Neuropsychological outcome and its correlates in the first year after adult mild traumatic brain injury: A population-based New Zealand study

On the lasting impact of mild traumatic brain injury on working memory: Behavioural and electrophysiological evidence

Despite increasing recognition of the significance of mild traumatic brain injury (mTBI), the long-term cognitive consequences of the injury remain unclear. More sensitive measures that can detect subtle cognitive changes and consideration of individual variability are needed to properly characterise cognitive outcomes following mTBI. Here, we used complex behavioural tasks, individual differences approaches, and electrophysiology to investigate the long-term cognitive effects of a history of mTBI. In Experiment 1, participants with self-reported mTBI history (n=82) showed poorer verbal working memory performance on the operation span task compared to control participants (n=88), but there were no group differences in visual working memory, multitasking, cognitive flexibility, attentional control, visuospatial ability, or information processing speed. Individual differences analyses revealed that time since injury and presence of memory loss predicted visual working memory capacity and visuospatial ability, respectively, in those with mTBI history. In Experiment 2, participants with mTBI history (n=20) again demonstrated poorer verbal working memory on the operation span task compared to control participants (n=38), but no group differences were revealed on a visuospatial complex span task or simpler visual working memory measures. We also explored the electrophysiological indices of visual working memory using EEG during a change detection task. No differences were observed in early sensory event-related potentials (P1, N1) or the later negative slow wave associated with visual working memory capacity. Together, these findings suggest that mTBI history may be associated with a lasting, isolated disruption in the subsystem underlying verbal working memory storage. The results emphasise the importance of sensitive cognitive measures and accounting for individual variability in injury characteristics when assessing mTBI outcomes.

Sports-Related Concussion in Collegiate Athletes: The Potential Benefits of Using Graded Neuropsychological Tests With High Ceilings

OBJECTIVE

Sports-related concussion management in collegiate athletes has been focused on return-to-play. However, resuming schoolwork without a gradual stepwise reintroduction contributes to symptom exacerbation, delayed recovery, and adverse academic performance. Return-to-learn guidelines are limited by a lack of sensitivity in methods monitoring cognitive function. This study evaluated 2 neuropsychological tests, the Sternberg test and the Paced Auditory Serial Addition Test (PASAT), with high ceilings for sensitivity to deficits in speed of information processing, cognitive efficiency, and complex attention.

SETTING

Academic center research laboratory.

PARTICIPANTS

We recruited 56 male and female collegiate contact and noncontact sports athletes. They were categorized into as follows: (1) nonconcussed ( n = 23; 7F, 16M); (2) chronic ( n = 21; 4F, 17M), at least 1 year from their last concussion; and (3) acute ( n = 12; 1F, 11M), within 2 weeks from concussion.

DESIGN

Observational cohort study.

MAIN MEASURES

The PASAT assesses complex attention. The Sternberg test examines processing speed and cognitive efficiency. Cognitive difficulty increases with progression through the tasks for both the PASAT and the Sternberg test. The mean outcome differences of the 3 groups (nonconcussed, acute, and chronic) across the 3 or 4 conditions (difficulty level) were measured with repeated-measures analysis of variance and subsequent pairwise comparison.

RESULTS

For processing speed (Sternberg reaction time), the acute group responded slower than the chronic group on the medium ( P = .021, Bonferroni corrected) and hard difficulty tasks ( P = .030, Bonferroni corrected). For cognitive efficiency (Sternberg reaction time variability), the acute group had increased reaction time variability compared with the chronic group on the medium difficulty task ( P = .04, Bonferroni corrected). For complex attention (PASAT omissions), there was a difference between the acute and nonconcussed groups on the moderate-hard difficulty trial ( P = .023, least significant difference [LSD] corrected) and between the acute and chronic groups for hard difficulty trial ( P = .020, LSD corrected). The acute group performed worse, with progressively shorter interstimulus intervals.

CONCLUSION

Neuropsychological testing without ceiling effects can capture higher-level cognitive dysfunction and and use of such tests can contribute to the understanding of how collegiate athletes are affected by SRC. Future studies can investigate optimal testing batteries that include neuropsychological testing with high ceilings and whether the pattern of performance has implications for the return-to-learn process after SRC in the college setting.

Mechanisms of vascular injury in neurotrauma: A critical review of the literature

One in every two individuals will experience a traumatic brain injury in their lifetime with significant impacts on the global economy and healthcare system each year. Neurovascular injury is a key aspect of neurotrauma to both the brain and the spinal cord and an important avenue of current and future research seeking innovative therapies. In this paper, we discuss primary and secondary neurotrauma, mechanisms of injury, the glymphatic system, repair and recovery. Each of these topics are directly connected to the vasculature of the central nervous system, affecting severity of injury and recovery. Consequently, neurovascular injury in trauma represents a promising target for future therapeutics and innovation.

An Exploratory Analysis of Physical Examination Subtypes in Pediatric Athletes With Concussion

OBJECTIVE

Pediatric athletes with concussion present with a variety of impairments on clinical assessment and require individualized treatment. The Buffalo Concussion Physical Examination is a brief, pertinent clinical assessment for individuals with concussion. The purpose of this study was to identify physical examination subtypes in pediatric athletes with concussion within 2 weeks of injury that are relevant to diagnosis and treatment.

DESIGN

Secondary analysis of a published cohort study and clinician consensus.

SETTING

Three university-affiliated sports medicine centers.

PARTICIPANTS

Two hundred seventy children (14.9 ± 1.9 years).

INDEPENDENT VARIABLES

Orthostatic intolerance, horizontal and vertical saccades, smooth pursuits, vestibulo-ocular reflex, near-point convergence, complex tandem gait, neck range of motion, neck tenderness, and neck spasm.

MAIN OUTCOME MEASURES

Correlations between independent variables were calculated, and network graphs were made. k -means and hierarchical clustering were used to identify clusters of impairments. Optimal number of clusters was assessed. Results were reviewed by experienced clinicians and consensus was reached on proposed subtypes.

RESULTS

Physical examination clusters overlapped with each other, and no optimal number of clusters was identified. Clinician consensus suggested 3 possible subtypes: (1) visio-vestibular (horizontal and vertical saccades, smooth pursuits, and vestibulo-ocular reflex), (2) cervicogenic (neck range of motion and spasm), and (3) autonomic/balance (orthostatic intolerance and complex tandem gait).

CONCLUSIONS

Although we identified 3 physical examination subtypes, it seemed that physical examination findings alone are not enough to define subtypes that are both statistically supported and clinically relevant, likely because they do not include symptoms, assessment of mood or cognitive problems, or graded exertion testing.

Relationships between vestibular issues, noise sensitivity, anxiety and prolonged recovery from mild traumatic brain injury among adults: a scoping review

BACKGROUND

We investigated the extent of literature and findings on relationships between vestibular issues, noise sensitivity (NS), and anxiety. We were interested in how relationships among these factors impacted adults' recovery three months or more after mild traumatic brain injury (mTBI).

METHODS

We conducted a scoping review to evaluate the extent of evidence linking relationships between vestibular issues, NS and anxiety with recovery after mTBI. Data relating to study characteristics and key findings were extracted and used to inform a critical narrative synthesis of findings.

RESULTS

After screening and full-text review, we included two studies. Both studies considered the combination of vestibular issues, NS and anxiety and mTBI recovery. Vestibular issues, NS and anxiety were all significantly associated with one another and their presence was the strongest indicator that symptoms would extend beyond three-months after mTBI.

CONCLUSION

Few studies have focused on the relationships that vestibular issues, NS and anxiety have with one another and recovery after mTBI. Given the apparent strong relationships between these factors and prolonged recovery, we highlight this as an area warranting further investigation.

A strike to the head: Parallels between the pediatric and adult human and the rodent in traumatic brain injury

Traumatic brain injury (TBI) is a condition that occurs commonly in children from infancy through adolescence and is a global health concern. Pediatric TBI presents with a bimodal age distribution, with very young children (0-4 years) and adolescents (15-19 years) more commonly injured. Because children's brains are still developing, there is increased vulnerability to the effects of head trauma, which results in entirely different patterns of injury than in adults. Pediatric TBI has a profound and lasting impact on a child's development and quality of life, resulting in long-lasting consequences to physical, cognitive, and emotional development. Chronic issues like learning disabilities, behavioral problems, and emotional disturbances can develop. Early intervention and ongoing support are critical for minimizing these long-term deficits. Many animal models of TBI exist, and each varies significantly, displaying different characteristics of clinical TBI. The neurodevelopment differs in the rodent from the human in timing and effect, so TBI outcomes in the juvenile rodent can thus vary from the human child. The current review compares findings from preclinical TBI work in juvenile and adult rodents to clinical TBI research in pediatric and adult humans. We focus on the four brain regions most affected by TBI: the prefrontal cortex, corpus callosum, hippocampus, and hypothalamus. Each has its unique developmental projections and thus is impacted by TBI differently. This review aims to compare the healthy neurodevelopment of these four brain regions in humans to the developmental processes in rodents.

