Efficacy of Interventions to Improve Cognitive Function in Adults with Spinal Cord Injury: A Systematic Review.

Cognitive impairment is a common complication following spinal cord injury (SCI) and imposes a significant negative impact on adjustment, functional independence, physical and mental health, and quality of life. It is unclear whether interventions for cognitive impairment following SCI are effective. A systematic review of controlled trials was performed to evaluate the effect of interventions on cognitive functions in adults with SCI using search engines: Embase, The Cochrane Library, MEDLINE, Scopus, CINAHL, and Web of Science up to December 2023. Two reviewers independently screened the articles, and study findings were synthesized and summarized. The risk of bias was evaluated using the Cochrane Risk of Bias 2.0 tool. Eight moderate-quality studies were found that investigated the effects of physical exercise/activity-based therapy plus cognitive training or intermittent hypoxia, diet modification and dietary supplements, tibial nerve or cortical stimulation, and drug therapy on cognitive function in SCI. Physical exercise/activity-based therapy plus cognitive training showed most promise for improving cognitive functions, while drug therapy, diet modification, and dietary supplements showed potential for improving cognitive function. However, about half of the participants experienced heightened instability in blood pressure following the administration of midodrine, and one participant reported gastrointestinal side effects after taking omega-3 fatty acids. There was no evidence of improvement in cognitive function for stimulation techniques. The current review highlights the scarcity of research investigating the effectiveness of interventions that target cognitive function after SCI. Further, the effects of these eight studies are uncertain due to concerns about the quality of designs and small sample sizes utilized in the trials, as well as the employment of insensitive neurocognitive tests when applied to adults with SCI. This review highlights a significant gap in knowledge related to SCI cognitive rehabilitation.

The importance of self-regulation and mental health for effective recovery after traffic injuries: A comprehensive network analysis approach.

OBJECTIVE: Traffic injuries significantly impact people's psychological, physical and social wellbeing, and involve complex self-regulation responses. Psychological impacts are seldom recognized and addressed holistically. This study employs network analysis to investigate the interconnectedness between different dimensions that influence mental health vulnerability and recovery after traffic injuries. METHODS: 120 adults with mild-to-moderate traffic injuries and 112 non-injured controls were recruited. The network investigation employed two main approaches. Four cross-sectional networks examined the interrelationships between self-regulation responses (cognitive and autonomic) and various health dimensions (psychological, physical, social) over time (1, 3, 6, 12 months). Three predictive networks explored influences of acute self-regulation responses (1 month) on long-term outcomes. Network analyses focused on between-group differences in overall connectivity and centrality measures (nodal strength). RESULTS: An overall measure of psychological wellbeing consistently emerged as the most central (strongest) node in both groups' networks. Injured individuals showed higher overall connectivity and differences in the centrality of self-regulation nodes compared to controls, at 1-month and 12-months post-injury. These patterns were similarly observed in the predictive networks, including differences in cognitive and autonomic self-regulation influences. CONCLUSIONS: Network analyses highlighted the crucial role of psychological health and self-regulation, in promoting optimal wellbeing and effective recovery. Post-traffic injury, increased connectivity indicated prolonged vulnerability for at least a year, underscoring the need of ongoing support beyond the initial improvements. A comprehensive approach that prioritizes psychological health and self-regulation through psychologically informed services, early psychological screening, and interventions promoting cognitive and autonomic self-regulation is crucial for mitigating morbidity and facilitating recovery. TRIAL REGISTRATION: IMPRINT study, ACTRN 12616001445460.

Heart Rate Variability Biofeedback in Adults with a Spinal Cord Injury: A Laboratory Framework and Case Series.

Heart rate variability biofeedback (HRV-F) is a neurocardiac self-regulation therapy that aims to regulate cardiac autonomic nervous system activity and improve cardiac balance. Despite benefits in various clinical populations, no study has reported the effects of HRV-F in adults with a spinal cord injury (SCI). This article provides an overview of a neuropsychophysiological laboratory framework and reports the impact of an HRV-F training program on two adults with chronic SCI (T1 AIS A and T3 AIS C) with different degrees of remaining cardiac autonomic function. The HRV-F intervention involved 10 weeks of face-to-face and telehealth sessions with daily HRV-F home practice. Physiological (HRV, blood pressure variability (BPV), baroreflex sensitivity (BRS)), and self-reported assessments (Fatigue Severity Scale, Generalised Anxiety Disorder Scale, Patient Health Questionnaire, Appraisal of Disability and Participation Scale, EuroQol Visual Analogue Scale) were conducted at baseline and 10 weeks. Participants also completed weekly diaries capturing mood, anxiety, pain, sleep quality, fatigue, and adverse events. Results showed some improvement in HRV, BPV, and BRS. Additionally, participants self-reported some improvements in mood, fatigue, pain, quality of life, and self-perception. A 10-week HRV-F intervention was feasible in two participants with chronic SCI, warranting further investigation into its autonomic and psychosocial effects.

