Functional Recovery After Severe Traumatic Brain Injury: An Individual Growth Curve Approach

Chronic motor performance following different traumatic brain injury severity-A systematic review

Introduction

Traumatic brain injury (TBI) is now known to be a chronic disease, causing ongoing neurodegeneration and linked to increased risk of neurodegenerative motor diseases, such as Parkinson's disease and amyotrophic lateral sclerosis. While the presentation of motor deficits acutely following traumatic brain injury is well-documented, however, less is known about how these evolve in the long-term post-injury, or how the initial severity of injury affects these outcomes. The purpose of this review, therefore, was to examine objective assessment of chronic motor impairment across the spectrum of TBI in both preclinical and clinical models.

Methods

PubMed, Embase, Scopus, and PsycINFO databases were searched with a search strategy containing key search terms for TBI and motor function. Original research articles reporting chronic motor outcomes with a clearly defined TBI severity (mild, repeated mild, moderate, moderate-severe, and severe) in an adult population were included.

Results

A total of 97 studies met the inclusion criteria, incorporating 62 preclinical and 35 clinical studies. Motor domains examined included neuroscore, gait, fine-motor, balance, and locomotion for preclinical studies and neuroscore, fine-motor, posture, and gait for clinical studies. There was little consensus among the articles presented, with extensive differences both in assessment methodology of the tests and parameters reported. In general, an effect of severity was seen, with more severe injury leading to persistent motor deficits, although subtle fine motor deficits were also seen clinically following repeated injury. Only six clinical studies investigated motor outcomes beyond 10 years post-injury and two preclinical studies to 18-24 months post-injury, and, as such, the interaction between a previous TBI and aging on motor performance is yet to be comprehensively examined.

Conclusion

Further research is required to establish standardized motor assessment procedures to fully characterize chronic motor impairment across the spectrum of TBI with comprehensive outcomes and consistent protocols. Longitudinal studies investigating the same cohort over time are also a key for understanding the interaction between TBI and aging. This is particularly critical, given the risk of neurodegenerative motor disease development following TBI.

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

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

Social Determinants of Health in Physiatry: Challenges and Opportunities for Clinical Decision Making and Improving Treatment Precision

Physiatry is a medical specialty focused on improving functional outcomes in patients with a variety of medical conditions that affect the brain, spinal cord, peripheral nerves, muscles, bones, joints, ligaments, and tendons. Social determinants of health (SDH) play a key role in determining therapeutic process and patient functional outcomes. Big data and precision medicine have been used in other fields and to some extent in physiatry to predict patient outcomes, however many challenges remain. The interplay between SDH and physiatry outcomes is highly variable depending on different phases of care, and more favorable patient profiles in acute care may be less favorable in the outpatient setting. Furthermore, SDH influence which treatments or interventional procedures are accessible to the patient and thus determine outcomes. This opinion paper describes utility of existing datasets in combination with novel data such as movement, gait patterning and patient perceived outcomes could be analyzed with artificial intelligence methods to determine the best treatment plan for individual patients in order to achieve maximal functional capacity.

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

Purpose In both basic science and intervention research in traumatic brain injury (TBI), heterogeneity in the patient population is frequently cited as a limitation and is often interpreted as a factor reducing certainty in the generalizability of research findings and as a source of conflicting findings across studies. Historically, much of TBI research in rehabilitation and cognition has relied upon case-control studies, with small to modest sample sizes. In this context, heterogeneity is indeed a significant limitation. Here, however, we argue that heterogeneity in patient profiles is a hallmark characteristic of TBI and therefore cannot be avoided or ignored. We argue that this inherent heterogeneity must be acknowledged and accounted for prior to study design. Fortunately, advances in statistical methods and computing power allow researchers to leverage heterogeneity, rather than be constrained by it. Method In this article, we review sources of heterogeneity that contribute to challenges in TBI research, highlight methodological advances in statistical analysis and in other fields with high degrees of heterogeneity (e.g., psychiatry) that may be fruitfully applied to decomposing heterogeneity in TBI, and offer an example from our research group incorporating this approach. Conclusion Only by adopting new methodological approaches can we advance the science of rehabilitation following TBI in ways that will impact clinical practice and inform decision making, allowing us to understand and respond to the range of individual differences that are a hallmark in this population.

