosis for coOKing (COOK) was developed in partnership with an alternative residential resource for people with severe TBI. However, little is known about the usability of this technology to support people with TBI living in their own homes.

METHODS

A usability study was conducted using a mixed-methods single-case design with a 35-year-old man with severe TBI living alone at home. The number of assistances provided, time taken and the percentage of unnecessary actions during a meal preparation task were documented nine times to explore the usability of COOK. Interviews were also conducted with the participant to document his satisfaction with COOK. Potential benefits were explored via the number of meals prepared per week.

RESULTS

The usability of COOK was shown to be promising as the technology helped the participant prepare complex meals, while also reducing the number of assistances needed and the percentage of unnecessary actions. However, several technical issues and contextual factors influenced the efficiency and the participant's satisfaction with COOK. Despite improving his self-confidence, COOK did not help the participant prepare more meals over time.

CONCLUSION

This study showed that COOK was easy to use and promising, despite technical and configuration issues. Results suggest the importance of further technological developments to improve COOK's usability and fit with the needs of people with TBI living in their own homes.

Patterns and predictors of ten-year mortality after discharge from community-based post-acute care for acquired brain injury: A retrospective cohort study (ABI-RESTaRT), Western Australia, 1991-2017

BACKGROUND

Survivors of acquired brain injury (ABI) are left with long-term disability and an increased risk of mortality years post-injury.

OBJECTIVE

To examine 10-year mortality in adults with ABI after discharge from post-acute care and identify modifiable risk factors to reduce long-term mortality risk.

METHODS

Retrospective cohort study of 586 adults with traumatic (TBI) or non-traumatic brain injury (NTBI), or neurologic condition, consecutively discharged from a post-acute rehabilitation service in Western Australia from 1-Mar-1991 to 31-Dec-2017. Data sources included rehabilitation records, and linked mortality, hospital, and emergency department data. Survival status at 10 years post-discharge was determined. All-cause and cause-specific age- and sex-adjusted standardised mortality ratios (SMR) by ABI diagnosis were calculated using Australian population reference data. Risk factors were examined using multilevel cox proportional hazards regression.

RESULTS

Compared with the Australian population, 10-year all-cause mortality was significantly elevated for all diagnosis cohorts, with the first 12 months the highest risk period. Accidents or intentional self-harm deaths were elevated in TBI (13.2, 95%CI 5.4; 12.1). Neurodegenerative disease deaths were elevated in Neurologic (21.9, 95%CI 13.0; 30.9) and Stroke (19.8; 95%CI 2.4; 27.2) cohorts. Stroke (20.8; 95%CI 7.9; 33.8) and circulatory disease deaths (6.2; 95%CI 2.3; 9.9) were also elevated in Stroke. Psychiatric comorbidity was the strongest risk factor followed by older age, geographical remoteness, and cardiac, vascular, genitourinary and renal comorbidity. Clinically significant improvement in functional independence and psychosocial functioning significantly reduced mortality risk.

CONCLUSIONS

Individuals with ABI have an elevated risk of mortality years post-injury. Comorbidity management, continuity of care, and rehabilitation are important to reduce long-term mortality risk.

Measurement of Sleep in Chronic Traumatic Brain Injury: Relationship Between Self-report and Actigraphy

OBJECTIVE

To examine the relationship between self-report and actigraphy measurement of sleep in people with and without traumatic brain injury (TBI) by addressing 2 aims: (1) to assess the relationship between self-report and actigraphy for sleep quantity in people with and without TBI; and (2) to explore how self-report and actigraphy capture sleep quality in TBI.

SETTING

Participants completed the study over 2 weeks in their own homes. They wore activity monitors, day and night, throughout the experiment and completed morning sleep diaries while interacting with an experimenter on videoconference.

PARTICIPANTS

This project was embedded in a larger study on sleep and word learning in 100 adults: 50 with chronic, moderate-severe TBI and 50 demographically matched noninjured peers. Of the 100 participants who completed the larger study, 92 participants (45 with TBI and 47 noninjured peers) had sufficient actigraphy data for inclusion in the current study.

DESIGN

We used multilevel linear regression models and correlation analyses to assess how well participants' self-report corresponded to actigraphy measurement of sleep.

MAIN MEASURES

Actigraphy measures included nightly sleep duration and nighttime wakeups. Sleep diary measures included self-reported nightly sleep duration, nighttime wakeups, sleep quality, and morning fatigue.

RESULTS

People with and without TBI did not differ in the relationship between self-reported and actigraphy measurement of sleep quantity. Performance on a neuropsychological memory assessment did not correlate with the difference in self-reported and actigraphy-measured sleep in the TBI group. Sleep characteristics that were measured by actigraphy did not predict subjective experiences of sleep quality or fatigue.

CONCLUSIONS

Short-term self-report diaries capture accurate information about sleep quantity in individuals with TBI and may support self-report of other daily habits. Future research is needed to identify reliable metrics of sleep quality, and how they relate to other domains such as memory and mood, in the chronic phase of TBI.

Focal Traumatic Brain Injury Impairs the Integrity of the Basement Membrane of Hindlimb Muscle Fibers Revealed by Extracellular Matrix Immunoreactivity

Traumatic brain injury (TBI) stands as a prominent global cause of disability, with motor deficits being a common consequence. Despite its widespread impact, the precise pathological mechanisms underlying motor deficits after TBI remain elusive. In this study, hindlimb postural asymmetry (HL-PA) development in rats subjected to focal TBI was investigated to explore the potential roles of collagen IV and laminin within the extracellular matrix (ECM) of selected hindlimb muscles in the emergence of motor deficits following TBI. A focal TBI was induced by ablating the left sensorimotor cortex in rats and motor deficits were assessed by measuring HL-PA. The expression of laminin and collagen IV in eight selected muscles on each side of the hindlimbs from both TBI- and sham-operated rats were studied using immunohistochemistry and semi-quantitatively analyzed. The results indicated that the TBI rats exhibited HL-PA, characterized by flexion of the contralateral (right) hindlimb. In the sham-operated rats, the immunoreactive components of laminin and collagen IV were evenly and smoothly distributed along the border of the muscle fibers in all the investigated muscles. In contrast, in the TBI rats, the pattern was broken into aggregated, granule-like, immunoreactive components. Such a labeling pattern was detected in all the investigated muscles both from the contra- and ipsilateral sides of the TBI rats. However, in TBI rats, most of the muscles from the contralateral hindlimb showed a significantly increased expression of these two proteins in comparison with those from the ipsilateral hindlimb. In comparison to sham-operated rats, there was a significant increase in laminin and collagen IV expression in various contralateral hindlimb muscles in the TBI rats. These findings suggest potential implications of laminin and collagen IV in the development of motor deficits following a focal TBI.

An overview of preclinical models of traumatic brain injury (TBI): relevance to pathophysiological mechanisms

Background

Traumatic brain injury (TBI) is a major cause of morbidity and mortality, affecting millions annually worldwide. Although the majority of TBI patients return to premorbid baseline, a subset of patient can develop persistent and often debilitating neurocognitive and behavioral changes. The etiology of TBI within the clinical setting is inherently heterogenous, ranging from sport related injuries, fall related injuries and motor vehicle accidents in the civilian setting, to blast injuries in the military setting.

Objective

Animal models of TBI, offer the distinct advantage of controlling for injury modality, duration and severity. Furthermore, preclinical models of TBI have provided the necessary temporal opportunity to study the chronic neuropathological sequelae of TBI, including neurodegenerative sequelae such as tauopathy and neuroinflammation within the finite experimental timeline. Despite the high prevalence of TBI, there are currently no disease modifying regimen for TBI, and the current clinical treatments remain largely symptom based. The preclinical models have provided the necessary biological substrate to examine the disease modifying effect of various pharmacological agents and have imperative translational value.

