Cognitive Reserve and Age Predict Cognitive Recovery after Mild to Severe Traumatic Brain Injury

Detecting and Predicting Cognitive Decline in Individuals with Traumatic Brain Injury: A Longitudinal Telephone-Based Study

Traumatic brain injuries (TBIs) can lead to long-lasting cognitive impairments, and some survivors experience cognitive decline post-recovery. Early detection of decline is important for care planning, and understanding risk factors for decline can elucidate targets for prevention. While neuropsychological testing is the gold standard approach to characterizing cognitive function, there is a need for brief, scalable tools that are capable of detecting clinically significant changes in post-TBI cognition. This study examines whether a clinically significant change can be detected using the Brief Test of Adult Cognition by Telephone (BTACT) in a sample of individuals with chronic TBI and investigates whether potentially modifiable factors are associated with cognitive decline. Ninety participants aged 40 or older with complicated mild-to-severe TBI participated in two telephone-based study visits ∼1 year apart. Demographic, head trauma exposure, comorbid medical conditions, physical, and psychosocial functioning data were collected via self-report. The BTACT, a brief measure of global cognitive function, was used to assess cognitive performance across six domains. A reliable change index for quantifying clinically significant changes in BTACT performance was calculated. Results revealed cognitive decline in 10-27% of participants across various cognitive domains. More specifically, only depressive symptoms, including depressed affect and anhedonia, were significantly associated with cognitive decline after correcting for multiple comparisons using false discovery rate (FDR). Other factors such as the number of blows to the head, male gender, dyspnea, increased anxiety symptoms, seizures, illicit drug use, and fewer cardiovascular comorbidities should be considered hypothesis generating. Importantly, age was not a significant predictor of cognitive decline, which challenges the assumption that cognitive decline is solely related to the natural aging process. It suggests that there are unique factors associated with TBI that impact cognitive function, and these factors can affect individuals across the lifespan. The BTACT is a brief and sensitive tool for identifying clinically meaningful changes in cognitive function over a relatively brief period (i.e., 1 year) in a sample of individuals in the chronic stages of TBI (i.e., x̄ = 6.7 years post-TBI). Thus, the BTACT may be useful in surveillance efforts aimed at understanding and detecting decline, particularly in situations where in-person cognitive screening is impractical or unfeasible. We also identified potentially modifiable targets for the prevention of post-TBI cognitive decline. These findings can offer insights into treatment goals and preventive strategies for individuals at risk for cognitive decline, as well as help to facilitate early identification efforts.

The impact of age on outcome 2 years after traumatic brain injury: Case control study

BACKGROUND

Age is associated with outcome after traumatic brain injury (TBI). However, there are mixed findings across outcome domains and most studies lack controls.

OBJECTIVES

This cross-sectional study examined the association between age group (15-24 years, 25-34 years, 35-44 years, 45-54 years, 55-64 years, and 65 years or more) and outcomes 2 years after TBI in independence in daily activities, driving, public transportation use, employment, leisure activities, social integration, relationships and emotional functioning, relative to healthy controls. It was hypothesized that older individuals with TBI would have significantly poorer outcomes than controls in all domains except anxiety and depression, for which it was expected they would show better outcomes. Global functional outcome (measured using the Glasgow Outcome Scale-Extended) was also examined, and we hypothesized that older adults would have poorer outcomes than younger adults.

METHODS

Participants were 1897 individuals with TBI (mean, SD age 36.7, 17.7 years) who completed measures 2 years post-injury and 110 healthy controls (age 38.3, 17.5 years).

RESULTS

Compared to controls, individuals with TBI were less independent in most activities of daily living, participated less in leisure activities and employment, and were more socially isolated, anxious and depressed (p < 0.001). Those who were older in age were disproportionately less likely to be independent in light domestic activities, shopping and driving; and participated less in occupational activities relative to controls. Functional outcome was significantly higher in the youngest age group than in all older age groups (p < 0.001), but the younger groups were more likely to report being socially isolated (p < 0.001), depressed (p = 0.005) and anxious (p = 0.02), and less likely to be married or in a relationship (p < 0.001).

CONCLUSION

A greater focus is needed on addressing psychosocial issues in younger individuals with TBI, whereas those who are older may require more intensive therapy to maximise independence in activities of daily living and return to employment.

The experience of traumatic brain injury in a culturally and linguistically diverse sample in Australia

PURPOSE

Individuals from culturally and linguistically diverse (CALD) backgrounds experience poorer outcomes following traumatic brain injury (TBI), including poorer quality of life. The reasons for these poorer outcomes are unclear. Therefore, this study aimed to qualitatively investigate the experience of injury, rehabilitation, and recovery amongst individuals from a CALD background following TBI.

MATERIALS AND METHODS

Fifteen semi-structured interviews were conducted, and qualitatively analysed using reflexive thematic analysis.

RESULTS

It was demonstrated that: (a) the cognitive and behavioural consequences of TBI were accompanied by stigma and loss of independence; (b) participants held many beliefs related to their TBI, ranging from bad luck to acceptance. Participants' personal values and beliefs provided strength and resilience, with many viewing the injury as a positive event in their lives; (c) participants were appreciative of the high standard of care they received in hospital and rehabilitation, although communication barriers were experienced; (d) many participants identified with Australian culture, and few believed their cultural background negatively impacted their experience of TBI; (e) external support, particularly from family, was considered central to recovery.

CONCLUSION

These findings offer insight into the challenges CALD individuals face and factors that may facilitate their recovery and improve functional outcomes.

Trajectories of fatigue and related outcomes following mild acquired brain injury: a multivariate latent class growth analysis

OBJECTIVE

Fatigue is a common symptom following acquired brain injury although the severity and course differs for many individuals. This longitudinal study aimed to identify latent trajectory classes of fatigue and associated outcomes following mild brain injury.

METHODS

204 adults with mild traumatic brain injury (159; 78%) or minor stroke (45; 22%) were assessed 4 times over 1 year. Subjective measures of fatigue, anxiety, depression, cognitive complaints and societal participation were collected. Multivariate Latent Class Growth Analysis identified classes of participants with similar longitudinal patterns. Demographic and injury characteristics were used to predict class membership.

RESULTS

Analysis revealed four classes. Class 1 (53%) had mild, decreasing fatigue with no other problems. Class 2 (29%) experienced high persistent fatigue, moderate cognitive complaints and societal participation problems. Class 3 (11%) had high persistent fatigue with anxiety, depression, cognitive complaints and participation problems. Class 4 (7%) experienced decreasing fatigue with anxiety and depression but no cognitive or participation problems. Women and older individuals were more likely to be in class 2.

CONCLUSION

Half the participants had a favourable outcome while the remaining classes were characterised by persistent fatigue with cognitive complaints (class 2), decreasing fatigue with mood problems (class 4) or fatigue with both cognitive and mood problems (class 3). Fatigue treatment should target combinations of problems in such individual trajectories after mild brain injury.

Considering the Importance of Personal and Injury Factors Influencing Outcome After Traumatic Brain Injury

OBJECTIVE

Given the high variability in traumatic brain injury (TBI) outcomes and relative lack of examination of the influence of noninjury factors on outcome, this study aimed to examine factors associated with functional outcome at 1 and 2 years after moderate to severe TBI, including both preinjury and injury-related factors.

DESIGN

Observational cohort study.

SETTING

Inpatient hospital recruitment with outpatient follow-up at 1 and 2 years post injury.

PARTICIPANTS

Individuals with moderate to severe TBI were recruited prospectively into a Longitudinal Head Injury Outcome Study. Of the eligible 3253 individuals who were eligible, 1899 participants consented to the study (N=1899).

MAIN OUTCOME MEASURE

Functional outcome was measured using the Glasgow Outcome Scale-Extended (GOS-E).

RESULTS

1476 participants (73.6% males) and 1365 participants (73% males) completed the GOS-E at 1 and 2 years post injury. They had a mean age at injury of 40 years and mean duration of post-traumatic amnesia (PTA) of 26 days. Good recovery, representing return to previous activities on the GOS-E (score 7-8), was present in 31% of participants at 1 year post injury and 33.5% at 2 years post injury. When predictor variables were entered into regression together, good outcome was significantly associated with not being from a culturally and linguistically diverse background and not having preinjury mental health or alcohol treatment, shorter PTA duration, and absence of limb injuries at both 1 and 2 years; higher education was also a significant predictor at 1 year post injury.

CONCLUSIONS

Alongside consideration of injury severity, understanding and addressing preinjury factors is important to maximize outcomes.

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

BACKGROUND

There is a lack of evidence relating to cognitive-communication difficulties following traumatic brain injury (TBI) sustained in older adulthood. A prominent area in which post-TBI cognitive-communication difficulties manifest is at the level of social communication. An investigation of social communication focusing on comparison of those injured in older and younger adulthood is a practical starting point for age-related cognitive-communication outcome comparison.

AIMS

The overall objective of this study was to explore the social communication of individuals who sustained severe TBI in an early period of older adulthood (50-70 years) compared to younger adulthood (18-40 years), as informed by self and close other reports.

METHODS & PROCEDURES

This exploratory controlled group comparison study involved analysis of self-reported and close other reported La Trobe Communication Questionnaire data for 22 adults with severe TBI (11 older at injury; 11 younger at injury) and 22 control participants (11 older; 11 younger). TBI participants were matched for injury variables and participant groups were matched for sex, age and education.