Cognitive Failure in Adults with Spinal Cord Injury: A Valuable Adjunct Measure for Enhancing Cognitive Assessment and Rehabilitation Outcomes.

Cognitive impairment is common in persons with spinal cord injury (SCI), impacting their daily functioning and rehabilitation. This study assesses the extent of self-reported cognitive failures in everyday life in persons with SCI and its relationships with objective neurocognitive measures and psychosocial factors, including depressive mood, anxiety, perceived control, and fatigue. The differences between forty-one adults with a chronic SCI and forty-one able-bodied controls were examined. The participants completed the Cognitive Failures Questionnaire (CFQ) to assess cognitive failure and neurocognitive tests assessing attention and executive functions, as well as a psychosocial assessment. The SCI group reported higher cognitive failure rates than the able-bodied group (31.7% versus 19%, p > 0.05). Objective neurocognitive tests did not significantly correlate with the CFQ scores in either group. However, the CFQ scores were positively associated with most psychosocial factors, even after controlling for covariates. The CFQ scores were significantly associated with depressive mood in persons with SCI. These findings highlight the importance of incorporating self-reported cognitive measures into neurocognitive assessments and rehabilitation planning for adults with SCI. Self-reports capture everyday cognitive challenges that objective tests may miss. Additionally, this study highlights the strong connections between cognitive failures and psychosocial issues, particularly mood disorders, emphasizing the need for comprehensive rehabilitation and psychosocial support post-SCI, addressing both cognitive and emotional wellbeing.

Cognitive Reserve and Its Association with Cognitive and Mental Health Status following an Acute Spinal Cord Injury.

BACKGROUND: Mild cognitive impairment (MCI) is a common secondary condition associated with spinal cord injury (SCI). Cognitive reserve (CR) is believed to protect against cognitive decline and can be assessed by premorbid intelligence (pmIQ). Despite the potential utility of pmIQ as a complementary metric in the evaluation of MCI in SCI, this approach has been infrequently employed. The purpose of this study was to examine the association between MCI and pmIQ in adults with SCI with the aim of exploring the potential value of pmIQ as a marker of CR in this population. METHODS: Cognitive function was assessed on three occasions in adults with SCI over a 12-month period post-injury, and pmIQ was assessed once at baseline. Demographic and mental health measures were also collected, and logistic regression was conducted to determine the strength of association between pmIQ and MCI while adjusting for factors such as mental health and age. RESULTS: The regression analysis revealed that at the time of admission to SCI rehabilitation, the MCI assessed by a valid neurocognitive screen was strongly associated with pmIQ. That is, if a person has MCI, there was 5.4 greater odds (p < 0.01) that they will have poor pmIQ compared to a person without MCI after adjustment for age and mental health. CONCLUSIONS: The assessment of CR is an important area that should be considered to improve the process of diagnosing MCI in adults with an acute SCI and potentially facilitate earlier intervention to slow or prevent cognitive decline.

Pulse rate variability: An alternative to heart rate variability in adults with spinal cord injury.

Pulse rate variability (PRV) is often used as an alternative to heart rate variability (HRV) to measure psychophysiological function. However, its validity to do so is unclear, especially in adults with spinal cord injury (SCI). This study compared PRV and HRV in adults with higher-level SCI (SCI-H, n = 23), lower-level SCI (SCI-L, n = 22), and able-bodied participants (AB n = 44), in a seated position as a function of performance in a reactivity task (Oxford Sleep Resistance Test: OSLER). PRV and HRV was measured using reflective finger-based photoplethysmography (PPG) and electrocardiography, respectively, at baseline, immediately post-OSLER, and after five-minute recovery. Agreement between PRV and HRV was determined by Bland-Altman analysis and differences between PRV and HRV over time by linear mixed effects model (LMM) analysis. Concurrent validity was assessed through correlation analyses between PRV and HRV. Additional correlation analyses were performed with psychosocial factors. Results indicated insufficient to moderate agreement between PRV and HRV. LMM analyses indicated no differences over time for standard deviation of normal-to-normal intervals and low-frequency power but significant differences for root mean square of successive differences and high frequency power. Nevertheless, PRV and HRV were highly correlated (Median r = .878 (.675-.990)) during all assessment periods suggesting sufficient concurrent validity. Similar correlation patterns were also found for PRV and HRV with psychosocial outcomes. While differences existed, results suggest PRV derived from reflective finger-based PPG is a valid proxy of HRV in tracking psychophysiological function in adults with SCI and could therefore be used as a more accessible monitoring tool.

