Clinical Outcomes After Traumatic Brain Injury and Exposure to Extracranial Surgery: A TRACK-TBI Study

Importance

Traumatic brain injury (TBI) is associated with persistent functional and cognitive deficits, which may be susceptible to secondary insults. The implications of exposure to surgery and anesthesia after TBI warrant investigation, given that surgery has been associated with neurocognitive disorders.

Objective

To examine whether exposure to extracranial (EC) surgery and anesthesia is related to worse functional and cognitive outcomes after TBI.

Design, Setting, and Participants

This study was a retrospective, secondary analysis of data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, a prospective cohort study that assessed longitudinal outcomes of participants enrolled at 18 level I US trauma centers between February 1, 2014, and August 31, 2018. Participants were 17 years or older, presented within 24 hours of trauma, were admitted to an inpatient unit from the emergency department, had known Glasgow Coma Scale (GCS) and head computed tomography (CT) status, and did not undergo cranial surgery. This analysis was conducted between January 2, 2020, and August 8, 2023.

Exposure

Participants who underwent EC surgery during the index admission were compared with participants with no surgery in groups with a peripheral orthopedic injury or a TBI and were classified as having uncomplicated mild TBI (GCS score of 13-15 and negative CT results [CT- mTBI]), complicated mild TBI (GCS score of 13-15 and positive CT results [CT+ mTBI]), or moderate to severe TBI (GCS score of 3-12 [m/sTBI]).

Main Outcomes and Measures

The primary outcomes were functional limitations quantified by the Glasgow Outcome Scale-Extended for all injuries (GOSE-ALL) and brain injury (GOSE-TBI) and neurocognitive outcomes at 2 weeks and 6 months after injury.

Results

A total of 1835 participants (mean [SD] age, 42.2 [17.8] years; 1279 [70%] male; 299 Black, 1412 White, and 96 other) were analyzed, including 1349 nonsurgical participants and 486 participants undergoing EC surgery. The participants undergoing EC surgery across all TBI severities had significantly worse GOSE-ALL scores at 2 weeks and 6 months compared with their nonsurgical counterparts. At 6 months after injury, m/sTBI and CT+ mTBI participants who underwent EC surgery had significantly worse GOSE-TBI scores (B = -1.11 [95% CI, -1.53 to -0.68] in participants with m/sTBI and -0.39 [95% CI, -0.77 to -0.01] in participants with CT+ mTBI) and performed worse on the Trail Making Test Part B (B = 30.1 [95% CI, 11.9-48.2] in participants with m/sTBI and 26.3 [95% CI, 11.3-41.2] in participants with CT+ mTBI).

Conclusions and Relevance

This study found that exposure to EC surgery and anesthesia was associated with adverse functional outcomes and impaired executive function after TBI. This unfavorable association warrants further investigation of the potential mechanisms and clinical implications that could inform decisions regarding the timing of surgical interventions in patients after TBI.

Combat Deployed Service Members by Blast TBI and Service Separation Status 5-years Post-deployment: Comparison of Cognitive, Neurobehavioral, and Psychological Profiles of Those Who Left vs. Those Still Serving

INTRODUCTION

Longitudinal research regarding the pre- and post-separation experience has been relatively limited, despite its potential as a major life transition. Separating from the military and re-integration to civilian life is noted to be a period of increased risk of significant adjustment challenges, which impacts a service member in a multitude of areas. Active duty service members with combat-related physical or mental health or pre-existing adjustment conditions may be more likely to separate from service and more at risk for post-military service adjustment problems.

MATERIALS AND METHODS

This is a secondary data analysis from a prospective, observational, longitudinal, multicohort study involving deployed service members originally enrolled between 2008 and 2013 in combat or following medical evacuation to Landstuhl, Germany. Two combat-deployed cohorts were examined: non-head-injured control without blast exposure (n = 109) and combat-related concussion arising from blast (n = 165). Comprehensive clinical evaluations performed at 1 year and 5 year follow-up included identical assessment batteries for neurobehavioral, psychiatric, and cognitive outcomes. In addition to demographics collected at each study visit, the current analysis leveraged the Glasgow Outcome Scale Extended (GOS-E), a measure of overall global disability. For neurobehavioral impairment, the Neurobehavioral Rating Scale-Revised (NRS) was used as well as the Headache Impact Test (HIT-6) to assess headache burden. To compare psychiatric symptom burden between those separated to those still serving, the Clinician-Administered PTSD Scale for DSM-IV (CAPS) and Montgomery-Asberg Depression Rating Scale (MADRS) for depression were used as well as the Michigan Alcohol Screening Test (MAST) to be able to compare alcohol misuse across groups. Overall cognitive function/performance was defined for each service member by aggregating the 19 neuropsychological measures.

RESULTS

Overall comparisons following adjustment by linear regression and correction for multiple comparisons by separation status subgroup for non-blast control or blast traumatic brain injury (TBI) identified significant differences at 5 years post-enrollment in measures of global disability, neurobehavioral impairment, and psychiatric symptom burden. Those who separated had worse global disability, worse neurobehavioral symptoms, worse Post-Traumatic Stress Disorder symptoms, and worse depression symptoms than active duty service members. While service members who sustain a mild blast TBI during combat are more likely to separate from service within 5 years, there is a proportion of those non-injured who also leave during this time frame. Clinical profiles of both groups suggest service members who separated have elevated psychiatric and neurobehavioral symptoms but not cognitive dysfunction. Interestingly, the symptom load in these same domains is lower for those without blast TBI who separated during this time frame.

CONCLUSIONS

These results appear to support previous research depicting that, for some service members, transitioning out of the military and re-integrating into civilian life can be a challenging adjustment. Many factors, including personal and social circumstances, prior mental or emotional difficulties, availability of social or community support or resources, can influence the adjustment outcomes of veterans. Service members with prior adjustment difficulties and/or those with blast TBI history (and ongoing neurobehavioral symptoms) may find the transition from military to civilian life even more challenging, given the potential substantial changes in lifestyle, structure, identity, and support.

Impact of Therapeutic Interventions on Cerebral Autoregulatory Function Following Severe Traumatic Brain Injury: A Secondary Analysis of the BOOST-II Study

BACKGROUND

The Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase II randomized controlled trial used a tier-based management protocol based on brain tissue oxygen (PbtO2) and intracranial pressure (ICP) monitoring to reduce brain tissue hypoxia after severe traumatic brain injury. We performed a secondary analysis to explore the relationship between brain tissue hypoxia, blood pressure (BP), and interventions to improve cerebral perfusion pressure (CPP). We hypothesized that BP management below the lower limit of autoregulation would lead to cerebral hypoperfusion and brain tissue hypoxia that could be improved with hemodynamic augmentation.

METHODS

Of the 119 patients enrolled in the Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase II trial, 55 patients had simultaneous recordings of arterial BP, ICP, and PbtO2. Autoregulatory function was measured by interrogating changes in ICP and PbtO2 in response to fluctuations in CPP using time-correlation analysis. The resulting autoregulatory indices (pressure reactivity index and oxygen reactivity index) were used to identify the "optimal" CPP and limits of autoregulation for each patient. Autoregulatory function and percent time with CPP outside personalized limits of autoregulation were calculated before, during, and after all interventions directed to optimize CPP.

RESULTS

Individualized limits of autoregulation were computed in 55 patients (mean age 38 years, mean monitoring time 92 h). We identified 35 episodes of brain tissue hypoxia (PbtO2 < 20 mm Hg) treated with CPP augmentation. Following each intervention, mean CPP increased from 73 ± 14 mm Hg to 79 ± 17 mm Hg (p = 0.15), and mean PbtO2 improved from 18.4 ± 5.6 mm Hg to 21.9 ± 5.6 mm Hg (p = 0.01), whereas autoregulatory function trended toward improvement (oxygen reactivity index 0.42 vs. 0.37, p = 0.14; pressure reactivity index 0.25 vs. 0.21, p = 0.2). Although optimal CPP and limits remained relatively unchanged, there was a significant decrease in the percent time with CPP below the lower limit of autoregulation in the 60 min after compared with before an intervention (11% vs. 23%, p = 0.05).

CONCLUSIONS

Our analysis suggests that brain tissue hypoxia is associated with cerebral hypoperfusion characterized by increased time with CPP below the lower limit of autoregulation. Interventions to increase CPP appear to improve autoregulation. Further studies are needed to validate the importance of autoregulation as a modifiable variable with the potential to improve outcomes.

Predicting Functional Dependency in Patients with Disorders of Consciousness: A TBI-Model Systems and TRACK-TBI Study

OBJECTIVE

It is not currently possible to predict long-term functional dependency in patients with disorders of consciousness (DoC) after traumatic brain injury (TBI). Our objective was to fit and externally validate a prediction model for 1-year dependency in patients with DoC ≥ 2 weeks after TBI.

METHODS

We included adults with TBI enrolled in TBI Model Systems (TBI-MS) or Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) studies who were not following commands at rehabilitation admission or 2 weeks post-injury, respectively. We fit a logistic regression model in TBI-MS and validated it in TRACK-TBI. The primary outcome was death or dependency at 1 year post-injury, defined using the Disability Rating Scale.

RESULTS

In the TBI-MS Discovery Sample, 1,960 participants (mean age 40 [18] years, 76% male, 68% white) met inclusion criteria, and 406 (27%) were dependent 1 year post-injury. In a TBI-MS held out cohort, the dependency prediction model's area under the receiver operating characteristic curve was 0.79 (95% CI 0.74-0.85), positive predictive value was 53% and negative predictive value was 86%. In the TRACK-TBI external validation (n = 124, age 40 [16] years, 77% male, 81% white), the area under the receiver operating characteristic curve was 0.66 (0.53, 0.79), equivalent to the standard IMPACTcore + CT score (p = 0.8).

INTERPRETATION

We developed a 1-year dependency prediction model using the largest existing cohort of patients with DoC after TBI. The sensitivity and negative predictive values were greater than specificity and positive predictive values. Accuracy was diminished in an external sample, but equivalent to the IMPACT model. Further research is needed to improve dependency prediction in patients with DoC after TBI. ANN NEUROL 2023;94:1008-1023.

Collaborative Care Versus Usual Care to Improve Quality of Life, Pain, Depression, and Physical Activity in Outpatients With Spinal Cord Injury: The SCI-CARE Randomized Controlled Clinical Trial

Our goal was to test the effectiveness of collaborative care (CC) versus usual care (UC) to improve treatment of pain, depression, physical inactivity, and quality of life in outpatients with spinal cord injury (SCI). We conducted a single blind parallel group randomized controlled trial. The setting was two outpatient SCI rehabilitation clinics within a large academic medical center. Participants were 174 outpatients who were on average 47.7 years old, 76% male, 76% white, 8% Hispanic, 47% tetraplegic, 95% more than 1 year post-SCI, and 45% on Medicare. The intervention consisted of a mental health-trained collaborative care manager (CM) integrated into two SCI rehabilitation medicine clinics and supervised by content experts in pain and mental health treatment. The CM provided assessment, medical care coordination, adherence support, outcome monitoring, and decision support along with brief psychological interventions to the patients via up to 12 in-person or telephone sessions. Among all participants, 61% chose to focus on pain; 31% on physical activity and 8% on depression. The primary outcome was quality of life as measured by the World Health Organization Quality of Life-BREF at the end of treatment (4 months). Secondary outcomes were quality of life at 8 months and pain intensity and interference, depression severity, and minutes per week of moderate to vigorous physical activity at 4 and 8 months. A total of 174 participants were randomized 1:1 to CC (n = 89) versus UC (n = 85). The primary analysis, a mixed-effects linear regression adjusting for time since injury and sex, revealed a non-significant trend for greater improvement in quality of life in CC versus UC at 4 months (p = 0.083). Secondary analyses showed that those receiving CC reported significantly greater improvement in pain interference at 4- and 8-months and in depression at 4-months, but no significant effect on physical activity. We conclude that in an outpatient SCI care setting, CC is a promising model for delivering integrated medical and psychological care and improving management of common, chronic, disabling conditions such and pain and depression.