Applicability and clinical utility of the German rivermead post-concussion symptoms questionnaire in proxies of children after traumatic brain injury: an instrument validation study

BACKGROUND

The German Rivermead Post-Concussion Symptoms Questionnaire (RPQ) can be used to assess post-concussion symptoms (PCS) after traumatic brain injury (TBI) in adults, adolescents, and children.

METHODS

In this study, we examined the psychometric properties of the German RPQ proxy version (N = 146) for children (8-12 years) after TBI at the item, total and scale score level. Construct validity was analyzed using rank correlations with the proxy-assessed Post-Concussion Symptoms Inventory (PCSI-P), the Patient Health Questionnaire 9 (PHQ-9), and the Generalized Anxiety Disorder Scale 7 (GAD-7). Furthermore, sensitivity testing was performed concerning subjects' sociodemographic and injury-related characteristics. Differential item functioning (DIF) was analyzed to assess the comparability of RPQ proxy ratings for children with those for adolescents.

RESULTS

Good internal consistency was demonstrated regarding Cronbach's α (0.81-0.90) and McDonald's ω (0.84-0.92). The factorial validity of a three-factor model was superior to the original one-factor model. Proxy ratings of the RPQ total and scale scores were strongly correlated with the PCSI-P (ϱ = 0.50-0.69), as well as moderately to strongly correlated with the PHQ-9 (ϱ = 0.49-0.65) and the GAD-7 (ϱ = 0.44-0.64). The DIF analysis revealed no relevant differences between the child and adolescent proxy versions.

CONCLUSIONS

The German RPQ proxy is a psychometrically reliable and valid instrument for assessing PCS in children after TBI. Therefore, RPQ self- and proxy-ratings can be used to assess PCS in childhood as well as along the lifespan of an individual after TBI.

Prevalence and trajectories of neuropsychological post-COVID-19 symptoms in initially hospitalized patients

OBJECTIVE

To investigate the prevalence and trajectories of post-COVID-19 neuropsychological symptoms.

DESIGN

Prospective longitudinal multicentre cohort study.

SUBJECTS

A total of 205 patients initially hospitalized with SARS-CoV-2 (COVID-19).

METHODS

Validated questionnaires were administered at 9 months (T1) and 15 months (T2) post-hospital discharge to assess fatigue, cognitive complaints, insomnia, anxiety, depression, and post-traumatic stress symptoms.

RESULTS

Analyses included 184 out of 205 patients. Approximately 50% experienced high cognitive complaints at T1 and T2, while severe fatigue affected 52.5% at T1 and 55.6% at T2. Clinically relevant insomnia scores were observed in 25% of patients at both time-points. Clinically relevant anxiety scores were present in 18.3% at T1 and 16.7% at T2, depression in 15.0% at T1 and 18.9% at T2, and PTSD in 12.4% at T1 and 11.8% at T2. Most symptoms remained stable, with 59.2% of patients experiencing at least 1 persistent symptom. In addition, 31.5% of patients developed delayed-onset symptoms.

CONCLUSION

Post-COVID-19 cognitive complaints and fatigue are highly prevalent and often persist. A subgroup develops delayed symptoms. Emotional distress is limited. Screening can help identify most patients experiencing long-term problems. Future research should determine risk factors for persistent and delayed onset symptoms.

Cognitive Performance, Depression, and Anxiety 1 Year After Traumatic Brain Injury

OBJECTIVES

To evaluate associations between depression, anxiety, and cognitive impairment among individuals with complicated mild to severe traumatic brain injury (TBI) 1 year after injury.

SETTING

Multiple inpatient rehabilitation units across the United States.

PARTICIPANTS

A total of 498 adults 16 years and older who completed inpatient rehabilitation for complicated mild to severe TBI.

DESIGN

Secondary analysis of a prospective, multicenter, cross-sectional observational cohort study.

MAIN MEASURES

Assessments of depression (Traumatic Brain Injury Quality of Life [TBI-QOL] Depression) and anxiety (TBI-QOL Anxiety) as well as a telephone-based brief screening measure of cognitive functioning (Brief Test of Adult Cognition by Telephone [BTACT]).

RESULTS

We found an inverse relationship between self-reported depression symptoms and the BTACT Composite score (β = -0.18, P < .01) and anxiety symptoms and the BTACT Composite score (β = -0.20, P < .01). There was no evidence this relationship varied by injury severity. Exploratory analyses showed depression and anxiety were negatively correlated with both BTACT Executive Function factor score and BTACT Memory factor score.

CONCLUSIONS

Both depression and anxiety have a small but significant negative association with cognitive performance in the context of complicated mild to severe TBI. These findings highlight the importance of considering depression and anxiety when interpreting TBI-related neuropsychological impairments, even among more severe TBI.

Effects of intravascular photobiomodulation on cognitive impairment and crossed cerebellar diaschisis in patients with traumatic brain injury: a longitudinal study

The association between intravascular photobiomodulation (iPBM) and crossed cerebellar diaschisis (CCD) and cognitive dysfunction in patients with traumatic brain injury (TBI) remains unknown. We postulate that iPBM might enable greater neurologic improvements. The objective of this study was to evaluate the clinical impact of iPBM on the prognosis of patients with TBI. In this longitudinal study, patients who were diagnosed with TBI were recruited. CCD was identified from brain perfusion images when the uptake difference of both cerebella was > 20%. Thus, two groups were identified: CCD( +) and CCD( -). All patients received general traditional physical therapy and three courses of iPBM (helium-neon laser illuminator, 632.8 nm). Treatment assemblies were conducted on weekdays for 2 consecutive weeks as a solitary treatment course. Three courses of iPBM were performed over 2-3 months, with 1-3 weeks of rest between each course. The outcomes were measured using the Rancho Los Amigos Levels of Cognitive Functioning (LCF) tool. The chi-square test was used to compare categorical variables. Generalized estimating equations were used to verify the associations of various effects between the two groups. p < 0.05 indicated a statistically significant difference. Thirty patients were included and classified into the CCD( +) and CCD( -) groups (n = 15, each group). Statistics showed that before iPBM, CCD in the CCD( +) group was 2.74 (exp 1.0081) times higher than that of CCD( -) group (p = 0.1632). After iPBM, the CCD was 0.64 (exp-0.4436) times lower in the CCD( +) group than in the CCD( -) group (p < 0.0001). Cognitive assessment revealed that, before iPBM, the CCD( +) group had a non-significantly 0.1030 lower LCF score than that of CCD( -) group (p = 0.1632). Similarly, the CCD( +) group had a non-significantly 0.0013 higher score than that of CCD( -) after iPBM treatment (p = 0.7041), indicating no significant differences between the CCD( +) or CCD( -) following iPBM and general physical therapy. CCD was less likely to appear in iPBM-treated patients. Additionally, iPBM was not associated with LCF score. Administration of iPBM could be applied in TBI patients to reduce the occurrence of CCD. The study failed to show differences in cognitive function after iPBM, which still serves as an alternative non-pharmacological intervention.

Assessment and rehabilitation of acquired communication disorders in Aboriginal and Torres Strait Islander adults with stroke or traumatic brain injury: a retrospective chart review

PURPOSE

Speech-language pathologists' (SLP) management practices for Aboriginal and Torres Strait Islander adults with acquired communication disorder (ACD), following stroke or traumatic brain injury (TBI), are not well understood. This study explores SLPs' management approaches for ACDs for Aboriginal and Torres Strait Islander adults post-stroke or TBI.

MATERIALS AND METHODS

SLPs' documented notes were analysed from a two-year retrospective medical record review of Aboriginal and Torres Strait Islander adults (≥18 years), admitted to a regional Queensland hospital with principal diagnoses of stroke or TBI.

RESULTS

SLPs frequently used informal approaches to assess ACDs. English-language formal assessment tools were also used in conjunction with the informal approaches. ACD diagnosis was more common in stroke than TBI patients. One-third of patients with ACD received inpatient rehabilitation at the study site. SLPs infrequently documented cultural or linguistic adaptions to assessment or interventions.

