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.

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.

Evaluating mortality and 6-month functional outcomes of patients with dural venous sinus thrombosis in traumatic brain injury.

OBJECTIVE: Patients with dural venous sinus thrombosis (DVST) in select populations following traumatic brain injury (TBI), including those with blunt mechanism or depressed skull fractures, have been shown to have an increased risk of mortality. The purpose of this study was to assess these findings in a mixed population of head trauma patients. METHODS: The authors performed a case-control study using propensity score matching by reviewing 17 years (2004-2021) of data from their institutional trauma registry. Patients with imaging-confirmed DVST were matched to a control group of TBI patients without identified DVST based on age, sex, postresuscitation Glasgow Coma Scale (GCS) score, and Injury Severity Score. All age groups and injury mechanisms were included with a head Abbreviated Injury Scale score ≥ 3. Data on demographics, injury and radiographic characteristics, and patient outcomes were collected. Multivariable logistic regression was performed to identify predictors of inpatient mortality. An additional subgroup analysis of patients with concurrent DVST and blunt cerebrovascular injury (BCVI) was planned a priori. RESULTS: The authors identified 9875 patients who presented to their institution over the study period with TBIs, with a 1.64% incidence of DVST. Concurrent BCVI was diagnosed in 23.5% of patients with a DVST. Following matching, the presence of DVST itself was not significantly associated with inpatient mortality (OR 0.68, 95% CI 0.24-1.88). On regression analysis, penetrating injuries (8.19, 95% CI 1.21-80.0) and lower postresuscitation GCS scores (0.69, 95% CI 0.53-0.84) were independently associated with inpatient mortality for patients with traumatic DVST. Significantly worse functional outcomes were observed in those with DVST at 3 months, with no significant difference at 6 months. CONCLUSIONS: The authors observed a prevalence of traumatic DVST of 1.64% in a mixed population of head-injured patients, with 23.5% of patients with DVST having concurrent BCVI. Traumatic DVST alone was not associated with a significantly increased risk of inpatient mortality.

Post-traumatic Middle Meningeal Artery Pseudoaneurysm Treated With Endovascular Coil Embolization.

Pseudoaneurysms of the middle meningeal artery are rare events following head trauma. Given the potential for significant morbidity and mortality associated with pseudoaneurysm rupture, it is recommended that they be treated early. Endovascular embolization is a viable alternative to open surgical intervention. Here, we describe a case of an incidentally found middle meningeal artery pseudoaneurysm in a patient with a carotid-cavernous fistula after head injury. The pseudoaneurysm was treated with endovascular coil embolization.

Pharmacokinetics of Levetiracetam Seizure Prophylaxis in Severe Traumatic Brain Injury.

BACKGROUND: Drug pharmacokinetics (PK) are altered in neurocritically ill patients, and optimal levetiracetam dosing for seizure prophylaxis is unknown. OBJECTIVE: This study evaluates levetiracetam PK in critically ill patients with severe traumatic brain injury (sTBI) receiving intravenous levetiracetam 1000 mg every 8 (LEV8) to 12 (LEV12) hours for seizure prophylaxis. METHODS: This prospective, open-label study was conducted at a level 1 trauma, academic, quaternary care center. Patients with sTBI receiving seizure prophylaxis with LEV8 or LEV12 were eligible for enrollment. Five sequential, steady-state, postdose serum levetiracetam concentrations were obtained. Non-compartmental analysis (NCA) and compartmental approaches were employed for estimating pharmacokinetic parameters and projecting steady-state trough concentrations. Pharmacokinetic parameters were compared between LEV8 and LEV12 patients. Monte Carlo simulations (MCS) were performed to determine probability of target trough attainment (PTA) of 6 to 20 mg/L. A secondary analysis evaluated PTA for weight-tiered levetiracetam dosing. RESULTS: Ten male patients (5 LEV8; 5 LEV12) were included. The NCA-based systemic clearance and elimination half-life were 5.3 ± 1.2 L/h and 4.8 ± 0.64 hours. A one-compartment model provided a higher steady-state trough concentration for the LEV8 group compared with the LEV12 group (13.7 ± 4.3 mg/L vs 6.3 ± 1.7 mg/L; P = 0.008). Monte Carlo simulations predicted regimens of 500 mg every 6 hours, 1000 mg every 8 hours, and 2000 mg every 12 hours achieved therapeutic target attainment. Weight-tiered dosing regimens achieved therapeutic target attainment using a 75 kg breakpoint. CONCLUSION AND RELEVANCE: Neurocritically ill patients exhibit rapid levetiracetam clearance resulting in a short elimination half-life. Findings of this study suggest regimens of levetiracetam 500 mg every 6 hours, 1000 mg every 8 hours, or 2000 mg every 12 hours may be required for optimal therapeutic target attainment. Patient weight of 75 kg may serve as a breakpoint for weight-guided dosing to optimize levetiracetam therapeutic target attainment for seizure prophylaxis.