OUTCOMES & RESULTS

The close others of the older and younger adults with TBI reported them to have significantly more frequent difficulty with social communication than the close others of age-matched control groups. Older adults with TBI reported significantly more frequent difficulty with social communication than uninjured older adults. In contrast, younger adults with TBI and uninjured younger adults reported a similar frequency of difficulty with social communication. No age-based difference in the frequency of social communication difficulty was evident when comparing the self or close other reports of older and younger adults with TBI. Awareness of social communication difficulty, as indexed by comparing self and close other perceptions, showed a different pattern across the TBI groups. The older TBI group rated themselves as having significantly less frequent social communication difficulty than was perceived by their close others. In contrast, no statistically significant difference was evident between the self and close other social communication ratings of the younger TBI group.

CONCLUSIONS AND IMPLICATIONS

Where possible clinicians need to work with close communication partners to understand the nature and degree of social communication difficulty following severe TBI. This may be especially important when working with people who sustain TBI in older adulthood if future research shows that this population have greater difficulty with self-awareness of social communication difficulty.

WHAT THIS PAPER ADDS

What is already known on the subject Cognitive-communication difficulties are a common consequence of traumatic brain injury (TBI) that can have long-term impact on everyday functioning. These challenges have primarily been investigated in individuals who sustained TBI in younger adulthood. What this paper adds to existing knowledge Individuals who sustain severe TBI in early older adulthood have a higher frequency of reported social communication difficulty to non-injured adults of a similar age, albeit they may underreport such difficulties potentially in the context of reduced self-awareness. What are the potential or actual clinical implications of this work? Social communication difficulty is an issue for people who sustain severe TBI in early older adulthood. However, a poorer overall social communication outcome in comparison to those injured in younger adulthood should not be assumed. Clinical service delivery for these challenges is most optimally delivered in a collaborative manner with the individual and their close others. Future research is required to investigate the identified trends from this study.

Factors Influencing Self-Esteem After a Traumatic Brain Injury

OBJECTIVE

Traumatic brain injury (TBI) and its consequences can significantly impact an individual's identity and self-esteem. However, there is limited research with respect to the trajectory of change over time and factors that may influence self-esteem levels. This study aimed to investigate: (1) changes in self-esteem over 3 years post-TBI; and (2) factors associated with self-esteem post-TBI.

SETTING

Outpatient.

PARTICIPANTS, DESIGN, AND MEASURES

Self-esteem was measured in 1267 individuals with predominantly moderate to severe TBI (mean age = 36.38 years, mean days in posttraumatic amnesia = 26.16 days) using the Rosenberg Self-Esteem Scale at 1-, 2, and 3 years post-injury. Participants also completed the Structured Outcome Questionnaire and the Glasgow Outcome Scale-Extended (GOS-E).

RESULTS

Linear mixed modeling indicated that self-esteem significantly declined between 1 and 2 years but remained stable between 2 and 3 years post-injury. Higher self-esteem was significantly associated with better functional outcomes (as measured by the GOS-E), more years of education, more participation in leisure activities, and lower reported anxiety and depression levels.

CONCLUSIONS

Findings suggest that functional impacts of injury and emotional functioning influence self-esteem increasingly between 1 and 2 years post-injury. This highlights the importance of timely psychological interventions to maximize self-esteem in individuals with TBI post-injury.

The role of cognitive reserve in traumatic brain injury: a systematic review of observational studies

OBJECTIVE

Evaluate the role of cognitive reserve (CR) on cognitive and physical sequelae in traumatic brain injury (TBI).

METHODS

A comprehensive search strategy was conducted in four databases in English and Spanish in the last 12 years (2011-2023). Inclusion criteria: original cross-sectional and longitudinal studies whose main or secondary objective was to evaluate the effect of CR in adult patients with TBI. PRISMA guidelines were used to report the search and selection method and STROBE checklist was used to evaluate the quality of studies.

RESULTS

Eighteen observational studies were included in this review. Multiple sources of variability were observed: number of patients, time of evolution, severity of the TBI, type of CR proxy, cognitive assessment instrument, etc. However, the most commonly used indicators of CR were premorbid IQ and educational attainment. A positive and consistent association between CR and performance on cognitive tests after injury was found.

CONCLUSIONS

CR has a consistent positive effect on cognition and on some other aspects of recovery in traumatic brain injury. In future studies, it will be necessary to promote the use of CR indices based on various indicators and explore the effects of CR on other aspects related to the recovery of brain trauma.

ANTI-CD49D ANTIBODY TREATMENT IMPROVES SURVIVAL AND ATTENUATES NEUROCOGNITIVE DEFICITS AFTER TRAUMATIC BRAIN INJURY IN AGED MICE

ABSTRACT

Patients 65 years and older account for an increasing proportion of traumatic brain injury (TBI) patients. Aged TBI patients experience increased morbidity and mortality compared with young TBI patients. We previously demonstrated a marked accumulation of CD8 + T-cells within the brains of aged TBI mice compared with young TBI mice. Therefore, we hypothesized that blocking peripheral T-cell infiltration into the injured brain would improve neurocognitive outcomes in aged mice after TBI. Young and aged male C57BL/6 mice underwent TBI via controlled cortical impact versus sham injury. Two hours after injuries, mice received an anti-CD49d antibody (aCD49d Ab) to block peripheral lymphocyte infiltration or its isotype control. Dosing was repeated every 2 weeks. Mortality was tracked. Neurocognitive testing for anxiety, associative learning, and memory was assessed. Motor function was evaluated. Plasma was collected for cytokine analysis. Flow cytometry was used to phenotype different immune cells within the brains. Consequently, aCD49d Ab treatment significantly improved post-TBI survival, anxiety level, associative learning, memory, and motor function in aged mice 2 months after TBI compared with isotype control treated mice. aCD49d Ab treatment augmented T H 2 response in the plasma of aged mice 2 months after TBI compared with isotype control-treated mice. Notably, aCD49d Ab treatment significantly reduced activated CD8 + cytotoxic T-cells within aged mouse brains after TBI. Contrastingly, no difference was detected in young mice after aCD49d Ab treatment. Collectively, aCD49 Ab treatment reduced T-cells in the injured brain, improved survival, and attenuated neurocognitive and gait deficits. Hence, aCD49d Ab may be a promising therapeutic intervention in aged TBI subjects-a population often excluded in TBI clinical trials.

Investigating cognitive reserve, symptom resolution and brain connectivity in mild traumatic brain injury

BACKGROUND

A proportion of patients with mild traumatic brain injury (mTBI) suffer long-term consequences, and the reasons behind this are still poorly understood. One factor that may affect outcomes is cognitive reserve, which is the brain's ability to maintain cognitive function despite injury. It is often assessed through educational level or premorbid IQ tests. This study aimed to explore whether there were differences in post-concussion symptoms and symptom resolution between patients with mTBI and minor orthopedic injuries one week and three months after injury. Additional aims were to explore the relationship between cognitive reserve and outcome, as well as functional connectivity according to resting state functional magnetic resonance imaging (rs-fMRI).

METHOD

Fifteen patients with mTBI and 15 controls with minor orthopedic injuries were recruited from the emergency department. Assessments, including Rivermead Post-Concussion Questionnaire (RPQ), neuropsychological testing, and rs-fMRI scans, were conducted on average 7 days (SD = 2) and 122 days (SD = 51) after injury.

RESULTS

At the first time point, significantly higher rates of post-concussion symptoms (U = 40.0, p = 0.003), state fatigue (U = 56.5, p = 0.014), and fatigability (U = 58.5, p = 0.025) were observed among the mTBI group than among the controls. However, after three months, only the difference in post-concussion symptoms remained significant (U = 27.0, p = 0.003). Improvement in post-concussion symptoms was found to be significantly correlated with cognitive reserve, but only in the mTBI group (Spearman's rho = -0.579, p = .038). Differences in the trajectory of recovery were also observed for fatigability between the two groups (U = 36.5, p = 0.015). Moreover, functional connectivity differences in the frontoparietal network were observed between the groups, and for mTBI patients, functional connectivity differences in an executive control network were observed over time.

CONCLUSION

The findings of this pilot study suggest that mTBI, compared to minor orthopedic trauma, is associated to both functional connectivity changes in the brain and concussion-related symptoms. While there is improvement in these symptoms over time, a small subgroup with lower cognitive reserve appears to experience more persistent and possibly worsening symptoms over time. This, however, needs to be validated in larger studies.

TRIAL REGISTRATION

NCT05593172. Retrospectively registered.

Cognitive Performance of Brazilian Patients With Favorable Outcomes After Severe Traumatic Brain Injury: A Prospective Study

OBJECTIVE

The aim of this study was to investigate the cognitive performance of patients with favorable outcomes, determined by the Glasgow Outcome Scale, 1 yr after hospital discharge due to severe traumatic brain injury.

DESIGN

This was a prospective case-control study. From 163 consecutive adult patients with severe traumatic brain injury included in the study, 73 patients had a favorable outcome (Glasgow Outcome Scale score of 4 or 5) 1 yr after hospital discharge and were eligible for the cognitive evaluation, of which 28 completed the evaluations. The latter were compared with 44 healthy controls.