Neural Connectivity Changes Facilitated by Familiar Auditory Sensory Training in Disordered Consciousness: A TBI Pilot Study

For people with disordered consciousness (DoC) after traumatic brain injury (TBI), relationships between treatment-induced changes in neural connectivity and neurobehavioral recovery have not been explored. To begin building a body of evidence regarding the unique contributions of treatments to changes in neural network connectivity relative to neurobehavioral recovery, we conducted a pilot study to identify relationships meriting additional examination in future research. To address this objective, we examined previously unpublished neural connectivity data derived from a randomized clinical trial (RCT). We leveraged these data because treatment efficacy, in the RCT, was based on a comparison of a placebo control with a specific intervention, the familiar auditory sensory training (FAST) intervention, consisting of autobiographical auditory-linguistic stimuli. We selected a subgroup of RCT participants with high-quality imaging data (FAST n = 4 and placebo n = 4) to examine treatment-related changes in brain network connectivity and how and if these changes relate to neurobehavioral recovery. To discover promising relationships among the FAST intervention, changes in neural connectivity, and neurobehavioral recovery, we examined 26 brain regions and 19 white matter tracts associated with default mode, salience, attention, and language networks, as well as three neurobehavioral measures. Of the relationships discovered, the systematic filtering process yielded evidence supporting further investigation of the relationship among the FAST intervention, connectivity of the left inferior longitudinal fasciculus, and auditory-language skills. Evidence also suggests that future mechanistic research should focus on examining the possibility that the FAST supports connectivity changes by facilitating redistribution of brain resources. For a patient population with limited treatment options, the reported findings suggest that a simple, yet targeted, passive sensory stimulation treatment may have altered functional and structural connectivity. If replicated in future research, then these findings provide the foundation for characterizing the unique contributions of the FAST intervention and could inform development of new treatment strategies. For persons with severely damaged brain networks, this report represents a first step toward advancing understanding of the unique contributions of treatments to changing brain network connectivity and how these changes relate to neurobehavioral recovery for persons with DoC after TBI.

Clinical Trial Registry: NCT00557076, The Efficacy of Familiar Voice Stimulation During Coma Recovery (http://www.clinicaltrials.gov).

Epilepsy after severe traumatic brain injury: frequency and injury severity

Objective: To estimate national frequency of posttraumatic epilepsy (PTE) after severe traumatic brain injury (TBI) and assess injury severity (Glasgow Coma Scale (GCS) and posttraumatic amnesia (PTA)) as prognostic factors for PTE.

METHODS

Data on patients ≥18 years surviving severe TBI 2004-2016 were retrieved from the Danish Head Trauma Database (n = 1010). The cumulative incidence proportion (CIP) was estimated using death as competing event. The association between injury severity and PTE was assessed using multivariable competing risk regressions.

RESULTS

CIP of PTE 28 days and one year post-TBI was 6.8% (95% confidence interval (CI) 5.4-8.5) and 18.5% (95% CI 16.1-21.1%), respectively. Injury severity was not associated with PTE within 28 days post-TBI but indicated higher PTE-rates in less severely injured patients. PTA-duration >70 days was associated with PTE 29-365 days post-TBI (Adjusted sub-hazard ratio 4.23 (95% CI 1.79-9.99)). GCS was not associated with PTE 29-365 days post-TBI.

CONCLUSION

The PTE frequency was higher compared to previous estimates. Increasing injury severity was associated with PTE 29-365 days post-TBI when measured with PTA, but not with GCS. Though nonsignificant, the increased PTE-risk within 28 days in lower severity suggests an underdiagnosing of PTE.