Methods

The current review will include a comprehensive survey of well-established preclinical models, including classic preclinical models including weight drop, blast injury, fluid percussion injury, controlled cortical impact injury, as well as more novel injury models including closed-head impact model of engineered rotational acceleration (CHIMERA) models and closed-head projectile concussive impact model (PCI). In addition to rodent preclinical models, the review will include an overview of other species including large animal models and Drosophila.

Results

There are major neuropathological perturbations post TBI captured in various preclinical models, which include neuroinflammation, calcium dysregulation, tauopathy, mitochondrial dysfunction and oxidative stress, axonopathy, as well as glymphatic system disruption.

Conclusion

The preclinical models of TBI continue to offer valuable translational insight, as well as essential neurobiological basis to examine specific disease modifying therapeutic regimen.

The Australian Traumatic Brain Injury Initiative: Review and Recommendations for Outcome Measures for Use With Adults and Children After Moderate-to-Severe Traumatic Brain Injury

The Australian Traumatic Brain Injury Initiative (AUS-TBI) aims to select a set of measures to comprehensively predict and assess outcomes following moderate-to-severe traumatic brain injury (TBI) across Australia. The aim of this article was to report on the implementation and findings of an evidence-based consensus approach to develop AUS-TBI recommendations for outcome measures following adult and pediatric moderate-to-severe TBI. Following consultation with a panel of expert clinicians, Aboriginal and Torres Strait Islander representatives and a Living Experience group, and preliminary literature searches with a broader focus, a decision was made to focus on measures of mortality, everyday functional outcomes, and quality of life. Standardized searches of bibliographic databases were conducted through March 2022. Characteristics of 75 outcome measures were extracted from 1485 primary studies. Consensus meetings among the AUS-TBI Steering Committee, an expert panel of clinicians and researchers and a group of individuals with lived experience of TBI resulted in the production of a final list of 11 core outcome measures: the Functional Independence Measure (FIM); Glasgow Outcome Scale-Extended (GOS-E); Satisfaction With Life Scale (SWLS) (adult); mortality; EuroQol-5 Dimensions (EQ5D); Mayo-Portland Adaptability Inventory (MPAI); Return to Work /Study (adult and pediatric); Functional Independence Measure for Children (WEEFIM); Glasgow Outcome Scale Modified for Children (GOS-E PEDS); Paediatric Quality of Life Scale (PEDS-QL); and Strengths and Difficulties Questionnaire (pediatric). These 11 outcome measures will be included as common data elements in the AUS-TBI data dictionary. Review Registration PROSPERO (CRD42022290954).

The effects of symbolic gestural training on enhancing recovery of spoken naming in people with aphasia: A systematic review and meta-analysis

PURPOSE

This study aimed to evaluate the effects of symbolic gestural training on enhancing recovery of spoken naming in people with aphasia (PWA) using a systematic review and meta-analysis.

METHOD

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, article search was conducted from four databases: Web of Science Core Collection, Medline, PsycINFO, and EBSCO. A total of 45 participants from four studies investigating the symbolic gestural training effects on PWA and outcome measures of spoken naming were included.

RESULT

The meta-analysis showed a medium overall effect of symbolic gestural training on enhancing recovery of spoken naming in PWA. Subgroup analysis also revealed that the training effect was more remarkable in the gesture + verbal training paradigm than in the gesture-only training paradigm. However, the differences in the training effects between short and long duration, and training supplied with and without feedback, were nonsignificant.

CONCLUSION

This study illustrates the current state of the literature on symbolic gestural training in PWA, and serves as a reference for clinicians, patients, and health policy-makers regarding the application of symbolic gestural training in clinical or rehabilitation programs.

Use of Social Media Data Mining to Examine Needs, Concerns, and Experiences of People With Traumatic Brain Injury

PURPOSE

Given the limited availability of topic-specific resources, many people turn to anonymous social media platforms such as Reddit to seek information and connect to others with similar experiences and needs. Mining of such data can therefore identify unmet needs within the community and allow speech-language pathologists to incorporate clients' real-life insights into clinical practices.

METHOD

A mixed-method analysis was performed on 3,648 traumatic brain injury (TBI) subreddit posts created between 2013 and 2021. Sentiment analysis was used to determine the sentiment expressed in each post; topic modeling and qualitative content analysis were used to uncover the main topics discussed across posts. Subgroup analyses were conducted based on injury severity, chronicity, and whether the post was authored by a person with TBI or a close other.

RESULTS

There was no significant difference between the number of posts with positive sentiment and the number of posts with negative sentiment. Comparisons between subgroups showed significantly higher positive sentiment in posts by or about people with moderate-to-severe TBI (compared to mild TBI) and who were more than 1 month postinjury (compared to less than 1 month). Posts by close others had significantly higher positive sentiment than posts by people with TBI. Topic modeling identified three meta-themes: Recovery, Symptoms, and Medical Care. Qualitative content analysis further revealed that returning to productivity and life as well as sharing recovery tips were the primary focus under the Recovery theme. Symptom-related posts often discussed symptom management and validation of experiences. The Medical Care theme encompassed concerns regarding diagnosis, medication, and treatment.

CONCLUSIONS

Concerns and needs shift over time following TBI, and they extend beyond health and functioning to participation in meaningful daily activities. The findings can inform the development of tailored educational resources and rehabilitative approaches, facilitating recovery and community building for individuals with TBI.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24881340.

ENIGMA's simple seven: Recommendations to enhance the reproducibility of resting-state fMRI in traumatic brain injury

Resting state functional magnetic resonance imaging (rsfMRI) provides researchers and clinicians with a powerful tool to examine functional connectivity across large-scale brain networks, with ever-increasing applications to the study of neurological disorders, such as traumatic brain injury (TBI). While rsfMRI holds unparalleled promise in systems neurosciences, its acquisition and analytical methodology across research groups is variable, resulting in a literature that is challenging to integrate and interpret. The focus of this narrative review is to address the primary methodological issues including investigator decision points in the application of rsfMRI to study the consequences of TBI. As part of the ENIGMA Brain Injury working group, we have collaborated to identify a minimum set of recommendations that are designed to produce results that are reliable, harmonizable, and reproducible for the TBI imaging research community. Part one of this review provides the results of a literature search of current rsfMRI studies of TBI, highlighting key design considerations and data processing pipelines. Part two outlines seven data acquisition, processing, and analysis recommendations with the goal of maximizing study reliability and between-site comparability, while preserving investigator autonomy. Part three summarizes new directions and opportunities for future rsfMRI studies in TBI patients. The goal is to galvanize the TBI community to gain consensus for a set of rigorous and reproducible methods, and to increase analytical transparency and data sharing to address the reproducibility crisis in the field.