CONCLUSIONS

Informal approaches to assess ACDs were commonly employed which may be because they are perceived to be more culturally appropriate. Clinical guidelines for stroke and TBI should accommodate the diversity of cultures and languages. Better consideration of Aboriginal and Torres Strait Islander communication styles and incorporation of these into SLP ACD management approaches may facilitate accurate diagnosis and culturally safe rehabilitation services.Implications for RehabilitationInformal approaches for assessment and intervention of ACDs, that incorporate yarning and salient tasks, are likely to be more culturally appropriate and safe for Aboriginal and Torres Strait Islander peoples.More flexibility and guidance in the use of culturally and linguistically appropriate alternative assessment approaches are required in the National stroke guidelines for Aboriginal and Torres Strait Islander peoples.The adoption of enhanced models of culturally secure ACD service provision, that incorporate frequent SLP engagement with an Aboriginal or Torres Strait Islander support person during assessment and rehabilitation, are needed.There is an imperative for health professionals to actively account for culture and language difference in rehabilitation practices to ensure Indigenous peoples worldwide receive equitable and culturally-responsive services.

The association between self-reported traumatic brain injury, neuropsychological function, and compliance among people serving community sentences

BACKGROUND

Traumatic brain injury is overrepresented in incarcerated samples and has been linked to a number of poor correctional outcomes. Despite this, no research has explored the impact of a recent TBI on compliance outcomes for individuals serving community-based.

METHOD

We screened for a history of TBI in 106 adults on community sentences and collected compliance (arrests, sentence violations) and related variables (e.g., risk scores, substance use) over 6 months. Sixty-four participants also completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), the Comprehensive Trail Making Test and Color-Word Inference Test.

RESULTS

A TBI in the last year predicted a significantly higher likelihood of arrest, even when controlling for risk of reconviction and current substance use, but was not associated with non-compliance with sentence conditions nor with performance on the neuropsychological tests. In addition, no significant associations were found between performance on neuropsychological tests and measures of non-compliance.

CONCLUSIONS

TBI in the last year was an independent predictor of arrest. This result suggests that those with a recent TBI on a community sentence may need additional monitoring or support to reduce the risk of reoffending.

Relationship between psychosocial and psychiatric risk factors and poor long-term outcome following mild traumatic brain injury: A systematic review

BACKGROUND AND PURPOSE

Mild traumatic brain injury (mTBI) has an estimated worldwide incidence of >60 million per year, and long-term persistent postconcussion symptoms (PPCS) are increasingly recognized as being predicted by psychosocial variables. Patients at risk for PPCS may be amenable to closer follow-up to treat modifiable symptoms and prevent chronicity. In this regard, similarities seem to exist with psychosocial risk factors for chronicity in other health-related conditions. However, as opposed to other conditions, no screening instruments exist for mTBI.

METHODS

A systematic search of the literature on psychological and psychiatric predictors of long-term symptoms in mTBI was performed by two independent reviewers using PubMed, Embase, and Web of Science.

RESULTS

Fifty papers were included in the systematic analysis. Anxiety, depressive symptoms, and emotional distress early after injury predict PPCS burden and functional outcome up to 1 year after injury. In addition, coping styles and preinjury psychiatric disorders and mental health also correlate with PPCS burden and functional outcome. Associations between PPCS and personality and beliefs were reported, but either these effects were small or evidence was limited.

CONCLUSIONS

Early psychological and psychiatric factors may negatively interact with recovery potential to increase the risk of chronicity of PPCS burden after mTBI. This opens opportunities for research on screening tools and early intervention in patients at risk.

The incidence and severity of symptoms similiar to peristing concussion symptoms in neurologically healthy individuals in aotearoa New Zealand

The non-specificity of persisting concussion symptoms (PCS) following concussion can make treatment and rehabilitation a complex and challenging endeavour for clinicians. International studies have demonstrated that in neurologically healthy individuals similar symptoms also exist. This study aimed to examine the presence and frequency of symptoms similar to PCS in neurologically healthy adults in Aotearoa New Zealand and compare these to PCS following concussion. 252 neurologically healthy adults (34.22 years); completed the Rivermead Post-Concussion Questionnaire (RPQ). Scores on this measure were evaluated and compared with 146 individuals who were at least three months post-injury (34.62 years). 25.79% (n = 65) of the neurologically healthy individuals had scores on the RPQ of ≥16. Fatigue was the most commonly endorsed symptom (67.9%), followed by sleep disturbances (59.9%). Certain demographic factors (age, education history and gender) were associated with higher endorsement but only on specific symptoms. The concussion group had significantly higher scores on the RPQ and significantly more individuals with PCS. However, at the individual item level, just over half of PCS symptoms were significantly higher in the concussion group. These symptoms were predominately neurological, with only forgetfulness and irritability significantly different between the concussion and neurologically healthy groups. Symptoms similar to PCS are prevalent in neurologically healthy individuals in Aotearoa New Zealand. The implications of these findings on the rehabilitation and management of PCS are discussed.

Neuropsychological Profile of Traumatic Brain Injury Patients with Medicolegal Cases: A Pilot Study

Introduction Traumatic brain injury (TBI) is a global health problem and is a silent epidemic of the modern times. Studies indicate litigation is a prominent factor that accounts for poor outcome and prolonged recovery from mild TBI. Depression is the most frequently diagnosed psychiatric disorder after TBI. Postconcussion symptoms, litigation, and suboptimal effort could contribute to the neuropsychological functioning of TBI patients medicolegal cases (MLCs). With increase in TBI and medicolegal cases, there is a requirement for comprehensive neuropsychological assessment.

Method The aim of the study was to evaluate the cognitive functions, postconcussion, and depressive symptoms in TBI patients with MLC and without MLCs (non-MLC). Patients were also assessed on electrophysiological parameters. An observational cross-sectional design was adopted, the sample size was 30 TBI patients in total, 15 (MLC) and 15 (non-MLC), and 11 patients from each group for electrophysiological assessment. The patients were in the age range of 18 to 50 years.

Results The MLC group had poor performance compared with the non-MLC group on both neuropsychological and electrophysiological measures. There was evidence of significant difference in verbal working memory, verbal learning, and memory and visuoconstructive ability. In the MLC group, postconcussion and depressive scores were negatively correlated with visuospatial span.

Conclusion Findings from this study indicate differences in the neuropsychological performance and electroencephalographic measures in between MLC and non-MLC groups. The results could be indicative of persistent cognitive problems associated with TBI for patients pursuing litigation. Poor performance could also be attributed to suboptimal level of effort. However, being a preliminary study with a small sample size, the findings need to be treated with caution.

Interdisciplinary Rehabilitation for Concussion Recovery (i-RECOveR): protocol of an investigator-blinded, randomised, case series with multiple baseline design to evaluate the feasibility and preliminary efficacy of a 12-week treatment for persistent post-concussion symptoms

BACKGROUND

Up to 25% of concussed individuals experience persistent post-concussion symptoms (PPCSs) which may interfere with the return to pre-injury activities and cause significant stress. Given that multiple etiological factors are thought to contribute to PPCSs, an interdisciplinary approach is recommended. This pilot study aims to primarily investigate the feasibility of a novel interdisciplinary treatment for PPCSs. Given this intervention is novel, uncertainty exists in terms of potential recruitment and retention rates, adverse events, and treatment adherence and fidelity. These factors will be explored to inform the feasibility of a phase-2 randomised controlled trial. Preliminary efficacy of this intervention will also be explored.

METHODS

Fifteen individuals with mild traumatic brain injury and PPCSs will receive up to 12 weeks of interdisciplinary treatments including psychology, physiotherapy, and medical interventions. Primary feasibility outcomes including data on recruitment and retention rates and treatment adherence will be explored descriptively. The cognitive therapy rating scale will be used to assess treatment fidelity. A single-case series with multiple baseline design will be used to explore preliminary efficacy. Participants will be randomly assigned to baseline phases of 2, 4, or 6 weeks. Regarding patient-centred secondary outcomes, the Rivermead Post-Concussion Symptoms Questionnaire will be assessed three times a week during baseline and treatment phases. Secondary outcomes also include measures of mood, sleep and fatigue, physical functioning, return to activity, and health-related quality of life. Patient-centred outcomes will be assessed at baseline, pretreatment, post-treatment, and one- and three-month follow-up. Thematic analysis of participant experiences will be explored through qualitative interviews.

DISCUSSION

Results from this trial will inform the feasibility and preliminary efficacy of this interdisciplinary concussion intervention and whether proceeding to a future definitive phase-2 randomised controlled trial is worthwhile. Understanding the end-user perspective of the treatment will also enable modifications to the treatment protocol for future trials to best suit the needs of individuals with PPCSs after mTBI. Outcomes from this trial can be directly translated into community rehabilitation programmes.

TRIAL REGISTRATION

ANZCTR, ACTRN12620001111965. Registered 27 October 2020, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=379118.

