Heart rate variability (HRV) after traumatic brain injury (TBI): a scoping review.

BACKGROUND: Heart rate variability (HRV), defined as the variability between successive heart beats, is a noninvasive measure of autonomic nervous system (ANS) function, which may be altered following traumatic brain injury (TBI). This scoping review summarizes the existing literature regarding changes in HRV after TBI as well as the association between measures of HRV and outcomes following TBI. METHODS: A literature search for articles assessing 'heart rate variability' and 'brain injury' or 'concussion' was completed. Articles were included if HRV was measured in human subjects with TBI or concussion. Review articles, protocol papers, and studies including non-traumatic injuries were excluded. RESULTS: Sixty-three articles were included in this review. Varied methods were used to measure HRV in the different studies. Forty articles included information about differences in HRV measures after TBI and/or longitudinal changes after TBI. Fifteen studies assessed HRV and symptoms following TBI, and 15 studies assessed HRV and either functional or cognitive outcomes after TBI. CONCLUSIONS: HRV has been studied in the context of mortality, clinical symptoms, and medical, functional, or cognitive outcomes following TBI. Methods used to measure HRV have varied amongst the different studies, which may impact findings, standardized protocols are needed for future research.

10-year variability in high and low life satisfaction trajectories post-traumatic brain injury: a TBI model systems study.

PURPOSE: To determine how life satisfaction changes across the first 10 years following traumatic brain injury (TBI). METHODS: Participants included 1,941 individuals from the TBI Model Systems database with life satisfaction data at 1-, 5-, and 10-years post-TBI. Based on Satisfaction With Life Scale scores, individuals were characterized as having one of the five 10-year life satisfaction trajectories: 'Stable High,' 'Stable Low,' 'Increased to High,' 'Decreased to Low,' and 'Unstable.' These were analyzed for group differences in demographics and psychosocial and functional outcomes. RESULTS: Sixty percent participants had 'Stable High' or 'Increasing to High' trajectories. Approximately 25% had "Stable Low' or 'Decreasing to Low' trajectories, and approximately 15% had unstable trajectories. Higher life satisfaction trajectories were associated with the best psychosocial and functional outcomes whereas lower trajectories were associated with the worst psychosocial and functional outcomes. Trajectories were indistinguishable based on demographics. CONCLUSION: Life satisfaction over the first 10 years following TBI is dynamic, with most individuals reporting high life satisfaction by 10 years post-TBI. Examination of psychosocial and functional factors related to life satisfaction trajectories may inform community-based intervention recommendations, resources, and supports to maximize long-term satisfaction with life.

Rehabilitation Treatment Specification System: Identifying Barriers, Facilitators, and Strategies for Implementation in Research, Education, and Clinical Care.

OBJECTIVE: To explore rehabilitation professionals' experiences and perspectives of barriers and facilitators to implementing the Rehabilitation Treatment Specification System (RTSS) in research, education, and clinical care. DESIGN: A cross-sectional survey with free text and binary responses was completed by rehabilitation professionals. Survey data were analyzed with a deductive approach of directed content analysis using 2 implementation science frameworks: Consolidated Framework for Implementation Research (CFIR) and the Expert Recommendations for Implementing Change (ERIC). SETTING: Rehabilitation professionals across research, educational, and clinical settings. PARTICIPANTS: One hundred and eleven rehabilitation professionals-including speech-language pathologists, occupational therapists, physical therapists, physicians, psychologists, researchers, and clinic directors-who explored possible uses or applications of the RTSS for clinical care, education, or research (N=111). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Frequency of reported CFIR barriers and facilitators, as well as keywords related to CFIR and ERIC constructs. RESULTS: The barriers and facilitating strategies differed according to the end-users' intended use, that is, research, education, or clinical. Overall, the 4 most frequently encountered CFIR barriers were the RTSS's complexity, a lack of available RTSS resources, reduced access to knowledge and information about the RTSS, and limited knowledge and beliefs about the RTSS. The ERIC-CFIR matching tool identified 7 ERIC strategies to address these barriers, which include conducting educational meetings, developing and distributing educational materials, accessing new funding, capturing and sharing local knowledge, identifying and preparing champions, and promoting adaptability. CONCLUSIONS: When attempting to use the RTSS, rehabilitation professionals commonly encountered barriers to understanding and skillfully using the framework. Theory-driven implementation strategies have been identified that have potential for addressing the RTSS's complexity and lack of educational and skill-building resources. Future work can develop the identified implementation strategies and evaluate their effects on RTSS implementation.