RESULTS

The average loss of cognitive performance among participants with traumatic brain injury varied between 13.35% and 43.49% compared with the control group. Between 21.4% and 32% of the patients performed below the 10th percentile on three language tests and two verbal memory tests, whereas 39% to 50% performed below this threshold on one language test and three memory tests. Longer hospital stay, older age, and lower education were the most important predictors of worse cognitive performance.

CONCLUSION

One year after a severe traumatic brain injury, a significant proportion of Brazilian patients with the favorable outcome determined by Glasgow Outcome Scale still showed significant cognitive impairment in verbal memory and language domains.

s-CRIq: the online short version of the Cognitive Reserve Index Questionnaire

BACKGROUND

The wide use of the term Cognitive Reserve (CR) is in need of a clear and shared definition of its concept and of the development of new tools, quick and easy to use and updated for the people of today. This study describes the online short CRIq (s-CRIq), the new shorter version of the CRIq, following an item analysis revision, and compares the data distribution of different samples.

METHODS

The s-CRIq was administered online to 435 people while another 440 filled out the s-CRIq in self-administration. A further 588 participants had been administered the original paper-and-pencil long CRIq and 344 the online long CRIq.

RESULTS

The major difference in the databases of s-CRIq versus the long versions is an increased score in education and in leisure activity. However, the density distributions of the total score of CRI in the 4 databases share 64% of their areas, and at least two of them share 84%.

CONCLUSION

The s-CRIq proved to be a simple and easy-to-administer tool. Similarly, to the original version, the s-CRIq is freely available on the web, and it is our hope that it will be of fruitful use for researchers and clinicians alike.

Changing Epidemiology and Functional Outcomes of Inpatient Rehabilitation in Asian Traumatic Brain Injury Cases before and during the COVID-19 Pandemic: A Retrospective Cohort Study

BACKGROUND

This study aimed to compare acute injury and rehabilitation characteristics for traumatic brain injury (TBI) inpatients during the pre and post COVID-19 pandemic periods.

METHODS

A retrospective study of TBI inpatients between 1 April 2018 and 31 December 2019 (pre COVID-19 period), and 1 July 2020 and 31 March 2022 (post COVID-19 period) was performed to compare demographics, premorbid comorbidity, TBI characteristics, rehabilitation complications, admission and discharge functional independence measure (FIM^®), length of stay and discharge status.

RESULTS

A total of 187 data sets were analyzed (82 pre COVID-19 and 105 post COVID-19). Post COVID-19 TBI inpatients were older by 11 years (pre COVID-19 mean 55 years vs. post COVID-19 mean 66 years, and p < 0.001), with 23% higher female inpatients (pre COVID-19 13.4% vs. post COVID-19 36.2%, and p < 0.001) and 25% higher presence of comorbidities (pre COVID-19 52.4% vs. post COVID-19 77.1%, and p < 0.001). In the post COVID-19 group, total discharge FIM (Td-FIM) was significantly lower by ~12 points (pre COVID-19 94.5 vs. post COVID-19 82, and p = 0.011), Td-FIM ≥ 91 was lower by ~18% (pre COVID-19 53.7% vs. post COVID-19 36.2%, and p = 0.017), and the need for caregivers increased by ~17% (pre COVID-19 68% vs. post COVID-19 85.4%, and p = 0.006) Conclusions: Our findings signal a demographic shift towards older, frailer TBI with lower functional independence levels post COVID-19.

Translation, cross-cultural adaptation and validation of the 10-item Weekly Calendar Planning Activity in Spanish-speaking ABI patients: a multicenter study

We present the process of translation, adaptation, and validation in the Spanish context of the 10-item version of the Weekly Calendar Planning Activity (WCPA-10), a performance-based measure of cognitive instrumental activities of daily living (C-IADL). The study consisted of two phases: I) translation/cultural adaptation of the WCPA, conducted by professional bilingual translators, a panel of experts, and a pilot study, and II) validation in a sample of 42 acquired brain injury patients (ABI) and 42 healthy participants (HC). WCPA primary outcomes showed expected convergent/discriminant validity patterns with socio-demographical and clinical variables and cognitive processes identifying those WCPA outcomes that best predicted executive and memory deficits measured with a battery of traditional neuropsychological tests. In addition, performance on the WCPA was a significant predictor of everyday functioning over variables such as socio-demographics or global cognition when measured with traditional tests. External validity was established by the WCPA's ability to identify everyday cognitive deficits in ABI patients compared to HC, even in those with subtle cognitive impairment based on neuropsychological tests. The Spanish WCPA-10 seems an appropriate and sensitive assessment tool to identify cognitive-functional impairment in ABI-patients, even those with subtle cognitive impairment. The results also highlight the relevance of this kind of test, as they indicate a better prediction of patients' real-world functioning than traditional neuropsychological tests.

Association Between the Attention Network Test, Neuropsychological Measures, and Disability in Post-Acute Traumatic Brain Injury

Cognitive impairment after traumatic brain injury (TBI) is persistent and disabling. Assessing cognitive function in a reliable and valid manner, using measures that are sensitive to the integrity of underlying neural substrates, is crucial in clinical research. The Attention Network Test (ANT) is one such assessment measure that has demonstrated associations with neural regions involved in attention; however, clinical utility of the ANT is limited because its relationship with neuropsychological measures of cognitive function (i.e., its construct validity) has not yet been established in TBI. We evaluated the association between the ANT and 1) a neuropsychological battery assessing executive function and memory and 2) global function assessed by the Glasgow Outcome Scale-Extended (GOSE). Forty-eight adults with complicated mild-severe TBI were evaluated ∼5 months post-injury. Using principal component analysis and multi-variate linear regression adjusted for age, gender, education, and cause of injury, we found that ANT reaction time and executive network scores predicted a principal component assessing processing speed and executive function. Conversely, the ANT did not predict a principal component assessing memory. The ANT was weakly associated with the GOSE. Among persons with TBI during the post-acute phase of recovery, the ANT has good construct validity as evidenced by its associations with neuropsychological measures of processing speed and executive function, but not memory. Given that ANT networks are known to relate to specific neuroanatomical regions, the ANT may be a useful outcome measure for evaluating novel therapeutics targeting attention and executive functions after TBI.

Depression Severity Is Different in Dysosmic Patients Who Have Experienced Traumatic Brain Injury Compared with Those Who Have Not

Traumatic brain injury (TBI) in humans can result in olfactory, cognitive, and affective changes. Surprisingly, research on the consequences of TBI often did not control for olfactory function in the investigated groups. Consequently, the affective or cognitive differences might be misleading as related rather to different olfactory performance than to a TBI experience. Hence, our study aimed to investigate whether TBI occurrence would lead to altered affective and cognitive functioning in two groups of dysosmic patients, one with TBI experience and one without. In total, 51 patients with TBI experience and 50 controls with varied causes of olfactory loss were thoroughly examined in terms of olfactory, cognitive, and affective performance. Student t-tests demonstrated that the only significant difference between the groups appeared in the depression severity, with TBI patients being more depressed (t = 2.3, p = 0.011, Cohen's d = -0.47). Regression analyses further showed that TBI experience was significantly associated with depression severity (R2 = 0.05, F [1, 96] = 5.5, p = 0.021, beta = 1.4). In conclusion, the present study showed that TBI experience is linked to depression, which is more pronounced compared to individuals with olfactory loss without TBI.

Longitudinal Abnormalities in White Matter Extracellular Free Water Volume Fraction and Neuropsychological Functioning in Patients with Traumatic Brain Injury

Traumatic brain injury is a global public health problem associated with chronic neurological complications and long-term disability. Biomarkers that map onto the underlying brain pathology driving these complications are urgently needed to identify individuals at risk for poor recovery and to inform design of clinical trials of neuroprotective therapies. Neuroinflammation and neurodegeneration are two endophenotypes potentially associated with increases in brain extracellular water content, but the nature of extracellular free water abnormalities after neurotrauma and its relationship to measures typically thought to reflect traumatic axonal injury are not well characterized. The objective of this study was to describe the relationship between a neuroimaging biomarker of extracellular free water content and the clinical features of a cohort with primarily complicated mild traumatic brain injury. We analyzed a cohort of 59 adult patients requiring hospitalization for non-penetrating traumatic brain injury of all severities as well as 36 healthy controls. Patients underwent brain magnetic resonance imaging (MRI) at 2 weeks (n = 59) and 6 months (n = 29) post-injury, and controls underwent a single MRI. Of the participants with TBI, 50 underwent clinical neuropsychological assessment at 2 weeks and 28 at 6 months. For each subject, we derived a summary score representing deviations in whole brain white matter extracellular free water volume fraction (VF) and free water-corrected fractional anisotropy (fw-FA). The summary specific anomaly score (SAS) for VF was significantly higher in TBI patients at 2 weeks and 6 months post-injury relative to controls. SAS for VF exhibited moderate correlation with neuropsychological functioning, particularly on measures of executive function. These findings indicate abnormalities in whole brain white matter extracellular water fraction in patients with TBI and are an important step toward identifying and validating noninvasive biomarkers that map onto the pathology driving disability after TBI.