Modeling Longitudinal Outcomes: A Contrast of Two Methods

Background: Repeated measures analysis of variance (ANOVA) is frequently used to model longitudinal data but does not appropriately account for within-person correlations over time, does not explicitly model time, and cannot flexibly handle missing data. In contrast, mixed-effects regression addresses these limitations. In this commentary, we compare these two methods using openly available tools. Methods: We emulated a real developmental study of elite skiers, tracking national rankings from 2011 to 2018. We constructed unconditional models of time (establishing the “pattern” of change) and conditional models of time (identifying factors that affect change over time), and contrasted these models against comparable repeated measures ANOVAs. Results: Mixed-effects regression allowed for linear and non-linear modeling of the skiers’ longitudinal trajectories despite missing data. Missing data is still a concern in mixed-effects regression models, but in the present dataset missingness could be accounted for by skiers’ ages, satisfying the missing at random assumption. Discussion: Although ANOVA and mixed-effects regression are both suitable for time-series data, their applications differ. ANOVA will be most parsimonious when the research question focuses on group-level mean differences at arbitrary time points. However, mixed-effects regression is more suitable where time is inherently important to the outcome, and where individual differences are of interest.

Factors Associated With Gains in Performance During Rehabilitation After Pediatric Brain Injury: Growth Curve Analysis

OBJECTIVE

Predicting recovery of functional performance within pediatric rehabilitation after brain injury is important for health professionals and families, but information regarding factors associated with change in functional skills ("what the child can do") and functional independence ("what the child does") is limited. The aim of the study was to examine change in functional skills and independence over time in children with moderate-severe brain injury during prolonged inpatient rehabilitation.

DESIGN

This study used a retrospective cohort design. Longitudinal data from 139 children (age 1.6-20.6 yrs), hospitalized for 115.4 ± 72 days, were examined. Growth curve analysis was used to examine factors associated with change in the Pediatric Evaluation of Disability Inventory (functional skills and caregiver assistance, ie, functional independence) in mobility and self-care. Typical estimates for change per hospitalization day were obtained.

RESULTS

Traumatic brain injury and older age at injury, but not sex, were associated with faster recovery. Length of stay was associated with rate of change in functional skills but not in functional independence, suggesting that improvement in functional independence during rehabilitation may be associated with other factors.

CONCLUSIONS

Identifying the factors associated with individual profiles of functional improvement can provide valuable information for clinicians and decision-makers to optimize performance after prolonged inpatient rehabilitation.

Patterns of traumatic brain injury and six-month neuropsychological outcomes in Uganda

BACKGROUND

Traumatic brain injuries in Uganda are on the increase, however little is known about the neuropsychological outcomes in survivors. This study characterized patients with traumatic brain injury (TBI) and the associated six-month neuropsychological outcomes in a Ugandan tertiary hospital.

METHODS

Patients admitted at Mulago Hospital with head injury from November 2015 to April 2016 were prospectively enrolled during admission and followed up at six months after discharge to assess cognition, posttraumatic stress symptoms (PTSS), depression symptoms and physical disability. The outcomes were compared to a non-head-injury group recruited from among the caretakers, siblings and neighbours of the patients with age and sex entered as covariates.

RESULTS

One hundred and seventy-one patients and 145 non-head injury participants were enrolled. The age range for the whole sample was 1 to 69 years with the non-head injury group being older (mean age (SD) 33.34 (13.35) vs 29.34 (14.13) years of age, p = 0.01). Overall, motorcycle crashes (36/171, 38.6%) and being hit by an object (58/171, 33.9%) were the leading causes of TBI. Head injury from falls occurred more frequently in children < 18 years (13.8% vs 2.8%, p = 0.03). In adults 18 years and older, patients had higher rates of neurocognitive impairment (28.4% vs 6.6%, p < 0.0001), PTSS (43.9% vs 7.9%, p < 0.0001), depression symptoms (55.4% vs 10%, p < 0.0001) and physical disability (7.2% vs 0%, p = 0.002). Lower Glasgow Coma Score (GCS) on admission was associated with neurocognitive impairment (11.6 vs 13.1, p = 0.04) and physical disability (10 vs 12.9, p = 0.01) six months later.

CONCLUSION

This first such study in the East-African region shows that depth of coma on admission in TBI is associated with neurocognitive impairment and physical disability.