Societal Participation of People With Traumatic Brain Injury Before and During the COVID-19 Pandemic: A NIDILRR Traumatic Brain Injury Model Systems Study.

OBJECTIVE: To examine the effect of the COVID-19 pandemic on societal participation in people with moderate-to-severe traumatic brain injury (TBI). DESIGN: Cross-sectional retrospective cohort. SETTING: National TBI Model Systems centers, United States. PARTICIPANTS: TBI Model Systems enrollees (N=7003), ages 16 and older and 1-30 years postinjury, interviewed either prepandemic (PP) or during the pandemic (DP). The sample was primarily male (72.4%) and White (69.5%), with motor vehicle collisions as the most common cause of injury (55.1%). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The 3 subscales of the Participation Assessment with Recombined Tools-Objective: Out and About (community involvement), Productivity, and Social Relations. RESULTS: Out and About, but not Productivity or Social Relations, scores were appreciably lower among DP participants compared to PP participants (medium effect). Demographic and clinical characteristics showed similar patterns of association with participation domains across PP and DP. When their unique contributions were examined in regression models, age, self-identified race, education level, employment status, marital status, income level, disability severity, and life satisfaction were variably predictive of participation domains, though most effects were small or medium in size. Depression and anxiety symptom severities each showed small zero-order correlations with participation domains across PP and DP but had negligible effects in regression analyses. CONCLUSIONS: Consistent with the effect of COVID-19 on participation levels in the general population, people with TBI reported less community involvement during the pandemic, potentially compounding existing postinjury challenges to societal integration. The pandemic does not appear to have altered patterns of association between demographic/clinical characteristics and participation. Assessing and addressing barriers to community involvement should be a priority for TBI treatment providers. Longitudinal studies of TBI that consider pandemic-related effects on participation and other societally linked outcomes will help to elucidate the potential longer-term effect the pandemic has on behavioral health in this population.

Early Factors Predictive of Extreme High and Low Life Satisfaction 10 Years Post-Moderate to Severe Traumatic Brain Injury.

OBJECTIVE: To identify demographic, injury-related, and 1-year postinjury clinical and functional predictors of high and low life satisfaction at 10 years after moderate to severe traumatic brain injury (TBI) using an extreme phenotyping approach. SETTING: Multicenter longitudinal database study. PARTICIPANTS: A total of 3040 people from the National Institute on Disability, Independent Living, and Rehabilitation Research TBI Model Systems database with life satisfaction data at 10 years post-TBI. DESIGN: Multicenter, cross-sectional, observational design. MAIN MEASURES: Satisfaction With Life Scale (outcome), Glasgow Coma Scale, Disability Rating Scale, Functional Independence Measure, Participation Assessment with Recombined Tools-Objective, Patient Health Questionnaire-9, and General Anxiety Disorder-7 (standardized predictors). RESULTS: Greater cognitive and motor independence, more frequent community participation, and less depressive symptoms 1 year post-moderate to severe TBI predicted extreme high life satisfaction 10 years later. Non-Hispanic White and Hispanic individuals were significantly more likely than Black individuals to have extreme high life satisfaction 10 years post-TBI. CONCLUSIONS: Extreme phenotyping analysis complements existing knowledge regarding life satisfaction post-moderate to severe TBI. From a chronic disease management perspective, future studies are needed to examine the feasibility and impact of early postinjury medical and rehabilitative interventions targeting cognitive and motor function, community participation, and mood on the maintenance/enhancement of long-term life satisfaction post-TBI.