Impact of Sociodemographic, Premorbid, and Injury-Related Factors on Patient-Reported Outcome Trajectories after Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) remains one of the leading causes of death and disability worldwide. To better understand its impact on various outcome domains, this study pursues the following: (1) longitudinal outcome assessments at three, six, and twelve months post-injury; (2) an evaluation of sociodemographic, premorbid, and injury-related factors, and functional recovery contributing to worsening or improving outcomes after TBI. Using patient-reported outcome measures, recuperation trends after TBI were identified by applying Multivariate Latent Class Mixed Models (MLCMM). Instruments were grouped into TBI-specific and generic health-related quality of life (HRQoL; QOLIBRI-OS, SF-12v2), and psychological and post-concussion symptoms (GAD-7, PHQ-9, PCL-5, RPQ). Multinomial logistic regressions were carried out to identify contributing factors. For both outcome sets, the four-class solution provided the best match between goodness of fit indices and meaningful clinical interpretability. Both models revealed similar trajectory classes: stable good health status (HRQoL: n = 1944; symptoms: n = 1963), persistent health impairments (HRQoL: n = 442; symptoms: n = 179), improving health status (HRQoL: n = 83; symptoms: n = 243), and deteriorating health status (HRQoL: n = 86; symptoms: n = 170). Compared to individuals with stable good health status, the other groups were more likely to have a lower functional recovery status at three months after TBI (i.e., the GOSE), psychological problems, and a lower educational attainment. Outcome trajectories after TBI show clearly distinguishable patterns which are reproducible across different measures. Individuals characterized by persistent health impairments and deterioration require special attention and long-term clinical monitoring and therapy.

Traumatic brain injury and post-traumatic stress disorder are not associated with Alzheimer's disease pathology measured with biomarkers

INTRODUCTION

Epidemiological studies report an association between traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) and clinically diagnosed Alzheimer's disease (AD). We examined the association between TBI/PTSD and biomarker-defined AD.

METHODS

We identified 289 non-demented veterans with TBI and/or PTSD and controls who underwent clinical evaluation, cerebrospinal fluid (CSF) collection, magnetic resonance imaging (MRI), amyloid beta (Aβ) and tau positron emission tomography, and apolipoprotein E testing. Participants were followed for up to 5.2 years.

RESULTS

Exposure groups (TBI, PTSD, and TBI + PTSD) had higher prevalence of mild cognitive impairment (MCI: P < .0001) and worse Mini-Mental State Examination scores (PTSD: P = .008; TBI & PTSD: P = .009) than controls. There were no significant differences in other cognitive scores, MRI volumes, Aβ or tau accumulation, or in most longitudinal measures.

DISCUSSION

TBI and/or PTSD were not associated with elevated AD biomarkers. The poorer cognitive status of exposed veterans may be due to other comorbid pathologies.

Predictors of cognitive gains during inpatient rehabilitation for older adults with traumatic brain injury

INTRODUCTION

Traumatic brain injury (TBI) among older adults is increasing and can affect cognition. To effectively meet the rehabilitation needs of older adults, a clearer picture is needed of patient-, clinical-, and facility-level characteristics that affect cognitive recovery during inpatient rehabilitation facility (IRF) stays.

OBJECTIVE

To identify patient, clinical, and facility factors associated with cognitive recovery among older adults with TBI who received IRF care.

DESIGN

Secondary data analysis.

SETTING

Uniform Data System for Medical Rehabilitation-participating IRFs in the United States.

PATIENTS

Patients were 65 to 99 years of age at IRF admission for TBI. Participants received IRF care between 2002 and 2018 (N = 137,583); 56.3% were male; 84.2% were white; mean age was 78.7 years.

MAIN OUTCOME MEASURE

Change in Functional Independence Measure Cognitive Score (FIM-Cognitive) from IRF admission to discharge, categorized as favorable (FIM-cognitive score gains ≥3 points) or poor (FIM-cognitive score gains <3 points) cognitive outcomes.

INTERVENTIONS

Not applicable.

RESULTS

Patients had greater odds of favorable cognitive recovery if they were female (adjusted odds ratio [aOR] 1.05, 95% confidence interval [CI] 1.05-1.08), had higher motor functioning at IRF admission (aOR 1.03, 95% CI 1.03-1.04), longer length of stay (aOR 1.07, 95% CI 1.06-1.07), or received care at a freestanding IRF (vs. hospital rehab unit) (aOR 1.57, 95% CI 1.52-1.61). Patients who were older (aOR 0.99, 95% CI 0.98-0.99), Black (aOR 0.79, 95% CI 0.75-0.83), Hispanic or Latino (aOR 0.97, 95% CI 0.91-1.02), or were part of another racial or ethnic group (aOR 0.85, 95% CI 0.81-0.90) (vs. White), had high-cost comorbid conditions (aOR 0.71, 95% CI 0.65-0.76), or who had higher cognitive functioning at IRF admission (aOR 0.90, 95% CI 0.90-0.91) had lower odds of favorable cognitive recovery.

CONCLUSIONS

Patient (age, sex, race, ethnicity), clinical (level of functioning at IRF admission, length of stay) and facility (e.g., freestanding IRF) factors contributed to the cognitive recoveries of older adults during IRF stays.

MICROGLIA AND INFILTRATING T-CELLS ADOPT LONG-TERM, AGE-SPECIFIC, TRANSCRIPTIONAL CHANGES AFTER TRAUMATIC BRAIN INJURY IN MICE

ABSTRACT

Aged traumatic brain injury (TBI) patients suffer increased mortality and long-term neurocognitive and neuropsychiatric morbidity compared with younger patients. Microglia, the resident innate immune cells of the brain, are complicit in both. We hypothesized that aged microglia would fail to return to a homeostatic state after TBI and adopt a long-term injury-associated state within aged brains compared with young brains after TBI. Young and aged male C57BL/6 mice underwent TBI via controlled cortical impact versus sham injury and were sacrificed 4 months post-TBI. We used single-cell RNA sequencing to examine age-associated cellular responses after TBI. Brains were harvested, and CD45+ cells were isolated via fluorescence-activated cell sorting. cDNA libraries were prepared using the 10x Genomics Chromium Single Cell 3' Reagent Kit, followed by sequencing on a HiSeq 4,000 instrument and computational analyses. Post-injury, aged mice demonstrated a disparate microglial gene signature and an increase in infiltrating T cells compared with young adult mice. Notably, aged mice post-injury had a subpopulation of age-specific, immune-inflammatory microglia resembling the gene profile of neurodegenerative disease-associated microglia with enriched pathways involved in leukocyte recruitment and brain-derived neurotrophic factor signaling. Meanwhile, post-injury, aged mice demonstrated heterogeneous T-cell infiltration with gene profiles corresponding to CD8 effector memory, CD8 naive-like, CD8 early active T cells, and Th1 cells with enriched pathways, such as macromolecule synthesis. Taken together, our data showed that the aged brain had an age-specific gene signature change in both T-cell infiltrates and microglia, which may contribute to its increased vulnerability to TBI and the long-term sequelae of TBI.

Long term effects of severe acquired brain injury: A follow-up investigation on the role of cognitive reserve on cognitive outcomes

In a recent study we showed that Cognitive Reserve (CR) did not significantly predict the neuropsychological outcomes of patients with severe Acquired Brain Injury (sABI), after a rehabilitation program. The present study aims to extend the previous results by assessing the role of CR on long-term neuropsychological outcomes of a subgroup (N = 27) of that same population. Patients took part in a telephone interview, where Tele-Global Examination Mental State (Tele-GEMS) and Glasgow Outcome Scale Extended (GOS-E) were administered. A linear regression model was conducted considering Tele-GEMS and GOS-E as dependent variables, while the scores on Cognitive Reserve Index questionnaire (CRIq), Disability Rating Scale (DRS), and Level of Cognitive Functioning (LCF), administered at discharge, were considered as predictors. Results show that higher levels of CR and LCF, significantly predicted cognitive performance 4 years later. However, in the same follow-up, CR did not predict functional outcome, which was only predicted by lower disability scores at discharge. Thus, even if CR seems not showing an effect on cognitive efficiency when tested after the first rehabilitation intervention, current results show that CR has significant effects on long-term cognitive outcomes.

Cognitive reserve index and long-term disability in patients with severe traumatic brain injury discharged from the intensive rehabilitation unit

Objectives

The "cognitive reserve" (CR) theory posits that higher premorbid cognitive activities can mitigate the effects of brain damage. This study aimed to investigate the association between CR and long-term functional autonomy in patients surviving a severe traumatic brain injury (sTBI).

Setting

Data were collected from the database of inpatients with severe acquired brain injury in a rehabilitation unit admitted from August 2012 to May 2020.

Participants

Patients that had incurred an sTBI, aged 18+ years, completing the phone Glasgow Outcome Scale-Expanded at follow-up (pGOS-E) in absence of previous brain trauma or neurological disease, or cognitive disorders were included. Patients with severe brain injury from non-traumatic etiologies were not included in the study.

Design

In this longitudinal study, all patients underwent a multidimensional assessment including the cognitive reserve index questionnaire (CRIq), the coma recovery scale-revised, the level of cognitive functioning, the Disability Rating Scale (DRS), and the Galveston Orientation and Amnesia Test at admission. At discharge, functional scales were administered again together with the Glasgow Outcome Scale. The pGOS-E was assessed at follow-up.