Proposing a "Brain Health Checkup (BHC)" as a Global Potential "Standard of Care" to Overcome Reward Dysregulation in Primary Care Medicine: Coupling Genetic Risk Testing and Induction of "Dopamine Homeostasis"

In 2021, over 100,000 people died prematurely from opioid overdoses. Neuropsychiatric and cognitive impairments are underreported comorbidities of reward dysregulation due to genetic antecedents and epigenetic insults. Recent genome-wide association studies involving millions of subjects revealed frequent comorbidity with substance use disorder (SUD) in a sizeable meta-analysis of depression. It found significant associations with the expression of NEGR1 in the hypothalamus and DRD2 in the nucleus accumbens, among others. However, despite the rise in SUD and neuropsychiatric illness, there are currently no standard objective brain assessments being performed on a routine basis. The rationale for encouraging a standard objective Brain Health Check (BHC) is to have extensive data available to treat clinical syndromes in psychiatric patients. The BHC would consist of a group of reliable, accurate, cost-effective, objective assessments involving the following domains: Memory, Attention, Neuropsychiatry, and Neurological Imaging. Utilizing primarily PUBMED, over 36 years of virtually all the computerized and written-based assessments of Memory, Attention, Psychiatric, and Neurological imaging were reviewed, and the following assessments are recommended for use in the BHC: Central Nervous System Vital Signs (Memory), Test of Variables of Attention (Attention), Millon Clinical Multiaxial Inventory III (Neuropsychiatric), and Quantitative Electroencephalogram/P300/Evoked Potential (Neurological Imaging). Finally, we suggest continuing research into incorporating a new standard BHC coupled with qEEG/P300/Evoked Potentials and genetically guided precision induction of "dopamine homeostasis" to diagnose and treat reward dysregulation to prevent the consequences of dopamine dysregulation from being epigenetically passed on to generations of our children.

OUP accepted manuscript

OBJECTIVE

The etiology of persistent memory complaints after concussion is poorly understood. Memory perfectionism (highly valuing memory ability and intolerance of minor memory lapses) may help explain why some people report persistent subjective memory problems in the absence of corresponding objective memory impairment. This study investigated the relationship between memory perfectionism and persistent memory complaints after concussion.

METHODS

Secondary analysis of baseline data from a randomized controlled trial. Adults (N = 77; 61% women) with persistent symptoms following concussion were recruited from outpatient specialty clinics. Participants completed the National Institutes of Health Toolbox Cognition Battery, Test of Memory Malingering-Trial 1, and questionnaires measuring memory perfectionism (Metamemory in Adulthood-Achievement subscale), forgetfulness and other postconcussion symptoms (Rivermead Postconcussion Symptoms Questionnaire; RPQ), and depression (Patient Health Questionnaire-2) at M = 17.8 weeks postinjury. Patients with versus without severe memory complaints (based on the RPQ) were compared.

RESULTS

Memory perfectionism was associated cross-sectionally with severe memory complaint, after controlling for objective memory ability, overall cognitive ability, and depression (95% confidence interval for odds ratio = 1.11-1.40). Sensitivity analyses showed that this relationship did not depend on use of specific objective memory tests nor on inclusion of participants who failed performance validity testing. In a control comparison to test the specificity of identified relationships, memory perfectionism was not associated with severe fatigue (95% confidence interval for odds ratio = 0.91-1.07).

CONCLUSIONS

Memory perfectionism may be a risk factor for persistent memory symptoms after concussion, with potential relevance to the spectrum of functional cognitive disorders more broadly.

Oculometric Feature Changes During Acute Hypoxia in a Simulated High-Altitude Airdrop Scenario

BACKGROUND: Severe acute hypoxia results in a rapid deterioration of cognitive functioning and thus poses a risk for human operations in high altitude environments. This study aimed at investigating the effects of oxygen system failure during a high-altitude high-opening (HAHO) parachute jump scenario from 30,000 ft (9144 m) on human physiology and cognitive performance using a noncontact eye-tracking task.METHODS: Nine healthy male volunteers (ages 27-48) were recruited from the Norwegian Special Operations Commandos. Eye-tracking data were collected to derive information on cognitive performance in the context of rapid dynamic changes in pressure altitude while performing a modified King-Devick test. The baseline data was collected at 8000 ft (2438 m) while breathing 100% oxygen during decompression. For every test, the corresponding arterial blood gas analysis was performed.RESULTS: The study subjects endured severe hypoxia, which resulted in significant prolongations of fixation time (range: 284.1-245.6 ms) until 23,397 ft (131 m) and fixation size (range: 34.6-32.4 mm) until 25,389 ft (7739 m) as compared to the baseline (217.6 ± 17.8 ms and 27.2 ± 4.5 mm, respectively). The increase in the saccadic movement and decrease in the saccadic velocity was observed until 28,998 ft and 27,360 ft (8839 and 8339 m), respectively.DISCUSSION: This is the first study to investigate cognitive performance from measured oculometric variables during severe hypobaric hypoxia in a simulated high-altitude airdrop mission scenario. The measurement of altered oculometric variables under hypoxic conditions represents a potential avenue to study altered cognitive performance using noncontact sensors that can derive information and serve to provide the individual with a warning from impending incapacitation.Pradhan GN, Ottestad W, Meland A, Kåsin JI, Høiseth LØ, Cevette MJ, Stepanek J. Oculometric feature changes during acute hypoxia in a simulated high-altitude airdrop scenario. Aerosp Med Hum Perform. 2021; 92(12):928-936.

Prevalence of insomnia and insomnia symptoms following mild-traumatic brain injury: A systematic review and meta-analysis

Sleep is commonly disrupted following mild traumatic brain injury (mTBI), however there is a lack of consensus in the existing literature regarding the prevalence of insomnia/insomnia symptoms after injury. The aim of this review was to conduct a systematic review and meta-analysis of insomnia and insomnia symptoms' prevalence following mTBI. Full-text articles published in English in peer-reviewed journals, including adults with a clinical or self-reported mild traumatic brain injury diagnosis, were eligible for inclusion. Studies that assessed insomnia/insomnia symptoms after injury were included. Of the 2091 records identified, 20 studies were included in the review. 19 of these were meta-analysed (n = 95,195), indicating high heterogeneity among studies. Subgroup analyses indicated pooled prevalence estimates of post-mTBI insomnia disorder of 27.0% (95% CI 6.49-54.68) and insomnia symptoms of 71.7% (95% CI 60.31-81.85). The prevalence of insomnia is significantly higher in individuals who have sustained mild traumatic brain injury compared to prevalence estimates reported in the general population but high heterogeneity and methodological differences among studies make it difficult to provide reliable prevalence estimates. Future research should continue to advance our understanding of the onset, progression and impact of post-mild traumatic brain injury insomnia to promote the recovery and wellbeing of affected individuals. PROSPERO registration CRD42020168563.

The Relationship Between Cognitive Functioning and Symptoms of Depression, Anxiety, and Post-Traumatic Stress Disorder in Adults with a Traumatic Brain Injury: a Meta-Analysis

A thorough understanding of the relationship between cognitive test performance and symptoms of depression, anxiety, or post-traumatic stress disorder (PTSD) in people with traumatic brain injury (TBI) is important given the high prevalence of these emotional symptoms following injury. It is also important to understand whether these relationships are affected by TBI severity, and the validity of test performance and symptom report. This meta-analysis was conducted to investigate whether these symptoms are associated with cognitive test performance alterations in adults with a TBI. This meta-analysis was prospectively registered on the PROSPERO International Prospective Register of Systematic Reviews website (registration number: CRD42018089194). The electronic databases Medline, PsycINFO, and CINAHL were searched for journal articles published up until May 2020. In total, 61 studies were included, which enabled calculation of pooled effect sizes for the cognitive domains of immediate memory (verbal and visual), recent memory (verbal and visual), attention, executive function, processing speed, and language. Depression had a small, negative relationship with most cognitive domains. These relationships remained, for the most part, when samples with mild TBI (mTBI)-only were analysed separately, but not for samples with more severe TBI (sTBI)-only. A similar pattern of results was found in the anxiety analysis. PTSD had a small, negative relationship with verbal memory, in samples with mTBI-only. No data were available for the PTSD analysis with sTBI samples. Moderator analyses indicated that the relationships between emotional symptoms and cognitive test performance may be impacted to some degree by exclusion of participants with atypical performance on performance validity tests (PVTs) or symptom validity tests (SVTs), however there were small study numbers and changes in effect size were not statistically significant. These findings are useful in synthesising what is currently known about the relationship between cognitive test performance and emotional symptoms in adults with TBI, demonstrating significant, albeit small, relationships between emotional symptoms and cognitive test performance in multiple domains, in non-military samples. Some of these relationships appeared to be mildly impacted by controlling for performance validity or symptom validity, however this was based on the relatively few studies using validity tests. More research including PVTs and SVTs whilst examining the relationship between emotional symptoms and cognitive outcomes is needed.