Predictors of High School and College Graduation After Sustaining a Moderate-to-Severe Traumatic Brain Injury.

OBJECTIVE: To identify early predictors of US high school and college graduation after moderate-to-severe traumatic brain injury (TBI). SETTING: Inpatient rehabilitation and community. PARTICIPANTS: TBI Model Systems participants, aged 16 to 24 years, enrolled as high school or college students at time of injury. DESIGN: Prospective cohort study. MAIN MEASURES: Successful graduation was defined as having a diploma (high school) or an associate/bachelor's degree (college) at 1-, 2-, or 5-year follow-up. Predictors were sex, race/ethnicity, urbanicity, preinjury substance abuse, primary rehabilitation payer, and functional independence at inpatient rehabilitation discharge. METHOD: We descriptively characterized differences between those who did and did not graduate high school and college within the first 5 years postinjury and identified early predictors of successful high school and college graduation using 2 binomial logistic regressions. RESULTS: Of those with known graduation status, 81.2% of high school and 41.8% of college students successfully graduated. Graduates in both groups were more often White than Black and had more functional independence at discharge. Among high school students, preinjury substance abuse was also a risk factor for not graduating, as was identifying as Hispanic or "other" race. CONCLUSIONS: Sociodemographic factors and disability influence graduation outcomes, requiring structural, institutional, and personal interventions for success.

Factors Associated With High and Low Life Satisfaction 10 Years After Traumatic Brain Injury.

OBJECTIVE: To identify correlates of life satisfaction at 10 years after moderate to severe traumatic brain injury (TBI) using an extreme phenotyping approach. DESIGN: Effect sizes were calculated in this observational cohort study to estimate relationships of 10-year postinjury extremely high, extremely low, and moderate life satisfaction with (1) pre-injury demographics, injury-related factors, and functional characteristics at inpatient rehabilitation admission and discharge; and (2) postinjury demographics and clinical and functional measures at 10 years postinjury. SETTING: Multicenter longitudinal database study. PARTICIPANTS: People identified from the National Institute on Disability, Independent Living, and Rehabilitation Research TBI Database with life satisfaction data at 10 years post TBI (N=4800). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Satisfaction With Life Scale. RESULTS: Although few pre-injury factors or clinical and functional factors shortly after injury were associated with 10-year life satisfaction groups, the following 10-year postinjury factors were associated with extremely high vs extremely low life satisfaction group membership: greater independent functioning, less disability, more frequent community participation, being employed, and having fewer depressive and anxiety symptoms. Those with extremely high life satisfaction were distinctly different from those with moderate and extremely low satisfaction. Extremely high life satisfaction was underrepresented among non-Hispanic Black persons relative to non-Hispanic White persons. Relationships between life satisfaction and independent functioning, disability, and participation were attenuated among non-Hispanic Black persons. CONCLUSIONS: Extreme phenotyping analysis complements existing knowledge regarding life satisfaction after moderate to severe TBI and may inform acute and postacute clinical service delivery by comparing extremely high and extremely low life satisfaction subgroups. Findings suggest little association among personal, clinical, and functional characteristics early post TBI and life satisfaction 10 years later. Contemporaneous correlates of extremely high life satisfaction exist at 10 years post TBI, although the positive relationship of these variables to life satisfaction may be attenuated for non-Hispanic Black persons.

Effect of Preexisting and Co-Occurring Comorbid Conditions on Recovery in the 5 Years After Rehabilitation for Traumatic Brain Injury.