Main measures

pGOS-E.

Results

A total of 106 patients/caregivers underwent the pGOS-E after 5.8 [3.6] years from the event. Among them, 46 (43.4%) died after discharge, and 60 patients [men: 48 (80%); median age: 54 years; median time post-onset: 37 days; median education level: 10 years; median CRIq total score: 91] were included in the analysis exploring the association between pGOS-E and demographic data, cognitive reserve surrogates, and clinical variables at admission and discharge from the rehabilitation unit. A younger age (B = -0.035, p = 0.004) and a lower DRS category at discharge (B = -0.392, p = 0.029) were significantly related to a higher long-term functional autonomy in the multivariate analysis.

Conclusion

Long-term functional autonomy was not influenced by CR as assessed through the educational level and the CRIq.

Prognostic value of global deep white matter DTI metrics for 1-year outcome prediction in ICU traumatic brain injury patients: an MRI-COMA and CENTER-TBI combined study

PURPOSE

A reliable tool for outcome prognostication in severe traumatic brain injury (TBI) would improve intensive care unit (ICU) decision-making process by providing objective information to caregivers and family. This study aimed at designing a new classification score based on magnetic resonance (MR) diffusion metrics measured in the deep white matter between day 7 and day 35 after TBI to predict 1-year clinical outcome.

METHODS

Two multicenter cohorts (29 centers) were used. MRI-COMA cohort (NCT00577954) was split into MRI-COMA-Train (50 patients enrolled between 2006 and mid-2014) and MRI-COMA-Test (140 patients followed up in clinical routine from 2014) sub-cohorts. These latter patients were pooled with 56 ICU patients (enrolled from 2014 to 2020) from CENTER-TBI cohort (NCT02210221). Patients were dichotomised depending on their 1-year Glasgow outcome scale extended (GOSE) score: GOSE 1-3, unfavorable outcome (UFO); GOSE 4-8, favorable outcome (FO). A support vector classifier incorporating fractional anisotropy and mean diffusivity measured in deep white matter, and age at the time of injury was developed to predict whether the patients would be either UFO or FO.

RESULTS

The model achieved an area under the ROC curve of 0.93 on MRI-COMA-Train training dataset, and 49% sensitivity for 96.8% specificity in predicting UFO and 58.5% sensitivity for 97.1% specificity in predicting FO on the pooled MRI-COMA-Test and CENTER-TBI validation datasets.

CONCLUSION

The model successfully identified, with a specificity compatible with a personalized decision-making process in ICU, one in two patients who had an unfavorable outcome at 1 year after the injury, and two-thirds of the patients who experienced a favorable outcome.

Effect of traumatic brain injury on mild behavioral impairment domains prior to all-cause dementia diagnosis and throughout disease progression

Introduction

Traumatic brain injury (TBI) may alter dementia progression, although co-occurring neuropsychiatric symptoms (NPS) have received less attention. Originally designed to evaluate behavioral disruption prior to dementia diagnosis, the mild behavioral impairment (MBI) construct relates NPS to underlying neural circuit disruptions, with probable relevance across the progression of neurodegenerative disease. Therefore, the MBI construct may represent a valuable tool to identify and evaluate related NPS both preceding diagnosis of all-cause dementia throughout the progression of disease, representing an important area of inquiry regarding TBI and dementia. This investigation sought to evaluate the effect of TBI on NPS related by the MBI construct in participants progressing from normal cognitive status to all-cause dementia.

Methods

Using National Alzheimer's Coordinating Center data, individuals progressing from normal cognition to all-cause dementia (clinician diagnosed) over 7.6 ± 3.0 years were studied to estimate prevalence of MBI domains in 124 participants with prior TBI history (57 with loss of consciousness [LOC] <5 minutes, 22 with LOC >5 min, 45 unknown severity) compared to 822 without. MBI domain prevalence was evaluated (1) prior to dementia onset (including only time points preceding time at dementia diagnosis, as per MBI's original definition) and (2) throughout dementia progression (evaluating all available time points, including both before and after dementia diagnosis).

Results

More severe TBI (LOC >5 minutes) was associated with the social inappropriateness MBI domain (adjusted odds ratio = 4.034; P = 0.024) prior to dementia onset, and the abnormal perception/thought content domain looking across dementia progression (adjusted hazard ratio [HRadj] = 3.703; P = 0.005). TBI (all severities) was associated with the decreased motivation domain looking throughout dementia progression (HRadj. = 1.546; P = 0.014).

Discussion

TBI history is associated with particular MBI profiles prior to onset and throughout progression of dementia. Understanding TBI's impact on inter-related NPS may help elucidate underlying neuropathology with implications for surveillance, detection, and treatment of behavioral concerns in aging TBI survivors.

Highlights

The mild behavioral impairment (MBI) construct links related neuropsychiatric symptoms (NPS) by probable underlying neural network dysfunction.Traumatic brain injury (TBI) with loss of consciousness (LOC) > 5 minutes was associated with pre-dementia social inappropriateness.TBI was associated with decreased motivation looking across dementia progression.TBI with LOC > 5 minutes was associated with abnormal perception/thought content.The MBI construct may be useful for examining related NPS across dementia progression.

Insight into the potential role of ferroptosis in neurodegenerative diseases

Ferroptosis is a newly discovered way of programmed cell death, mainly caused by the accumulation of iron-dependent lipid peroxides in cells, which is morphologically, biochemically and genetically different from the previously reported apoptosis, necrosis and autophagy. Studies have found that ferroptosis plays a key role in the occurrence and development of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease and vascular dementia, which suggest that ferroptosis may be involved in regulating the progression of neurodegenerative diseases. At present, on the underlying mechanism of ferroptosis in neurodegenerative diseases is still unclear, and relevant research is urgently needed to clarify the regulatory mechanism and provide the possibility for the development of agents targeting ferroptosis. This review focused on the regulatory mechanism of ferroptosis and its various effects in neurodegenerative diseases, in order to provide reference for the research on ferroptosis in neurodegenerative diseases.

Cognitive performance in older people after mild traumatic brain injury: Trauma effects and other risk factors

OBJECTIVE

Cognitive symptoms are common in the initial weeks after mTBI, but recovery is generally expected within three months. However, there is limited information about recovery specifically in older age cohorts. Therefore, this study investigated cognitive outcome three months after mTBI in older adults (≥ 65 years) compared to trauma and community age-matched controls and explored risk factors for outcome after traumatic injury.

METHODS

Older mTBI patients (n = 40) and older adults with mild traumatic injury but without head injury (n = 66) were compared to a noninjured community control group (n = 47). Cognitive assessment included neuropsychological and computerized tests. Group differences were compared on individual tasks and overall cognitive performances using composite scores. Regression analyses identified predictors of outcome for trauma patients and moderator analyses explored possible interactions of mTBI severity with age and cognition.

RESULTS

As well as lower performances in processing speed and memory, both trauma groups had significantly lower performance on composite neuropsychological (d = .557 and .670) and computerized tasks (d = .783 and .824) compared to noninjured controls. Age, education, and history of depression were direct predictors of cognitive performance after mild traumatic injury (with or without head injury). Further moderation analysis demonstrated that mTBI severity (Glasgow Coma Scale < 15) moderated the impact of older age on computerized assessment (β = -.138).

CONCLUSIONS

Three months after mild trauma (regardless of head injury), older people demonstrate lower cognition compared to noninjured peers. However, severity of mTBI (Glasgow Coma Scale < 15) can interact with older age to predict poorer cognitive outcomes.

Effect of computerized cognitive rehabilitation in comparison between young and old age after traumatic brain injury

INTRODUCTION

Cognitive dysfunction reduces patients' quality of life and social participation with traumatic brain injury (TBI). Computerized cognitive rehabilitation is increasingly being used for cognitive therapy in TBI patients. The purpose of this study was to investigate the influence of age on the effect of computerized cognitive rehabilitation in cognitive dysfunction after TBI.

MATERIAL AND METHODS

A total of 34 patients with cognitive dysfunction after TBI were enrolled. Participants performed 30 sessions of computerized cognitive rehabilitation (Comcog) for 6 weeks. A cognitive evaluation was performed before and after treatment with Mini-Mental State Examination (MMSE) and Computerized Neurophyschologic Test (CNT).

RESULTS

There were no cognitive tests that differed between the young group and the old group at baseline. However, after computerized cognitive rehabilitation, the young group showed significant improvement compared to the old group in verbal memory, visual memory, attention, and visuo-motor coordination tests. The young group showed improvement in MMSE, verbal and visual memory, and visuo-motor coordination tests after computerized cognitive rehabilitation. In contrast, the old group showed significant improvement only in MMSE and visual learning test, one of the visual memory tests.

CONCLUSION

Our findings demonstrate that age may be an important factor related to the effect of computer cognitive rehabilitation on cognitive dysfunction after TBI. Methodologically more ordered studies with larger sample sizes are needed in the future.

The Chinese Translation Study of the Cognitive Reserve Index Questionnaire

Purpose

The purpose of this study was to perform the translation and adaption of the Cognitive Reserve Index questionnaire into Chinese and assess the reliability of the Chinese version.