Can the neck contribute to persistent symptoms post concussion? Long-term follow up from a prospective descriptive case series

OBJECTIVE

To describe individual long-term outcomes of people with persistent symptoms following a concussion who received neck treatment as part of multidisciplinary concussion care. A secondary objective is to report on how participants describe the outcomes of neck treatmentMethods: Long-term follow-up for a subgroup of participants in a prospective case series (n = 11). Data were collected at initial assessment, completion of neck treatment, 6 and 12 months including standard questionnaires (Rivermead post-concussion symptoms questionnaire, neck disability index, dizziness handicap inventory); patient-reported measures of headache, dizziness and neck pain and participant descriptions of the effects of neck treatmentResults: Grouped measures of post-concussion symptoms were further improved or sustained at 6 and 12 months. Ten of the 11 participants reported neck treatment as a beneficial part of their care and described the effects on the neck, multiple symptoms and their overall recovery. However, seven participants experienced recurrent headache, neck pain or dizziness at 6- or 12-month follow-up.

CONCLUSION

Long-term follow-up of individuals receiving neck treatment shows improvement across a range of patient reported outcomes, yet highlights frequent recurrence of symptoms. Neck treatment can play a valuable role in people's recovery that extends beyond local effects on the neck.

Mechanisms of Local Stress Amplification in Axons near the Gray-White Matter Interface

Diffuse axonal injury is a primary neuropathological feature of concussion and is thought to greatly contribute to the classical symptoms of decreased processing speed and memory dysfunction. Although previous studies have investigated the injury biomechanics at the micro- and mesoscale of concussion, few have addressed the multiscale transmission of mechanical loading at thresholds that can induce diffuse axonal injury. Because it has been recognized that axonal pathology is commonly found at anatomic interfaces across all severities of traumatic brain injury, we combined computational, analytical, and experimental approaches to investigate the potential mechanical vulnerability of axons that span the gray-white tissue interface. Our computational models predict that material heterogeneities at the gray-white interface lead to a highly nonuniform distribution of stress in axons, which was most amplified in axonal regions near the interface. This mechanism was confirmed using an analytical model of an individual fiber in a strained bimaterial interface. Comparisons of these collective data with histopathological evaluation of a swine model of concussion demonstrated a notably similar pattern of axonal damage adjacent to the gray-white interface. The results suggest that the tissue property mismatch at the gray-white matter interface places axons crossing this region at greater risk of mechanical damage during brain tissue deformation from traumatic brain injury.

Clinical profile of Aboriginal and Torres Strait Islander adults with stroke and traumatic brain injury at a regional Australian hospital: a retrospective chart audit

Background:

The clinical profile of Aboriginal and Torres Strait Islander adults admitted to hospital with neurological injury is not well documented. Understanding these profiles may enable health professionals to provide more culturally responsive health care for this patient group. This study aimed to report the clinical profile of Aboriginal and Torres Strait Islander adults admitted to a regional Queensland hospital due to stroke or traumatic brain injury (TBI).

Method:

A 2-year retrospective medical record review of Aboriginal and Torres Strait Islander adults (≥18 years) admitted to a regional Queensland hospital with principal diagnoses of stroke or TBI.

Results:

There were 132 Aboriginal and Torres Strait Islander adult stroke (51.5%) or TBI (48.5%) admissions. The mean ages were 56.7 years for stroke and 42.7 years for TBI. The majority of patients (83.3%) were of Aboriginal descent with others identifying as Torres Strait Islander only, or both Aboriginal and Torres Strait Islander. Patients were from 26 diverse home locations across northern Australia, primarily Outer Regional or Remote/Very Remote geographical locations. All patients’ language backgrounds were documented as English only. Over 90% of stroke and 50% of TBI patients presented with medical co-morbidities.

Conclusions:

Patients had diverse geographical locations and cultural backgrounds, with many likely impacted by dislocation from home and country, as well as potential delays in receiving treatment. Despite this diversity, English was documented in patients’ medical records as their only language. The majority of patients also presented with multiple medical co-morbidities. Health professionals should consider these factors to ensure patients receive optimum and culturally responsive health care.

Cognitive complaint and objective cognition during the post-acute period after mild traumatic brain injury in pre-morbidly healthy adults

Primary Objective:The most widely used proxies of cognitive complaint after mTBI are post-concussion syndrome (PCS) symptom checklists, which do not have a clear relationship with cognition. This study investigated whether an mTBI-specific cognitive complaint measure would have clearer associations with objective cognition than a widely used PCS symptom checklist.Research Design:An observational design was used. A sample of 109 participants (52 mTBI and 57 healthy controls) completed a PCS symptom checklist, a cognitive complaint measure, and measures of information processing speed, attention, memory, executive function, depression and anxiety.Main Outcomes and Results:In the healthy control group, cognitive complaint was significantly associated with objective cognitive performance and was not associated with psychological status. In contrast, PCS endorsement was unrelated to objective cognition but was associated with psychological status. For the mTBI group, neither PCS endorsement nor cognitive complaint was associated with cognitive performance, but both measures were associated with psychological status.Conclusions:This study indicates that neither cognitive nor PCS symptom measures are reliable indicators of underlying cognitive function in the post-acute period after mTBI. Further, suffering an mTBI may affect the linear relationship that exists between cognitive symptom endorsement and cognitive function in healthy adults.

Long-term psychosocial outcome following mild traumatic brain injury and minor stroke: a direct longitudinal comparison

Background and purpose

Research suggests comparable long-term psychosocial outcomes following mild traumatic brain injury (mTBI) and minor stroke, but no direct comparison has been made. This study aimed to directly compare psychosocial outcome over time in persons with mTBI and minor stroke.

Methods

In this multicenter, prospective longitudinal cohort study, community-dwelling persons with mTBI (n = 182) and minor stroke (n = 48) were assessed at 6 weeks, 3, 6 and 12 months post-injury. Outcome measures included anxiety and depression symptoms (Hospital Anxiety and Depression Scale—HADS), cognitive problems in daily life (Checklist for Cognitive and Emotional Consequences of Stroke—CLCE-24) and quality of life (EuroQol-5D-5L—EQ-5D-5L). Multilevel growth curve modeling, controlled for demographic variables, was used to determine outcomes over time between groups. Proportions of persons reporting persistent psychosocial symptoms at 6 months post-injury were compared using Pearson’s Chi-squared tests.

Results

Improvements in outcomes were observed in the first 6 months and effects stabilized to 12 months post-injury in both groups. Minor stroke cases reported significantly higher levels of HADS anxiety and a significantly reduced increase in EQ-5D-5L utility scores than mTBI cases, but differences were small in absolute numbers. No significant differences were observed between groups regarding HADS depression and CLCE-24 cognition scores. Proportions of persons reporting persistent psychosocial symptoms were equal between groups.

Conclusions

Psychosocial outcome is largely comparable following mTBI and minor stroke. Specific attention should be paid to anxiety symptoms and cognitive problems in daily life for which uniform aftercare seems appropriate.

Traumatic Brain Injury: Effect of Litigation Status on Executive Functioning—A Pilot Study

Traumatic brain injury (TBI) is associated with a wide range of physiological, behavioral, emotional, and cognitive sequelae. Litigation status is one of the many factors that has an impact on recovery. The aim of this study was to compare executive functions, postconcussion, and depressive symptoms in TBI patients with and without litigation. A sample of 30 patients with TBI, 15 patients with litigation (medicolegal case [MLC]), and 15 without litigation (non-MLC) was assessed. The tools used were sociodemographic and clinical proforma, executive function tests, Rivermead Post-Concussion Symptom Questionnaire, and Beck Depression Inventory. Assessment revealed that more than 50% of patients showed deficits in category fluency, set shifting, and concept formation. The MLC group showed significant impairment on verbal working memory in comparison to the non-MLC group. The performance of both groups was comparable on tests of semantic fluency, visuospatial working memory, concept formation, set shifting, planning, and response inhibition. The MLC group showed more verbal working memory deficits in the absence of significant postconcussion and depressive symptoms on self-report measures.

Influence of blast exposure on cognitive functioning in combat veterans

OBJECTIVE

We evaluated the contribution of blast-pressure severity to cognitive functioning beyond posttraumatic stress disorder (PTSD) severity and traumatic brain injury (TBI).

METHOD

Post-9/11 veterans (N = 254, 86.22% male) completed the Wechsler Adult Intelligence Scale (WAIS-IV) and Trail Making Test (TMT). The Clinician-Administered PTSD Scale (CAPS-5), Mid-Atlantic MIRECC Assessment of TBI, and the Salisbury Blast Interview evaluated PTSD diagnosis/severity, deployment TBI history/severity, and blast-exposure history/severity, respectively.