Profiles of Cognitive Functioning at 6 Months After Traumatic Brain Injury Among Patients in Level I Trauma Centers: A TRACK-TBI Study

Importance

Cognitive dysfunction is common after traumatic brain injury (TBI), with a well-established dose-response relationship between TBI severity and likelihood or magnitude of persistent cognitive impairment. However, patterns of cognitive dysfunction in the long-term (eg, 6-month) recovery period are less well known.

Objective

To characterize the prevalence of cognitive dysfunction within and across cognitive domains (processing speed, memory, and executive functioning) 6 months after injury in patients with TBI seen at level I trauma centers.

Design, Setting, and Participants

This prospective longitudinal cohort study used data from Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) and included patients aged 17 years or older presenting at 18 US level I trauma center emergency departments or inpatient units within 24 hours of head injury, control individuals with orthopedic injury recruited from the same centers, and uninjured friend and family controls. Participants were enrolled between March 2, 2014, and July 27, 2018. Data were analyzed from March 5, 2020, through October 3, 2023.

Exposures

Traumatic brain injury (Glasgow Coma Scale score of 3-15) or orthopedic injury.

Main Outcomes and Measures

Performance on standard neuropsychological tests, including premorbid cognitive ability (National Institutes of Health Toolbox Picture Vocabulary Test), verbal memory (Rey Auditory Verbal Learning Test), processing speed (Wechsler Adult Intelligence Scale [4th edition] Processing Speed Index), and executive functioning (Trail Making Test).

Results

The sample included 1057 persons with TBI (mean [SD] age, 39.3 [16.4] years; 705 [67%] male) and 327 controls without TBI (mean [SD] age, 38.4 [15.1] years; 222 [68%] male). Most persons with TBI demonstrated performance within 1.5 SDs or better of the control group (49.3% [95% CI, 39.5%-59.2%] to 67.5% [95% CI, 63.7%-71.2%] showed no evidence of impairment). Similarly, 64.4% (95% CI, 54.5%-73.4%) to 78.8% (95% CI, 75.4%-81.9%) of participants demonstrated no evidence of cognitive decline (defined as performance within 1.5 SDs of estimated premorbid ability). For individuals with evidence of either cognitive impairment or decline, diverse profiles of impairment across memory, speed, and executive functioning domains were observed (ie, the prevalence was >0 in each of the 7 combinations of impairment across these 3 cognitive domains for most TBI subgroups).

Conclusions and Relevance

In this cohort study of patients seen at level I trauma centers 6 months after TBI, many patients with TBI demonstrated no cognitive impairment. Impairment was more prevalent in persons with more severe TBI and manifested in variable ways across individuals. The findings may guide future research and treatment recommendations.

Acute Extra-Arachnoid Subdural Hematomas in Patients 50 Years and Older: When Subdurals Act Like Epidurals

BACKGROUND

Some patients with subdural hematoma (SDH) with acute extra-arachnoid lesions and without concomitant subarachnoid blood or contusions may present in similarly grave neurological condition compared with the general population of patients with SDH. However, these patients often make an impressive neurological recovery. This study compared neurological outcomes in patients with extra-arachnoid SDH with all other SDH patients.

METHODS

We compared a prospective series of extra-arachnoid SDH patients without subarachnoid hemorrhage or other concomitant intracranial injury with a Transforming Research and Clinical Knowledge in TBI control group with SDH only. We performed inverse probability weighting for key characteristics and ordinal regression with and without controlling for midline shift comparing neurological outcomes (Extended Glasgow Outcome Scale score) at 2 weeks. We used the Corticosteroid Randomization After Significant Head Injury prognostic model to predict mortality based on age, Glasgow Coma Scale score, pupil reactivity, and major extracranial injury.

RESULTS

Mean midline shift was significantly different between extra-arachnoid SDH and control groups (7.2 mm vs. 2.7 mm, P < 0.001). After weighting for group allocation and controlling for midline shift, extra-arachnoid SDH patients had 5.68 greater odds (P < 0.001) of a better 2-week Extended Glasgow Outcome Scale score than control patients. Mortality in the extra-arachnoid SDH group was less than predicted by the Corticosteroid Randomization After Significant Head Injury prognostic model (10% vs. 21% predicted).

CONCLUSIONS

Patients with extra-arachnoid SDH have significantly better 2-week neurological outcomes and lower mortality than predicted by the Corticosteroid Randomization After Significant Head Injury model. Neurosurgeons should consider surgery for this patient subset even in cases of poor neurological examination, older age, and large hematoma with high degree of midline shift.

Prevalence of and Risk Factors for Post-traumatic Headache in Civilian Patients After Mild Traumatic Brain Injury: A TRACK-TBI Study

OBJECTIVE

To ascertain the prevalence of and risk factors for post-traumatic headache (PTH) attributed to mild traumatic brain injury (mTBI).

PATIENTS AND METHODS

A prospective, longitudinal, multicenter cohort study of patients with mTBI and orthopedic trauma controls who were enrolled from February 26, 2014, to August 8, 2018. The baseline assessment was conducted as soon as possible following evaluation at the emergency department. Follow-ups were scheduled at 2 weeks, 3 months, 6 months, and 12 months postinjury. Eligible patients with mTBI included those 18 years of age or older who presented to the emergency department within 24 hours of head injury warranting evaluation by noncontrast head computed tomography scan. Acute PTH was considered present when a patient reported a headache score of greater than or equal to 2 on the Rivermead Post-concussion Questionnaire at 2 weeks postinjury (ie, headache is at least a mild problem compared with pre-injury). Persistent PTH was defined when a patient with acute PTH reported a Rivermead Post-concussion Questionnaire headache score of greater than or equal to 2 at the scheduled follow-up examinations.

RESULTS

Acute PTH was reported by 963 (60.4%) of 1594 patients with mTBI at 2 weeks postinjury. Among those with acute PTH, 439 (52.4%) of 837 patients reported persistent PTH at 3 months postinjury. This figure decreased over time and 278 (37.5%) of 742 patients continued to report persistent PTH at 6 months, whereas 187 (28.9%) of 646 patients did so as well at 12 months postinjury. Risk factors for acute PTH included younger age, female sex, fewer years of formal education, computed tomography-positive scans, alteration of consciousness, psychiatric history, and history of migraine. Risk factors for persistent PTH included female sex, fewer years of formal education, and history of migraine.

CONCLUSION

Post-traumatic headache is a prevalent sequela of mTBI that persists for at least 12 months in a considerable proportion of affected individuals. The attributable burden necessitates better patient follow-up, disease characterization, improved awareness of PTH in clinical practice, and identification of effective therapies.

Longitudinal Recovery Following Repetitive Traumatic Brain Injury

Importance

One traumatic brain injury (TBI) increases the risk of subsequent TBIs. Research on longitudinal outcomes of civilian repetitive TBIs is limited.

Objective

To investigate associations between sustaining 1 or more TBIs (ie, postindex TBIs) after study enrollment (ie, index TBIs) and multidimensional outcomes at 1 year and 3 to 7 years.

Design, Setting, and Participants

This cohort study included participants presenting to emergency departments enrolled within 24 hours of TBI in the prospective, 18-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study (enrollment years, February 2014 to July 2020). Participants who completed outcome assessments at 1 year and 3 to 7 years were included. Data were analyzed from September 2022 to August 2023.

Exposures

Postindex TBI(s).

Main Outcomes and Measures

Demographic and clinical factors, prior TBI (ie, preindex TBI), and functional (Glasgow Outcome Scale-Extended [GOSE]), postconcussive (Rivermead Post-Concussion Symptoms Questionnaire [RPQ]), psychological distress (Brief Symptom Inventory-18 [BSI-18]), depressive (Patient Health Questionnaire-9 [PHQ-9]), posttraumatic stress disorder (PTSD; PTSD Checklist for DSM-5 [PCL-5]), and health-related quality-of-life (Quality of Life After Brain Injury-Overall Scale [QOLIBRI-OS]) outcomes were assessed. Adjusted mean differences (aMDs) and adjusted relative risks are reported with 95% CIs.

Results

Of 2417 TRACK-TBI participants, 1572 completed the outcomes assessment at 1 year (1049 [66.7%] male; mean [SD] age, 41.6 [17.5] years) and 1084 completed the outcomes assessment at 3 to 7 years (714 [65.9%] male; mean [SD] age, 40.6 [17.0] years). At 1 year, a total of 60 participants (4%) were Asian, 255 (16%) were Black, 1213 (77%) were White, 39 (2%) were another race, and 5 (0.3%) had unknown race. At 3 to 7 years, 39 (4%) were Asian, 149 (14%) were Black, 868 (80%) were White, 26 (2%) had another race, and 2 (0.2%) had unknown race. A total of 50 (3.2%) and 132 (12.2%) reported 1 or more postindex TBIs at 1 year and 3 to 7 years, respectively. Risk factors for postindex TBI were psychiatric history, preindex TBI, and extracranial injury severity. At 1 year, compared with those without postindex TBI, participants with postindex TBI had worse functional recovery (GOSE score of 8: adjusted relative risk, 0.57; 95% CI, 0.34-0.96) and health-related quality of life (QOLIBRI-OS: aMD, -15.9; 95% CI, -22.6 to -9.1), and greater postconcussive symptoms (RPQ: aMD, 8.1; 95% CI, 4.2-11.9), psychological distress symptoms (BSI-18: aMD, 5.3; 95% CI, 2.1-8.6), depression symptoms (PHQ-9: aMD, 3.0; 95% CI, 1.5-4.4), and PTSD symptoms (PCL-5: aMD, 7.8; 95% CI, 3.2-12.4). At 3 to 7 years, these associations remained statistically significant. Multiple (2 or more) postindex TBIs were associated with poorer outcomes across all domains.

Conclusions and Relevance

In this cohort study of patients with acute TBI, postindex TBI was associated with worse symptomatology across outcome domains at 1 year and 3 to 7 years postinjury, and there was a dose-dependent response with multiple postindex TBIs. These results underscore the critical need to provide TBI prevention, education, counseling, and follow-up care to at-risk patients.

Chronic frontal neurobehavioural symptoms in combat-deployed military personnel with and without a history of blast-related mild traumatic brain injury

OBJECTIVE

This study evaluated frontal behavioural symptoms, via the FrSBe self-report, in military personnel with and without a history of blast-related mild traumatic brain injury (mild TBI).

METHODS

Prospective observational cohort study of combat-deployed service members leveraging 1-year and 5-year demographic and follow up clinical outcome data.

RESULTS

The blast mild TBI group (n = 164) showed greater frontal behavioural symptoms, including clinically elevated apathy, disinhibition, and executive dysfunction, during a 5-year follow-up, compared to a group of combat-deployed controls (n = 107) without mild TBI history or history of blast exposure. We also explored changes inbehaviourall symptoms over a 4-year span, which showed clinically significant increases in disinhibition in the blast mild TBI group, whereas the control group did not show significant increases in symptoms over time.