Practice Standards for the Use of Multimodality Neuromonitoring: A Delphi Consensus Process.

OBJECTIVES: To address areas in which there is no consensus for the technologies, effort, and training necessary to integrate and interpret information from multimodality neuromonitoring (MNM). DESIGN: A three-round Delphi consensus process. SETTING: Electronic surveys and virtual meeting. SUBJECTS: Participants with broad MNM expertise from adult and pediatric intensive care backgrounds. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Two rounds of surveys were completed followed by a virtual meeting to resolve areas without consensus and a final survey to conclude the Delphi process. With 35 participants consensus was achieved on 49% statements concerning MNM. Neurologic impairment and the potential for MNM to guide management were important clinical considerations. Experts reached consensus for the use of MNM-both invasive and noninvasive-for patients in coma with traumatic brain injury, aneurysmal subarachnoid hemorrhage, and intracranial hemorrhage. There was consensus that effort to integrate and interpret MNM requires time independent of daily clinical duties, along with specific skills and expertise. Consensus was reached that training and educational platforms are necessary to develop this expertise and to provide clinical correlation. CONCLUSIONS: We provide expert consensus in the clinical considerations, minimum necessary technologies, implementation, and training/education to provide practice standards for the use of MNM to individualize clinical care.

Toward global availability of low-cost, patient-specific cranial implants: creation and validation of automated CranialRebuild freeware application.

PURPOSE: Financial restrictions limit the options for hermetically precise, patient-specific cranial implants (PSCIs) after decompressive hemicraniectomy (DHC) in low-income countries. Use of image segmentation, modeling software, and 3D printers has lowered costs associated with PSCIs. However, requirements of time and technical expertise have prevented widespread utilization. Our objective was to create a fully automated software algorithm that is able to generate a virtual model (.STL) of a negative of an implant using CT imaging following DHC. METHODS: A freeware algorithm (CranialRebuild) was constructed with the following capabilities: (1) after the upload of digital imaging and communications in medicine files, the normal side is analyzed in reference to the side of DHC, (2) Boolean subtraction is used to obtain a virtual image of the desired implant, and (3) a two-piece virtual model (.STL) of the PSCI mold is generated. In four cadaveric specimens, a standard DHC was performed. Post-DHC CT imaging was used to obtain a .STL of the negative of the implant, which was then printed using poly-lactic acid (PLA). Methylmethacrylate cement was used to generate a PSCI from the mold. The PSCIs were implanted into the index specimens; cosmesis was subjectively evaluated using a 5-point Likert scale. RESULTS: Two specimens were graded as 4/5, indicating that minor post-processing modification was needed for optimal cosmesis. Two specimens were graded as 3/5, indicating that optimal cosmesis could be obtained following moderate post-processing modification. CONCLUSIONS: CranialRebuild can be used to create hermetically precise PSCIs at a fraction of the price of third-party vendors. Validation of this technology has significant implications for the accessibility of customized cranial implants worldwide.

Improving Neurotrauma by Depolarization Inhibition With Combination Therapy: A Phase 2 Randomized Feasibility Trial.