RESULTS

Veterans with mild deployment TBI had overall significantly lower T scores on the WAIS-IV Verbal Comprehension Index (d = .13), Working Memory Index (d = .30), and Processing Speed Index (d = .25); the Trail Making Test A (TMT-A; d = .50); and the Trail Making Test B (TMT-B; d = .37). Mild deployment TBI was significantly associated with TMT-A (ΔR² = .05, p < .001) and TMT-B (ΔR² = .03, p = .001) performance. Blast-pressure severity moderated the association between mild deployment TBI and TMT-A (ΔR² = .02, p = .039, B = -2.01).

CONCLUSION

Blast-pressure severity exacerbated the effects of mild TBI on a simple attention task, such that participants with TBI had gradual decrements in attention as blast severity increased. Veterans who incur a TBI and are exposed to blasts during deployment may experience persisting difficulties with cognitive functioning as a result of alterations in basic attention abilities. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Towards the Development of an Integrative, Evidence-Based Suite of Indicators for the Prediction of Outcome Following Mild Traumatic Brain Injury: Results from a Pilot Study

Background: Persisting post-concussion symptoms (PPCS) is a complex, multifaceted condition in which individuals continue to experience the symptoms of mild traumatic brain injury (mTBI; concussion) beyond the timeframe that it typically takes to recover. Currently, there is no way of knowing which individuals may develop this condition. Method: Patients presenting to a hospital emergency department (ED) within 48 h of sustaining a mTBI underwent neuropsychological assessment and demographic, injury-related information and blood samples were collected. Concentrations of blood-based biomarkers neuron specific enolase, neurofilament protein-light, and glial fibrillary acidic protein were assessed, and a subset of patients also underwent diffusion tensor–magnetic resonance imaging; both relative to healthy controls. Individuals were classified as having PPCS if they reported a score of 25 or higher on the Rivermead Postconcussion Symptoms Questionnaire at ~28 days post-injury. Univariate exact logistic regression was performed to identify measures that may be predictive of PPCS. Neuroimaging data were examined for differences in fractional anisotropy (FA) and mean diffusivity in regions of interest. Results: Of n = 36 individuals, three (8.33%) were classified as having PPCS. Increased performance on the Repeatable Battery for the Assessment of Neuropsychological Status Update Total Score (OR = 0.81, 95% CI: 0.61–0.95, p = 0.004), Immediate Memory (OR = 0.79, 95% CI: 0.56–0.94, p = 0.001), and Attention (OR = 0.86, 95% CI: 0.71–0.97, p = 0.007) indices, as well as faster completion of the Trails Making Test B (OR = 1.06, 95% CI: 1.00–1.12, p = 0.032) at ED presentation were associated with a statistically significant decreased odds of an individual being classified as having PPCS. There was no significant association between blood-based biomarkers and PPCS in this small sample, although glial fibrillary acidic protein (GFAP) was significantly increased in individuals with mTBI relative to healthy controls. Furthermore, relative to healthy age and sex-matched controls (n = 8), individuals with mTBI (n = 14) had higher levels of FA within the left inferior frontal occipital fasciculus (t (18.06) = −3.01, p = 0.008). Conclusion: Performance on neuropsychological measures may be useful for predicting PPCS, but further investigation is required to elucidate the utility of this and other potential predictors.

Three methods for examining trajectories in neuropsychological performance across the first 4 years after mild Traumatic Brain Injury

Background:

Emerging data suggest that recovery from mild traumatic brain injury (mTBI) takes longer than previously thought. This paper examines trajectories for cognitive recovery up to 48 months post-mTBI, presenting these visually using a Sankey diagram and growth curve analysis.

Methods:

This sample (n = 301) represents adults (≥16 years) from a population-based Brain Injury Outcomes in the New Zealand Community study over a 4-year follow-up on the CNS-Vital Signs neuropsychological test. Data were collected within 2 weeks of injury, and then at 1, 6, 12 and 48 months post-injury.

Results:

Significant improvement in cognitive functioning was seen up to 6 months post-injury. Using growth curve modelling, we found significant improvements in overall neurocognition from baseline to 6 months, on average participants improved one point per month (0.9; 95% CI 0.42–1.39) p < 0.001. No change in neurocognition was found within the time periods 6–12 months or 12–48 months. The Sankey highlighted that at each time point, a small proportion of participants remained unchanged or declined. Proportionally, few show any improvement after the first 6 months.

Conclusion:

Most individuals remained stable or improved over time to 6 months post-injury. Summary statistics are informative regarding overall trends, but can mask differing trajectories for recovery. The Sankey diagram indicates that not all improve, as well as the potential impact of individuals moving in and out of the study. The Sankey diagram also indicated the level of functioning of those most likely to withdraw, allowing targeting of retention strategies.

Subcortical shape and neuropsychological function among U.S. service members with mild traumatic brain injury

In a recent manuscript, our group demonstrated shape differences in the thalamus, nucleus accumbens, and amygdala in a cohort of U.S. Service Members with mild traumatic brain injury (mTBI). Given the significant role these structures play in cognitive function, this study directly examined the relationship between shape metrics and neuropsychological performance. The imaging and neuropsychological data from 135 post-deployed United States Service Members from two groups (mTBI and orthopedic injured) were examined. Two shape features modeling local deformations in thickness (RD) and surface area (JD) were defined vertex-wise on parametric mesh-representations of 7 bilateral subcortical gray matter structures. Linear regression was used to model associations between subcortical morphometry and neuropsychological performance as a function of either TBI status or, among TBI patients, subjective reporting of initial concussion severity (CS). Results demonstrated several significant group-by-cognition relationships with shape metrics across multiple cognitive domains including processing speed, memory, and executive function. Higher processing speed was robustly associated with more dilation of caudate surface area among patients with mTBI who reported more than one CS variables (loss of consciousness (LOC), alteration of consciousness (AOC), and/or post-traumatic amnesia (PTA)). These significant patterns indicate the importance of subcortical structures in cognitive performance and support a growing functional neuroanatomical literature in TBI and other neurologic disorders. However, prospective research will be required before exact directional evolution and progression of shape can be understood and utilized in predicting or tracking cognitive outcomes in this patient population.

Associations between brain drawings following mild traumatic brain injury and negative illness perceptions and post-concussion symptoms at 4 years

Characteristics of patient's drawings have been linked to short-term health-related outcomes across a range of health conditions. This study examined associations between brain drawings at 1 month and illness perceptions and post-concussion symptoms at 4 years in 92 adults following mild traumatic brain injury. Greater damage depicted at 1 month was correlated with perceived greater impact on life, duration of injury, symptoms of brain injury, emotional consequences and late-onset post-concussion symptoms. Results indicate that brain drawings shortly after traumatic brain injury offer a simple and insightful tool that may help to identify those who need additional support to improve long-term outcomes.

Auditory and Cognitive Behavioral Performance Deficits and Symptom Reporting in Postconcussion Syndrome Following Mild Traumatic Brain Injury

Purpose This study examined auditory deficits and symptom reporting in individuals with long-term postconcussion symptoms following a single mild traumatic brain injury (mTBI) compared to age- and gender-matched controls without a history of mTBI. Method Case history interviews, symptom questionnaires, and a battery of central auditory and neuropsychological tests were administered to 2 groups. The mTBI group was a civilian population recruited from a local concussion management program who were seeking rehabilitation for postconcussion-related problems in a postacute period between 3 and 18 months following injury. Symptom validity testing was included to assess the rate of possible insufficient test effort and its influence on scores for all outcome measures. Analyses of group differences in test scores were performed both with and without the participants who showed insufficient test effort. Rates of symptom reporting, correlations among symptoms and behavioral test outcomes, and the relationships between auditory and cognitive test performance were analyzed. Results The mTBI group reported a high rate of auditory symptoms and general postconcussion symptoms. Performance on neuropsychological tests of cognitive function showed some differences in raw scores between groups, but when effort was considered, there were no significant differences in the rate of abnormal performance between groups. In contrast, there were significant differences in both raw scores and the rate of abnormal performance between groups for some auditory tests when only considering participants with sufficient effort. Auditory symptoms were strongly correlated with other general postconcussion symptoms. Conclusions Significant auditory symptoms and evidence of long-term central auditory dysfunction were found in a subset of individuals who had chronic postconcussion symptoms after a single mTBI unrelated to blast trauma. The rate of abnormal performance on auditory behavioral tests exceeded the rate of abnormal performance on tests of cognitive function. Supplemental Material https://doi.org/10.23641/asha.8329955.