CONCLUSION

Our findings add to the growing evidence that a proportion of individuals who sustain mild TBI experience persistent behavioural symptoms. We also offer a demonstration of a novel use of the FrSBe as a tool for longitudinal symptom monitoring in a military mild TBI population.

Predicting Functional Dependency in Patients with Disorders of Consciousness: A TBI-Model Systems and TRACK-TBI Study

Importance

There are currently no models that predict long-term functional dependency in patients with disorders of consciousness (DoC) after traumatic brain injury (TBI).

Objective

Fit, test, and externally validate a prediction model for 1-year dependency in patients with DoC 2 or more weeks after TBI.

Design

Secondary analysis of patients enrolled in TBI Model Systems (TBI-MS, 1988-2020, Discovery Sample) or Transforming Research and Clinical Knowledge in TBI (TRACK-TBI, 2013-2018, Validation Sample) and followed 1-year post-injury.

Setting

Multi-center study at USA rehabilitation hospitals (TBI-MS) and acute care hospitals (TRACK-TBI).

Participants

Adults with TBI who were not following commands at rehabilitation admission (TBI-MS; days post-injury vary) or 2-weeks post-injury (TRACK-TBI).

Exposures

In the TBI-MS database (model fitting and testing), we screened demographic, radiological, clinical variables, and Disability Rating Scale (DRS) item scores for association with the primary outcome.

Main Outcome

The primary outcome was death or complete functional dependency at 1-year post-injury, defined using a DRS-based binary measure (DRS Depend ), indicating need for assistance with all activities and concomitant cognitive impairment.

Results

In the TBI-MS Discovery Sample, 1,960 subjects (mean age 40 [18] years, 76% male, 68% white) met inclusion criteria and 406 (27%) were dependent at 1-year post-injury. A dependency prediction model had an area under the receiver operating characteristic curve (AUROC) of 0.79 [0.74, 0.85], positive predictive value of 53%, and negative predictive value of 86% for dependency in a held-out TBI-MS Testing cohort. Within the TRACK-TBI external validation sample (N=124, age 40 [16], 77% male, 81% white), a model modified to remove variables not collected in TRACK-TBI, had an AUROC of 0.66 [0.53, 0.79], equivalent to the gold-standard IMPACT core+CT score (0.68; 95% AUROC difference CI: -0.2 to 0.2, p=0.8).

Conclusions and Relevance

We used the largest existing cohort of patients with DoC after TBI to develop, test and externally validate a prediction model of 1-year dependency. The model’s sensitivity and negative predictive value were greater than specificity and positive predictive value. Accuracy was diminished in an external sample, but equivalent to the best-available models. Further research is needed to improve dependency prediction in patients with DoC after TBI.

Functional Recovery, Symptoms, and Quality of Life 1 to 5 Years After Traumatic Brain Injury

Importance

Many level I trauma center patients experience clinical sequelae at 1 year following traumatic brain injury (TBI). Longer-term outcome data are needed to develop better monitoring and rehabilitation services.

Objective

To examine functional recovery, TBI-related symptoms, and quality of life from 1 to 5 years postinjury.

Design, Setting, and Participants

This cohort study enrolled trauma patients across 18 US level I trauma centers between 2014 and 2018. Eligible participants were enrolled within 24 hours of injury and followed up to 5 years postinjury. Data were analyzed January 2023.

Exposures

Mild TBI (mTBI), moderate-severe TBI (msTBI), or orthopedic traumatic controls (OTC).

Main Outcomes and Measures

Functional independence (Glasgow Outcome Scale-Extended [GOSE] score 5 or higher), complete functional recovery (GOSE score, 8), better (ie, lower) TBI-related symptom burden (Rivermead Post Concussion Symptoms Questionnaire score of 15 or lower), and better (ie, higher) health-related quality of life (Quality of Life After Brain Injury Scale-Overall Scale score 52 or higher); mortality was analyzed as a secondary outcome.

Results

A total 1196 patients were included in analysis (mean [SD] age, 40.8 [16.9] years; 781 [65%] male; 158 [13%] Black, 965 [81%] White). mTBI and OTC groups demonstrated stable, high rates of functional independence (98% to 100% across time). While odds of independence were lower among msTBI survivors, the majority were independent at 1 year (72%), and this proportion increased over time (80% at 5 years; group × year, P = .005; independence per year: odds ratio [OR] for msTBI, 1.28; 95% CI, 1.03-1.58; OR for mTBI, 0.81; 95% CI, 0.64-1.03). For other outcomes, group differences at 1 year remained stable over time (group × year, P ≥ .44). Odds of complete functional recovery remained lower for persons with mTBI vs OTC (OR, 0.39; 95% CI, 0.28-0.56) and lower for msTBI vs mTBI (OR, 0.34; 95% CI, 0.24-0.48). Odds of better TBI-related symptom burden and quality of life were similar for both TBI subgroups and lower than OTCs. Mortality between 1 and 5 years was higher for msTBI (5.5%) than mTBI (1.5%) and OTC (0.7%; P = .02).

Conclusions and Relevance

In this cohort study, patients with previous msTBI displayed increased independence over 5 years; msTBI was also associated with increased mortality. These findings, in combination with the persistently elevated rates of unfavorable outcomes in mTBI vs controls imply that more monitoring and rehabilitation are needed for TBI.

Dizziness After Traumatic Brain Injury: A Prospective TRACK-TBI Analysis of Risk Factors, Quality of Life, and Neurocognitive Effects

OBJECTIVE

To determine the longitudinal incidence of dizziness and its association with demographic factors, neurocognitive effects, functionality, and quality of life.

STUDY DESIGN

Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) is a prospective, longitudinal cohort study in which TBI patients were assessed at the emergency department and 2-week, 3-month, 6-month, and 12-month follow-up via telephone and/or in-person visits.

SETTING

Multicenter study in emergency departments of 18 academic medical centers in the United States.

PATIENTS

A total of 1,514 patients 17 years or older with a diagnosis of TBI, injury occurrence within 24 hours of admission, fluency in English or Spanish, and completed Rivermead Post-Concussion Symptoms Questionnaire (RPQ) at 12 months were enrolled between February 2014 and August 2018.

MAIN OUTCOME MEASURE

RPQ, Short Form-12 Version 2, Wechsler Adult Intelligence Scale IV, Trail Making Test, Patient Health Questionnaire-9, PROMIS-PAIN, and Glasgow Outcome Scale-Extended Revised. The primary outcome measure was a self-report of "feelings of dizziness" on RPQ at 12 months post-TBI.

RESULTS

Of the 1,514 participants, 1,002 (66%) were male and 512 (34%) were female. The mean age was 41.6 (SD, 17.4) years. At 12 months, 26% experienced dizziness, with 9% experiencing moderate or severe dizziness. Dizziness was strongly associated with headache (odds ratio [OR], 3.45; 95% confidence interval [CI], 2.92-4.07; p < 0.001), nausea (OR, 4.43; 95% CI, 3.45-5.69; p < 0.001), worse hearing (OR, 3.57; 95% CI, 2.64-4.82; p < 0.001), noise sensitivity (OR, 3.02; 95% CI, 2.54-3.59; p < 0.001), and light sensitivity (OR, 3.51; 95% CI, 2.91-4.23; p < 0.001). In multivariable regression models, participants with severe dizziness demonstrated lower performance compared with those without new or worse dizziness on the Wechsler Adult Intelligence Scale IV (-6.64; p < 0.001), Trail Making Test part A (7.90; p = 0.003) and part B (19.77; p = 0.028), and Short Form-12 physical (-13.60; p < 0.001) and mental health (-11.17; p < 0.001), after controlling for age, sex, education, and TBI severity.

CONCLUSION

Dizziness is common among TBI patients and relates to quality of life and neurocognitive performance.

Association Between TBI-Related Hearing Impairment and Cognition: A TRACK-TBI Study

OBJECTIVE

To examine the association between hearing impairment and cognitive function after traumatic brain injury (TBI).

SETTING

A total of 18 level I trauma centers throughout the United States in the T ransforming R esearch a nd C linical K nowledge in TBI (TRACK-TBI) study.

PARTICIPANTS

From February 2014 to June 2018, a total of 2697 participants with TBI were enrolled in TRACK-TBI. Key eligibility criteria included external force trauma to the head, presentation to a participating level I trauma center, and receipt of a clinically indicated head computed tomographic (CT) scan within 24 hours of injury. A total of 1267 participants were evaluated in the study, with 216 participants with hearing impairment and 1051 participants without hearing impairment. Those with missing or unknown hearing status or cognitive assessment were excluded from analysis.

DESIGN

Prospective, observational cohort study.

MAIN MEASURES

Hearing impairment at 2 weeks post-TBI was based on self-report. Participants who indicated worse hearing in one or both ears were defined as having hearing impairment, whereas those who denied worse hearing in either ear were defined as not having hearing impairment and served as the reference group. Cognitive outcomes at 6 months post-TBI included executive functioning and processing speed, as measured by the Trail Making Test (TMT) B/A and the Wechsler Adult Intelligence Scale, Fourth Edition, Processing Speed Index subscale (WAIS-IV PSI), respectively.

RESULTS

TBI-related hearing impairment had a small but significantly greater TMT B/A ratio than without TBI-related hearing impairment: mean difference ( B ) = 0.25; 95% CI, 0.07 to 0.43; P = .005. No significant mean differences on WAIS-IV PSI scores were found between participants with and without TBI-related hearing impairment: B = 0.36; 95% CI, -2.07 to 2.60; P = .825.

CONCLUSION

We conclude that TBI-related hearing impairment at 6 months postinjury was significantly associated with worse executive functioning but not cognitive processing speed.

Outcomes in Patients With Mild Traumatic Brain Injury Without Acute Intracranial Traumatic Injury

IMPORTANCE

Traumatic brain injury (TBI) affects millions of people in the US each year. Most patients with TBI seen in emergency departments (EDs) have a Glasgow Coma Scale (GCS) score of 15 and a head computed tomography (CT) scan showing no acute intracranial traumatic injury (negative head CT scan), yet the short-term and long-term functional outcomes of this subset of patients remain unclear.

OBJECTIVE

To describe the 2-week and 6-month recovery outcomes in a cohort of patients with mild TBI with a GCS score of 15 and a negative head CT scan.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study analyzed participants who were enrolled from January 1, 2014, to December 31, 2018, in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, a prospective, observational cohort study of patients with TBI that was conducted in EDs of 18 level I trauma centers in urban areas. Of the total 2697 participants in the TRACK-TBI study, 991 had a GCS score of 15 and negative head CT scan and were eligible for inclusion in this analysis. Data were analyzed from September 1, 2021, to May 30, 2022.

MAIN OUTCOMES AND MEASURES

The primary outcome was the Glasgow Outcome Scale-Extended (GOS-E) score, which was stratified according to functional recovery (GOS-E score, 8) vs incomplete recovery (GOS-E score, <8), at 2 weeks and 6 months after the injury. The secondary outcome was severity of mild TBI-related symptoms assessed by the Rivermead Post Concussion Symptoms Questionnaire (RPQ) total score.