OBJECTIVE: To determine the relationship between comorbid health conditions and the trajectory of functional recovery 5 years following traumatic brain injury (TBI) rehabilitation. SETTING: Two acute rehabilitation facilities. PARTICIPANTS: A total of 407 patients with primary diagnosis of TBI. DESIGN: Prospective, observational. MAIN MEASURES: Functional Independence Measure Cognitive and Motor scores. RESULTS: Female gender was negatively associated with the trajectory of motor recovery (P < .001). TBI severity was negatively associated with both motor and cognitive recovery and interacted with time after injury (both Ps < .0001). Hypertension was negatively associated with both motor (P < .0001) and cognitive (P = .0121) recovery, although this relationship diminished over time for motor function (P = .0447). Cardiac conditions were negatively associated with motor recovery (P = .0204), and rate of cognitive recovery was more rapid for patients with cardiac conditions (P = .0088). Depressed patients recovered cognitive function more quickly than those who were not depressed (P = .0196). Diabetes was negatively associated with motor function (P = .0088). Drug/alcohol use was positively associated with motor function (P = .0036). CONCLUSIONS: Injury severity remains an important predictor of long-term recovery; however, certain comorbid medical conditions are negatively associated with functional abilities over the first 5 years after injury. Patients being discharged from TBI rehabilitation with comorbid cardiac, hypertensive, diabetic, and/or depressive conditions may benefit from early and ongoing clinical surveillance.

Prevalence of Cardiovascular Conditions After Traumatic Brain Injury: A Comparison Between the Traumatic Brain Injury Model Systems and the National Health and Nutrition Examination Survey.

BACKGROUND: The purpose of this study is to compare the prevalence of self-reported cardiovascular conditions among individuals with moderate to severe traumatic brain injury (TBI) to a propensity-matched control cohort. METHODS AND RESULTS: A cross-sectional study described self-reported cardiovascular conditions (hypertension, congestive heart failure [CHF], myocardial infarction [MI], and stroke) from participants who completed interviews between January 2015 and March 2020 in 2 harmonized large cohort studies, the TBI Model Systems and the National Health and Nutrition Examination Survey. Mixed-effect logistic regression models were used to compare the prevalence of cardiovascular conditions after 1:1 propensity-score matching based on age, sex, race, ethnicity, body mass index, education level, and smoking status. The final sample was 4690 matched pairs. Individuals with TBI were more likely to report hypertension (odds ratio [OR], 1.18 [95% CI, 1.08-1.28]) and stroke (OR, 1.70 [95% CI, 1.56-1.98]) but less likely to report CHF (OR, 0.81 [95% CI, 0.67-0.99]) or MI (OR, 0.66 [95% CI, 0.55-0.79]). There was no difference in rate of CHF or MI for those ≤50 years old; however, rates of CHF and MI were lower in the TBI group for individuals >50 years old. Over 65% of individuals who died before the first follow-up interview at 1 year post-TBI were >50 years old, and those >50 years old were more likely to die of heart disease than those ≤50 years old (17.6% versus 8.6%). CONCLUSIONS: Individuals with moderate to severe TBI had an increased rate of self-reported hypertension and stroke but lower rate of MI and CHF than uninjured adults, which may be due to survival bias.

Prevalence of Self-Reported COVID-19 Infection in Persons with Complicated Mild to Severe Traumatic Brain Injury (TBI): A TBI Model Systems Study.

OBJECTIVE: To describe the incidence of self-reported COVID-19 history in a longitudinal cohort of individuals with complicated mild to severe traumatic brain injury (TBI) and describe demographic, injury and functional differences based on history of COVID-19 infection. DESIGN: Individuals with complicated mild to severe TBI aged 16 or older at time of injury who were enrolled in the TBI Model Systems longitudinal cohort study, completed a baseline or follow-up interview between October 1, 2021-March 31, 2023, and provided information about COVID-19 history and timing of COVID-19 infection was collected. RESULTS: Of the 3,627 individuals included in the analysis, 29.5% reported a history of COVID-19 infection. Those with reported COVID-19 history tended to be younger, not of a racial/ethnic minority background, and greater functional status at follow up based on the Glasgow Outcome Scale-Extended scale compared to those with no reported COVID-19 history (p < 0.05). Among those with COVID-19 history, 61.8% did not receive medical care, 27.6% received medical care but no hospitalization, and 10.5% were hospitalized. Of those hospitalized, 21.4% required ventilator use. CONCLUSION: Incidence of COVID-19 diagnosis and related hospitalization characteristics in persons with complicated mild to severe TBI was similar to national incidence between March 2020-2023. Secondary effects of the COVID-19 pandemic on persons with TBI require investigation.