Five-year motor functional outcome in children with acquired brain injury. Yet to the end of the story?

PURPOSE

The description of motor changes and clinical evolution of a pediatric cohort with acquired brain injury (ABI) over 5 years by the functional independence measure for children (WeeFIM).

METHODS

We analyzed retrospective data from 496 patients (aged 0-18 years) with severe ABI admitted for rehabilitation. WeeFIM scores and disability rating scale (reference scale) were collected at admission, discharge and yearly, up to year 5.

RESULTS

Functional limitations gradually reduced after ABI, but children still had residual disabilities at the endpoint. Seventeen percent of patients demonstrated no improvement at WeeFIM. Gait analysis showed that decreased WeeFIM scores in the mobility domain are associated with slower and shorter steps, and increased step width, compensating for imbalance.

CONCLUSIONS

Five years after ABI, improvement is still found in the mobility domain of WeeFIM. This work adds evidence that margin still exists at least until year 5 after injury for profitably continuing the rehabilitation effort.

Trajectory of Functional Independent Measurements during First Five Years after Moderate and Severe Traumatic Brain Injury

A better understanding of long-term functional recovery process for patients with traumatic brain injury (TBI) facilitates effective rehabilitations. The aim of this study was to classify and characterize patients with moderate-to-severe TBI based on their functional trajectories up to 5 years post-injury. The study included 121 patients with moderate-to-severe TBIs (International Classification of Diseases, Tenth Revision [ICD-10], S06.0-S06.9), 16-55 years of age, and admitted at Trauma Referral Hospital within 24 h of injury between 2005 and 2007. Demographics and injury characteristics were documented at the admission, and functional status was recorded at 3 months and 1 and 5 years post-injury using Functional Independence Measure motor (FIM-M) and cognitive (FIM-C) subscales. We used group-based trajectory models to classify patients' functional trajectories over a 5-year period. For FIM-M, three trajectories were identified: 8.2% of patients showed stable low recovery (13.6 ± 1.5, 17.9 ± 8.8, and 21.0 ± 17.9), 9.2% elevated good recovery (35.8 ± 14.5, 75.5 ± 12.4, and 85.5 ± 8.1), and 82.6% stable good recovery (89.0 ± 3.6, 90.3 ± 1.9, and 90.8 ± 1.0) at the three follow-up points, respectively. For FIM-C, four trajectories were revealed: 4.1% of patients showed stable low recovery (5.0 ± 0, 5.0 ± 0, and 5.0 ± 0), 12.6% delayed moderate recovery (8.9 ± 3.5, 20.6 ± 4.6, and 28.3 ± 3.8), 28.7% elevated good recovery (27.0 ± 3.8, 30.4 ± 7.3, and 31.1 ± 2.3), and 54.6% stable good recovery (32.8 ± 2.3, 34.6 ± 1.0, and 34.7 ± 1.0). The results suggest that three FIM-M and four FIM-C trajectories described various patterns of functional recovery 5 years after moderate-to-severe TBI, with stable good recovery being the most common trajectory. Identifying and characterizing the trajectory memberships should enable targeted rehabilitation programs, inform patient-centered care, and improve long-term outcomes.

Return to Work After Severe Traumatic Brain Injury: A Nationwide Follow-up Study

OBJECTIVE

To determine return to work (RTW) after severe traumatic brain injury (TBI) and to compare long-term labor market attachment (LMA) with the general population.

PARTICIPANTS

All persons aged 18 to 64 years who received highly specialized neurorehabilitation after severe TBI between 2004 and 2012 (n = 637) were matched to general population controls on age, sex, preinjury employment status, educational level, and residence (n = 2497).

DESIGN

Nationwide follow-up study using weekly records on public assistance benefits.

MAIN MEASURES

Both RTW and LMA were defined as having no public assistance benefits except education grants/leave. Stable LMA was defined as weeks with LMA of 75% or more. LMA among persons with severe TBI and controls was compared using multivariable conditional logistic regression.