RESULTS

A total of 991 participants (mean [SD] age, 38.5 [15.8] years; 631 male individuals [64%]) were included. Of these participants, 751 (76%) were followed up at 2 weeks after the injury: 204 (27%) had a GOS-E score of 8 (functional recovery), and 547 (73%) had a GOS-E scores less than 8 (incomplete recovery). Of 659 participants (66%) followed up at 6 months after the injury, 287 (44%) had functional recovery and 372 (56%) had incomplete recovery. Most participants with incomplete recovery reported that they had not returned to baseline or preinjury life (88% [479 of 546]; 95% CI, 85%-90%). Mean RPQ score was 16 (95% CI, 14-18; P < .001) points lower at 2 weeks (7 vs 23) and 18 (95% CI, 16-20; P < .001) points lower at 6 months (4 vs 22) in participants with a GOS-E score of 8 compared with those with a GOS-E score less than 8.

CONCLUSIONS AND RELEVANCE

This study found that most participants with a GCS score of 15 and negative head CT scan reported incomplete recovery at 2 weeks and 6 months after their injury. The findings suggest that emergency department clinicians should recommend 2-week follow-up visits for these patients to identify those with incomplete recovery and to facilitate their rehabilitation.

Improving the Precision of the Glasgow Outcome Scale-Extended Using Item Response Theory: A TRACK-TBI Study

The Glasgow Outcome Scale-Extended (GOSE) is a functional outcome measure intended to place individuals with traumatic brain injury (TBI) into one of eight broad levels of injury-related disability. This simplicity is not always optimal, particularly when more granular assessment of individuals' injury recovery is desired. The GOSE, however, is customarily assessed using a multi-question interview that contains richer information than is reflected in the GOSE score. Using data from the multi-center Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study (N = 1544), we used item response theory (IRT) to evaluate whether rescoring the GOSE using IRT, which posits that a continuous latent variable (disability) underlies responses, can yield a more precise index of injury-related functional limitations. We fit IRT models to GOSE interview responses collected at three months post-injury. Each participant's level of functional limitation was estimated from the model (GOSE-IRT) and comparisons were made between IRT-based and standard (GOSE-Ordinal) scores. The IRT scoring resulted in 141 possible scores (vs. 7 GOSE-Ordinal scores in this sample of individuals with GOSE scores ranging between 2 and 8). Moreover, GOSE-IRT scores were significantly more strongly associated with measures of TBI-related symptoms, psychological symptoms, and quality of life. Our findings demonstrate that rescoring the GOSE interview using IRT yields more granular, meaningful measurement of injury-related functional limitations, while adding no additional respondent or examiner burden. This technique may have utility for many applications, such as clinical trials aiming to detect small treatment effects, and small-scale studies that need to maximize statistical efficiency.

How Do Scores on the Functional Status Examination (FSE) Correspond to Scores on the Glasgow Outcome Scale-Extended (GOSE)?

This study was designed to determine how raw scores correspond between two alternative measures of functional recovery from traumatic brain injury (TBI), the Functional Status Examination (FSE) and the Glasgow Outcome Scale-Extended (GOSE). Using data from 357 persons with moderate-severe TBI who participated in a large clinical trial, we performed item response theory analysis to characterize the relationship between functional ability measured by the FSE and GOSE at 6 months post-injury. Results revealed that raw scores for the FSE and GOSE can be linked, and a table is provided to translate scores from one instrument to the other. For example, a FSE score of 7 (on its 0-21 scale, where higher scores reflect more impairment) is equivalent to a GOSE score of 6 (where GOSE is scaled on an 8-point scale, with higher scores reflecting less impairment). These results allow clinicians or researchers who have a score for a person on one instrument to cross-reference it to a score on the other instrument. Importantly, this enables researchers to combine data sets where some persons only completed the GOSE and some only the FSE. In addition, an investigator could save participant time by eliminating one instrument from a battery of tests, yet still retain a score on that instrument for each participant. More broadly, the findings help anchor scores from these two instruments to the broader continuum of injury-related functional limitations.

Functional Status Examination Yields Higher Measurement Precision than the Glasgow Outcome Scale-Extended after Moderate-to-Severe Traumatic Brain Injury

A limited evidence base supports the Functional Status Examination (FSE) as superior to the more commonly used Glasgow Outcome Scale-Extended (GOSE) for precisely characterizing injury-related functional limitations. The aim of this study was to use modern psychometric tools to test the hypothesis that the FSE is more precise than the GOSE in characterizing individual differences in functional limitations after moderate-to-severe traumatic brain injury (TBI). Secondarily, we sought to confirm that the type of interviewee (patient, significant other) does not affect the test performance of the FSE. Using data from 357 individuals with TBI who participated in the Magnesium Sulfate clinical trial and had six-month outcome data, we performed item response theory (IRT) analyses comparing the FSE and GOSE at six months post-injury. Results showed that the FSE yielded higher measurement precision (IRT test information) than the GOSE across most of the disability severity spectrum. The GOSE yielded more information than the FSE at a very high level of disability, because of the GOSE's assignment of a unique score for individuals who are in a vegetative state. Finally, the FSE showed no evidence of differential item functioning by interviewee, indicating it is appropriate to interview either persons with TBI or significant others and combine data across respondents as is typically done. The findings support the FSE as a viable and oftentimes advantageous substitute for the GOSE in clinical trials and translational studies of TBI.

Association of Posttraumatic Epilepsy With 1-Year Outcomes After Traumatic Brain Injury

IMPORTANCE

Posttraumatic epilepsy (PTE) is a recognized sequela of traumatic brain injury (TBI), but the long-term outcomes associated with PTE independent of injury severity are not precisely known.

OBJECTIVE

To determine the incidence, risk factors, and association with functional outcomes and self-reported somatic, cognitive, and psychological concerns of self-reported PTE in a large, prospectively collected TBI cohort.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, prospective cohort study was conducted as part of the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study and identified patients presenting with TBI to 1 of 18 participating level 1 US trauma centers from February 2014 to July 2018. Patients with TBI, extracranial orthopedic injuries (orthopedic controls), and individuals without reported injuries (eg, friends and family of participants; hereafter friend controls) were prospectively followed for 12 months. Data were analyzed from January 2020 to April 2021.

EXPOSURE

Demographic, imaging, and clinical information was collected according to TBI Common Data Elements. Incidence of self-reported PTE was assessed using the National Institute of Neurological Disorders and Stroke Epilepsy Screening Questionnaire (NINDS-ESQ).

MAIN OUTCOMES AND MEASURES

Primary outcomes included Glasgow Outcome Scale Extended, Rivermead Cognitive Metric (RCM; derived from the Rivermead Post Concussion Symptoms Questionnaire), and the Brief Symptom Inventory-18 (BSI).

RESULTS

Of 3296 participants identified as part of the study, 3044 met inclusion criteria, and 1885 participants (mean [SD] age, 41.3 [17.1] years; 1241 [65.8%] men and 644 [34.2%] women) had follow-up information at 12 months, including 1493 patients with TBI; 182 orthopedic controls, 210 uninjured friend controls; 41 patients with TBI (2.8%) and no controls had positive screening results for PTE. Compared with a negative screening result for PTE, having a positive screening result for PTE was associated with presenting Glasgow Coma Scale score (8.1 [4.8] vs.13.5 [3.3]; P < .001) as well as with anomalous acute head imaging findings (risk ratio, 6.42 [95% CI, 2.71-15.22]). After controlling for age, initial Glasgow Coma Scale score, and imaging findings, compared with patients with TBI and without PTE, patients with TBI and with positive PTE screening results had significantly lower Glasgow Outcome Scale Extended scores (mean [SD], 6.1 [1.7] vs 4.7 [1.5]; P < .001), higher BSI scores (mean [SD], 50.2 [10.7] vs 58.6 [10.8]; P = .02), and higher RCM scores (mean [SD], 3.1 [2.6] vs 5.3 [1.9]; P = .002) at 12 months.

CONCLUSIONS AND RELEVANCE

In this cohort study, the incidence of self-reported PTE after TBI was found to be 2.8% and was independently associated with unfavorable outcomes. These findings highlight the need for effective antiepileptogenic therapies after TBI.

Interrater Reliability of National Institutes of Health Traumatic Brain Injury Imaging Common Data Elements for Brain Magnetic Resonance Imaging in Mild Traumatic Brain Injury

The National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH-NINDS) Traumatic Brain Injury (TBI) Imaging Common Data Elements (CDEs) are standardized definitions for pathological intracranial lesions based on their appearance on neuroimaging studies. The NIH-NINDS TBI Imaging CDEs were designed to be as consistent as possible with the U.S. Food and Drug Administration (FDA) definition of biomarkers as "an indicator of normal biological processes, pathogenic processes, or biological responses to an exposure or intervention." However, the FDA qualification process for biomarkers requires proof of reliable biomarker test measurements. We determined the interrater reliability of TBI Imaging CDEs on subacute brain magnetic resonance imaging (MRI) performed on 517 mild TBI patients presenting to 11 U.S. level 1 trauma centers. Three U.S. board-certified neuroradiologists independently evaluated brain MRI performed 2 weeks post-injury for the following CDEs: traumatic axonal injury (TAI), diffuse axonal injury (DAI), and brain contusion. We found very high interrater agreement for brain contusion, with prevalence- and bias-adjusted kappa (PABAK) values for pairs of readers from 0.92 [95% confidence interval, 0.88-0.95] to 0.94 [0.90-0.96]. We found intermediate agreement for TAI and DAI, with PABAK values of 0.74-0.78 [0.70-0.82]. The near-perfect agreement for subacute brain contusion is likely attributable to the high conspicuity and distinctive appearance of these lesions on T1-weighted images. Interrater agreement for TAI and DAI was lower, because signal void in small vascular structures, and artifactual foci of signal void, can be difficult to distinguish from the punctate round or linear areas of slight hemorrhage that are a common hallmark of TAI/DAI on MRI.

Depression in Older Adults 12 Months Following Traumatic Brain Injury: A TRACK-TBI Study

OBJECTIVE

To investigate depression at 12 months following traumatic brain injury (TBI) in older compared with younger adults.

DESIGN

Prospective longitudinal cohort study of persons with medically documented mild, moderate, and severe TBI at 12 months post-injury.

SETTING

Eighteen participating Level One trauma centers in the U.S.

PARTICIPANTS

1,505 participants with TBI and primary outcome data at 12-month follow-up.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE

Patient Health Questionnaire-9 (PHQ-9).

RESULTS

PHQ-9 total scores were significantly lower for older adults (age≥65)(M = 3.2) as compared with younger adults (age<65)(M = 5.0) (B = -1.63, p < .001), indicating less depressive symptoms in older adults. Age did not interact with education, sex, race/ethnicity, psychiatric history, substance use, or GCS severity to impact PHQ-9 scores. Of the 29% of older adults who endorsed symptoms consistent with depression, 14% were classified as minor depression and 15% as major depression. The odds of older adults falling in the major depression vs. no depression group was significantly lower (decreased by 56%) as compared with younger adults (OR = 0.44, p =.001).

CONCLUSIONS

At 12-months post-TBI, older adults endorse lower depressive symptoms than their younger counterparts and are less likely to experience major depression; however, over one-fourth of older adults endorsed symptoms consistent with depression, warranting evaluation and treatment.

Hypothermia for Patients Requiring Evacuation of Subdural Hematoma: A Multicenter Randomized Clinical Trial

Background

Hypothermia is neuroprotective in some ischemia–reperfusion injuries. Ischemia–reperfusion injury may occur with traumatic subdural hematoma (SDH). This study aimed to determine whether early induction and maintenance of hypothermia in patients with acute SDH would lead to decreased ischemia–reperfusion injury and improve global neurologic outcome.