Mild Traumatic Brain Injury Affects Cognitive Processing and Modifies Oscillatory Brain Activity during Attentional Tasks

Despite the high prevalence of mild traumatic brain injury (mTBI), current diagnostic tools to objectively assess cognitive complaints after mTBI continue to be inadequate. Our aim was to identify neuronal correlates for cognitive difficulties in mTBI patients by evaluating the possible alterations in oscillatory brain activity during a behavioral task known to be sensitive to cognitive impairment after mTBI. We compared oscillatory brain activity during rest and cognitive tasks (Paced Auditory Serial Addition Test [PASAT] and a vigilance test [VT]) with magnetoencephalography between 25 mTBI patients and 20 healthy controls. Whereas VT induced no significant differences compared with resting state in either group, patients exhibited stronger attenuation of 8- to 14-Hz oscillatory activity during PASAT than healthy controls in the left parietotemporal cortex (p ≤ 0.05). Further, significant task-related modulation in the left superior frontal gyrus and right prefrontal cortex was detected only in patients. The ∼10-Hz (alpha) peak frequency declined in frontal, temporal, and parietal regions during PASAT compared with rest (p < 0.016) in patients, whereas in controls it remained the same or showed a tendency to increase. In patients, the ∼10-Hz peak amplitude was negatively correlated with behavioral performance in the Trail Making Test. The observed alterations in the cortical oscillatory activity during cognitive load may provide measurable neurophysiological correlates of cognitive difficulties in mTBI patients, even at the individual level.

Cognitive Impairment Following Acute Mild Traumatic Brain Injury

Patients with mild traumatic brain injury (mTBI) may present cognitive deficits within the first 24 h after trauma, herein called "acute phase," which in turn may lead to long-term functional impairment and decrease in quality of life. Few studies investigated cognition in mTBI patients during the acute phase. The objectives of this study were to investigate the cognitive profile of patients with mTBI during the acute phase, compared to controls and normative data, and whether loss of consciousness (LOC), previous TBI and level of education influence cognition at this stage. Fifty-three patients with mTBI (aged 19-64 years) and 28 healthy controls participated in the study. All patients were evaluated at bedside within 24 h post-injury. Demographic and clinical data were registered. Cognitive function was assessed with the Mini-mental state examination (MMSE), the Frontal Assessment Battery (FAB), Digit Span (working memory), and the Visual Memory Test/Brief Cognitive Battery (for episodic memory). The clinical sample was composed mainly by men (58.5%). The mean age was 39 years-old and 64.3% of the patients had more than 8 years of education. The most common causes of mTBI were fall from own height (28.3%), aggression (24.5%), and fall from variable heights (24.5%). Compared to controls, mTBI patients exhibited significantly worse performance on MMSE, FAB, naming, incidental memory, immediate memory, learning, and delayed recall. Compared to normative data, 26.4% of patients had reduced global cognition as measured by the MMSE. Episodic memory impairment (13.2%) was more frequent than executive dysfunction (9.4%). No significant differences were found in cognitive performance when comparing patients with or without LOC or those with or without history of previous TBI. Patients with lower educational level had higher rates of cognitive impairment (VMT naming-28.6 vs. 4.2%; VMT immediate memory-32 vs. 4.2%; VMT learning-39.3 vs. 4.2%, all p < 0.05). In sum, we found significant cognitive impairment in the acute phase of mTBI, which was not associated with LOC or history of TBI, but appeared more frequently in patients with lower educational level.

Improvement and Prediction of Memory and Executive Functions in Patients Admitted to a Neurosurgery Service With Complicated and Uncomplicated Mild Traumatic Brain Injury

OBJECTIVES

To compare neuropsychological performances between patients with and without intracranial abnormalities after mild traumatic brain injury (mTBI) and assess the relationship between demographics, injury severity, and self-reported symptom characteristics with improvements in memory and executive functions (8 weeks to 1 year postinjury).

SETTING

Inpatient/outpatient followed up at the Department of Physical Medicine and Rehabilitation, Oslo, Norway.

PARTICIPANTS

Patients were divided into groups of complicated (n = 73) or uncomplicated mTBIs (n = 77) based on intracranial findings on computed tomographic or magnetic resonance imaging brain scans.

DESIGN

Prospective, longitudinal cohort study.

MAIN MEASURES

Neuropsychological assessments of memory and executive functions, self-reports of postconcussion, depression, posttraumatic stress symptoms, and general functioning at 8 weeks and 1 year postinjury.

RESULTS

Longitudinal data showed that patients with complicated and uncomplicated mTBIs had similar cognitive performance and improvements. Hierarchical linear modeling revealed that individuals with early posttraumatic stress disorder and/or depressive symptoms performed worse on measures of Memory functions, and those with younger age (<40 years) and lower education (<12 years) performed worse on measures of Executive functions.

CONCLUSION

Findings are suggestive of a good cognitive outcome following complicated and uncomplicated mTBIs. Early assessments of posttraumatic stress disorder and depression seem useful in identifying those most vulnerable having poorer cognitive outcomes, providing further interventions that may affect emotional and cognitive recovery.

Alterations in dual-task walking persist two months after mild traumatic brain injury in young adults

Objectives

To compare dual-task performance involving different cognitive-locomotor combinations between healthy controls and participants with sub-acute mild traumatic brain injury (mTBI) and to correlate dual-task performances to history of prior head injuries.

Methods

Eighteen participants having recently sustained mTBI and 15 controls performed nine dual-tasks combining locomotor (level-walking, narrow obstacle, deep obstacle) and cognitive (Stroop task, Verbal fluency, Counting backwards) tasks. Previous history of concussion was also investigated.

Results

Slower gait speeds were observed in the mTBI group compared to controls during both single and dual-tasks. Longer response times to cognitive tasks in the mTBI group further suggested the presence of residual impairments two months following injury. No combination of dual-task was more sensitive. Correlations were observed between history of mTBI and several measures of dual-task performance, underlying the need to further consider the effects of multiple injuries in relation to dual-task walking.

Conclusion

Dual-tasks using simultaneously locomotor and cognitive functions represent an ecological way for clinicians to detect residual, but subtle, alterations post-mTBI. History of previous mTBI needs to be considered as a personal characteristic which may influence dual-task walking performance.

Exercise training and physiological responses to acute stress: study protocol and methodological considerations of a randomised controlled trial

Background

This paper describes the protocol and methodological prerequisites for a randomised controlled exercise intervention. Selected baseline data from the study are also presented, demonstrating some methodological challenges related to exercise intervention trials. The aim of the trial was to study the effects of exercise training on physiological responses to acute psychosocial stress in untrained individuals.

Methods

Individuals with a low level of physical activity were invited to participate in an exercise intervention lasting for 6 months. A total of 119 participants were included and went through a peak oxygen uptake test and a psychosocial stress test at baseline. Adrenocorticotropic hormone (ACTH) and cortisol were measured in connection to the stress test to identify the physiological response.

Results

Almost 90% of the participants reported themselves as untrained, but results from the objectively measured oxygen uptake did not seem to correspond to the reported sedentary lifestyle. The primary outcome measures at baseline varied between individuals. The mean change from pre-test to peak value was 214% for ACTH and 94% for cortisol. Of these, 13 individuals did not respond in ACTH and/or and cortisol.

Discussion

Supposedly untrained individuals seeking participation in an exercise intervention might not be as untrained as they report, a methodological consideration of importance when evaluating the effects of training. Another important consideration is related to the primary outcome measure, which should be measurable and possible to affect. Absence of reaction at baseline means that changes can only be detected as an increased reaction.

Neuropsychological correlates of self-reported impulsivity and informant-reported maladaptive behaviour among veterans with posttraumatic stress disorder and traumatic brain injury history

OBJECTIVE

Frontal lobe deficits resulting from traumatic brain injury (TBI) and/or posttraumatic stress disorder (PTSD) have been linked to impulsive behaviour. We sought to examine whether neuropsychological performance predicted self-reported impulsivity and informant-reported maladaptive behaviour.

METHOD

We administered the Delis-Kaplan Executive Function System (D-KEFS) to 116 Iraq/Afghanistan-era veterans diagnosed with a history of TBI and PTSD.

RESULTS

Poorer performance on D-KEFS Stroop Task (both colour and word, separately) and Trail making (letter sequencing and motor speed) tasks and higher PTSD symptom severity were associated with higher self-reported impulsivity. Trail making letter sequencing performance was negatively associated with informant-reported maladaptive behaviour. Regression analyses revealed PTSD symptom severity and Trail making letter sequencing best predicted self-reported impulsivity, even when accounting for age, sex, and education. Only Trail making letter sequencing predicted informant-reported maladaptive behaviour when accounting for other variables in the model.

CONCLUSIONS

Attention and processing speed impairments and PTSD symptom severity appear to be important predictors of impulsivity and problematic behaviour among veterans. Findings have implications for theoretical models of aggression and violence and inform the assessment and treatment of individuals with TBI and PTSD.