A Narrative Review of Research on Adjustment to Spinal Cord Injury and Mental Health: Gaps, Future Directions, and Practice Recommendations.

Spinal cord injury (SCI) results in autonomic, motor, and sensory impairments that can compromise mental health. Guidelines directing the management of mental health following SCI presently address clinical anxiety, depression, post-traumatic stress, substance use disorders, and suicide. However, evidence suggests that perhaps as many as 70% of individuals with SCI do not develop a clinically diagnosable mental health disorder. Therefore, the authors contend that understanding non-clinical cognitive and psychological aspects of adjustment post-SCI is paramount and that the application of this knowledge to the formulation of adjustment-enhancing interventions is crucial. To assist with this endeavour, we examine existing mental health guidelines targeting SCI, and present a narrative review of research on the under-represented topics of adjustment, coping, grief, and resilience. We include mild cognitive impairment, which reflects a common factor that can compromise adjustment. Loss and stress trigger processes of adjustment, coping, grief, and resilience. SCI involves loss and stress triggering these processes, arguably without exception. Our study applied a narrative review methodology searching Google Scholar and PsychInfo databases for terms adjustment, coping, grief, resilience, and cognitive impairment. Qualitative studies and quantitative studies were selected to capture bottom-up and top-down perspectives. Reference lists of retrieved papers were searched as appropriate. Reviewed literature suggested that existing guidelines concerning mental health following SCI neglect positive processes of adjustment and suggest this neglect contributes to a deficits-based view of mental health following SCI. Research into "positive" or adjustment-enhancing processes is mostly cross-sectional, heterogenous, and poorly positioned to inform future guideline-development. Researchers should achieve consensus over the operationalisation of essential processes and overcome a fixation with "outcomes" to better inform management of mental health after SCI.

Cognitive Impairment in Individuals With Spinal Cord Injury: Findings of a Systematic Review With Robust Variance and Network Meta-analyses.

BACKGROUND AND OBJECTIVES: Estimates of the prevalence (10-60%) of cognitive impairment in individuals with spinal cord injury (SCI) are too broad and which domains of cognition are most affected is unclear. We performed a meta-analysis to investigate impairments across domains of cognitive functioning to provide a nuanced picture of research conducted to date into cognitive impairment following SCI. METHODS: Results of peer reviewed studies published in English between 1980 and 2021 comparing ≥20 participants with SCI to able-bodied controls were synthesized using meta-analysis. The primary outcomes were neurocognitive test scores categorized into five cognitive domains as listed in the Diagnostic and Statistical Manual of Mental Disorders: Complex Attention, Executive Functioning, Learning and Memory, Language, and Perceptual Motor Function. Two researchers independently assessed and verified extracted data to comply with meta-analytic reporting guidelines. Robust variance estimation (RVE) meta-analysis was conducted to determine an overall pooled effect size across all cognitive domains using data extracted from studies. Using network meta-analysis, we synthesised eligible studies and made comparisons with the five domains of cognitive functioning serving as the outcomes and SCI as the condition. RESULTS: Of 4,783 potential studies, 13 met final inclusion criteria. Studies met 6 of 8 quality assessment criteria generally. Results suggested that adults with SCI have reduced cognitive functioning (effect size:-0.84; 95%CI: -1.24, -0.44, p < .001) compared to able-bodied individuals, with deficits mostly in attention (g= -0.64; 95%CI: -0.92, -0.38) and executive functioning (g= -0.61, 95%CI: -0.89, -0.04). Publication bias and high heterogeneity (I2:86%) qualify these findings and highlight the need to improve research methods in this area. DISCUSSION: Adults with SCI appear more likely than adults who are able-bodied to display cognitive impairments mostly in areas of attention and executive functioning. Research practices must become consistent to reduce heterogeneity so that the validity and reliability of the results of future studies into cognitive impairment following SCI improves.