Histological comparison of repeated mild weight drop and lateral fluid percussion injury models of traumatic brain injury (TBI) in female and male rats

Traumatic brain injury (TBI) heterogeneity has led to the development of several preclinical models, each modeling a distinct subset of outcomes. Selection of an injury model should be guided by the research question and the specific outcome measures of interest. Consequently, there is a need for conducting direct comparisons of different TBI models. Here, we used immunohistochemistry to directly compare the outcomes from two common models, lateral fluid percussion (LFP) and repeat mild weight drop (rmWD), on neuropathology in adult female and male Wistar rats. Specifically, we used immunohistochemistry to measure the effects of LFP and rmWD on cerebrovascular and tight junction disruption, inflammatory markers, mature neurons and perineuronal nets in the cortical site of injury, cortex adjacent to injury, dentate gyrus, and the CA2/3 area of the hippocampus. Animals were randomized into either LFP or rmWD groups. The LFP group received a craniotomy prior to LFP (or corresponding sham procedure) three days later, while rmWD animals underwent either weight drop or sham (isoflurane only) on each of those four days. After a recovery period of 7 days, animals were euthanized, and brains were harvested for analysis of RECA-1, claudin-5, GFAP, Iba-1, CD-68, NeuN, and wisteria floribunda lectin. Overall, our observations revealed that the most significant disruptions were evident in response to LFP, followed by craniotomy-only, while rmWD animals showed the least residual changes compared to isoflurane-only controls. These findings support consideration of rmWD as a mild, transient injury. LFP leads to longer-lasting disruptions that are more closely associated with a moderate TBI. We further show that both craniotomy and LFP produced greater disruptions in females relative to males at 7 days post-injury. These findings support the inclusion of a time-matched experimentally-naïve or anesthesia-only control group in preclinical TBI research to enhance the validity of data interpretation and conclusions.

Characterizing depression after traumatic brain injury using a symptom-oriented approach

BACKGROUND

Progress in addressing depression after traumatic brain injury (TBI) has been limited. Traditional approaches to measuring depression classify individuals with diverse symptoms as having the same problem. We adopted a novel, symptom-oriented approach to characterize post-TBI depression, emphasizing specific symptoms rather than the number of symptoms.

METHODS

We assessed depressive symptoms cross-sectionally in 393 participants with moderate-severe TBI (range 0.4-35.4 years post-injury; M = 12.6) using the Inventory of Depression and Anxiety Symptoms - Expanded Version (IDAS-II). We analyzed symptoms of DSM-5 major depressive disorder (MDD), separating compound symptoms into sub-symptoms. We quantified depression heterogeneity across 16 specific symptoms and explored associations between each symptom and personal, injury-related, treatment, and functional/psychosocial outcome factors.

RESULTS

28 % of participants self-reported a current depression diagnosis, and 35 % met DSM-5 symptom criteria for MDD. Depressed participants (according to either self-reported diagnosis or MDD symptom criteria) were more likely to endorse each specific depressive symptom, including those that overlap with TBI. Post-TBI depression was highly heterogeneous, with 84-91 % of depressed participants (depending on classification method) showing a unique symptom profile not shared with any other individual. The most common symptom profile was shared by only three individuals. This heterogeneity was meaningful, as specific depressive symptoms had distinct associations with personal, injury-related, treatment, and outcome factors.

LIMITATIONS

Cross-sectional design. We only analyzed DSM-5 MDD symptoms, and some symptoms were assessed using only one item.

CONCLUSIONS

A symptom-oriented approach to post-TBI depression captures the individual's unique profile of depressive symptoms, which relate differently to outcomes and other factors. We recommend future studies investigating post-TBI depression analyze specific symptoms alongside overall depression scores.

Correlates of Longitudinal Trajectories of Depressive Symptoms in Adolescents With Traumatic Brain Injuries

OBJECTIVE

Depression poses a significant threat to the health and well-being of adolescents with traumatic brain injury. Existing research has limitations in longitudinal follow-up period, consideration of sample heterogeneity, and outcome measurement modeling. This study aimed to address these gaps by applying the second-order growth mixture model (SO-GMM) to examine the 10-year post-injury depression trajectories in adolescents with TBI.

METHODS

A total of 1,989 adolescents with TBI 16-21 years old from the Traumatic Brain Injury Model System National Data Bank were analyzed up to 10 years post-injury. Depressive symptoms were measured by Patient Health Questionnaire-9. Covariates included age, sex, race/ethnicity, employment, Functional Independence Measure Cognition, TBI severity, pre-injury disability, and substance use. Longitudinal measurement invariance was tested at the configural, metric, and scalar levels before SO-GMM was fit. Logistic regression was conducted for disparities in depression trajectories by covariates.

RESULTS

A 2-class SO-GMM was identified with a low-stable group (85% of the sample) and a high-increasing group (15% of the sample) on depression levels. Older age, being a Native American, and having Hispanic origin was associated with a higher likelihood of being in the high-increasing class (odds ratios [ORs] = 1.165-4.989 and 1.609, respectively), while patients with higher education and being male were less likely to be in the high-increasing class (ORs = 0.735 and 0.557, respectively).

CONCLUSIONS

This study examined the disparities in depression among two distinct longitudinal groups of adolescents with TBI 10 years post-injury. Findings of the study are informative for intervention development to improve long-term mental health in adolescents with TBI.

Self-Reported Symptoms of Vertigo and Imbalance Are Prevalent Among Adults With Chronic Moderate-Severe Traumatic Brain Injury: A Preliminary Analysis

PURPOSE

Dizziness and imbalance are common symptoms during the acute phase of traumatic brain injury (TBI). However, there is evidence to suggest that these symptoms persist into the chronic phase of injury. Few prospective studies have examined the frequency and type of dizziness and imbalance in adults with chronic moderate-severe TBI. The aim of this preliminary analysis was to investigate the prevalence of these symptoms in adults with chronic moderate-severe TBI.

METHOD

Twenty-four adults with chronic moderate-severe TBI and a group of 19 age-, sex-, and education-matched noninjured comparison participants were recruited. Self-reported dizziness and imbalance were measured using a modified version of a standard case history form. Significant associations between group (TBI group or noninjured comparison [NC] participants) and self-reports of dizziness, imbalance, and related symptoms (endorsed "yes" or "no") were explored.

RESULTS

The TBI group most reported lightheadedness (75%), vertigo (38%), and imbalance and/or falling (46%). The most common related symptom reported by the TBI group was headache (63%) and nausea (46%). Significant associations revealed that the TBI group responded "yes" in higher percentages than the NC group across all categories (dizziness, imbalance, and related symptoms). There were no statistically significant relationships among dizziness, imbalance, or headache symptoms within the TBI group.

CONCLUSIONS

These preliminary findings suggest that dizziness and imbalance are prevalent in adults with chronic moderate-severe TBI. Persistent vertiginous symptoms may point to an underlying vestibular impairment. However, further research is needed to characterize vestibular function in chronic moderate-severe TBI.

Communication and Psychosocial Outcomes 2-Years After Severe Traumatic Brain Injury: Development of a Prognostic Model

OBJECTIVE

To examine predictive factors underlying communication and psychosocial outcomes at 2 years post-injury. Prognosis of communication and psychosocial outcomes after severe traumatic brain injury (TBI) is largely unknown yet is relevant for clinical service provision, resource allocation, and managing patient and family expectations for recovery.

DESIGN

A prospective longitudinal inception design was employed with assessments at 3 months, 6 months, and 2 years.

PARTICIPANTS

The cohort included 57 participants with severe TBI (N=57).

SETTING

Subacute and post-acute rehabilitation.

MAIN OUTCOME MEASURES

Preinjury/injury measures included age, sex, education years, Glasgow Coma Scale, and PTA. The 3-month and 6-month data points included speech, language, and communication measures across the ICF domains and measures of cognition. The 2-year outcome measures included conversation, perceived communication skills, and psychosocial functioning. Predictors were examined using multiple regression.

INTERVENTIONS

Not applicable.