MLC901 (NeuroAiD II™) for cognition after traumatic brain injury: a pilot randomized clinical trial

Background and purpose

Treatments to facilitate recovery after traumatic brain injury (TBI) are urgently needed. We conducted a 9‐month pilot, randomized placebo‐controlled clinical trial to examine the safety and potential effects of the herbal supplement MLC901 (NeuroAiD II™) on cognitive functioning following TBI.

Methods

Adults aged 18–65 years at 1–12 months after mild or moderate TBI were randomized to receive MLC901 (0.8 g capsules 3 times daily) or placebo for 6 months. The primary outcome was cognitive functioning as assessed by the CNS Vital Signs online neuropsychological test. Secondary outcomes included the Cognitive Failures Questionnaire, the Rivermead Post‐concussion Symptom Questionnaire (neurobehavioral sequelae), Quality of Life after Brain Injury, Hospital Anxiety and Depression Scale, Modified Fatigue Impact Scale and extended Glasgow Outcome Scale (physical disability). Assessments were completed at baseline and at 3‐, 6‐ and 9‐month follow‐up. Linear mixed‐effects models were conducted, with the primary outcome time‐point of 6 months.

Results

A total of 78 participants [mean age 37.5 ± 14.8 years, 39 (50%) female] were included in the analysis. Baseline variables were similar between groups (treatment group, n = 36; control group, n = 42). Linear mixed‐effects models controlling for time, group allocation, repeated measurements, adherence and baseline assessment scores revealed significant improvements in complex attention (P = 0.04, d = 0.6) and executive functioning (P = 0.04, d = 0.4) at 6 months in the MLC901 group compared with controls. There were no significant differences between the groups for neurobehavioral sequelae, mood, fatigue, physical disability or overall quality of life at 6 months. No serious adverse events were reported.

Conclusions

MLC901 was safe and well tolerated post‐TBI. This study provided Class I/II evidence that, for patients with mild to moderate TBI, 6 months of MLC901 improved cognitive functioning.

Population-based cohort study of the impacts of mild traumatic brain injury in adults four years post-injury

There is increasing evidence that some people can experience persistent symptoms for up to a year following mild TBI. However, few longitudinal studies of mild TBI exist and the longer-term impact remains unclear. The purpose of this study is to determine if there are long-term effects of mild traumatic brain injury (TBI) four-years later. Adults (aged ≥16 years) identified as part of a TBI incidence study who experienced a mild-TBI four-years ago (N = 232) were compared to age-sex matched controls (N = 232). Sociodemographic variables, prior TBI and symptoms were assessed at the time of injury. Four years post-injury participants completed the Rivermead Post-Concussion Symptom Questionnaire, Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index and the Participation Assessment with Recombined Tools. Analysis of covariance was used to compare differences between TBI cases four years post-injury and controls, controlling for prior TBI and depression. A multiple regression model was used to identify the predictors of increased symptoms and reduced participation. The mild-TBI sample experienced significantly increased self-reported cognitive symptoms (F = 19.90, p = <0.01) four years post-injury than controls. There were no differences between the groups for somatic (F = 0.02, p = 0.89) or emotional symptoms (F = 0.31, p = 0.58). Additionally, the mild-TBI group reported significantly poorer community participation across all three domains: productivity (F = 199.07, p = <0.00), social relations (F = 13.93, p = <0.00) and getting out and about (F = 364.69, p = <0.00) compared to controls. A regression model accounting for 41% of the variance in cognitive symptoms in TBI cases revealed a history of TBI, receiving acute medical attention and baseline cognitive symptoms, sleep quality, anxiety and depression were predictive of outcome. The results indicate that whilst somatic and emotional symptoms resolve over time, cognitive symptoms can become persistent and that mild TBI can impact longer-term community participation. Early intervention is needed to reduce the longer-term impact of cognitive symptoms and facilitate participation.

Stuck in a State of Inattention? Functional Hyperconnectivity as an Indicator of Disturbed Intrinsic Brain Dynamics in Adolescents With Concussion: A Pilot Study

Sports-related concussion in youth is a major public health issue. Evaluating the diffuse and often subtle changes in structure and function that occur in the brain, particularly in this population, remains a significant challenge. The goal of this pilot study was to evaluate the relationship between the intrinsic dynamics of the brain using resting-state functional magnetic resonance imaging (rs-fMRI) and relate these findings to structural brain correlates from diffusion tensor imaging in a group of adolescents with sports-related concussions ( n = 6) and a group of healthy adolescent athletes ( n = 6). We analyzed rs-fMRI data using a sliding windows approach and related the functional findings to structural brain correlates by applying graph theory analysis to the diffusion tensor imaging data. Within the resting-state condition, we extracted three separate brain states in both groups. Our analysis revealed that the brain dynamics in healthy adolescents was characterized by a dynamic pattern, shifting equally between three brain states; however, in adolescents with concussion, the pattern was more static with a longer time spent in one brain state. Importantly, this lack of dynamic flexibility in the concussed group was associated with increased nodal strength in the left middle frontal gyrus, suggesting reorganization in a region related to attention. This preliminary report shows that both the intrinsic brain dynamics and structural organization are altered in networks related to attention in adolescents with concussion. This first report in adolescents will be used to inform future studies in a larger cohort.

Use of general practice before and after mild traumatic brain injury: a nationwide population-based cohort study in Denmark

OBJECTIVES

Traumatic brain injury (TBI) is commonly seen in the emergency department (ED). Approximately 85%-90% of TBIs are mild (mTBI). Some cause symptoms such as headache, dizziness, anxiety, blurred vision, insomnia and concentration difficulties, collectively known as postconcussion syndrome (PCS). Some studies suggest that recovery from mTBI is complete. Others find that symptoms persist for months, even years. The aim of this study was to describe the use of general practice, before and after mTBI, as a proxy for symptoms in a large cohort.

DESIGN

Nationwide population-based matched cohort study.

SETTING

Danish EDs and general practice.

PARTICIPANTS

All patients (aged ≥18 years), first-time diagnosed with mTBI in a Danish ED between 1 January 1998 and 31 December 2010 (n=93 517). Ten reference persons per patient with mTBI were randomly matched on gender, age and general practice (n=935 170).

PRIMARY OUTCOME

Overall use of general practice; consultations relating to mental and physical health.

RESULTS

We found higher use of general practice during the first year after mTBI for all ages, both genders and all types of contacts. Age 18-40 years: women, incidence rate ratio (IRR) 1.59 (95% CI 1.57 to 1.61); men, IRR 1.82 (95% CI 1.80 to 1.85). Age 41-65 years: women, IRR 1.75 (95% CI 1.72 to 1.78); men, IRR 1.85(95% CI 1.82 to 1.89). Age 66+ years: women, IRR 1.55 (95% CI 1.52 to 1.58); men, IRR 1.55 (95% CI 1.51 to 1.59). After the first year, the use decreased to the level before mTBI. Individuals with mTBI and higher use of general practice before mTBI had lower socioeconomic status and more comorbidities (P<0.001).

CONCLUSIONS

The use of general practice was higher in the first year after mTBI, specifically in the first 3 months. Patients with mTBI had different healthcare-seeking behaviour several years before diagnosis than their matched reference persons. Pretraumatic morbidity should be considered in the evaluation of PCS.

The Structure of the Rivermead Post-Concussion Symptoms Questionnaire in Australian Adults with Traumatic Brain Injury

Background and aims: Many sustaining traumatic brain injury (TBI) suffer ongoing post-concussion symptoms (PCS). The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) is widely used, although there is disagreement about its structure. This study compared the fit of published RPQ structures with a four-factor structure derived from a large adult sample with TBI in Tasmania.

Method: 661 adults with TBI completed the RPQ at approximately one month post injury. Exploratory factor analysis (EFA), using the first half of the sample (n = 330), suggested a four-factor solution. This was compared with models reported in the literature with the second half of the sample (n = 331), using structural equation modelling. Trajectory of recovery across these factors was examined within subsamples at 1, 3, 6 and 12 months following TBI.

Results: Inter-correlations between items were strongest for somatic, cognitive and emotional functioning items and the EFA identified a four-factor model. Fit was examined utilising bootstrapping for model comparison. The data at 1 month following TBI best fitted the four-factor model (CFI = .95, RMSEA = .060 (.049–.071) and factors had adequate internal consistency (r = .61–.89). This model appeared a good fit and clinically useful across time points to 12 months post injury.

Conclusions: Data best fitted a four-factor model, identified using a rigorous statistical approach. Clinicians and clinical researchers may use this preferred model to provide more specific measurement of the severity of PCS. Future research could attempt replication within international samples.