Materials and Methods

The Chinese version of the Cognitive Reserve Index questionnaire was created from a standard forward-backward translation. A total of 371 volunteers, aged between 20 and 89 years, participated in this survey. Participants were divided into three age-groups (Young, Middle-aged, and Elderly), and subgroup differences were examined by independent samples t-tests, ANOVA analysis as well as post-hoc analysis. Pearson correlation analysis was applied to test the association between the total scores and each subscore (CRI-Education, CRI-WorkingActivity, and CRI-LeisureTime). The internal consistency and test-retest reliability of the Cognitive Reserve Index questionnaire were assessed. The test-retest reliability was measured among 40 participants with a 2-week interval using intraclass correlation coefficient.

Results

Strong correlations were observed between the total scores and each subscore (CRI-Education, CRI-WorkingActivity, and CRI-LeisureTime: r = 0.65, 0.79, and 0.70, respectively). In contrast, it was found low to moderate correlations among three subscores. The internal consistency was acceptable (Cronbach's alpha coefficient = 0.68). The intraclass correlation coefficient for total scores of the Chinese version of the Cognitive Reserve Index questionnaire was 0.87 (95% CI 0.74–0.93).

Conclusion

The Chinese version of the Cognitive Reserve Index questionnaire was a potentially reliable and practical tool for evaluating cognitive reserve accumulated through a person's life span.

Cognitive profiles in the acute phase of traumatic brain injury according to injury severity

Although several studies have documented the chronic phase of traumatic brain injury (TBI), few verified the nature and severity of cognitive impairments during the acute phase. Among the studies carried out during the acute phase, instrumental functions were rarely examined compared to attention, memory, and executive functions. This study aimed to compare the nature and intensity of cognitive problems in the acute phase according to TBI severity and age. It was hypothesized that cognitive impairments would increase in line with TBI severity and age, and that instrumental functions would be less affected in victims of mild or moderate TBI than in those with severe TBI. The Brief Cognitive Exam in Traumatology (EXACT), a new and reliable test specifically designed and validated to briefly assess global cognitive functioning during the acute phase, was administered to 319 mild to severe TBI victims (aged 16 to 96 years), within three months post-accident. The EXACT evaluates five domains: Language, Instrumental functions (other than language), Attention and working memory, Episodic memory, and Executive functions and behavioral regulation. Results confirmed the negative influence of TBI severity and age on global cognitive functioning. Also, compared to victims with a mild or moderate TBI, a higher proportion of those with a severe TBI presented impaired instrumental functions (calculation, praxis, and gnosis). Thus, during the acute phase, the nature and severity of cognitive impairments vary according to TBI severity.

Cognitive Reserve, Early Cognitive Screening, and Relationship to Long-Term Outcome after Severe Traumatic Brain Injury

The objective was to investigate the relationship between early global cognitive functioning using the Barrow Neurological Institute Screen for Higher Cerebral Functions (BNIS) and cognitive flexibility (Trail Making Test (TMT), TMT B-A), with long-term outcome assessed by the Mayo-Portland Adaptability Index (MPAI-4) in severe traumatic brain injury (sTBI) controlling for the influence of cognitive reserve, age, and injury severity. Of 114 patients aged 18–65 with acute Glasgow Coma Scale 3–8, 41 patients were able to complete (BNIS) at 3 months after injury and MPAI-4 5–8 years after injury. Of these, 33 patients also completed TMT at 3 months. Global cognition and cognitive flexibility correlated significantly with long-term outcome measured with MPAI-4 total score (r_BNIS = 0.315; r_TMT = 0.355). Global cognition correlated significantly with the participation subscale (r = 0.388), while cognitive flexibility correlated with the adjustment (r = 0.364) and ability (r = 0.364) subscales. Adjusting for cognitive reserve and acute injury severity did not alter these relationships. The effect size for education on BNIS and TMT scores was large (d ≈ 0.85). Early screenings with BNIS and TMT are related to long-term outcome after sTBI and seem to measure complementary aspects of outcome. As early as 3 months after sTBI, educational level influences the scores on neuropsychological screening instruments.

Cognitive Outcome 1 Year After Mild Traumatic Brain Injury: Results From the TRACK-TBI Study

BACKGROUND AND OBJECTIVES

The objectives of this study were to develop and establish concurrent validity of a clinically relevant definition of poor cognitive outcome 1 year after mild traumatic brain injury (mTBI), to compare baseline characteristics across cognitive outcome groups, and to determine whether poor 1-year cognitive outcome can be predicted by routinely available baseline clinical variables.

METHODS

Prospective cohort study included 656 participants ≥17 years of age presenting to level 1 trauma centers within 24 hours of mTBI (Glasgow Coma Scale score 13-15) and 156 demographically similar healthy controls enrolled in the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study. Poor 1-year cognitive outcome was defined as cognitive impairment (below the ninth percentile of normative data on ≥2 cognitive tests), cognitive decline (change score [1-year score minus best 2-week or 6-month score] exceeding the 90% reliable change index on ≥2 cognitive tests), or both. Associations of poor 1-year cognitive outcome with 1-year neurobehavioral outcomes were performed to establish concurrent validity. Baseline characteristics were compared across cognitive outcome groups, and backward elimination logistic regression was used to build a prediction model.

RESULTS

Mean age of participants with mTBI was 40.2 years; 36.6% were female; 76.6% were White. Poor 1-year cognitive outcome was associated with worse 1-year functional outcome, more neurobehavioral symptoms, greater psychological distress, and lower satisfaction with life (all p < 0.05), establishing concurrent validity. At 1 year, 13.5% of participants with mTBI had a poor cognitive outcome vs 4.5% of controls (p = 0.003). In univariable analyses, poor 1-year cognitive outcome was associated with non-White race, lower education, lower income, lack of health insurance, hyperglycemia, preinjury depression, and greater injury severity (all p < 0.05). The final multivariable prediction model included education, health insurance, preinjury depression, hyperglycemia, and Rotterdam CT score ≥3 and achieved an area under the curve of 0.69 (95% CI 0.62-0.75) for the prediction of a poor 1-year cognitive outcome, with each variable associated with >2-fold increased odds of poor 1-year cognitive outcome.

DISCUSSION

Poor 1-year cognitive outcome is common, affecting 13.5% of patients with mTBI vs 4.5% of controls. These results highlight the need for better understanding of mechanisms underlying poor cognitive outcome after mTBI to inform interventions to optimize cognitive recovery.

The influence of cognitive reserve in the protection of the cognitive status after an acquired brain injury: A systematic review

BACKGROUND

Cognitive Reserve (CR) hypothesis was introduced to account for the variability in cognitive performance of patients with similar degrees of brain injury or pathology. The individual variability of CR is modulated by the interaction of innate capacities and exposures throughout life, which can act as protectors against neuropathology's clinical effects. Individuals with higher CR appear to have better cognitive performance after a brain injury. The present review aimed to identify and map the scientific evidence available in literature regarding CR's influence in protecting the cognitive status after an Acquired Brain Injury (ABI).

METHOD

A systematic review was performed for published studies until October 2020 in PubMed, Scopus, and CINAHL electronic databases. Studies regarding CR's influence in protecting the cognitive status after an ABI were included in this review. The Newcastle-Ottawa Scale was used to assess risk of bias in the included studies. This systematic review was recorded in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42021236594.

RESULTS

Twenty-one studies published between 2003 and 2020 were selected and analyzed. The literature analysis showed that CR has a positive effect on cognitive status after an ABI. Various proxies were used to estimate CR, including estimated premorbid IQ, education, occupation attainment, socioeconomic status, leisure activities, bilingualism, and social integration. CR proxies constitute a set of variables that may have a significant influence on cognitive status. Higher CR levels were associated with lower cognitive impairment after an ABI.

CONCLUSIONS

Although more research is necessary for a complete understanding of CR's impact on cognition, the synthesis of these studies confirmed that there is evidence on the beneficial impact of CR on cognitive status after an ABI. These findings support CR's cognitive status role following an ABI and may provide additional information for prognosis and rehabilitation plans.

Cognitive and functional outcomes following a traumatic brain injury sustained 22 years after epilepsy surgery: A case report

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Long-term outcomes were presented for a patient status post epilepsy surgery and TBI.

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Cognitive stability was documented over a 22-year follow-up period.

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Good cognitive and functional outcomes were demonstrated in late life.

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Protective factors include seizure outcome, cognitive reserve, and medical status.

Anterior temporal lobectomy (ATL) is an effective treatment for drug-resistant epilepsy, and risk for post-surgical naming and verbal memory decline after dominant hemisphere ATL is well-established. However, less is known about later life cognitive and functional outcomes following ATL performed in early or mid-life, as there are few studies that report very long-term outcomes, and the intersection of epilepsy and the aging process is not well-understood. Factors that may promote healthy cognitive aging or confer increased risk for cognitive decline in late life for those with seizure onset in early or mid-life have yet to be determined. This case report describes an individual with drug-resistant epilepsy who was treated with left ATL in mid-life, and then subsequently sustained a moderate traumatic brain injury 22 years later. The excellent recovery and remarkable stability of cognitive performance over time may be associated with several protective factors such as favorable seizure outcome, high cognitive reserve, and the absence of co-occurring medical conditions. This case also highlights the clinical utility of serial neuropsychological testing at multiple timepoints across the lifespan for those with epilepsy, and the importance of considering the clinical significance, or functional impact, of cognitive deficits in this population.