Investigating Dynamics of the Spinal Cord Injury Adjustment Model: Mediation Model Analysis.

Spinal cord injury (SCI) is a severe neurological injury that results in damage to multiple bodily systems. SCI rehabilitation requires a significant focus on improving adjustment to the injury. This paper presents a detailed description of the Spinal Cord Injury Adjustment Model (SCIAM), which clarifies how individuals adjust to SCI and contends that adjustment to SCI is a multifactorial process involving non-linear dynamic adaptation over time. Evidence supporting SCIAM is also discussed. Mediation analyses were conducted to test the mediator dynamics proposed by the model. The analyses tested the relationship between two moderators (self-care and secondary health conditions), mediators (two self-efficacy items and appraisal of quality of life or QoL), and positive versus negative vitality/mental health as outcomes. Results showed that higher self-efficacy and perceived QoL was related to greater independence in self-care and reduced negative impacts of secondary health conditions. This study supported the mediation role of self-efficacy and other appraisals such as perceived QoL in enhancing self-care and buffering the negative impact of health challenges. In conclusion, it is important to employ a holistic model such as SCIAM to conceptualise and increase understanding of the process of adjustment following a severe neurological injury such as SCI.

Factors associated with long term work incapacity following a non-catastrophic road traffic injury: analysis of a two-year prospective cohort study.

BACKGROUND: Road traffic injuries (RTIs), primarily musculoskeletal in nature, are the leading cause of unintentional injury worldwide, incurring significant individual and societal burden. Investigation of a large representative cohort is needed to validate early identifiable predictors of long-term work incapacity post-RTI. Therefore, up until two years post-RTI we aimed to: evaluate absolute occurrence of return-to-work (RTW) and occurrence by injury compensation claimant status; evaluate early factors (e.g., biopsychosocial and injury-related) that influence RTW longitudinally; and identify factors potentially modifiable with intervention (e.g., psychological distress and pain). METHODS: Prospective cohort study of 2019 adult participants, recruited within 28 days of a non-catastrophic RTI, predominantly of mild-to-moderate severity, in New South Wales, Australia. Biopsychosocial, injury, and compensation data were collected via telephone interview within one-month of injury (baseline). Work status was self-reported at baseline, 6-, 12-, and 24-months. Analyses were restricted to participants who reported paid work pre-injury (N = 1533). Type-3 global p-values were used to evaluate explanatory factors for returning to 'any' or 'full duties' paid work across factor subcategories. Modified Poisson regression modelling was used to evaluate factors associated with RTW with adjustment for potential covariates. RESULTS: Only ~ 30% of people with RTI returned to full work duties within one-month post-injury, but the majority (76.7%) resumed full duties by 6-months. A significant portion of participants were working with modified duties (~ 10%) or not working at all (~ 10%) at 6-, 12-, and 24-months. Female sex, low education, low income, physically demanding occupations, pre-injury comorbidities, and high injury severity were negatively associated with RTW. Claiming injury compensation in the fault-based scheme operating at the time, and early identified post-injury pain and psychological distress, were key factors negatively associated with RTW up until two years post-injury. CONCLUSIONS: Long-term work incapacity was observed in 20% of people following RTI. Our findings have implications that suggest review of the design of injury compensation schemes and processes, early identification of those at risk of delayed RTW using validated pain and psychological health assessment tools, and improved interventions to address risks, may facilitate sustainable RTW. TRIAL REGISTRATION: This study was registered prospectively with the Australian New Zealand Clinical Trials Registry (ACTRN12613000889752).

Health literacy and recovery following a non-catastrophic road traffic injury.