RESULTS

The cognitive and communication measures at 6 months significantly predicted conversation measures at 2 years and psychosocial functioning as reported by others at 2 years. At 6 months, 69% of participants presented with a cognitive-communication disorder (Functional Assessment of Verbal Reasoning and Executive Strategies [FAVRES]). The unique variance accounted for by the FAVRES measure was 7% for conversation measures and 9% for psychosocial functioning. Psychosocial functioning at 2 years was also predicted by pre-injury/injury factors and 3-month communication measures. Pre-injury education level was a unique predictor, accounting for 17% of the variance, and processing speed/memory at 3 months uniquely accounted for 14% of the variance.

CONCLUSION

Cognitive-communication skills at 6 months are a potent predictor of persisting communication challenges and poor psychosocial outcomes up to 2 years after a severe TBI. Findings emphasize the importance of addressing modifiable cognitive and communication outcomes variables during the first 2 years after severe TBI to maximize functional patient outcomes.

Intact speech-gesture integration in narrative recall by adults with moderate-severe traumatic brain injury

PURPOSE

Real-world communication is situated in rich multimodal contexts, containing speech and gesture. Speakers often convey unique information in gesture that is not present in the speech signal (e.g., saying "He searched for a new recipe" while making a typing gesture). We examine the narrative retellings of participants with and without moderate-severe traumatic brain injury across three timepoints over two online Zoom sessions to investigate whether people with TBI can integrate information from co-occurring speech and gesture and if information from gesture persists across delays.

METHODS

60 participants with TBI and 60 non-injured peers watched videos of a narrator telling four short stories. On key details, the narrator produced complementary gestures that conveyed unique information. Participants retold the stories at three timepoints: immediately after, 20-min later, and one-week later. We examined the words participants used when retelling these key details, coding them as a Speech Match (e.g., "He searched for a new recipe"), a Gesture Match (e.g., "He searched for a new recipe online), or Other ("He looked for a new recipe"). We also examined whether participants produced representative gestures themselves when retelling these details.

RESULTS

Despite recalling fewer story details, participants with TBI were as likely as non-injured peers to report information from gesture in their narrative retellings. All participants were more likely to report information from gesture and produce representative gestures themselves one-week later compared to immediately after hearing the story.

CONCLUSION

We demonstrated that speech-gesture integration is intact after TBI in narrative retellings. This finding has exciting implications for the utility of gesture to support comprehension and memory after TBI and expands our understanding of naturalistic multimodal language processing in this population.

Memory in Social Interactions: The Effects of Introspection on Destination Memory in Traumatic Brain Injury

Destination memory, which is the ability to remember to whom one has sent information, is intimately associated with social cognition. We assessed whether processing attributes of destinations would improve destination memory in patients with traumatic brain injury (TBI). In this cross-sectional study, we tested the destination memory of 24 patients with TBI and 25 control participants in two conditions. On the first one (control condition), we invited participants to tell proverbs to celebrities' faces in order to decide, on a subsequent recognition test, whether they previously told that proverb to that celebrity or not. On the second condition (experimental introspection condition), the same procedures were repeated. However, after telling the proverbs, we invited participants to introspect about what the destination might believe about the proverbs (e.g., "What do you think that the celebrities would think about the proverbs?"). Group comparisons demonstrated better destination memory after the introspection than when no introspection was implemented in control participants, but there were no significant differences between the two conditions in patients with TBI. However, analyses of individual profiles demonstrated that more than half (n = 13) of the patients with TBI demonstrated better destination memory after introspection. While these results demonstrate a beneficial effect of introspection on destination memory for some cases of patients with TBI, more research is needed to reveal how introspection may influence patients' memory in social interactions.

The Measure of an Outcome: Comparing Norming and Stacking to Benchmark the Effectiveness of Brain Injury Rehabilitation Services

Practitioners have a clinical, ethical, academic, and economic responsibility to dispassionately consider how effective their services are. Approaches to measure how "good" or "bad" healthcare is include clinical audit, satisfaction surveys, and routine outcome measurement. However, the process of comparing the clinical outcomes of a specific service against the 'best' services in the same specialism, also known as benchmarking, remains challenging, and it is unclear how it affects quality improvement. This paper piloted and compared two different approaches to benchmarking to assess clinical outcomes in neurorehabilitation. Norming involved comparing routine measures of clinical outcome with external validators. Stacking involved pooling and comparing internal data across several years. The analyses of routine clinical outcome data from 167 patients revealed significant differences in the patient characteristics of those admitted to the same service provider over time, but no differences in outcomes achieved when comparing with historical data or with external reference data. These findings illustrate the potential advantages and limitations of using stacking and norming to benchmark clinical outcomes, and how the results from each approach might be used to evaluate service effectiveness and inform quality improvement within the field of brain injury rehabilitation.

Development of expert consensus to guide physical rehabilitation in children and adolescents with acquired brain injury during the subacute phase

OBJECTIVE

To develop consensus among experts to guide physical rehabilitation in children and adolescents with acquired brain injury during the subacute phase.

DESIGN

International Delphi study.

METHODS

A 3-round online Delphi study was conducted with 11 international experts in rehabilitation for children and adolescents with acquired brain injury. The first round consisted of open-ended questions; the second and third round consisted of ranking 139 statements on a 5-point Likert scale.

RESULTS

The panel reached consensus on 116/139 statements. Consensus was reached on the importance of age, pre-injury developmental stage and the clinical presentation of the child when determining content and focus of physical rehabilitation. In addition, consensus was reached on the importance of participation-focused interventions, and involvement of family members in goal-setting and therapeutic activities. Although dosage was deemed very important, no consensus was reached for determination of dose-response variables to suit and influence the child's needs.

CONCLUSION

This study provides a framework for clinicians to design physical rehabilitation interventions in children with acquired brain injury in the sub-acute recovery phase. The promotion of physical activity in meaningful contexts and involvement of family members are considered as important components to optimize recovery.

Towards PPG-based anger detection for emotion regulation

BACKGROUND

Anger dyscontrol is a common issue after traumatic brain injury (TBI). With the growth of wearable physiological sensors, there is new potential to facilitate the rehabilitation of such anger in the context of daily life. This potential, however, depends on how well physiological markers can distinguish changing emotional states and for such markers to generalize to real-world settings. Our study explores how wearable photoplethysmography (PPG), one of the most widely available physiological sensors, could be used detect anger within a heterogeneous population.

METHODS

This study collected the TRIEP (Toronto Rehabilitation Institute Emotion-Physiology) dataset, which comprised of 32 individuals (10 TBI), exposed to a variety of elicitation material (film, pictures, self-statements, personal recall), over two day sessions. This complex dataset allowed for exploration into how the emotion-PPG relationship varied over changes in individuals, endogenous/exogenous drivers of emotion, and day-to-day differences. A multi-stage analysis was conducted looking at: (1) times-series visual clustering, (2) discriminative time-interval features of anger, and (3) out-of-sample anger classification.

RESULTS

Characteristics of PPG are largely dominated by inter-subject (between individuals) differences first, then intra-subject (day-to-day) changes, before differentiation into emotion. Both TBI and non-TBI individuals showed evidence of linear separable features that could differentiate anger from non-anger classes within time-interval analysis. However, what is more challenging is that these separable features for anger have various degrees of stability across individuals and days.

CONCLUSION

This work highlights how there are contextual, non-stationary challenges to the emotion-physiology relationship that must be accounted for before emotion regulation technology can perform in real-world scenarios. It also affirms the need for a larger breadth of emotional sampling when building classification models.

Emotion recognition of faces and emoji in individuals with moderate-severe traumatic brain injury

BACKGROUND

Facial emotion recognition deficits are common after moderate-severe traumatic brain injury (TBI) and linked to poor social outcomes. We examine whether emotion recognition deficits extend to facial expressions depicted by emoji.