Methods

This international, multicenter randomized controlled trial enrolled adult patients with SDH requiring evacuation of hematoma within 6 h of injury. The intervention was controlled temperature management of hypothermia to 35 °C prior to dura opening followed by 33 °C for 48 h compared with normothermia (37 °C). Investigators randomly assigned patients at a 1:1 ratio between hypothermia and normothermia. Blinded evaluators assessed outcome using a 6-month Glasgow Outcome Scale Extended score. Investigators measured circulating glial fibrillary acidic protein and ubiquitin C-terminal hydrolase L1 levels.

Results

Independent statisticians performed an interim analysis of 31 patients to assess the predictive probability of success and the Data and Safety Monitoring Board recommended the early termination of the study because of futility. Thirty-two patients, 16 per arm, were analyzed. Favorable 6-month Glasgow Outcome Scale Extended outcomes were not statistically significantly different between hypothermia vs. normothermia groups (6 of 16, 38% vs. 4 of 16, 25%; odds ratio 1.8 [95% confidence interval 0.39 to ∞], p = .35). Plasma levels of glial fibrillary acidic protein (p = .036), but not ubiquitin C-terminal hydrolase L1 (p = .26), were lower in the patients with favorable outcome compared with those with unfavorable outcome, but differences were not identified by temperature group. Adverse events were similar between groups.

Conclusions

This trial of hypothermia after acute SDH evacuation was terminated because of a low predictive probability of meeting the study objectives. There was no statistically significant difference in functional outcome identified between temperature groups.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01334-w.

A Manual for the Glasgow Outcome Scale-Extended Interview

The Glasgow Outcome Scale-Extended (GOSE) has become one of the most widely used outcome instruments to assess global disability and recovery after traumatic brain injury. Achieving consistency in the application of the assessment remains a challenge, particularly in multi-center studies involving many assessors. We present a manual for the GOSE interview that is designed to support both single- and multi-center studies and promote inter-rater agreement. Many patients fall clearly into a particular category; however, patients may have outcomes that are on the borderline between adjacent categories, and cases can present other challenges for assessment. The Manual includes the general principles of assessment, advice on administering each section of the GOSE interview, and guidance on "borderline" and "difficult" cases. Finally, we discuss the properties of the GOSE, including strengths and limitations, and outline recommendations for assessor training, accreditation, and monitoring.

Central Curation of Glasgow Outcome Scale-Extended Data: Lessons Learned from TRACK-TBI

The Glasgow Outcome Scale (GOS) in its original or extended (GOSE) form is the most widely used assessment of global disability in traumatic brain injury (TBI) research. Several publications have reported concerns about assessor scoring inconsistencies, but without documentation of contributing factors. We reviewed 6801 GOSE assessments collected longitudinally, across 18 sites in the 5-year, observational Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study. We recorded error rates (i.e., corrections to a section or an overall rating) based on site assessor documentation and categorized scoring issues, which then informed further training. In cohort 1 (n = 1261; February 2014 to May 2016), 24% of GOSEs had errors identified by central review. In cohort 2 (n = 1130; June 2016 to July 2018), acquired after curation of cohort 1 data, feedback, and further training of site assessors, the error rate was reduced to 10%. GOSE sections associated with the most frequent interpretation and scoring difficulties included whether current functioning represented a change from pre-injury (466 corrected ratings in cohort 1; 62 in cohort 2), defining dependency in the home and community (163 corrections in cohort 1; three in cohort 2) and return to work/school (72 corrections in cohort 1; 35 in cohort 2). These results highlight the importance of central review in improving consistency across sites and over time. Establishing clear scoring criteria, coupled with ongoing guidance and feedback to data collectors, is essential to avoid scoring errors and resultant misclassification, which carry potential to result in "failure" of clinical trials that rely on the GOSE as their primary outcome measure.

Functional Outcomes Over the First Year After Moderate to Severe Traumatic Brain Injury in the Prospective, Longitudinal TRACK-TBI Study

Importance

Moderate to severe traumatic brain injury (msTBI) is a major cause of death and disability in the US and worldwide. Few studies have enabled prospective, longitudinal outcome data collection from the acute to chronic phases of recovery after msTBI.

Objective

To prospectively assess outcomes in major areas of life function at 2 weeks and 3, 6, and 12 months after msTBI.

Design, Setting, and Participants

This cohort study, as part of the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study, was conducted at 18 level 1 trauma centers in the US from February 2014 to August 2018 and prospectively assessed longitudinal outcomes, with follow-up to 12 months postinjury. Participants were patients with msTBI (Glasgow Coma Scale scores 3-12) extracted from a larger group of patients with mild, moderate, or severe TBI who were enrolled in TRACK-TBI. Data analysis took place from October 2019 to April 2021.

Exposures

Moderate or severe TBI.

Main Outcomes and Measures

The Glasgow Outcome Scale-Extended (GOSE) and Disability Rating Scale (DRS) were used to assess global functional status 2 weeks and 3, 6, and 12 months postinjury. Scores on the GOSE were dichotomized to determine favorable (scores 4-8) vs unfavorable (scores 1-3) outcomes. Neurocognitive testing and patient reported outcomes at 12 months postinjury were analyzed.

Results

A total of 484 eligible patients were included from the 2679 individuals in the TRACK-TBI study. Participants with severe TBI (n = 362; 283 men [78.2%]; median [interquartile range] age, 35.5 [25-53] years) and moderate TBI (n = 122; 98 men [80.3%]; median [interquartile range] age, 38 [25-53] years) were comparable on demographic and premorbid variables. At 2 weeks postinjury, 36 of 290 participants with severe TBI (12.4%) and 38 of 93 participants with moderate TBI (41%) had favorable outcomes (GOSE scores 4-8); 301 of 322 in the severe TBI group (93.5%) and 81 of 103 in the moderate TBI group (78.6%) had moderate disability or worse on the DRS (total score ≥4). By 12 months postinjury, 142 of 271 with severe TBI (52.4%) and 54 of 72 with moderate TBI (75%) achieved favorable outcomes. Nearly 1 in 5 participants with severe TBI (52 of 270 [19.3%]) and 1 in 3 with moderate TBI (23 of 71 [32%]) reported no disability (DRS score 0) at 12 months. Among participants in a vegetative state at 2 weeks, 62 of 79 (78%) regained consciousness and 14 of 56 with available data (25%) regained orientation by 12 months.

Conclusions and Relevance

In this study, patients with msTBI frequently demonstrated major functional gains, including recovery of independence, between 2 weeks and 12 months postinjury. Severe impairment in the short term did not portend poor outcomes in a substantial minority of patients with msTBI. When discussing prognosis during the first 2 weeks after injury, clinicians should be particularly cautious about making early, definitive prognostic statements suggesting poor outcomes and withdrawal of life-sustaining treatment in patients with msTBI.

Prognostic Value of Hemorrhagic Brainstem Injury on Early Computed Tomography: A TRACK-TBI Study

BACKGROUND

Traumatic brainstem injury has yet to be incorporated into widely used imaging classification systems for traumatic brain injury (TBI), and questions remain regarding prognostic implications for this TBI subgroup. To address this, retrospective data on patients from the multicenter prospective Transforming Research and Clinical Knowledge in TBI study were studied.

METHODS

Patients with brainstem and cerebrum injury (BSI+) were matched by age, sex, and admission Glasgow Coma Scale (GCS) score to patients with cerebrum injuries only. All patients had an interpretable head computed tomography (CT) scan from the first 48 hours after injury and a 6-month Glasgow Outcome Scale Extended (GOSE) score. CT scans were reviewed for brainstem lesions and, when present, characterized by location, size, and type (traumatic axonal injury, contusion, or Duret hemorrhage). Clinical, demographic, and outcome data were then compared between the two groups.

RESULTS

Mann-Whitney U-tests showed no significant difference in 6-month GOSE scores in patients with BSI+ (mean 2.7) compared with patients with similar but only cerebrum injuries (mean 3.9), although there is a trend (p = 0.10). However, subclassification by brainstem lesion type, traumatic axonal injury (mean 4.0) versus Duret hemorrhage or contusion (mean 1.4), did identify a proportion of BSI+ with significantly less favorable outcome (p = 0.002). The incorporation of brainstem lesion type (traumatic axonal injury vs. contusion/Duret), along with GCS into a multivariate logistic regression model of favorable outcome (GOSE score 4-8) did show a significant contribution to the prognostication of this brainstem injury subgroup (odds ratio 0.08, 95% confidence interval 0.00-0.67, p = 0.01).

CONCLUSIONS

These findings suggest two groups of patients with brainstem injuries may exist with divergent recovery potential after TBI. These data support the notion that newer CT imaging classification systems may augment traditional clinical measures, such as GCS in identifying those patients with TBI and brainstem injuries that stand a higher chance of favorable outcome.

Pathological Computed Tomography Features Associated With Adverse Outcomes After Mild Traumatic Brain Injury: A TRACK-TBI Study With External Validation in CENTER-TBI

Question

Are different patterns of intracranial injury on head computed tomography associated with prognosis after mild traumatic brain injury (mTBI)?

Findings

In this cohort study, subarachnoid hemorrhage, subdural hematoma, and contusion often co-occurred and were associated with both incomplete recovery and more severe impairment out to 12 months after injury, while intraventricular and/or petechial hemorrhage co-occurred and were associated with more severe impairment up to 12 months after injury; epidural hematoma was associated with incomplete recovery at some points but not with more severe impairment. Some intracranial hemorrhage patterns were more strongly associated with outcomes than previously validated demographic and clinical variables.

Meaning

In this study, different pathological features on head computed tomography carried different implications for mild traumatic brain injury prognosis to 1 year.

Importance

A head computed tomography (CT) with positive results for acute intracranial hemorrhage is the gold-standard diagnostic biomarker for acute traumatic brain injury (TBI). In moderate to severe TBI (Glasgow Coma Scale [GCS] scores 3-12), some CT features have been shown to be associated with outcomes. In mild TBI (mTBI; GCS scores 13-15), distribution and co-occurrence of pathological CT features and their prognostic importance are not well understood.

Objective

To identify pathological CT features associated with adverse outcomes after mTBI.

Design, Setting, and Participants

The longitudinal, observational Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study enrolled patients with TBI, including those 17 years and older with GCS scores of 13 to 15 who presented to emergency departments at 18 US level 1 trauma centers between February 26, 2014, and August 8, 2018, and underwent head CT imaging within 24 hours of TBI. Evaluations of CT imaging used TBI Common Data Elements. Glasgow Outcome Scale–Extended (GOSE) scores were assessed at 2 weeks and 3, 6, and 12 months postinjury. External validation of results was performed via the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. Data analyses were completed from February 2020 to February 2021.

Exposures

Acute nonpenetrating head trauma.

Main Outcomes and Measures

Frequency, co-occurrence, and clustering of CT features; incomplete recovery (GOSE scores <8 vs 8); and an unfavorable outcome (GOSE scores <5 vs ≥5) at 2 weeks and 3, 6, and 12 months.