BACKGROUND: Health literacy (HL) is rarely addressed in rehabilitation research and practice but can play a substantial role in the recovery process after an injury. We aimed to identify factors associated with low HL and its relationship with 6-month health outcomes in individuals recovering from a non-catastrophic road traffic injury. METHODS: Four hundred ninety-three participants aged ≥17 years who had sustained a non-catastrophic injury in a land-transport crash, underwent a telephone-administered questionnaire. Information was obtained on socio-economic, pre-injury health and crash-related characteristics, and health outcomes (quality of life, pain related measures and psychological indices). Low HL was defined as scoring < 4 on either of the two scales of the Health Literacy Questionnaire that covered: ability to actively engage with healthcare providers ('Engagement' scale); and/or understanding health information well enough to know what to do ('Understanding' scale). RESULTS: Of the 493, 16.9 and 18.7% scored < 4 on the 'Understanding' and 'Engagement' scale (i.e. had low HL), respectively. Factors that were associated with low HL as assessed by both scales were: having pre-injury disability and psychological conditions; lodging a third-party insurance claim; experiencing overwhelming/great perceived sense of danger/death during the crash; type of road user; low levels of social satisfaction; higher pain severity; pain catastrophizing; and psychological- and trauma-related distress. Low HL (assessed by both scales) was associated with poorer recovery outcomes over 6 months. In these longitudinal analyses, the strongest association was with disability (p < 0.0001), and other significant associations were higher levels of catastrophizing (p = 0.01), pain severity (p = 0.04), psychological- (p ≤ 0.02) and trauma-related distress (p = 0.003), lower quality of life (p ≤ 0.03) and physical functioning (p ≤ 0.01). CONCLUSIONS: A wide spectrum of factors including claim status, pre-injury and psychological measures were associated with low HL in injured individuals. Our findings suggest that targeting low HL could help improve recovery outcomes after non-catastrophic injury.

The Need for a Specialized Neurocognitive Screen and Consistent Cognitive Impairment Criteria in Spinal Cord Injury: Analysis of the Suitability of the Neuropsychiatry Unit Cognitive Assessment Tool.

The assessment of mild cognitive impairment (MCI) following spinal cord injury (SCI) is vital. However, there are no neurocognitive screens which have been developed specifically to meet the unique requirements for SCI, nor are there consistent MCI criteria applied to determine the rates of MCI. The aim of this study was to determine the suitability of a neurocognitive screen for assessing MCI in adults with SCI. A total of 127 participants were recruited. Socio-demographic and injury related variables were assessed. All participants completed the screen. Descriptive statistics are provided for total/domain screen scores and all items, and the screen's ability to distinguish MCI was examined. Congeneric confirmatory factor analyses (CFA) were employed to investigate structural validity. The screen total score was sensitive to differences in neurocognitive capacity, as well as for time since the injury occurred (p < 0.01). The MCI rate ranged between 17−36%. CFA revealed attention and visuoconstruction domains had an adequate model fit and executive function had poor fit, while CFA models for memory and language did not fit the data (did not converge), hence could not be determined. While the screen differentiated between those with MCI and those without, and MCI as a function of time since injury, limitations of its suitability for assessing MCI after SCI exist, demonstrating the need for a specialized neurocognitive screen for adults with SCI.

Improving Assessment of Cognitive Impairment after Spinal Cord Injury: Methods to Reduce the Risk of Reporting False Positives.

Adults with spinal cord injury (SCI) are reported to have heightened risk of cognitive impairment, notably mild cognitive impairment (MCI). Reports of increased risk of MCI are almost exclusively based on cross-sectional assessments of cognitive function using norm-referenced scores. Norm-referenced single-point assessments do not reflect cognitive decline at the individual level but rather represent between group differences in cognitive function. The practice of relying solely on norm-referenced assessment to study MCI after SCI is therefore problematic as it lends to potential misclassification of MCI. Premorbid intelligence estimates permit comparison of people's actual versus expected cognitive function and thereby can be used to validate the presence of genuine cognitive decline. These are not utilized in the assessment of MCI after SCI. This study simulated data for 500,000 adults with SCI to compare norm-referenced and premorbid-intelligence methods of screening for MCI to examine the potential extent of MCI misclassification after SCI resulting from the overreliance on norm-referenced methods and exclusion of premorbid intelligence methods. One in five to one in 13 simulated adults with SCI were potentially misclassified as having MCI showing that measures of premorbid cognitive function must be included in assessment of cognitive function after SCI.

A neuro-cardiac self-regulation therapy to improve autonomic and neural function after SCI: a randomized controlled trial protocol.