METHODS

Fifty-one individuals with moderate-severe TBI (25 female) and fifty-one neurotypical peers (26 female) viewed photos of human faces and emoji. Participants selected the best-fitting label from a set of basic emotions (anger, disgust, fear, sadness, neutral, surprise, happy) or social emotions (embarrassed, remorseful, anxious, neutral, flirting, confident, proud).

RESULTS

We analyzed the likelihood of correctly labeling an emotion by group (neurotypical, TBI), stimulus condition (basic faces, basic emoji, social emoji), sex (female, male), and their interactions. Participants with TBI did not significantly differ from neurotypical peers in overall emotion labeling accuracy. Both groups had poorer labeling accuracy for emoji compared to faces. Participants with TBI (but not neurotypical peers) had poorer accuracy for labeling social emotions depicted by emoji compared to basic emotions depicted by emoji. There were no effects of participant sex.

DISCUSSION

Because emotion representation is more ambiguous in emoji than human faces, studying emoji use and perception in TBI is an important consideration for understanding functional communication and social participation after brain injury.

Computerised cognitive assessment in patients with traumatic brain injury: an observational study of feasibility and sensitivity relative to established clinical scales

Background

Online technology could potentially revolutionise how patients are cognitively assessed and monitored. However, it remains unclear whether assessments conducted remotely can match established pen-and-paper neuropsychological tests in terms of sensitivity and specificity.

Methods

This observational study aimed to optimise an online cognitive assessment for use in traumatic brain injury (TBI) clinics. The tertiary referral clinic in which this tool has been clinically implemented typically sees patients a minimum of 6 months post-injury in the chronic phase. Between March and August 2019, we conducted a cross-group, cross-device and factor analyses at the St. Mary's Hospital TBI clinic and major trauma wards at Imperial College NHS trust and St. George's Hospital in London (UK), to identify a battery of tasks that assess aspects of cognition affected by TBI. Between September 2019 and February 2020, we evaluated the online battery against standard face-to-face neuropsychological tests at the Imperial College London research centre. Canonical Correlation Analysis (CCA) determined the shared variance between the online battery and standard neuropsychological tests. Finally, between October 2020 and December 2021, the tests were integrated into a framework that automatically generates a results report where patients' performance is compared to a large normative dataset. We piloted this as a practical tool to be used under supervised and unsupervised conditions at the St. Mary's Hospital TBI clinic in London (UK).

Findings

The online assessment discriminated processing-speed, visual-attention, working-memory, and executive-function deficits in TBI. CCA identified two significant modes indicating shared variance with standard neuropsychological tests (r = 0.86, p < 0.001 and r = 0.81, p = 0.02). Sensitivity to cognitive deficits after TBI was evident in the TBI clinic setting under supervised and unsupervised conditions (F (15,555) = 3.99; p < 0.001).

Interpretation

Online cognitive assessment of TBI patients is feasible, sensitive, and efficient. When combined with normative sociodemographic models and autogenerated reports, it has the potential to transform cognitive assessment in the healthcare setting.

Funding

This work was funded by a National Institute for Health Research (NIHR) Invention for Innovation (i4i) grant awarded to DJS and AH (II-LB-0715-20006).

Decision-making abilities under risk and ambiguity in adults with traumatic brain injury: what do we know so far? A systematic review and meta-analysis

Traumatic brain injury (TBI) is a major health and socio-economic problem since it is one of the major sources of death and disability worldwide. TBI patients usually show high heterogeneity in their clinical features, including both cognitive and emotional/behavioral alterations. As it specifically concerns cognitive functioning, these patients usually show decision-making (DM) deficits. DM is commonly considered a complex and multistep process that is strictly linked to both hot and cold executive functioning and is pivotal for daily life functioning and patients' autonomy. However, the results are not always in agreement, with some studies that report huge alterations in the DM processes, while others do not. The present systematic review and meta-analysis aims to integrate past literature on this topic, providing a clear and handy picture both for researchers and clinicians. Thirteen studies addressing domain-general DM abilities were included from an initial N = 968 (from three databases). Results showed low heterogeneity between the studies (I2 = 7.90, Q (12) = 13.03, p = .37) supporting the fact that, overall, TBI patients showed lower performance in DM tasks as compared to healthy controls (k = 899, g = .48, 95% CI [0.33; 0.62]) both in tasks under ambiguity and under risk. The evidence that emerged from this meta-analysis denotes a clear deficit of DM abilities in TBI patients. However, DM tasks seemed to have good sensitivity but low specificity. A detailed description of patients' performances and the role of both bottom-up, hot executive functions and top-down control functions have been further discussed. Finally, future directions and practical implications for both researchers and clinicians have been put forward.

Word Learning as a Window to Memory and Rehabilitation Outcomes in Traumatic Brain Injury

PURPOSE

The purpose of this viewpoint is to advocate for increased study of word learning abilities and word learning interventions in traumatic brain injury (TBI).

METHOD

We describe the word learning process and the unique opportunities afforded by studying each component and stage. Building on discussions at the 2022 International Cognitive-Communication Disorders Conference, we describe how word learning may underlie a variety of functional outcomes after TBI, making it a promising target for rehabilitation. Finally, we discuss principles that may guide study in this critical area to advance outcomes after TBI for children and adults.

RESULTS

Word learning is a dynamic and iterative process taking place over time and in multiple stages. Thus, studying word learning affords the opportunity to parse the relative contributions of multiple memory systems to different phases and components of the process. However, single-timepoint designs are insufficient to capture the full word learning process, which occurs over time and across contexts. Word learning also presents an opportunity to assess the contributions of behavioral and lifestyle factors (e.g., sleep and exercise) to different memory phases. Understanding these interactions could drive clinical interventions aimed at improving memory through manipulable external behaviors.

CONCLUSIONS

Word learning is key to success in functional spheres across the life span. The importance of words to daily life remains after TBI, even as the memory systems that support word learning are disrupted. The empirical study of word learning and rehabilitation of word learning deficits in TBI presents a promising new direction in understanding the breadth of neurogenic cognitive-communication disorders and an opportunity to explore a potential driver of functional outcome and impactful rehabilitation target.

Establishment and Application of a Novel In Vitro Model of Microglial Activation in Traumatic Brain Injury

Mechanical impact-induced primary injury after traumatic brain injury (TBI) leads to acute microglial pro-inflammatory activation and consequently mediates neurodegeneration, which is a major secondary brain injury mechanism. However, the detailed pathologic cascades have not been fully elucidated, partially because of the pathologic complexity in animal TBI models. Although there are several in vitro TBI models, none of them closely mimic post-TBI microglial activation. In the present study, we aimed to establish an in vitro TBI model, specifically reconstituting the pro-inflammatory activation and associated neurodegeneration following TBI. We proposed three sets of experiments. First, we established a needle scratch injured neuron-induced microglial activation and neurodegeneration in vitro model of TBI. Second, we compared microglial pro-inflammatory cytokines profiles between the in vitro TBI model and TBI in male mice. Additionally, we validated the role of injured neurons-derived damage-associated molecular patterns in amplifying microglial pro-inflammatory pathways using the in vitro TBI model. Third, we applied the in vitro model for the first time to characterize the cellular metabolic profile of needle scratch injured-neuron-activated microglia, and define the role of metabolic reprogramming in mediating pro-inflammatory microglial activation and mediated neurodegeneration. Our results showed that we successfully established a novel in vitro TBI model, which closely mimics primary neuronal injury-triggered microglial pro-inflammatory activation and mediated neurodegeneration after TBI. This in vitro model provides an advanced and highly translational platform for dissecting interactions in the pathologic processes of neuronal injury-microglial activation-neuronal degeneration cascade, and elucidating the detailed underlying cellular and molecular insights after TBI.SIGNIFICANCE STATEMENT Microglial activation is a key component of acute neuroinflammation that leads to neurodegeneration and long-term neurologic outcome deficits after TBI. However, it is not feasible to truly dissect primary neuronal injury-induced microglia activation, and consequently mediated neurodegeneration in vivo Furthermore, there is currently lacking of in vitro TBI models closely mimicking the TBI primary injury-mediated microglial activation. In this study, we successfully established and validated a novel in vitro TBI model of microglial activation, and for the first time, characterized the cellular metabolic profile of microglia in this model. This novel microglial activation in vitro TBI model will help in elucidating microglial inflammatory activation and consequently associated neurodegeneration after TBI.