Factors associated with employment stability following traumatic brain injury, in a sample who have received comprehensive vocational rehabilitation

PURPOSE

To quantify employment stability of individuals with traumatic brain injury (TBI) who received comprehensive vocational rehabilitation (VR) using different measures to identify difficulties experienced and factors associated with employment stability.

MATERIALS AND METHODS

72 individuals with predominantly moderate-severe TBI were interviewed. Neuropsychological assessment scores were collected. Three employment stability measures were used: number of post-injury employers, duration with employer and average weekly hours. Descriptive and predictive analyses were performed.

RESULTS

90.2% remained employed at time of interview (Mean = 4.83 years post-injury). However, participants worked significantly fewer hours, 63.9% had changed roles or employers at least once and only 51% achieved their pre-injury level of responsibility. 61% reported a high level of employer support. Self-reported difficulties included physical sequelae, memory problems and fatigue. Post-injury testing found impaired memory (34.4%) and processing speed (49.2%). After accounting for time since injury, demographic and employment variables (older age, male gender, higher pre-injury skill-level, higher level of employer support), higher level of injury-related difficulties and lower level of cognitive function significantly predicted employment stability.

CONCLUSION

Injury-related difficulties impact employment long-term, necessitating ongoing work modifications. Individualised VR is important, not only to facilitate return to work but to support long-term employment stability after TBI.Implications for rehabilitationBeing male was associated with working more hours, and having faster processing speed, lower levels of fatigue and ongoing physical sequelae were associated with a longer duration with the same employer.Initial return to work is often the first step on a long journey as injury-related difficulties can continue to impact work in the-long term and require lasting modifications to duties and working hours.VR should include ongoing follow-up to facilitate work modifications and support both the employer and the employee in adjusting to these.VR should be individualised to support the impact of the unique cognitive and physical limitations experienced by each individual with TBI, based on the needs and employment demands of each workplace.

Loss of Motor Stability After Sports-Related Concussion: Opportunities for Motor Learning Strategies to Reduce Musculoskeletal Injury Risk

Current best practices to direct recovery after sports-related concussion (SRC) typically require asymptomatic presentation at both rest and during a graduated exercise progression, and cognitive performance resolution. However, this standard of care results in a significantly elevated risk for musculoskeletal (MSK) injury after return-to-sport (RTS). The elevated risk is likely secondary to, in part, residual neurophysiological and dual-task motor stability deficits that remain despite RTS. These deficits present as a loss of autonomous control of gait and posture and an increased need for cognition for motor stability. Thus, the incorporation of strategies that can enhance motor stability and restore autonomous control of gait and posture during SRC recovery and RTS progression may facilitate a reduction of the elevated risk of secondary MSK injury. We provide a theoretical framework for the application of motor learning principles to restore autonomous gait and postural stability after SRC via incorporation, or targeted manipulation, of external focus, enhanced expectations, autonomy support, practice schedule variability, and dual-task strategies during rehabilitation and RTS training.

Cognitive Reserve in Individuals Aging With Traumatic Brain Injury: Independent and Interactive Effects on Cognitive Functioning

OBJECTIVE

To examine the influence of 2 temporal factors-age and injury chronicity-on the relationship between cognitive reserve (CR) and cognitive functioning in older adults with chronic traumatic brain injury (TBI).

SETTING

Outpatient research laboratory.

PARTICIPANTS

Adults, 50 years or older, with a 1- to 45-year history of moderate or severe TBI (N = 108).

DESIGN

Cross-sectional observational study.

MAIN MEASURES

CR was estimated using demographically corrected performance on a word-reading test (an approximation of premorbid IQ). Injury chronicity was operationalized as number of years since the date of injury. Composite cognitive scores were computed from performances on neuropsychological tests of processing speed, executive functioning, and memory.

RESULTS

CR was positively and significantly related to all cognitive performances independent of age, injury chronicity, and injury severity. Greater injury chronicity significantly attenuated the effect of CR on processing speed such that individuals more distal from their injury date evidenced a weaker positive relationship between CR and performance.

CONCLUSION

Temporal factors may modify associations between CR and cognition. Findings suggest that the protective effects of CR are temporally delimited, potentially contending with declines in brain reserve. The prognostic value of traditional outcome determinants should be considered in the context of injury chronicity.

Does cognitive decline occur decades after moderate to severe traumatic brain injury? A prospective controlled study

This prospective controlled study examined long-term trajectories of neuropsychological performance in individuals with traumatic brain injury (TBI) compared to healthy controls, and the impact of IQ, age at injury, time since injury, and injury severity on change over time. Fifty-three individuals with moderate to severe TBI (60.37% male; M = 59.77 yrs, SD = 14.03), and 26 controls (46.15% male; M = 63.96 yrs, SD = 14.42) were studied prospectively (M = 12.72 yrs between assessments). Participants completed measures of premorbid IQ (Weschler Test of Adult Reading), processing speed (Digit Symbol Coding Test), working memory (Digit Span Backwards), memory (Rey Auditory Verbal Learning Test) and executive function (Trail Making Test Part B; Hayling Errors), at a mean of 10.62 yrs (Initial) and 23.91 yrs (Follow-Up) post injury. Individuals with TBI did not show a significantly greater decline in neuropsychological performance over time compared with demographically similar controls. There was no association between change over time with IQ, time since injury or injury severity. Being older at injury had a greater adverse impact on executive function at follow-up. In this small sample, a single moderate to severe TBI was not associated with ongoing cognitive decline up to three decades post injury. Changes in cognitive function were similar between the groups and likely reflect healthy aging.

Differential neuropathology and functional outcome after equivalent traumatic brain injury in aged versus young adult mice

The CDC estimate that nearly 3 million Americans sustain a traumatic brain injury (TBI) each year. Even when medical comorbidities are accounted for, age is an independent risk factor for poor outcome after TBI. Nonetheless, few studies have examined the pathophysiology of age-linked biologic outcomes in TBI. We hypothesized that aged mice would demonstrate more severe neuropathology and greater functional deficits as compared to young adult mice after equivalent traumatic brain injuries. Young adult (14-week-old) and aged (80-week-old) C57BL/6 male mice underwent an open-head controlled cortical impact to induce TBI or a sham injury. At 30-days post-injury groups underwent behavioral phenotyping, magnetic resonance imaging, and histologic analyses. Contrary to our hypothesis, young adult TBI mice exhibited more severe neuropathology and greater loss of white matter connectivity as compared to aged mice after TBI. These findings correlated to differential functional outcomes in anxiety response, learning, and memory between young adult and aged mice after TBI. Although the mechanisms underlying this age-effect remain unclear, attenuated signs of secondary brain injury in aged TBI mice point towards different inflammatory and repair processes between age groups. These data suggest that age may need to be an a priori consideration in future clinical trial design.

Reading Abilities Post Traumatic Brain Injury in Adolescents and Adults: A Systematic Review and Meta-Analysis

Purpose People with traumatic brain injury (TBI) often struggle with complex reading, limiting participation in work and educational settings. This systematic review and meta-analysis examined studies of reading conducted with adolescents and adults with TBI to describe reading problems post TBI and investigate underlying factors for the effects of TBI on reading abilities. Method The search was conducted in EBSCO (including MEDLINE, PsycINFO, etc.), BIOSIS, ProQuest, and Web of Science. Empirical studies that used samples with a mean age greater than 10 years, reported injury characteristics, and investigated complex reading abilities (defined as greater than single-word reading) were eligible for this review. Study quality was evaluated using QualSyst. Study and sample characteristics, measures, and outcomes of interest were extracted and synthesized in the review. Studies that compared reading abilities between people with and without TBI were included in the meta-analysis. Results Twenty-four studies met inclusion criteria, six of which addressed reading in pediatric samples. Findings from heterogeneous samples supported the existence of reading deficits post TBI, including mild TBI. In studies of children, comprehension was examined most frequently, whereas reading speed was the focus of most adult studies. Oculomotor functions and processing speed were related to reading speed; cognitive functions, such as attention and memory, were associated with reading comprehension. Intervention studies were limited, but most reported positive effects. The meta-analysis confirmed the impact of TBI on reading with a large effect size (g = 1.23). Demographic, injury, and study variables did not moderate overall reading outcomes, but male sex was a significant moderator of impairment in reading speed. Discussion Global reading ability, including both comprehension and speed, is negatively impacted by TBI. Future research should continue to explore reading after TBI, including its underlying mechanisms, effects on complex reading activities such as inferencing, development of screening and assessment tools that address a range of functional reading needs, and efficacy of reading-related interventions.