BACKGROUND: Spinal cord injury (SCI) is associated with autonomic imbalance and significant secondary conditions, including cardiac and brain dysfunction that adversely impact health and wellbeing. This study will investigate the effectiveness (intention-to-treat) of a neuro-cardiac self-regulation therapy to improve autonomic and neural/brain activity in adults with SCI living in the community. METHODS: A two-arm parallel, randomised controlled trial in which adults with SCI living in the community post-rehabilitation will be randomly assigned to a treatment or control group. The treatment group (N = 60) aged 18-70 years with a chronic traumatic or non-traumatic SCI, will receive intervention sessions once per week for 10 weeks, designed to regulate autonomic activity using computer-based feedback of heart rate variability and controlled breathing (called HRV-F). Comprehensive neurophysiological and psychological assessment will occur at baseline, immediate post-treatment, and 6 and 12-months post-treatment. Primary outcome measures include electrocardiography/heart rate variability (to assess autonomic nervous system function) and transcranial doppler sonography (to assess cerebral blood circulation in basal cerebral arteries). Secondary outcomes measures include continuous blood pressure, electroencephalography, functional near-infrared spectroscopy, respiration/breath rate, electrooculography, cognitive capacity, psychological status, pain, fatigue, sleep and quality of life. Controls (N = 60) will receive usual community care, reading material and a brief telephone call once per week for 10 weeks and be similarly assessed over the same time period as the HRV-F group. Linear mixed model analysis with repeated measures will determine effectiveness of HRV-F and latent class mixture modelling used to determine trajectories for primary and selected secondary outcomes of interest. DISCUSSION: Treatments for improving autonomic function after SCI are limited. It is therefore important to establish whether a neuro-cardiac self-regulation therapy can result in improved autonomic functioning post-SCI, as well as whether HRV-F is associated with better outcomes for secondary conditions such as cardiovascular health, cognitive capacity and mental health. TRIAL REGISTRATION: The study has been prospectively registered with the Australian and New Zealand Clinical Trial Registry ( ACTRN12621000870853 .aspx). Date of Registration: 6th July 2021. Trial Sponsor: The University of Sydney, NSW 2006. Protocol version: 22/07/2021.

The contribution of pre-injury vulnerability to risk of psychiatric morbidity in adults injured in a road traffic crash: Comparisons with non-injury controls.

People who sustain injury in a road traffic crash (RTC) have significant risk of psychiatric morbidity, but effective screening for identifying at-risk individuals soon after the RTC is lacking. We investigated whether pre-injury vulnerability can assist as an early screen to manage this risk. We recruited 120 adults who sustained physical injury in a RTC and admitted to an emergency department (ED). They were comprehensively assessed for acute and long-term presence of psychiatric disorder/morbidity and disability over 12-months after the injury, with comparisons to a non-injury control. Propensity matching based on six pre-injury vulnerability factors (age, sex, education, socioeconomic status, prior mental health, prior physical health) with the control group was used to determine membership of high vulnerability (HV) and low vulnerability (LV) injury sub-groups. Compared to the LV sub-group and controls that had similar pre-injury vulnerability, the HV sub-group had a worrying post-RTC recovery profile, with significantly higher rates of long-term psychiatric morbidity (42.2% vs. 23.1% and 15.9% respectively, p = .002) including post-traumatic stress disorder and/or depression, and poorer psychological adjustment over the 12-months. In contrast, the HV and LV sub-groups were similar in injury-related characteristics and post-injury physical (pain, fatigue, physical functioning) and participation outcomes. Findings provide preliminary evidence that pre-injury vulnerability, primarily prior mental health status, is a promising screen for early identification of people at risk of psychiatric morbidity post-RTC. It is suggested this screen could be implemented in ED to prevent chronicity and improve recovery following a traumatic injury. Further research is warranted to enhance the screen's effectiveness.

The role of stress reactivity and pre-injury psychosocial vulnerability to psychological and physical health immediately after traumatic injury.