Designing evidence-based support aids for social media access for individuals with moderate-severe traumatic brain injury: A preliminary acceptability study

Background

Adults with traumatic brain injury (TBI) report significant barriers to using current social media platforms, including cognitive overload and challenges in interpreting social cues. Rehabilitation providers may be tasked with helping to address these barriers.

Objectives

To develop technological supports to increase social media accessibility for people with TBI-related cognitive impairments and to obtain preliminary data on the perceived acceptability, ease of use, and utility of proposed technology aids.

Methods

We identified four major barriers to social media use among individuals with TBI: sensory overload, memory impairments, misreading of social cues, and a lack of confidence to actively engage on social media platforms. We describe the process of developing prototypes of support aids aimed at reducing these specific social media barriers. We created mock-ups of these prototypes and asked 46 community-dwelling adults with TBI (24 females) to rate the proposed aids in terms of their acceptability, ease of use, and utility.

Results

Across all aids, nearly one-third of respondents agreed they would use the proposed aids frequently, and the majority of respondents rated the proposed aids as easy to use. Respondents indicated that they would be more likely to use the memory and post-writing aids than the attention and social cue interpretation aids.

Conclusions

Findings provide initial support for social-media-specific technology aids to support social media access and social participation for adults with TBI. Results from this study have design implications for future development of evidence-based social media support aids. Future work should develop and deploy such aids and investigate user experience.

Effects of comorbidity on post-acute outcomes in acquired brain injury: ABI-RESTaRT 1991-2020

BACKGROUND

Current understanding of comorbidities associated with acquired brain injury (ABI) and the effects on post-acute ABI outcomes is poor.

OBJECTIVE

To describe the prevalence, severity and patterns of comorbidity for the pre-injury, acute and post-acute phases, and to examine the effects of post-acute comorbidities on functional independence and length of stay (LOS) at discharge from post-acute care.

METHODS

Retrospective whole-population cohort study of n = 1,011 individuals with traumatic (TBI) or non-traumatic brain injury (NTBI), or eligible neurologic conditions admitted to a post-acute neurorehabilitation and disability support service in Western Australia (WA) between 1991 and 2020. Comorbidities were ascertained from internal electronic medical records and linked hospital and emergency department data from the WA Data Linkage System. We measured comorbidities across 14 body systems using the Cumulative Illness Rating Scale (CIRS) and Elixhauser Comorbidity Index (ECI), and functional independence with the UK Functional Independence Measure and Functional Assessment Measure (UK FIM+FAM). We used multilevel mixed-effect regression models to determine the effects of comorbidity on post-acute outcomes.

RESULTS

NTBI was the most common diagnosis (54%), followed by TBI (34%) and neurologic conditions (10%). Pre-injury comorbidities were present in over half the cohort. Comorbidity prevalence increased significantly from 57% to 84% (∆+27%) and severity (mean ECI score) increased significantly from 2.1 to 13.8 (∆+11.7) between pre-injury and the acute phase and remained elevated at admission to post-acute services (82%, mean ECI score 7.3). Psychiatric comorbidity was the most prevalent (56%) and was associated with significantly poorer functional outcomes at discharge and an increase in LOS of 6.5 months. Genitourinary, musculoskeletal, eye, ear nose and throat, and renal comorbidities also had significant effects on post-acute outcomes.

CONCLUSIONS

ABI has a long-term impact on multiple body systems. Identification and management of comorbidities is critical to maximize functional outcomes and reduce the cost of post-acute care.

Mediators, Moderators, and Covariates: Matching Analysis Approach for Improved Precision in Cognitive-Communication Rehabilitation Research

PURPOSE

The dual goals of this tutorial are (a) to increase awareness and use of mediation and moderation models in cognitive-communication rehabilitation research by describing options, benefits, and attainable analytic approaches for researchers with limited resources and sample sizes and (b) to describe how these findings may be interpreted for clinicians consuming research to inform clinical care.

METHOD

We highlight key insights from the social sciences literature pointing to the risks of common approaches to linear modeling, which may slow progress in clinical-translational research and reduce the clinical utility of our work. We discuss the potential of mediation and moderation analyses to reduce the research-to-practice gap and describe how researchers may begin to implement these models, even in smaller sample sizes. We discuss how these preliminary analyses can help focus resources for larger trials to fully encapsulate the heterogeneity of individuals with cognitive-communication disorders.

RESULTS

In rehabilitation research, we study groups, but we use the findings from those studies to treat individuals. The most functional clinical research is about more than establishing only whether a given effect exists for an "average person" in the group of interest. It is critical to understand the active ingredients and mechanisms of action by which a given treatment works (mediation) and to know which circumstances, contexts, or individual characteristics might make that treatment most beneficial (moderation).

CONCLUSIONS

Increased adoption of mediation and moderation approaches, executed in appropriate steps, could accelerate progress in cognitive-communication rehabilitation research and lead to the development of targeted treatments that work for more clients. In a field that has made limited progress in developing successful interventions for the last several decades, it is critical that we harness new approaches to advance clinical-translational research results for complex, heterogeneous groups with cognitive-communication disorders.

Still Searching for Understanding: The Importance of Diverse Research Designs, Methods, and Perspectives

BACKGROUND

Evidence-based medicine and evidence hierarchies have been widely adopted and have strongly influenced decision making across many fields, including clinical aphasiology. However, questions remain about the creation, usefulness, and validity of current evidence hierarchies.

AIMS

This article builds on ideas about scientific approaches and evidence originally shared by Elman (1995, 1998, 2006). This article reviews the history of evidence hierarchies and argues that improving the diversity of research designs, methods, and perspectives will improve understanding of the numerous and complex variables associated with aphasia intervention. Researchers and clinicians are encouraged to synthesize diverse types of scientific evidence. It is hoped that this article will stimulate thought and foster discussion in order to encourage high-caliber research of all types.

MAIN CONTRIBUTION

Concepts from a wide variety of fields including philosophy of science, research design and methodology, and precision medicine are brought together in an attempt to focus research on the scientific understanding of aphasia treatment effects.

CONCLUSION

It is hoped that by incorporating diverse research designs, methods, and perspectives, clinical aphasiologists will become better able to provide effective, personalized treatments, ensuring that each person with aphasia is able to improve their communication ability and quality of life.

Rehabilitation outcomes at discharge from staged community-based brain injury rehabilitation: A retrospective cohort study (ABI-RESTaRT), Western Australia, 2011–2020

Objective

To evaluate change in functional independence, psychosocial functioning, and goal attainment at discharge from a slow-stream Staged Community-Based Brain Injury Rehabilitation (SCBIR) service in Western Australia, 2011–2020.