RESULTS

RTW mainly occurred within first 2 years after severe TBI, with 30% of the people attempting RTW and 16% achieving stable LMA within 2 years. The prevalence of people with LMA decreased to 11% from 2½ years to 5 years postinjury. Adjusted odds ratios were 0.01 for LMA up to 2 years postinjury and 0.05 for stable LMA for persons with severe TBI compared with the general population.

CONCLUSION

Both RTW and long-term LMA after severe TBI were low in Denmark when compared with the general population and other countries.

Psychological outcome after severe traumatic brain injury in adolescents and young adults: The chronic phase

OBJECTIVES

Young individuals surviving severe traumatic brain injury (TBI) frequently experience a wide range of cognitive, emotional and behavioural consequences. This cross-sectional follow-up study investigated psychological outcome of young survivors in the chronic phase, and whether psychological outcome was associated with improvement of functional abilities during sub-acute admission.

METHODS

Patients, who acquired a severe TBI during adolescence or early adulthood (n = 36) and received early intensive rehabilitation, were contacted for follow-up assessment concerning psychological outcome and completed the Adult Self Report 18-59 (ASR18-59). Demographic data, functional outcomes and severity measures were obtained from the local database.

RESULTS

The participants had a mean age of 24.1 years (SD = 4.1) at follow-up, and the mean time since injury was 72.1 months (SD = 44.2). Results showed significantly higher scores compared with the normative reference population in relation to the subscales withdrawal/isolation (p = 0.013), attention problems (p = 0.008) and intrusive behaviour (p = 0.046). Pearson correlation analyses showed that young survivors experiencing more functional improvement during inpatient rehabilitation had fewer psychological problems during the chronic phase in the subscales: withdrawal/isolation, rule breaking, intrusive behaviour and total problems.

CONCLUSION

Young patients reported psychological problems in several areas during the chronic phase of injury, which may hinder complete reintegration and participation in society. Larger functional improvement during sub-acute rehabilitation seemed to be associated with less psychological problems in the chronic phase.

Trajectories of Functional Change After Inpatient Rehabilitation for Traumatic Brain Injury

OBJECTIVE

To examine trajectories of functional recovery after rehabilitation for traumatic brain injury (TBI).

DESIGN

Prospective study.

SETTING

Inpatient rehabilitation hospitals in the Uniform Data System for Medical Rehabilitation.

PARTICIPANTS

A subset of individuals receiving inpatient rehabilitation services for TBI from 2002 to 2010 who also had postdischarge measurement of functional independence (N=16,583).

INTERVENTIONS

Inpatient rehabilitation.

MAIN OUTCOMES MEASURES

Admission, discharge, and follow-up data were obtained from the Uniform Data System for Medical Rehabilitation. We used latent class mixture models to examine recovery trajectories for both cognitive and motor functioning as measured by the FIM instrument.

RESULTS

Latent class models identified 3 trajectories (low, medium, high) for both cognitive and motor FIM subscales. Factors associated with membership in the low cognition trajectory group included younger age, male sex, racial/ethnic minority, Medicare or Medicaid (vs commercial or other insurance), comorbid conditions, and greater duration from injury date to rehabilitation admission date. Factors associated with membership in the low motor trajectory group included older age, racial/ethnic minority, Medicare or Medicaid coverage, comorbid conditions, open head injury, and greater duration to admission.

CONCLUSIONS

Standard approaches to assessing recovery patterns after TBI obscure differences between subgroups with trajectories that differ from the overall mean. Select demographic and clinical characteristics can help classify patients with TBI into distinct functional recovery trajectories, which can enhance both patient-centered care and quality improvement efforts.

How Do Intensity and Duration of Rehabilitation Services Affect Outcomes From Severe Traumatic Brain Injury? A Natural Experiment Comparing Health Care Delivery Systems in 2 Developed Nations

OBJECTIVE

To determine the effects of inpatient and outpatient treatment intensity on functional and emotional well-being outcomes at 1 year after severe traumatic brain injury (TBI).