BACKGROUND: Traumatic injuries can have long-term negative impacts on health, especially psychological health. A biopsychosocial approach is recommended to identify those likely to experience psychosocial stress, however large individual differences exist in stress reactivity and post-injury health that remain unexplored. Therefore, we investigated autonomic nervous system (ANS) stress responses and pre-existing psychosocial vulnerability as contributors to health in individuals who sustained a traffic-related injury. METHODS: 120 adults with traffic-related injury and 112 non-injury controls underwent an integrative ANS (cardiac and skin conductance) assessment and a health-related assessment at 3-6 weeks post-injury. Propensity score matching based on six pre-injury psychosocial vulnerability factors (age, sex, education, prior mental/physical health, socioeconomic status) guided the definition of high vulnerability (HV) and low vulnerability (LV) injury subgroups, with the LV subgroup having similar propensity scores to non-injury controls. A three-group comparative analysis of ANS responsivity (baseline, reactivity, recovery/rebound) and post-injury health was performed. RESULTS: The HV subgroup exhibited the most negative immediate post-injury mental health profile and less adaptive ANS response patterns, indicating greater stress vulnerability/reactivity. Significant differences were found for psychological health (elevated psychological distress and catastrophizing), but not physical health (injury factors, pain, fatigue, physical wellbeing). HV participants showed sympathetic predominance at resting baseline (lower parasympathetic activity and/or elevated heart rate) compared to the LV and control groups, as well as smaller parasympathetic decrease during a cognitive task compared to controls. Despite preserved capacity for restoring initial homeostasis in both injury subgroups during recovery, there was some indication of blunted post-task sympathetic deactivation (larger sympathetic decrease) and reduced overall ANS adaptability (reduction in total power of heart rate variability spectrum), suggesting relative reduced capacity to face stressors compared to controls. CONCLUSIONS: Findings suggest that baseline resting ANS regulation, particularly parasympathetic activity, and pre-injury psychosocial factors are key contributors to individual psycho-biological responses following traumatic injury, and are therefore potential stress vulnerability markers. Post-stress recovery patterns may represent a novel physiological signature for a "biological intrinsic" vulnerability early after the injury. These findings provide direction for improved early identification and management of injured individuals, including innovative preventive interventions that target ANS regulation.

Twelve-month health outcomes for bicyclists and car occupants after a non-catastrophic traffic crash injury.

OBJECTIVE: In this inception cohort study, we investigated differences in health outcomes for bicyclists (cyclists) and car occupants (car driver and passengers) at 12months after a non-catastrophic traffic injury. We also aimed to determine the independent predictors of key health outcomes among cyclists. METHODS: Of the 2019 participants at baseline, 299 were cyclists and 927 were car occupants; 229 cyclists and 489 car occupants were followed up 12months after the injury. A telephone-administered questionnaire was used to obtain information on socio-economic, pre-injury health and injury-related characteristics. The survey also included tools on health outcomes: quality of life (SF-36 and EQ-5D-3L scales), pain severity, general psychological distress, trauma-related distress and pain catastrophizing. RESULTS: After adjusting for all potential confounders, general psychological distress scores and trauma-related distress scores were 2.05 and 0.60 units lower for cyclists than car occupants (P=0.01 and P<0.0001, respectively) at 12-month follow-up. Cyclists showed greater improvement than car occupants over 12months in mean pain severity ratings and SF-12 physical component summary (PCS) score (both P<0.0001) but had lower mean pain severity and similar PCS scores at baseline. However, cyclists showed less improvement in SF-12 mental component summary (MCS) scores (P=0.03) than car occupants but had higher mean MCS scores at baseline. Pre-injury and baseline quality-of-life scores and pain catastrophizing as well as injury involving the head or face were significant predictors of overall psychological functioning, general psychological distress and trauma-related distress in cyclists at 12months. CONCLUSIONS: Cyclists demonstrated better recovery than car occupants at 12months after sustaining a traffic crash injury. Prognostic indicators of long-term physical functioning and psychological well-being in cyclists were related to pre-injury and baseline quality of life and pain factors and injury location.

A prospective cohort study investigating contributors to mild cognitive impairment in adults with spinal cord injury: study protocol.

BACKGROUND: Studies report rates of mild cognitive impairment (MCI) in spinal cord injury (SCI) range between 10 and 60%. This broad estimate of MCI in SCI is most likely a result of: (i) inconsistent operationalization of MCI; (ii) heterogeneity among individuals with SCI; (iii) failure to account for MCI subtypes, thereby adding to the heterogeneity of samples; and, (iv) poor control for traumatic brain injury (TBI) that obscures differentiation of MCI attributable to TBI versus other factors. There is a paucity of longitudinal studies following the course of MCI in SCI, and none that account for multiple predictors of MCI, including interactions among predictors. METHODS: An inception cohort longitudinal study will assess approximately 100 individuals aged 17-80 years with acute SCI, with measures taken at three timepoints (baseline, 3 months post-baseline, and 12 months post-injury). Data relevant to medical care received within the first 24-48 h of presentation to the emergency department will be analysed, as will measures of cognition, injury characteristics, medical history, personal factors, psychological status, psychosocial functioning, and quality of life. Latent class mixture modelling will determine trajectories for the primary outcome of interest, cognitive functioning and its subtypes, and secondary outcomes of interest such as depression. Multiple regression analyses will identify predictors of MCI and its subtypes. DISCUSSION: The prospective design will reveal change in cognitive functioning across time and unveil different outcome trajectories; thus addressing the lack of knowledge on trajectories of MCI and MCI subtypes in SCI. Through subtyping MCI, we hope to yield groups of cognitively impaired individuals with SCI that are potentially more homogenous and thereby stable and predictable. This is the first study to capture emergency department and acute care diagnostic evidence of mild TBI, which has been poorly controlled in previous studies. Our study will also be the first to distinguish the contribution of TBI from other factors to the development of MCI in individuals with SCI. TRIAL REGISTRATION: The study was prospectively registered with the Australian and New Zealand Clinical Trial Registry ( ACTRN12619001702101 ) on 3rd December 2019.