Cognitive reserve in stroke patients

At present, a limited amount of information exists on the association between cognitive reserve and cognitive impairment in stroke populations. To determine predictors of cognitive reserve among stroke patients, 80 stroke patients attending the neurological and rehabilitation clinic in two different Malaysian general hospitals participated in this study. The Malay Cognitive Reserve Index questionnaire (CRIq-M), Depression Anxiety and Stress Scales-Short Form (DASS-21), WHO Quality of Life assessment BREF-21 (WHO-QOL BREF-21), Montreal Cognitive Assessment (MoCA), and modified Rankin Scale (mRS) were used as instruments in this study. The study found that cognitive reserve (CRIq-M) is positively correlated with cognitive function (MoCA), r = 0.529, p < .01. Multiregression showed that education was a significant predictor of cognitive impairment whereas cognitive impairment as assessed by the MoCA is a significant predictor for cognitive reserve in people with stroke. Early identification of cognitive impairment among stroke patients is important so that effective individual rehabilitation can be designed to enhance individual cognitive reserve and quality of life.

Communication skills training pilot programme after traumatic brain injury: short and medium-term benefits

Objective: The study aimed to evaluate whether a pilot communication rehabilitation programme improves different communicative modalities in people who have sustained a moderate to severe TBI immediately following the training and at 3 months follow up.Methods: We have recruited 12 participants who had moderate-to-severe TBI. Subjects were randomly divided into two groups, EG and CG. We have assessed the groups before and after treatment and we have performed a follow-up three months later, through of the ABaCo. The EG followed a very structured programme. In the CG, a programme to stimulate communication through free conversation was carried out. Each programme consisted of 24 group sessions, of 1h30 min, twice a week, for 12 weeks.Results: Improvements were observed in both groups, although more evident in the EG. Both groups had better results in extralinguistic production. In the EG, there was still an improvement in the paralinguistic production and extralinguistic comprehension, after ending the training. These improvements persisted 3 months after ending the programme.Conclusion: The results demonstrated the effectiveness of the intervention of a structured pragmatic rehabilitation programme. However, the existence of a communication group based solely on conversation can also have positive results and should be implemented whenever a more specific intervention is not possible. In future research, it will be important to increase the sample size and involve caregivers in person and regularly in the EG programme.

Cognitive-communication difficulties following traumatic brain injury sustained in older adulthood: a scoping review

BACKGROUND

Older adults are a peak incidence group for traumatic brain injury (TBI). However, empirical evidence on TBI in older adults is often limited to extrapolated findings from studies involving younger adults. While cognitive-communication deficits are an established consequence of TBI with substantial impact on social outcome for younger adults, little is known about the nature of cognitive-communication changes experienced by older adults following a new-onset TBI. In order to inform evidence-based service delivery and support older adults who sustain TBI, it is important to understand how these difficulties manifest in older adults.

AIMS

To review the empirical literature to determine the nature and breadth of research that has addressed the influence of older age on cognitive-communication outcomes following TBI sustained in older adulthood.

METHODS & PROCEDURES

A scoping review framework was used. Five electronic databases (Medline, PsycINFO, Embase, CINAHL and Scopus) were searched to locate peer-reviewed studies addressing cognitive-communication following TBI sustained at ≥ 55 years. Given the absence of dedicated investigations within the search yield, studies were included where at least 30% of participants were aged ≥ 55 years at injury, and age was a stated focus of the investigation.

OUTCOMES & RESULTS

A total of 2468 unique records were identified and reduced to 225 after title and abstract screening. Full-text review revealed only three studies that met the criteria. Collectively these studies included adults aged 55-93 years at injury. Two studies focused on age as a predictor for acute cognitive-communication difficulty, and one on the impact of age on facial emotion recognition in the chronic stages of injury. None of the studies had a dedicated focus on cognitive-communication outcomes for older adults who sustained a TBI within the defined period of older adulthood.

CONCLUSIONS & IMPLICATIONS

This scoping review produced limited results and insufficient evidence to inform rehabilitation for older adults. Indeed, very little is known about cognitive-communication outcomes for older adults who sustain a TBI. This review highlights the need, in the context of an ageing population, for research within this area to be prioritized. What this paper adds What is already known on the subject Empirical evidence to support the management of post-TBI cognitive-communication difficulties in adults predominantly stems from studies with young adults. However, the broader TBI literature suggests that outcome for older adults requires specific consideration due to its distinct nature and occurrence during a stage of life when there is the potential for subtle change to the processes of cognition and communication as part of typical ageing. What this paper adds to existing knowledge This scoping review identifies that research related to cognitive-communication outcomes for older adults who have sustained a TBI is very much in its infancy. Overarching statements about post-TBI cognitive-communication outcomes for older adults cannot be drawn, nor can it be determined if outcomes for older adults differ from younger adults. What are the potential or actual clinical implications of this work? The lack of research in this area means that tangible guidance cannot be provided to clinicians working with older adults following TBI to support evidence-based practice for cognitive-communication. This scoping review strongly supports the need for further research in this area.

The Effect of Cerebrolysin on the Predictive Value of Baseline Prognostic Risk Score in Moderate and Severe Traumatic Brain Injury

Cognitive dysfunction is a significant complaint among patients after moderate to severe traumatic brain injury (TBI), with devastating consequences on functional recovery and quality of life. Prognostic models allow a better assessment and management of neurotrauma patients.

The aim of the study was to demonstrate the predictive value of the Baseline Prognostic Risk Score (BPRS) in moderate to severe TBI, in a sample of patients treated with neurotrophic factors.

Eighty patients with moderate-severe TBI from the CAPTAIN II study were included in secondary data analysis. Patients received active treatment with Cerebrolysin, 50 mL per day for ten days, followed by two treatment cycles with 10 mL per day for ten days. BPRS was determined on admission; the age was recorded, and patients were evaluated using the following neurocognitive tests: Mini-Mental State Essay (MMSE), Wechsler Adult Intelligence Scale-Third Edition Processing Speed Index (WAIS-III PSI) and Stroop Colour Word Test-Victoria Version at 10, 30 and 90 days. Hierarchical regression analysis was performed to investigate the unique predictive value of BPRS on cognitive evolution, independent of age. BPRS independently predicted scores on the WAIS-III PSI DSCales and the Word subscale of the Stroop Colour Word Test at 90 days. Age was a significant predictor for all the investigated scales at 10, 30, and 90 days.

This study demonstrates the predictive value of a validated prognostic model (BPRS) for medium-term neurocognitive outcomes in a sample of moderate-severe traumatic brain injury treated with neurotrophic factors.

Blockage of AEP attenuates TBI-induced tau hyperphosphorylation and cognitive impairments in rats

Traumatic brain injury (TBI) is regarded as a high-risk factor for Alzheimer's disease (AD). Asparaginyl endopeptidase (AEP), a lysosomal cysteine protease involved in AD pathogenesis, is normally activated under acidic conditions and also in TBI. However, both the molecular mechanism underlying AEP activation-mediated TBI-related AD pathologies, and the role of AEP as an AD therapeutic target, still remain unclear. Here, we report that TBI induces hippocampus dependent cognitive deficit and synaptic dysfunction, accompanied with AEP activation, I2PP2A (inhibitor 2 of PP2A, also called SET) mis-translocation from neuronal nucleus to cytoplasm, an obvious increase in AEP interaction with SET, and tau hyperphosphorylation in hippocampus of rats. Oxygen-glucose deprivation (OGD), mimicking an acidic condition, also leads to AEP activation, SET mis-translocation, PP2A inhibition, tau hyperphosphorylation, and a decrease in synaptic proteins, all of which are abrogated by AEP inhibitor AENK in primary neurons. Interestingly, AENK restores SET back to the nucleus, mitigates tau pathologies, rescuing TBI-induced cognitive deficit in rats. These findings highlight a novel etiopathogenic mechanism of TBI-related AD, which is initiated by AEP activation, accumulating SET in cytoplasm, and favoring tau pathology and cognitive impairments. Lowering AEP activity by AEP inhibitor would be beneficial to AD patients with TBI.

United States Military Service Members Demonstrate Substantial and Heterogeneous Long-Term Neuropsychological Dysfunction after Moderate, Severe, and Penetrating Traumatic Brain Injury

The objective of the study was to examine long-term neuropsychological outcome after moderate, severe, and penetrating traumatic brain injury (TBI) in U.S. military service members and veterans (SMVs). Eighty-five SMVs with a history of moderate (n = 18), severe (n = 17), or penetrating (n = 26) TBI, or an injury without TBI (i.e., trauma control [TC], n = 24) were assessed five or more years (mean = 69.4 months; standard deviation = 35.6) post-injury. All passed performance validity tests. Participants completed a battery of neurocognitive tests and a personality inventory. Five cognitive domain composites, each composed of four test scores, and an overall test battery mean (OTBM) were computed. The penetrating TBI group performed worse than the TC group and/or the moderate TBI group on most cognitive domains and the OTBM. The severe TBI group also performed worse than the TC group and moderate TBI group on processing speed and the OTBM, and worse than the TC group on attention/working memory. Just more than half of participants with severe (56%) or penetrating (64%) TBI met criteria for mild neurocognitive disorder, with processing speed the most commonly impaired domain. In addition, 80% of TBI participants had one or more clinically elevated scales on the Minnesota Multiphasic Personality Inventory-2-Restructured Form^® (MMPI-2-RF), with somatic complaints the most common elevation. In conclusion, there was significantly reduced cognitive and psychological functioning many years after severe and penetrating TBI in SMVs. Cognitive and psychological dysfunction, however, were highly variable, with a substantial minority of SMVs having good outcome. Long-term individualized support is necessary for individuals after moderate, severe, and penetrating TBI.