Results

In 1935 patients with mTBI (mean [SD] age, 41.5 [17.6] years; 1286 men [66.5%]) in the TRACK-TBI cohort and 2594 patients with mTBI (mean [SD] age, 51.8 [20.3] years; 1658 men [63.9%]) in an external validation cohort, hierarchical cluster analysis identified 3 major clusters of CT features: contusion, subarachnoid hemorrhage, and/or subdural hematoma; intraventricular and/or petechial hemorrhage; and epidural hematoma. Contusion, subarachnoid hemorrhage, and/or subdural hematoma features were associated with incomplete recovery (odds ratios [ORs] for GOSE scores <8 at 1 year: TRACK-TBI, 1.80 [95% CI, 1.39-2.33]; CENTER-TBI, 2.73 [95% CI, 2.18-3.41]) and greater degrees of unfavorable outcomes (ORs for GOSE scores <5 at 1 year: TRACK-TBI, 3.23 [95% CI, 1.59-6.58]; CENTER-TBI, 1.68 [95% CI, 1.13-2.49]) out to 12 months after injury, but epidural hematoma was not. Intraventricular and/or petechial hemorrhage was associated with greater degrees of unfavorable outcomes up to 12 months after injury (eg, OR for GOSE scores <5 at 1 year in TRACK-TBI: 3.47 [95% CI, 1.66-7.26]). Some CT features were more strongly associated with outcomes than previously validated variables (eg, ORs for GOSE scores <5 at 1 year in TRACK-TBI: neuropsychiatric history, 1.43 [95% CI .98-2.10] vs contusion, subarachnoid hemorrhage, and/or subdural hematoma, 3.23 [95% CI 1.59-6.58]). Findings were externally validated in 2594 patients with mTBI enrolled in the CENTER-TBI study.

Conclusions and Relevance

In this study, pathological CT features carried different prognostic implications after mTBI to 1 year postinjury. Some patterns of injury were associated with worse outcomes than others. These results support that patients with mTBI and these CT features need TBI-specific education and systematic follow-up.

High-Sensitivity C-Reactive Protein is a Prognostic Biomarker of Six-Month Disability after Traumatic Brain Injury: Results from the TRACK-TBI Study

Systemic inflammation impacts outcome after traumatic brain injury (TBI), but most TBI biomarker studies have focused on brain-specific proteins. C-reactive protein (CRP) is a widely used biomarker of inflammation with potential as a prognostic biomarker after TBI. The Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study prospectively enrolled TBI patients within 24 h of injury, as well as orthopedic injury and uninjured controls; biospecimens were collected at enrollment. A subset of hospitalized participants had blood collected on day 3, day 5, and 2 weeks. High-sensitivity CRP (hsCRP) and glial fibrillary acidic protein (GFAP) were measured. Receiver operating characteristic analysis was used to evaluate the prognostic ability of hsCRP for 6-month outcome, using the Glasgow Outcome Scale-Extended (GOSE). We included 1206 TBI subjects, 122 orthopedic trauma controls (OTCs), and 209 healthy controls (HCs). Longitudinal biomarker sampling was performed in 254 hospitalized TBI subjects and 19 OTCs. hsCRP rose between days 1 and 5 for TBI and OTC subjects, and fell by 2 weeks, but remained elevated compared with HCs (p < 0.001). Longitudinally, hsCRP was significantly higher in the first 2 weeks for subjects with death/severe disability (GOSE <5) compared with those with moderate disability/good recovery (GOSE ≥5); AUC was highest at 2 weeks (AUC = 0.892). Combining hsCRP and GFAP at 2 weeks produced AUC = 0.939 for prediction of disability. Serum hsCRP measured within 2 weeks of TBI is a prognostic biomarker for disability 6 months later. hsCRP may have utility as a biomarker of target engagement for anti-inflammatory therapies.

Association of Sex and Age With Mild Traumatic Brain Injury-Related Symptoms: A TRACK-TBI Study

IMPORTANCE

Knowledge of differences in mild traumatic brain injury (mTBI) recovery by sex and age may inform individualized treatment of these patients.

OBJECTIVE

To identify sex-related differences in symptom recovery from mTBI; secondarily, to explore age differences within women, who demonstrate poorer outcomes after TBI.

DESIGN, SETTING, AND PARTICIPANTS

The prospective cohort study Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) recruited 2000 patients with mTBI from February 26, 2014, to July 3, 2018, and 299 patients with orthopedic trauma (who served as controls) from January 26, 2016, to July 27, 2018. Patients were recruited from 18 level I trauma centers and followed up for 12 months. Data were analyzed from August 19, 2020, to March 3, 2021.

EXPOSURES

Patients with mTBI (defined by a Glasgow Coma Scale score of 13-15) triaged to head computed tomography in 24 hours or less; patients with orthopedic trauma served as controls.

MAIN OUTCOMES AND MEASURES

Measured outcomes included (1) the Rivermead Post Concussion Symptoms Questionnaire (RPQ), a 16-item self-report scale that assesses postconcussion symptom severity over the past 7 days relative to preinjury; (2) the Posttraumatic Stress Disorder Checklist for the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (PCL-5), a 20-item test that measures the severity of posttraumatic stress disorder symptoms; (3) the Patient Health Questionnaire-9 (PHQ-9), a 9-item scale that measures depression based on symptom frequency over the past 2 weeks; and (4) the Brief Symptom Inventory-18 (BSI-18), an 18-item scale of psychological distress (split into Depression and Anxiety subscales).

RESULTS

A total of 2000 patients with mTBI (1331 men [67%; mean (SD) age, 41.0 (17.3) years; 1026 White (78%)] and 669 women [33%; mean (SD) age, 43.0 (18.5) years; 505 (76%) White]). After adjustment of multiple comparisons, significant TBI × sex interactions were observed for cognitive symptoms (B = 0.76; 5% false discovery rate-corrected P = .02) and somatic RPQ symptoms (B = 0.80; 5% false discovery rate-corrected P = .02), with worse symptoms in women with mTBI than men, but no sex difference in symptoms in control patients with orthopedic trauma. Within the female patients evaluated, there was a significant TBI × age interaction for somatic RPQ symptoms, which were worse in female patients with mTBI aged 35 to 49 years compared with those aged 17 to 34 years (B = 1.65; P = .02) or older than 50 years (B = 1.66; P = .02).

CONCLUSIONS AND RELEVANCE

This study found that women were more vulnerable than men to persistent mTBI-related cognitive and somatic symptoms, whereas no sex difference in symptom burden was seen after orthopedic injury. Postconcussion symptoms were also worse in women aged 35 to 49 years than in younger and older women, but further investigation is needed to corroborate these findings and to identify the mechanisms involved. Results suggest that individualized clinical management of mTBI should consider sex and age, as some women are especially predisposed to chronic postconcussion symptoms even 12 months after injury.

Re-examining decompressive craniectomy medial margin distance from midline as a metric for calculating the risk of post-traumatic hydrocephalus

Decompressive craniectomy (DC) is a life-saving procedure in severe traumatic brain injury, but is associated with higher rates of post-traumatic hydrocephalus (PTH). The relationship between the medial craniectomy margin's proximity to midline and frequency of developing PTH is controversial. The primary study objective was to determine whether average medial craniectomy margin distance from midline was closer to midline in patients who developed PTH after DC for severe TBI compared to patients that did not. The secondary objective was to determine if a threshold distance from midline could be identified, at which the risk of developing PTH increased if the DC was performed closer to midline than this threshold. A retrospective review was performed of 380 patients undergoing DC at a single institution between March 2004 and November 2014. Clinical, operative and demographic variables were collected, including age, sex, DC parameters and occurrence of PTH. Statistical analysis compared mean axial craniectomy margin distance from midline in patients with versus without PTH. Distances from midline were tested as potential thresholds. No significant difference was identified in mean axial craniectomy margin distance from midline in patients developing PTH compared with patients with no PTH (n = 24, 12.8 mm versus n = 356, 16.6 mm respectively, p = 0.086). No significant cutoff distance from midline was identified (n = 212, p = 0.201). This study, the largest to date, was unable to identify a threshold with sufficient discrimination to support clinical recommendations in terms of DC margins with regard to midline, including thresholds reportedly significant in previously published research.

Validity of the Brief Test of Adult Cognition by Telephone in Level 1 Trauma Center Patients Six Months Post-Traumatic Brain Injury: A TRACK-TBI Study

Our objective was to examine the construct validity of the Brief Test of Adult Cognition by Telephone (BTACT) and its relationship to traumatic brain injury (TBI) of differing severities. Data were analyzed on 1422 patients with TBI and 170 orthopedic trauma controls (OTC) from the multi-center Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study. Participants were assessed at 6 months post-injury with the BTACT and an in-person neuropsychological battery. We examined the BTACT's factor structure, factorial group invariance, convergent and discriminant validity, and relationship to TBI and TBI severity. Confirmatory factor analysis supported both a 1-factor model and a 2-factor model comprising correlated Episodic Memory and Executive Function (EF) factors. Both models demonstrated strict invariance across TBI severity and OTC groups. Correlations between BTACT and criterion measures suggested that the BTACT memory indices predominantly reflect verbal episodic memory, whereas the BTACT EF factor correlated with a diverse range of cognitive tests. Although the EF factor and other BTACT indices showed significant relationships with TBI and TBI severity, some group effect sizes were larger for more comprehensive in-person cognitive tests than the BTACT. The BTACT is a promising, brief, phone-based cognitive screening tool for patients with TBI. Although the BTACT's memory items appear to index verbal Episodic Memory, items that purport to assess EFs may reflect a broader array of cognitive domains. The sensitivity of the BTACT to TBI severity is lower than domain-specific neuropsychological measures, suggesting it should not be used as a substitute for comprehensive, in-person cognitive testing at 6 months post-TBI.

Comparison of Clinical Outcomes 1 and 5 Years Post-Injury Following Combat Concussion

OBJECTIVE

To compare 1-year and 5-year clinical outcomes in 2 groups of combat-deployed service members without brain injury to those of 2 groups with combat-related concussion to better understand long-term clinical outcome trajectories.

METHODS

This prospective, observational, longitudinal multicohort study examined 4 combat-deployed groups: controls without head injury with or without blast exposure and patients with combat concussion arising from blast or blunt trauma. One-year and 5-year clinical evaluations included identical batteries for neurobehavioral, psychiatric, and cognitive outcomes. A total of 347 participants completed both time points of evaluation. Cross-sectional and longitudinal comparisons were assessed. Overall group effect was modeled as a 4-category variable with rank regression adjusting for demographic factors using a 2-sided significance threshold of 0.05, with post hoc Tukey p values calculated for the pairwise comparisons.

RESULTS

Significant group differences in both combat concussion groups were identified cross-sectionally at 5-year follow-up compared to controls in neurobehavioral (Neurobehavioral Rating Scale-Revised [NRS]; Cohen d, -1.10 to -1.40, confidence intervals [CIs] [-0.82, -1.32] to [-0.97, -1.83] by group) and psychiatric domains (Clinician-Administered PTSD Scale for DSM-IV [CAPS]; Cohen d, -0.91 to -1.19, CIs [-0.63, -1.19] to [-0.76, -1.62] by group) symptoms with minimal differences in cognitive performance. Both combat concussion groups also showed clinically significant decline from 1- to 5-year evaluation (66%-76% neurobehavioral NRS; 41%-54% psychiatric CAPS by group). Both control groups fared better but a subset also had clinically significant decline (37%-50% neurobehavioral NRS; 9%-25% psychiatric CAPS by group).

CONCLUSIONS

There was an evolution, not resolution, of symptoms from 1- to 5-year evaluation, challenging the assumption that chronic stages of concussive injury are relatively stable. Even some of the combat-deployed controls worsened. The evidence supports new considerations for chronic trajectories of concussion outcome in combat-deployed service members.