Challenges in the acute identification of mild traumatic brain injuries: results from an emergency department surveillance study.

OBJECTIVES: To establish the proportion of mild traumatic brain injury (mTBI) diagnosis among people presenting to an emergency department (ED), to determine the accuracy of recorded ED diagnoses. We also aimed to describe challenges in mTBI case identification and its acute hospital management. DESIGN AND SETTING: A retrospective chart review of all ED attendances to a major trauma hospital, over a 9-month period (June 2015-February 2016). PARTICIPANTS: Adults aged 18-65 years consecutively presenting to an ED. PRIMARY OUTCOME MEASURES: Proportion of mTBI diagnosis among ED attendances (ie, confirmed mTBI based on the WHO criteria or indeterminate mTBI based on secondary criteria), and proportion of accurately recorded mTBI diagnosis by ED clinicians (ie, 'mTBI', 'concussion'). RESULTS: Of 30 479 ED attendances, 351 (1.15%) confirmed mTBI diagnosis and 180 (0.6%) indeterminate diagnosis were identified. Only 81 (23.1%) individuals with a confirmed mTBI had a 'mTBI diagnosis' clearly recorded in the medical notes. Of the allocated discharge diagnosis codes to the two identified cohorts, 89.8% were not indicative of mTBI. Intracranial injuries were found in 31 (8.5%) confirmed cases. Glasgow Coma Scale scores were consistently assessed in the ED but identified only 117 (33.3%) confirmed mTBI cases. Post-traumatic amnesia (PTA) testing was able to confirm acute cognitive impairment in 113 (62.1%) of those who were tested (182, 51.3%). CONCLUSIONS: mTBI is a common, but an under-recognised cause for ED attendance. Despite challenges, the use of an operational definition such as the WHO diagnostic criteria can improve accuracy in mTBI identification. Acute management may be enhanced by rapid assessment of PTA.

Biomarkers of autonomic regulation for predicting psychological distress and functional recovery following road traffic injuries: protocol for a prospective cohort study.

INTRODUCTION: Psychological distress is a prevalent condition often overlooked following a motor vehicle crash (MVC), particularly when injuries are not severe. The aim of this study is to examine whether biomarkers of autonomic regulation alone or in combination with other factors assessed shortly after MVC could predict risk of elevated psychological distress and poor functional recovery in the long term, and clarify links between mental and physical health consequences of traffic injury. METHODS AND ANALYSIS: This is a controlled longitudinal cohort study, with follow-up occurring at 3, 6 and 12 months. Participants include up to 120 mild to moderately injured MVC survivors who consecutively present to the emergency departments of two hospitals in Sydney and who agree to participate, and a group of up to 120 non-MVC controls, recruited with matched demographic characteristics, for comparison. WHO International Classification of Functioning is used as the framework for study assessment. The primary outcomes are the development of psychological distress (depressive mood and anxiety, post-traumatic stress symptoms, driving phobia, adjustment disorder) and biomarkers of autonomic regulation. Secondary outcomes include indicators of physical health (presence of pain/fatigue, physical functioning) and functional recovery (quality of life, return to function, participation) as well as measures of emotional and cognitive functioning. For each outcome, risk will be described by the frequency of occurrence over the 12 months, and pathways determined via latent class mixture growth modelling. Regression models will be used to identify best predictors/biomarkers and to study associations between mental and physical health. ETHICS AND DISSEMINATION: Ethical approvals were obtained from the Sydney Local Health District and the research sites Ethics Committees. Study findings will be disseminated to health professionals, related policy makers and the community through peer-reviewed journals, conference presentations and health forums. TRIAL REGISTRATION NUMBER: ACTRN12616001445460.