BACKGROUND AND OBJECTIVES: Spreading depolarizations (SDs) are a pathological mechanism that mediates lesion development in cerebral gray matter. They occur in ∼60% of patients with severe traumatic brain injury (TBI), often in recurring and progressive patterns from days 0 to 10 after injury, and are associated with worse outcomes. However, there are no protocols or trials suggesting how SD monitoring might be incorporated into clinical management. The objective of this protocol is to determine the feasibility and efficacy of implementing a treatment protocol for intensive care of patients with severe TBI that is guided by electrocorticographic monitoring of SDs. METHODS: Patients who undergo surgery for severe TBI with placement of a subdural electrode strip will be eligible for enrollment. Those who exhibit SDs on electrocorticography during intensive care will be randomized 1:1 to either (1) standard care that is blinded to the further course of SDs or (2) a tiered intervention protocol based on efficacy to suppress further SDs. Interventions aim to block the triggering and propagation of SDs and include adjusted targets for management of blood pressure, CO 2 , temperature, and glucose, as well as ketamine pharmacotherapy up to 4 mg/kg/ hour. Interventions will be escalated and de-escalated depending on the course of SD pathology. EXPECTED OUTCOMES: We expect to demonstrate that electrocorticographic monitoring of SDs can be used as a real- time diagnostic in intensive care that leads to meaningful changes in patient management and a reduction in secondary injury, as compared with standard care, without increasing medical complications or adverse events. DISCUSSION: This trial holds potential for personalization of intensive care management by tailoring therapies based on monitoring and confirmation of the targeted neuronal mechanism of SD. Results are expected to validate the concept of this approach, inform refinement of the treatment protocol, and lead to larger-scale trials.

Changes in patterns of traumatic brain injury in the Michigan Trauma Quality Improvement Program database early in the COVID-19 pandemic.

OBJECTIVE: The authors' objective was to investigate the impact of the global COVID-19 pandemic on hospital presentation and process of care for the treatment of traumatic brain injuries (TBIs). Improved understanding of these effects will inform sociopolitical and hospital policies in response to future pandemics. METHODS: The Michigan Trauma Quality Improvement Program (MTQIP) database, which contains data from 36 level I and II trauma centers in Michigan and Minnesota, was queried to identify patients who sustained TBI on the basis of head/neck Abbreviated Injury Scale (AIS) codes during the periods of March 13 through July 2 of 2017-2019 (pre-COVID-19 period) and March 13, 2020, through July 2, 2020 (COVID-19 period). Analyses were performed to detect differences in incidence, patient characteristics, injury severity, and outcomes. RESULTS: There was an 18% decrease in the rate of encounters with TBI in the first 8 weeks (March 13 through May 7), followed by a 16% increase during the last 8 weeks (May 8 through July 2), of our COVID-19 period compared with the pre-COVID-19 period. Cumulatively, there was no difference in the rates of encounters with TBI between the COVID-19 and pre-COVID-19 periods. Severity of TBI, as measured with maximum AIS score for the head/neck region and Glasgow Coma Scale score, was also similar between periods. During the COVID-19 period, a greater proportion of patients with TBI presented more than a day after sustaining their injuries (p = 0.046). COVID-19 was also associated with a doubling in the decubitus ulcer rate from 1.0% to 2.1% (p = 0.002) and change in the distribution of discharge status (p = 0.01). Multivariable analysis showed no differences in odds of death/hospice discharge, intensive care unit stay of at least a day, or need for a ventilator for at least a day between the COVID-19 and pre-COVID-19 periods. CONCLUSIONS: During the early months of the COVID-19 pandemic, the number of patients who presented with TBI was initially lower than in the years 2017-2019 prior to the pandemic. However, there was a subsequent increase in the rate of encounters with TBI, resulting in overall similar rates of TBI between March 13 through July 2 during the COVID-19 period and during the pre-COVID-19 period. The COVID-19 cohort was also associated with negative impacts on time to presentation, rate of decubitus ulcers, and discharge with supervision. Policies in response to future pandemics must consider the resources necessary to care for patients with TBI.

Feasibility and Utility of a Flexible Outcome Assessment Battery for Longitudinal Traumatic Brain Injury Research: A TRACK-TBI Study.

The effects of traumatic brain injury (TBI) are difficult to measure in longitudinal cohort studies, because disparate pre-injury characteristics and injury mechanisms produce variable impairment profiles and recovery trajectories. In preparation for the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study, which followed patients with injuries ranging from uncomplicated mild TBI to coma, we designed a multi-dimensional Flexible outcome Assessment Battery (FAB). The FAB relies on a decision-making algorithm that assigns participants to a Comprehensive (CAB) or Abbreviated Assessment Battery (AAB) and guides test selection across all phases of recovery. To assess feasibility of the FAB, we calculated the proportion of participants followed at 2 weeks (2w) and at 3, 6, and 12 months (3m, 6m, 12m) post-injury who completed the FAB and received valid scores. We evaluated utility of the FAB by examining differences in 6m and 12m Glasgow Outcome Scale-Extended (GOSE) scores between participant subgroups derived from the FAB-enabled versus traditional approach to outcome assessment applied at 2w. Among participants followed at 2w (n = 2094), 3m (n = 1871), 6m (n = 1736), and 12m (n = 1607) post-injury, 95-99% received valid completion scores on the FAB, in full or in part, either in person or by telephone. Level of function assessed by the FAB-enabled approach at 2w was associated with 6m and 12m GOSE scores (proportional odds p < 0.001). These findings suggest that the participant classification methodology afforded by the FAB may enable more effective data collection to improve detection of natural history changes and TBI treatment effects.