Statistical Guidelines for Handling Missing Data in Traumatic Brain Injury Clinical Research

Missing data is a persistent and unavoidable problem in even the most carefully designed traumatic brain injury (TBI) clinical research. Missing data patterns may result from participant dropout, non-compliance, technical issues, or even death. This review describes the types of missing data that are common in TBI research, and assesses the strengths and weaknesses of the statistical approaches used to draw conclusions and make clinical decisions from these data. We review recent innovations in missing values analysis (MVA), a relatively new branch of statistics, as applied to clinical TBI data. Our discussion focuses on studies from the International Traumatic Brain Injury Research (InTBIR) initiative project: Transforming Research and Clinical Knowledge in TBI (TRACK-TBI), Collaborative Research on Acute TBI in Intensive Care Medicine in Europe (CREACTIVE), and Approaches and Decisions in Acute Pediatric TBI Trial (ADAPT). In addition, using data from the TRACK-TBI pilot study (n = 586) and the completed clinical trial assessing valproate (VPA) for the treatment of post-traumatic epilepsy (n = 379) we present real-world examples of typical missing data patterns and the application of statistical techniques to mitigate the impact of missing data in order to draw sound conclusions from ongoing clinical studies.

The Functional Status Examination in Mild Traumatic Brain Injury: A TRACK-TBI Sub-Study

OBJECTIVE

The Functional Status Examination (FSE) is a comprehensive measure of functional status post-traumatic brain injury (TBI) that has primarily been used in studies of moderate-to-severe TBI. The present observational study examines functional status using the FSE among patients who sustained mild TBIs (mTBIs; defined as Glasgow Coma Scale [GCS] = 13-15 at admission) seen in a Level 1 trauma center. Study aims included examining the course of functional status following mTBI, as well as exploring relationships of the FSE and other relevant constructs among those with GCS = 13-15.

METHOD

Participants were assessed at 2 weeks (n = 112), 3 months (n = 113), 6 months (n = 106), and 12 months (n = 88) post-injury for changes in functional status resulting both (a) from all injuries and (b) from TBI only.

RESULTS

Among seven domains of day-to-day functioning, participants generally experienced the greatest disruption in their primary activity (work or school) and in leisure and recreation. Subjects' overall functional status tended to improve over time, with sharpest increases in functionality occurring in the first 3 months post-injury. However, some subjects continued to report functional limitations even at 12 months post-injury. Functional status was largely unrelated to neurocognitive functioning, but related strongly to post-traumatic symptoms, life satisfaction, and emotional well-being, particularly at 3 months post-injury and beyond.

CONCLUSION

Findings indicate that functional impairments related to mTBI may be more likely to persist than widely believed, with those who experience lingering functional deficits at particular risk for emotional health difficulties.

Recovery After Mild Traumatic Brain Injury in Patients Presenting to US Level I Trauma Centers: A Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Study

Importance

Most traumatic brain injuries (TBIs) are classified as mild (mTBI) based on admission Glasgow Coma Scale (GCS) scores of 13 to 15. The prevalence of persistent functional limitations for these patients is unclear.

Objectives

To characterize the natural history of recovery of daily function following mTBI vs peripheral orthopedic traumatic injury in the first 12 months postinjury using data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, and, using clinical computed tomographic (CT) scans, examine whether the presence (CT+) or absence (CT-) of acute intracranial findings in the mTBI group was associated with outcomes.

Design, Setting, and Participants

TRACK-TBI, a cohort study of patients with mTBI presenting to US level I trauma centers, enrolled patients from February 26, 2014, to August 8, 2018, and followed up for 12 months. A total of 1453 patients at 11 level I trauma center emergency departments or inpatient units met inclusion criteria (ie, mTBI [n = 1154] or peripheral orthopedic traumatic injury [n = 299]) and were enrolled within 24 hours of injury; mTBI participants had admission GCS scores of 13 to 15 and clinical head CT scans. Patients with peripheral orthopedic trauma injury served as the control (OTC) group.

Exposures

Participants with mTBI or OTC.

Main Outcomes and Measures

The Glasgow Outcome Scale Extended (GOSE) scale score, reflecting injury-related functional limitations across broad life domains at 2 weeks and 3, 6, and 12 months postinjury was the primary outcome. The possible score range of the GOSE score is 1 (dead) to 8 (upper good recovery), with a score less than 8 indicating some degree of functional impairment.

Results

Of the 1453 participants, 953 (65.6%) were men; mean (SD) age was 40.9 (17.1) years in the mTBI group and 40.9 (15.4) years in the OTC group. Most participants (mTBI, 87%; OTC, 93%) reported functional limitations (GOSE <8) at 2 weeks postinjury. At 12 months, the percentage of mTBI participants reporting functional limitations was 53% (95% CI, 49%-56%) vs 38% (95% CI, 30%-45%) for OTCs. A higher percentage of CT+ patients reported impairment (61%) compared with the mTBI CT- group (49%; relative risk [RR], 1.24; 95% CI, 1.08-1.43) and a higher percentage in the mTBI CT-group compared with the OTC group (RR, 1.28; 95% CI, 1.02-1.60).

Conclusions and Relevance

Most patients with mTBI presenting to US level I trauma centers report persistent, injury-related life difficulties at 1 year postinjury, suggesting the need for more systematic follow-up of patients with mTBI to provide treatments and reduce the risk of chronic problems after mTBI.

Functional Status Examination versus Glasgow Outcome Scale Extended as Outcome Measures in Traumatic Brain Injuries: How Do They Compare?

Outcome measures are essential components of natural history studies of recovery and treatment effects after traumatic brain injury (TBI). The Glasgow Outcome Scale (GOS) and its revised version, the Glasgow Outcome Scale Extended (GOSE), are well accepted and widely used for both observational and intervention studies, but there are concerns about their psychometric properties and aptness as outcome measures for TBI. The present study compares the Functional Status Examination (FSE) with the GOSE to assess outcome after TBI in a sample of 533 participants with TBI from the Magnesium Sulfate study and the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study by evaluating the sensitivity of each measure to severity of brain injury and recovery of function over time. The results indicate that both measures are strongly correlated with TBI severity. At three months, the correlation strengths between injury severity and each outcome measure do not differ (p = 0.88 for Glasgow Coma Scale [GCS], p = 0.13 for computed tomography [CT] abnormalities) but at six months, the FSE is more strongly related to TBI severity indices than is the GOSE (p = 0.045 for GCS, p = 0.014 for CT abnormalities). In addition, the FSE generally shows significantly more improvement over time than the GOSE (p < 0.001). Detailed, structured administration rules and a wider score range of the FSE likely yields more sensitive and precise assessment of functional level than the GOSE. The FSE may be a valuable alternative to the GOSE for assessing functional outcome after TBI.

Age and sex-mediated differences in six-month outcomes after mild traumatic brain injury in young adults: a TRACK-TBI study

Introduction: Risk factors for young adults with mTBI are not well understood. Improved understanding of age and sex as risk factors for impaired six-month outcomes in young adults is needed. Methods: Young adult mTBI subjects aged 18-39 years (18-29y; 30-39y) with six-month outcomes were extracted from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study. Multivariable regressions were performed for outcomes with age, sex, and the interaction factor age-group*sex as variables of interest, controlling for demographic and injury variables. Mean-differences (B) and 95% CIs are reported. Results: One hundred mTBI subjects (18-29y, 70%; 30-39y, 30%; male, 71%; female, 29%) met inclusion criteria. On multivariable analysis, age-group*sex was associated with six-month post-traumatic stress disorder (PTSD; PTSD Checklist-Civilian version); compared with female 30-39y, female 18-29y (B= -19.55 [-26.54, -4.45]), male 18-29y (B= -19.70 [-30.07, -9.33]), and male 30-39y (B= -15.49 [-26.54, -4.45]) were associated with decreased PTSD symptomatology. Female sex was associated with decreased six-month functional outcome (Glasgow Outcome Scale-Extended (GOSE): B= -0.6 [1.0, -0.1]). Comparatively, 30-39y scored higher on six-month nonverbal processing speed (Wechsler Adult Intelligence Scale-Processing Speed Index (WAIS-PSI); B= 11.88, 95% CI [1.66, 22.09]). Conclusions: Following mTBI, young adults aged 18-29y and 30-39y may have different risks for impairment. Sex may interact with age for PTSD symptomatology, with females 30-39y at highest risk. These results may be attributable to cortical maturation, biological response, social modifiers, and/or differential self-report. Confirmation in larger samples is needed; however, prevention and rehabilitation/counseling strategies after mTBI should likely be tailored for age and sex.

The Temporal Relationship of Mental Health Problems and Functional Limitations following mTBI: A TRACK-TBI and TED Study

Mental health problems, such as depression and anxiety, are often associated with functional limitations after traumatic brain injury (TBI), prompting researchers to explore which of these TBI-related sequelae tends to precede the other. Past studies among patients with injuries ranging in severity have predominantly reported that functional impairments predict subsequent psychological concerns, rather than the other way around; however, it remains unclear whether this directionality holds for individuals with mild TBI (mTBI). The present study utilized a cross-lagged panel design within a structural equation modeling analytical framework to explore the longitudinal relationships of symptoms of depression and anxiety to functional status among 717 adult mTBI patients, with assessments occurring at 2 weeks and 3 months post-injury. Symptoms of both depression and anxiety significantly predicted subsequent functional limitations (λs = -0.21 and -0.25), whereas the reverse effects were nonsignificant (λs = -0.05 and -0.03); thus, psychological concerns appeared to function as a precursor to functional impairment. This pattern was particularly pronounced among patients with normal head computed tomography (CT) results; however, results were less clear cut among those subjects whose injuries were accompanied by intracranial abnormalities detected on CT imaging, suggesting the possibility of a more reciprocal relationship in the case of CT-positive mTBI. These results may serve to partially explain the incidence of persistent functional limitations observed among subsets of mTBI patients in past studies. Findings likewise highlight the importance of assessment and treatment for mental health problems after mTBI as an important factor to promote psychological well-being and functional recovery.

Association of Early Myocardial Workload and Mortality Following Severe Traumatic Brain Injury

OBJECTIVES

To examine the impact of early myocardial workload on in-hospital mortality following isolated severe traumatic brain injury.

DESIGN

Retrospective cohort study.

SETTING

Data from the National Trauma Databank, a multicenter trauma registry operated by the American College of Surgeons, from 2007 to 2014.

PATIENTS

Adult patients with isolated severe traumatic brain injury (defined as admission Glasgow Coma Scale < 8 and head Abbreviated Injury Score ≥ 4).

INTERVENTIONS

Admission rate-pressure product, categorized into five levels based on published low, normal, and submaximal human thresholds: less than 5,000; 5,000-9,999; 10,000-14,999; 15,000-19,999; and greater than 20,000.

MEASUREMENTS AND MAIN RESULTS

Data from 26,412 patients were analyzed. Most patients had a normal rate-pressure product (43%), 35% had elevated rate-pressure product, and 22% had depressed rate-pressure product at hospital admission. Compared with the normal rate-pressure product group, in-hospital mortality was 22 percentage points higher in the lowest rate-pressure product group (cumulative mortality, 50.2%; 95% CI, 43.6-56.9%) and 11 percentage points higher in the highest rate-pressure product group (cumulative mortality, 39.2%; 95% CI, 37.4-40.9%). The lowest rate-pressure product group was associated with a 50% increased risk of mortality, compared with the normal rate-pressure product group (adjusted relative risk, 1.50; 95% CI, 1.31-1.76%; p < 0.0001), and the highest rate-pressure product group was associated with a 25% increased risk of mortality, compared with the normal rate-pressure product group (adjusted relative risk, 1.25; 95% CI, 1.18-1.92%; p < 0.0001). This relationship was blunted with increasing age. Among patients with normotension, those with depressed and elevated rate-pressure products experienced increased mortality.