Hyperbaric Oxygen Therapy versus placebo for post-concussion syndrome (HOT-POCS): A randomized, double-blinded controlled pilot study.

Post-Concussion Syndrome (PCS) refers to the persistence of physical, cognitive, and emotional symptoms following mild traumatic brain injury (mTBI)/concussion, occurring in roughly 15-30% of individuals. Hyperbaric oxygen therapy (HBOT) has been suggested as a potential treatment for PCS; however, the evidence to date is mixed due to inconsistencies in the treatment protocol and focus on veterans with combat-related injuries, which may not be generalizable to the general population. The goal of Hyperbaric Oxygen Therapy for Post-Concussion Syndrome (HOT-POCS) is to assess the efficacy and safety of HBOT for the treatment of PCS in the civilian population. This randomized, controlled pilot study will be using a standardized HBOT protocol (20 sessions of 100% O2 at 2.0 atm absolute [ATA]) compared with a true placebo gas system that mimics the oxygen composition at room air (20 sessions of 10.5% O2 and 89.5% nitrogen at 2.0 ATA) in a cohort of 100 adults with persistent post-concussive symptoms 3-12 months following injury. Change in symptoms on the Rivermead Post-concussion Questionnaire (RPQ) will be the primary outcome of interest. Secondary outcomes include the rate of adverse events, change in the quality of life, and change in cognitive function. Exploratory outcome measures will include changes in physical function and changes in cerebral brain perfusion and oxygen metabolism on MRI brain imaging. Overall, the HOT-POCS study will compare the efficacy of a standardized HBOT treatment protocol against a true placebo gas for the treatment of PCS within 12 months after injury.

Associations between early sleep-disordered breathing following moderate-to-severe traumatic brain injury and long-term chronic pain status: a Traumatic Brain Injury Model Systems study.

STUDY OBJECTIVES: To explore the relationship between polysomnography-derived respiratory indices and chronic pain status among individuals following traumatic brain injury (TBI). METHODS: Participants (n = 66) with moderate to severe TBI underwent polysomnography during inpatient acute rehabilitation and their chronic pain status was assessed at 1- to 2-year follow-up as part of the TBI Model Systems Pain Collaborative Study. Pairwise comparisons across pain cohorts (ie, chronic pain, no history of pain) were made to explore differences on polysomnography indices. RESULTS: Among our total sample, approximately three-quarters (74.2%) received sleep apnea diagnoses utilizing American Academy of Sleep Medicine criteria, with 61.9% of those endorsing a history of chronic pain. Of those endorsing chronic pain, the average pain score was 4.8 (standard deviation = 2.1), with a mean interference score of 5.3 (2.7). Pairwise comparisons revealed that those endorsing a chronic pain experience at follow-up experienced categorically worse indicators of sleep-related breathing disorders during acute rehabilitation relative to those who did not endorse chronic pain. Important differences were observed with elevations on central (chronic pain: 2.6; no pain: 0.8 per hour) and obstructive apnea (chronic pain: 15.7; no pain: 11.1 per hour) events, as well as oxygen desaturation indices (chronic pain: 19.6; no pain: 7.9 per hour). CONCLUSIONS: Sleep-disordered breathing appears worse among those who endorse chronic pain following moderate-to-severe TBI, but additional research is needed to understand its relation to postinjury pain. Prospective investigation is necessary to determine how clinical decisions (eg, opioid therapy) and intervention (eg, positive airway pressure) may mutually influence outcomes. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Comparison of Sleep Apnea Assessment Strategies to Maximize TBI Rehabilitation Participation and Outcome (C-SAS); URL: https://clinicaltrials.gov/ct2/show/NCT03033901; Identifier: NCT03033901. CITATION: Martin AM, Pinto SM, Tang X, et al. Associations between early sleep-disordered breathing following moderate-to-severe traumatic brain injury and long-term chronic pain status: a Traumatic Brain Injury Model Systems study. J Clin Sleep Med. 2023;19(1):135-143.