Methods

Retrospective cohort study of n = 323 adults with acquired brain injury (ABI) enrolled in a post-acute SCBIR service compared against a control cohort of n = 312 with ABI admitted to three non-rehabilitation programs. Outcome measures were the UK Functional Independence Measure and Functional Assessment Measure (FIM+FAM), Mayo Portland Adaptability Inventory-4 (MPAI-4), and Goal Attainment Scale. Change in FIM+FAM and MPAI-4 scores and predictors of goal attainment at discharge were evaluated using multilevel mixed-effects regression.

Results

Median SCBIR length of stay was 20.5 months. Rehabilitation clients demonstrated clinically significant functional gains at discharge, adjusted mean change = +20.3, p < 0.001 (FIM+FAM). Peak gains of +32.3 were observed after 24–30 months and clinically significant gains were observed 5 years post-admission. Individuals discharged ≤6 months had the smallest functional gains (+12.7). Small psychosocial improvements were evidenced at discharge, mean reduction = −2.9T, p < 0.001 (MPAI-4) but not clinically significant. 47% of rehabilitation clients achieved their goals at the expected level or higher at discharge. Compared to the control, rehabilitation clients evidenced significantly greater functional gains and psychosocial improvement but lower goal attainment. Significant predictors of goal attainment at discharge were >2 years since injury, higher cognitive function and higher emotional adjustment at admission.

Conclusions

Functional recovery after ABI is a gradual and ongoing process. SCBIR is effective for functional rehabilitation post-injury but can be improved to achieve clinically meaningful psychosocial improvement.

Exploring the measurement of pediatric cognitive-communication disorders in traumatic brain injury research: A scoping review

OBJECTIVE

To synthesize information about the constructs measured, measurement instruments used, and the timing of assessment of cognitive-communication disorders (CCDs) in pediatric traumatic brain injury (TBI) research.

METHODS AND PROCEDURES

Scoping review conducted in alignment with Arksey and O'Malley's five-stage methodological framework and reported per the PRISMA extension for Scoping Reviews. Inclusion criteria: (a) cohort description, case-control, and treatment studies; (b) participants with TBI aged 5-18 years; (c) communication or psychosocial outcomes; and (d) English full-text journal articles. The first author reviewed all titles, abstracts, and full-text articles; 10% were independently reviewed.

OUTCOMES AND RESULTS

Following screening, a total of 687 articles were included and 919 measurement instruments, measuring 2134 unique constructs, were extracted. The Child Behavior Checklist was the most used measurement instrument and 'Global Outcomes/Recovery' was the construct most frequently measured. The length of longitudinal monitoring ranged between ≤3 months and 16 years.

CONCLUSIONS AND IMPLICATIONS

We found considerable heterogeneity in the constructs measured, the measurement instruments used, and the timing of CCD assessment in pediatric TBI research. A consistent approach to measurement may support clinical decision-making and the efficient use of data beyond individual studies in systematic reviews and meta-analyses.

Towards PErsonalised PRognosis for children with traumatic brain injury: the PEPR study protocol

INTRODUCTION

Traumatic brain injury (TBI) in children can be associated with poor outcome in crucial functional domains, including motor, neurocognitive and behavioural functioning. However, outcome varies between patients and is mediated by complex interplay between demographic factors, premorbid functioning and (sub)acute clinical characteristics. At present, methods to understand let alone predict outcome on the basis of these variables are lacking, which contributes to unnecessary follow-up as well as undetected impairments in children. Therefore, this study aims to develop prognostic models for the individual outcome of children with TBI in a range of important developmental domains. In addition, the potential added value of advanced neuroimaging data and the use of machine learning algorithms in the development of prognostic models will be assessed.

METHODS AND ANALYSIS

210 children aged 4-18 years diagnosed with mild-to-severe TBI will be prospectively recruited from a research network of Dutch hospitals. They will be matched 2:1 to a control group of neurologically healthy children (n=105). Predictors in the model will include demographic, premorbid and clinical measures prospectively registered from the TBI hospital admission onwards as well as MRI metrics assessed at 1 month post-injury. Outcome measures of the prognostic models are (1) motor functioning, (2) intelligence, (3) behavioural functioning and (4) school performance, all assessed at 6 months post-injury.

ETHICS AND DISSEMINATION

Ethics has been obtained from the Medical Ethical Board of the Amsterdam UMC (location AMC). Findings of our multicentre prospective study will enable clinicians to identify TBI children at risk and aim towards a personalised prognosis. Lastly, findings will be submitted for publication in open access, international and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NL71283.018.19 and NL9051.

Learning Models for Traumatic Brain Injury Mortality Prediction on Pediatric Electronic Health Records

Background

Traumatic Brain Injury (TBI) is one of the leading causes of injury related mortality in the world, with severe cases reaching mortality rates of 30-40%. It is highly heterogeneous both in causes and consequences, complicating medical interpretation and prognosis. Gathering clinical, demographic, and laboratory data to perform a prognosis requires time and skill in several clinical specialties. Machine learning (ML) methods can take advantage of the data and guide physicians toward a better prognosis and, consequently, better healthcare. The objective of this study was to develop and test a wide range of machine learning models and evaluate their capability of predicting mortality of TBI, at hospital discharge, while assessing the similarity between the predictive value of the data and clinical significance.

Methods

The used dataset is the Hackathon Pediatric Traumatic Brain Injury (HPTBI) dataset, composed of electronic health records containing clinical annotations and demographic data of 300 patients. Four different classification models were tested, either with or without feature selection. For each combination of the classification model and feature selection method, the area under the receiver operator curve (ROC-AUC), balanced accuracy, precision, and recall were calculated.

Results

Methods based on decision trees perform better when using all features (Random Forest, AUC = 0.86 and XGBoost, AUC = 0.91) but other models require prior feature selection to obtain the best results (k-Nearest Neighbors, AUC = 0.90 and Artificial Neural Networks, AUC = 0.84). Additionally, Random Forest and XGBoost allow assessing the feature's importance, which could give insights for future strategies on the clinical routine.

Conclusion

Predictive capability depends greatly on the combination of model and feature selection methods used but, overall, ML models showed a very good performance in mortality prediction for TBI. The feature importance results indicate that predictive value is not directly related to clinical significance.

Common Bias and Challenges in Physical and Rehabilitation Medicine Research: How to Tackle Them

The importance of evidence-based medicine is crucial, especially in physical and rehabilitation medicine (PRM), where there is a need to conduct rigorous experimental protocols, as in any medical field. Currently, in clinical practice, therapeutic approaches are often based on empirical data rather than evidence-based medicine. However, the field of PRM faces several challenges that may complicate scientific research. In addition, there is often a lack of appropriate research training in educational programs. In this context, we aim to review the methodological challenges in PRM and provide clear examples for each of them as well as potential solutions when possible. This article will cover the following themes: (1) Choosing the right study design and conducting randomized and benchmarking controlled trials; (2). Selecting the appropriate controlled, placebo or sham condition and the issue of blinding in non-pharmacological trials; (3) The impact of populations' heterogeneity and multi-comorbidities; (4). The challenge of recruitment and adherence; (5). The importance of homogeneity and proper quantification of rehabilitative strategies; and (6). Ethical issues. We are convinced that teaching the basics of scientific research in PRM could help physicians and therapists to choose a treatment based on (novel) scientific evidence. It may also promote scientific research in PRM to develop novel and personalized rehabilitation strategies using rigorous methodologies and randomized or benchmarking controlled trials in order to improve patients' management.