CONCLUSIONS

Adults with severe traumatic brain injury experience heterogeneous myocardial workload profiles that have a "U-shaped" relationship with mortality, even in the presence of a normal blood pressure. Our findings are novel and suggest that cardiac performance is important following severe traumatic brain injury.

Functional Status Examination in Patients with Moderate-to-Severe Traumatic Brain Injuries

The assessment of functional status after traumatic brain injury (TBI) is important. The Glasgow Outcome Scale (GOS) and its revised version, the Glasgow Outcome Scale Extended (GOSE), have been used most frequently in TBI research, but there are concerns about the sensitivity of these measures. The current study evaluated the psychometric properties of the Functional Status Examination (FSE) using a sample of 448 moderately to severely injured subjects with TBI. It was shown that the FSE is significantly related to other measures of functional status including the GOSE, Short Form Health Survey, and European Quality of Life Checklist (p < 0.001), is sensitive to TBI severity (p < 0.001), and is responsive to recovery from 3 to 6 months post-injury (p < 0.001). In addition, there was a significant agreement (r = 0.817, p < 0.001) between the patient and significant other's assessment of functional status on the FSE at 6 months post-injury. The FSE may be a valuable measure of functional status after TBI given its strong psychometric properties, including validity, sensitivity to brain injury severity, and recovery over time.

The Outcome of Severe Traumatic Brain Injury in Latin America

BACKGROUND

Traumatic brain injury (TBI) disproportionately affects lower- and middle-income countries (LMIC). The factors influencing outcomes in LMIC have not been examined as rigorously as in higher-income countries.

METHODS

This study was conducted to examine clinical and demographic factors influencing TBI outcomes in Latin American LMIC. Data were prospectively collected during a randomized trial of intracranial pressure monitoring in severe TBI and a companion observational study. Participants were aged ≥13 years and admitted to study hospitals with Glasgow Coma Scale score ≤8. The primary outcome was Glasgow Outcome Scale, Extended (GOS-E) score at 6 months. Predictors were analyzed using a multivariable proportional odds model created by forward stepwise selection.

RESULTS

A total of 550 patients were identified. Six-month outcomes were available for 88%, of whom 37% had died and 44% had achieved a GOS-E score of 5-8. In multivariable proportional odds modeling, higher Glasgow Coma Scale motor score (odds ratio [OR], 1.41 per point; 95% confidence interval [CI], 1.23-1.61) and epidural hematoma (OR, 1.83; 95% CI, 1.17-2.86) were significant predictors of higher GOS-E score, whereas advanced age (OR, 0.65 per 10 years; 95% CI, 0.57-0.73) and cisternal effacement (P < 0.001) were associated with lower GOS-E score. Study site (P < 0.001) and race (P = 0.004) significantly predicted outcome, outweighing clinical variables such as hypotension and pupillary examination.

CONCLUSIONS

Mortality from severe TBI is high in Latin American LMIC, although the rate of favorable recovery is similar to that of high-income countries. Demographic factors such as race and study site played an outsized role in predicting outcome; further research is required to understand these associations.

Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase-II: A Phase II Randomized Trial

OBJECTIVES

A relationship between reduced brain tissue oxygenation and poor outcome following severe traumatic brain injury has been reported in observational studies. We designed a Phase II trial to assess whether a neurocritical care management protocol could improve brain tissue oxygenation levels in patients with severe traumatic brain injury and the feasibility of a Phase III efficacy study.

DESIGN

Randomized prospective clinical trial.

SETTING

Ten ICUs in the United States.

PATIENTS

One hundred nineteen severe traumatic brain injury patients.

INTERVENTIONS

Patients were randomized to treatment protocol based on intracranial pressure plus brain tissue oxygenation monitoring versus intracranial pressure monitoring alone. Brain tissue oxygenation data were recorded in the intracranial pressure -only group in blinded fashion. Tiered interventions in each arm were specified and impact on intracranial pressure and brain tissue oxygenation measured. Monitors were removed if values were normal for 48 hours consecutively, or after 5 days. Outcome was measured at 6 months using the Glasgow Outcome Scale-Extended.

MEASUREMENTS AND MAIN RESULTS

A management protocol based on brain tissue oxygenation and intracranial pressure monitoring reduced the proportion of time with brain tissue hypoxia after severe traumatic brain injury (0.45 in intracranial pressure-only group and 0.16 in intracranial pressure plus brain tissue oxygenation group; p < 0.0001). Intracranial pressure control was similar in both groups. Safety and feasibility of the tiered treatment protocol were confirmed. There were no procedure-related complications. Treatment of secondary injury after severe traumatic brain injury based on brain tissue oxygenation and intracranial pressure values was consistent with reduced mortality and increased proportions of patients with good recovery compared with intracranial pressure-only management; however, the study was not powered for clinical efficacy.

CONCLUSIONS

Management of severe traumatic brain injury informed by multimodal intracranial pressure and brain tissue oxygenation monitoring reduced brain tissue hypoxia with a trend toward lower mortality and more favorable outcomes than intracranial pressure-only treatment. A Phase III randomized trial to assess impact on neurologic outcome of intracranial pressure plus brain tissue oxygenation-directed treatment of severe traumatic brain injury is warranted.

Economic evaluation of telephone-based concussion management for combat-related mild traumatic brain injury

Introduction Mild traumatic brain injury (mTBI) is an unfortunately common repercussion of military service in a combat zone. The CONTACT study tested an individualized telephone support intervention employing problem solving therapy (PST) for mTBI in soldiers recently returned from deployment. We sought to determine the cost effectiveness of this intervention from a military healthcare system perspective. Methods We conducted an intent-to-treat post-hoc analysis by building a decision analytic model that evaluated the choice between using PST or education only (EO). The model included cost-minimization and cost-effectiveness analyses. The incremental cost-effectiveness ratios (ICERs) were calculated as the differences in costs of PST versus EO relative to the differences in the outcomes of participants. Results The PST intervention resulted in an annual per-enrolee cost of $1027 (95% CI: $836 to $1248), while EO costs were $32 (95% CI: $25 to $39), resulting in a net incremental cost of $996 per enrolee (95% CI: $806 to $1,217). The ICERs were $68,658/QALY based on EQ-5D (95% CI: -$463,535 to $596,661) and $49,284/QALY based on SF-6D (95% CI: $26,971 to $159,309). Estimates of treatment costs in a real-world setting were accompanied by substantially lower ICERs that are within accepted thresholds for willingness-to-pay. Discussion Although the intervention had short-term benefits sufficient to yield acceptable ICERs, there was no long-term effect of PST over EO observed in the study. Consequently, we suggest that future studies examine the use of low-cost approaches, such as booster relapse-prevention calls, that may lead to a sustained treatment benefit for this population.

DRD2 C957T polymorphism is associated with improved 6-month verbal learning following traumatic brain injury

Traumatic brain injury (TBI) often leads to heterogeneous clinical outcomes, which may be influenced by genetic variation. A single-nucleotide polymorphism (SNP) in the dopamine D2 receptor (DRD2) may influence cognitive deficits following TBI. However, part of the association with DRD2 has been attributed to genetic variability within the adjacent ankyrin repeat and kinase domain containing 1 protein (ANKK1). Here, we utilize the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study to investigate whether a novel DRD2 C957T polymorphism (rs6277) influences outcome on a cognitive battery at 6 months following TBI-California Verbal Learning Test (CVLT-II), Wechsler Adult Intelligence Test Processing Speed Index Composite Score (WAIS-PSI), and Trail Making Test (TMT). Results in 128 Caucasian subjects show that the rs6277 T-allele associates with better verbal learning and recall on CVLT-II Trials 1-5 (T-allele carrier 52.8 ± 1.3 points, C/C 47.9 ± 1.7 points; mean increase 4.9 points, 95% confidence interval [0.9 to 8.8]; p = 0.018), Short-Delay Free Recall (T-carrier 10.9 ± 0.4 points, C/C 9.7 ± 0.5 points; mean increase 1.2 points [0.1 to 2.5]; p = 0.046), and Long-Delay Free Recall (T-carrier 11.5 ± 0.4 points, C/C 10.2 ± 0.5 points; mean increase 1.3 points [0.1 to 2.5]; p = 0.041) after adjusting for age, education years, Glasgow Coma Scale, presence of acute intracranial pathology on head computed tomography scan, and genotype of the ANKK1 SNP rs1800497 using multivariable regression. No association was found between DRD2 C947T and non-verbal processing speed (WAIS-PSI) or mental flexibility (TMT) at 6 months. Hence, DRD2 C947T (rs6277) may be associated with better performance on select cognitive domains independent of ANKK1 following TBI.

Patterns of Alcohol Use after Traumatic Brain Injury

Alcohol misuse and traumatic brain injury (TBI) frequently co-occur. The negative consequences of this interaction are well documented, but the patterns of long-term post-injury alcohol consumption are less clear. This study examined patterns of alcohol use among 170 adults with a history of complicated mild to severe TBI. Participants were recruited from a Level 1 Trauma Center at the time of their injury and completed evaluations at 1 month, 6 months, 12 months, and 3-5 years post-injury. Pre-injury alcohol use was also assessed at the time of the 1-month assessment. A modified Quantity-Frequency Index of alcohol consumption was then calculated for each time point. The results revealed high levels of pre-injury alcohol consumption, followed by a reduction in consumption at 1-month post-injury. A significant increase in consumption was noted by 6 months post-injury, followed by more gradual increases in alcohol consumption at 1 year. Post-injury alcohol consumption was comparable to the general public at 6 months, 12 months, and 3-5 years post-injury. These results suggest that the first 6 months post-injury may be the critical window of opportunity for alcohol intervention.

COMT Val 158 Met polymorphism is associated with nonverbal cognition following mild traumatic brain injury

Mild traumatic brain injury (mTBI) results in variable clinical outcomes, which may be influenced by genetic variation. A single-nucleotide polymorphism in catechol-o-methyltransferase (COMT), an enzyme which degrades catecholamine neurotransmitters, may influence cognitive deficits following moderate and/or severe head trauma. However, this has been disputed, and its role in mTBI has not been studied. Here, we utilize the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study to investigate whether the COMT Val (158) Met polymorphism influences outcome on a cognitive battery 6 months following mTBI--Wechsler Adult Intelligence Test Processing Speed Index Composite Score (WAIS-PSI), Trail Making Test (TMT) Trail B minus Trail A time, and California Verbal Learning Test, Second Edition Trial 1-5 Standard Score (CVLT-II). All patients had an emergency department Glasgow Coma Scale (GCS) of 13-15, no acute intracranial pathology on head CT, and no polytrauma as defined by an Abbreviated Injury Scale (AIS) score of ≥3 in any extracranial region. Results in 100 subjects aged 40.9 (SD 15.2) years (COMT Met (158) /Met (158) 29 %, Met (158) /Val (158) 47 %, Val (158) /Val (158) 24 %) show that the COMT Met (158) allele (mean 101.6 ± SE 2.1) associates with higher nonverbal processing speed on the WAIS-PSI when compared to Val (158) /Val (158) homozygotes (93.8 ± SE 3.0) after controlling for demographics and injury severity (mean increase 7.9 points, 95 % CI [1.4 to 14.3], p = 0.017). The COMT Val (158) Met polymorphism did not associate with mental flexibility on the TMT or with verbal learning on the CVLT-II. Hence, COMT Val (158) Met may preferentially modulate nonverbal cognition following uncomplicated mTBI.Registry: ClinicalTrials.gov Identifier NCT01565551.