Mild Traumatic Brain Injury Is Associated With Increased Dual-Task Cost During Ambulation: A Preliminary Study.

OBJECTIVE: The aim of the study was to determine the impact of dual-task conditions on mobility after mild traumatic brain injury. DESIGN: Eleven adults with mild traumatic brain injury within 1 wk of injury and 10 age- and sex-matched healthy controls completed gait trials with a single-task condition and three separate dual-task conditions: counting by 1 (low), serial subtraction by 3 (medium), and alternating letters and numbers (high). Dual-task cost was calculated as dual-task cost = ([dual-task performance] - [single-task performance]) / [single-task performance] × 100%. RESULTS: Participants with mild traumatic brain injury ambulated slower than control subjects (P < 0.001). Significant differences in dual-task cost were noted for both group (P < 0.001) and dual-task condition (P = 0.005). Dual-task cost was greater for those with mild traumatic brain injury compared with controls with significant group differences for the low and high cognitive loads (P < 0.05). Only 1 of the 11 individuals with mild traumatic brain injury and 1 of the 10 controls demonstrated gait speed less than 80 cm/sec, which is predictive of community mobility, during any dual-task condition. Dual-task cost exceeded 11.9%, previously determined to be the minimal detectable change in healthy adults, for 9 of the 11 individuals with mild traumatic brain injury compared with 3 of the 10 controls. CONCLUSIONS: Dual-task cost may be a more sensitive measure for impairment during dual-task conditions than gait speed after mild traumatic brain injury.

Rehabilitation at the Time of Pandemic: Patient Journey Recommendations.

Purpose: The World Health Organization (WHO) declared severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) a pandemic in March 2020, causing almost 3.5 million coronavirus disease (COVID-19) related deaths worldwide. The COVID-19 pandemic has imposed a significant burden on healthcare systems, economies, and social systems in many countries around the world. The access and delivery of rehabilitation care were severely disrupted, and patients have faced several challenges during the COVID-19 outbreak. These challenges include addressing new functional impairments faced by survivors of COVID-19 and infection prevention to avoid the virus spread to healthcare workers and other patients not infected with COVID-19. In this scoping review, we aim to develop rehabilitation recommendations during the COVID-19 pandemic across the continuum of rehabilitation care. Materials and Methods: Established frameworks were used to guide the scoping review methodology. Medline, Embase, Pubmed, CINAHL databases from inception to August 1, 2020, and prominent rehabilitation organizations' websites were searched. Study Selection: We included articles and reports if they were focused on rehabilitation recommendations for COVID-19 survivors or the general population at the time of the COVID-19 pandemic. Data Extraction: Two of our team members used the pre-tested data extraction form to extract data from included full-text articles. The strength and the quality of the extracted recommendations were evaluated by two reviewers using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. Results: We retrieved 6,468 citations, of which 2,086 were eligible after removing duplicates. We excluded 1,980 citations based on the title and the abstract. Of the screened full-text articles, we included 106 studies. We present recommendations based on the patient journey at the time of the pandemic. We assessed the evidence to be of overall fair quality and strong for the recommendations. Conclusion: We have combined the latest research results and accumulated expert opinions on rehabilitation to develop acute and post-acute rehabilitation recommendations in response to the global COVID-19 pandemic. Further updates are warranted in order to incorporate the emerging evidence into rehabilitation guidelines.