Resting-state network organisation in children with traumatic brain injury

Children with traumatic brain injury are at risk of neurocognitive and behavioural impairment. Although there is evidence for abnormal brain activity in resting-state networks after TBI, the role of resting-state network organisation in paediatric TBI outcome remains poorly understood. This study is the first to investigate the impact of paediatric TBI on resting-state network organisation using graph theory, and its relevance for functional outcome. Participants were 8-14 years and included children with (i) mild TBI and risk factors for complicated TBI (mild^RF+, n = 20), (ii) moderate/severe TBI (n = 15), and (iii) trauma control injuries (n = 27). Children underwent resting-state functional magnetic resonance imaging (fMRI), neurocognitive testing, and behavioural assessment at 2.8 years post-injury. Graph theory was applied to fMRI timeseries to evaluate the impact of TBI on global and local organisation of the resting-state network, and relevance for neurocognitive and behavioural functioning. Children with TBI showed atypical global network organisation as compared to the trauma control group, reflected by lower modularity (mild^RF + TBI and moderate/severe TBI), higher smallworldness (mild^RF + TBI) and lower assortativity (moderate/severe TBI ps < .04, Cohen's ds: > .6). Regarding local network organisation, the relative importance of hub regions in the network did not differ between groups. Regression analyses showed relationships between global as well as local network parameters with neurocognitive functioning (i.e., working memory, memory encoding; R² = 23.3 - 38.5%) and behavioural functioning (i.e., externalising problems, R² = 36.1%). Findings indicate the impact of TBI on global functional network organisation, and the relevance of both global and local network organisation for long-term neurocognitive and behavioural outcome after paediatric TBI. The results suggest potential prognostic value of resting-state network organisation for outcome after paediatric TBI.

The Value of Patient Registries to Advance Basic and Translational Research in the Area of Traumatic Brain Injury

The number of individuals affected by traumatic brain injury (TBI) is growing globally. TBIs may cause a range of physical, cognitive, and psychiatric deficits that can negatively impact employment, academic attainment, community independence, and interpersonal relationships. Although there has been a significant decrease in the number of injury related deaths over the past several decades, there has been no corresponding reduction in injury related disability over the same time period. We propose that patient registries with large, representative samples and rich multidimensional and longitudinal data have tremendous value in advancing basic and translational research and in capturing, characterizing, and predicting individual differences in deficit profile and outcomes. Patient registries, together with recent theoretical and methodological advances in analytic approaches and neuroscience, provide powerful tools for brain injury research and for leveraging the heterogeneity that has traditionally been cited as a barrier inhibiting progress in treatment research and clinical practice. We report on our experiences, and challenges, in developing and maintaining our own patient registry. We conclude by pointing to some future opportunities for discovery that are afforded by a registry model.

Measurement Feedback System for Intensive Neurorehabilitation after Severe Acquired Brain Injury

Outcome of acquired brain injury (ABI) and the potential for neurorehabilitation are subject to distinct heterogeneity between patients. Limited knowledge of the complex constellation of determinants at play interferes with the possibility to deploy precision medicine in neurorehabilitation. Measurement Feedback Systems (MFS) structure clinical data collection and deliver the measurement results as feedback to clinicians, thereby facilitating progress monitoring, promoting balanced patient-centered discussion and shared decision making. Accumulation of clinical data in the MFS also enables data-driven precision rehabilitation medicine. This article describes the development and implementation of a MFS for neurorehabilitation after ABI. The MFS consists of specialized measurement tracks which are developed together with representatives of each discipline in the multidisciplinary team. The MFS is built into a digital platform that automatically distributes measurements among clinicians, at predetermined time points during the inpatient treatment, outpatient treatment and follow-up. The results of all measurements are visualized in individual patient dashboards that are accessible for all clinicians involved in treatment. Since step-wise implementation, 124 patients have been registered on the MFS platform so far, providing an average of more than 200 new measurements per week. Currently, more than 15,000 clinical measurements are captured in the MFS. The current overall completion rate of measurements is 86,4%. This study shows that structured clinical assessment and feedback is feasible in the context of neurorehabilitation after severe ABI. The future directions are discussed for MFS data in our Health Intelligence Program, which aims at periodic care evaluation and the transition of neurorehabilitation care towards precision medicine.

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

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.

Application of Second-Order Growth Mixture Modeling (SO-GMM) to Longitudinal TBI Outcome Research: 15-year Trajectories of Life Satisfaction in Adolescents and Young Adults (AYA) as an Example

OBJECTIVE

To demonstrate the application of Second-Order Growth Mixture Modeling using life satisfaction among adolescents and young adults with TBI up to 15 years post-injury.

DESIGN

SO-GMM, a data-driven modeling approach that accounts for measurement errors, was adopted to uncover distinct growth trajectories of life satisfaction over 15 years post-injury. Membership in growth trajectories was then linked with baseline characteristics to understand the contributing factors to distinct growth over time.

SETTING

Traumatic Brain Injury Model System National Database PARTICIPANTS: 3,756 AYAs with TBI aged 16 - 25 (M_age=20.49, SD_age=2.66; 27.24% female) INTERVENTIONS: Not Applicable MAIN OUTCOME MEASURES: Satisfaction with Life Scale RESULTS: Four quadratic growth trajectories were identified: low-stable (16.6%) that had low initial life satisfaction and remained low over time; high-stable (49.3%) that had high life satisfaction at the baseline and stayed high over time; high-decreasing (15.8%) that started with high life satisfaction but decreased over time; and low-increasing (18.2%) that started with low life satisfaction but increased over time. Sex, race, pre-injury employment status, age, and FIM cognition were associated with group assignment.

CONCLUSION

This study applied SO-GMM to a national TBI database and identified four longitudinal trajectories of life satisfaction among AYAs with TBI. Findings provided data-driven evidence for development of future interventions that are tailored at both temporal and personalized levels for improved health outcomes among AYAs with TBI.

Antioxidant therapies in traumatic brain injury

Oxidative stress plays a crucial role in traumatic brain injury (TBI) pathogenesis. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) formed in excess after TBI synergistically contribute to secondary brain damage together with lipid peroxidation products (reactive aldehydes) and inflammatory mediators. Furthermore, oxidative stress, endoplasmic reticulum stress and inflammation potentiate each other. Following TBI, excessive oxidative stress overloads the endogenous cellular antioxidant system leading to cell death. To combat oxidative stress, several antioxidant therapies were tested in preclinical animal models of TBI. These include free radical scavengers, activators of antioxidant systems, Inhibitors of free radical generating enzymes and antioxidant enzymes. Many of these therapies showed promising outcomes including reduced edema, blood-brain barrier (BBB) protection, smaller contusion volume, and less inflammation. In addition, many antioxidant therapies also promoted better sensory, motor, and cognitive functional recovery after TBI. Overall, preventing oxidative stress is a viable therapeutic option to minimize the secondary damage and to improve the quality of life after TBI.

Errorless and trial-and-error learning of object locations in patients with executive deficits after brain injury

Studies investigating the efficacy of errorless learning (EL), a rehabilitation method in which the occurrence of errors during learning are eliminated, have predominantly involved patients with memory impairment. However, the most recent perspective on the underlying mechanism of EL explicitly takes executive processes into account. The aim of this study was to investigate whether EL of object locations is beneficial for memory performance compared to trial-and-error learning (TEL) in patients with acquired brain injury (ABI) experiencing executive deficits (N = 15) and matched healthy controls (N = 15). Participants completed an EL and TEL condition of a computerized spatial learning task, in which the location of everyday objects had to be memorized. The number of errors made during learning was predetermined, varying from 0 (EL condition) to 1, 2, 3, 4 or 5 errors (TEL condition). Results showed a beneficial effect of EL on memory performance in both ABI patients and controls (p < .001), but this advantage was not larger in ABI patients compared to controls and was not moderated by the amount of errors made during learning.