DESIGN

Prospective, quasiexperimental study comparing outcomes in a U.S. TBI treatment center with those in a Denmark (DK) center providing significantly greater intensity and duration of rehabilitation.

SETTING

Inpatient and outpatient TBI rehabilitation.

PARTICIPANTS

Persons with severe TBI (N=274).

INTERVENTIONS

Inpatient rehabilitation interventions were counted daily by discipline. Outpatient treatments were estimated per discipline using a structured interview administered to patients, caregivers, or both, at 12 months.

MAIN OUTCOME MEASURES

FIM, Glasgow Outcome Scale-Extended, Disability Rating Scale, Participation Assessment with Recombined Tools-Objective, Perceived Quality of Life, Medical Outcomes Study 12-Item Short-Form Health Survey, Brief Symptom Inventory-18-item version.

RESULTS

Despite identical inclusion criteria, patient severity on admission was greater at the DK site. After adjustment for patient/injury characteristics, there were no site differences in either functional or emotional outcome at 12 months. Significantly more inpatient plus outpatient treatment was administered to DK patients than to those in the U.S. For functional but not emotional treatments, more severely impaired patients received higher doses. One-year outcomes were predicted by admission severity, age, employment, and other baseline characteristics.

CONCLUSIONS

Contrary to expectation, DK patients who received significantly more rehabilitation services during the year after severe TBI did not differ in outcome from their less intensively treated U.S. counterparts, after adjusting for initial severity. The negative association of functional treatment dose with extent of early disability suggests that dose was driven by unmeasured factors reflecting need for services. Improved measures of injury-related factors driving treatment allocation are needed to model the independent effects of treatment on outcomes.

Effects of Patient Preinjury and Injury Characteristics on Acute Rehabilitation Outcomes for Traumatic Brain Injury

OBJECTIVE

To examine associations of patient and injury characteristics with outcomes at inpatient rehabilitation discharge and 9 months postdischarge for patients with traumatic brain injury (TBI).

DESIGN

Prospective, longitudinal observational study.

SETTING

Inpatient rehabilitation centers.

PARTICIPANTS

Consecutive patients (N=2130) enrolled between 2008 and 2011, admitted for inpatient rehabilitation after index TBI, and divided into 5 subgroups based on rehabilitation admission FIM cognitive score.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Rehabilitation length of stay, discharge to home, and FIM at discharge and 9 months postdischarge.

RESULTS

Severity indices increased explained variation in outcomes beyond that accounted for by patient characteristics. FIM motor scores were generally the most predictable. Higher functioning subgroups had more predictable outcomes then subgroups with lower cognitive function at admission. Age at injury, time from injury to rehabilitation admission, and functional independence at rehabilitation admission were the most consistent predictors across all outcomes and subgroups.

CONCLUSIONS

Findings from previous studies of the relations among patient and injury characteristics and rehabilitation outcomes were largely replicated. Discharge outcomes were most strongly associated with injury severity characteristics, whereas predictors of functional independence at 9 months postdischarge included both patient and injury characteristics.

Rehabilitation after traumatic brain injury

Traumatic brain injury (TBI) is a growing problem in the US, with significant morbidity and economic implications. This diagnosis spans a wide breath of injuries from concussion to severe TBI. Thus, rehabilitation is equally diverse in its treatment strategies targeting those symptoms that are functionally limiting with the ultimate goal of independence and community reintegration. In severe TBI, rehabilitation can be lifelong. Acute care rehabilitation focuses on emergence from coma and prognostication of recovery. Therapeutic modalities and exercise, along with pharmacologic intervention, can target long-term motor and cognitive sequelae. Complications of severe TBI that are functionally limiting and impede therapy include heterotopic ossification, agitation, dysautonomia, and spasticity. In mild TBI, most patients recover quickly but education on repeat exposure is imperative, with the implications of consecutive injuries being potentially devastating. Furthermore, rehabilitation targets lingering symptoms including sleep disturbance, visuospatial deficits, headaches, and cognitive dysfunction. As research on the entire TBI population improves, commonalities in the disease process may emerge, helping rationalize therapeutic interventions and providing more robust targets for treatment.