The history of antibiotic irrigation and prophylaxis in operative neurotrauma: perpetuation of military care in civilian settings.

The benefit of antibiotic irrigation for prophylaxis against wound infections, not only for traumatic cranial injuries but also in elective neurosurgical care, has recently been called into question. Several articles have cast doubt on the utility of topical antibiotics, and recently, bacitracin irrigation was made unavailable in some US markets. The pervasive nature of antibiotic irrigation, considering the lack of evidence supporting its use, led the authors to question when and how neurosurgeons started using antibiotic irrigation in cranial neurosurgery. Through a review of historical literature, they highlight the adoption of antibiotic irrigation as it began in battlefield surgical practice, gradually leading to the modern concept of antibiotic prophylaxis in civilian and military care.

Carole A. Miller, MD: Matriarch of the Ohio State University's Department of Neurosurgery.

Carole A. Miller, M.D., was born (May 7, 1939) and raised in Kalamazoo, Michigan. She obtained her undergraduate and medical degrees at the Ohio State University. She went on to complete her neurosurgical training at the Ohio State University Medical Center. After her first faculty role at the University of Michigan (1971), she returned to the Ohio State University Medical Center (1975) where she spent nearly 4 decades. She thrived in the specialty, achieving in every facet of academic practice including scientific contributions, graduate medical education, clinical care, and leadership roles within her academic department, locally, and at the national level of organized neurosurgery. Dr. Miller passed away peacefully, on October 28, 2015, after a courageous battle with cancer. Based on her essential programmatic and specialty-related contributions, she is remembered as the 'founding mother' of neurosurgery at the Ohio State University.

Andexanet alfa after 4-factor PCC administration for intracranial hemorrhage: a case series.

The ongoing controversy regarding optimal reversal agent for factor Xa-inhibitors is mainly due to lack of comparative data of andexanet alfa (AA) to 4-factor prothrombin complex concentrate (4F-PCC), institutional formulary restrictions, and navigation of clinical scenarios involving patients clinically worsen despite initial reversal efforts. The combination use of 4F-PCC and AA has not been evaluated in clinical trials and the outcomes of such patients with FXA-inhibitor associated intracranial hemorrhage (ICH) are unknown. A total of five patients, including four outside hospital transfers, received 4F-PCC prior to AA for FXa-inhibitor associated ICH (n = 3 apixaban, n = 2 rivaroxaban; n = 4 ICH, n = 1 TBI). The doses of 4F-PCC ranged from 25 to 60 units/kg and were administered within a range of 1.5-4.2 h prior to AA. One patient required surgical intervention with craniotomy and three patients underwent external ventricular drain placement. Two of the five patients developed an ischemic or thromboembolic complication within one week from 4F-PCC and AA administration. This case series discusses multiple unique patient cases in which 4F-PCC and AA were both administered for FXa-inhibitor associated ICH. The results highlight the potentially increased thrombotic risk associated with combination use. Ongoing post-marketing data collection of real patient case scenarios are essential to the establishment of consensus guidelines on how to prioritize initial reversal efforts and manage these patients during the course of their bleed.

The Effects of the COVID-19 Pandemic on Penetrating Neurotrauma at a Level 1 Trauma Center.

BACKGROUND/OBJECTIVE: The COVID-19 pandemic has had a profound impact on the global delivery of health care. Recent data suggest a possible impact of the pandemic on patterns of neurotrauma. The aim was to assess the impact of the pandemic on the incidence of neurotrauma, with a focus on cranial gunshot wounds (cGSWs) at a large Midwestern level 1 trauma center. METHODS: We conducted a retrospective review of our trauma registry from March through September 2020 and compared it to the same months in 2019. Odds ratios were utilized to assess for differences in patient demographics, injury characteristics, rates of neurotrauma, and rates of cGSWs. RESULTS: A total of 1188 patients presented with neurotrauma, 558 in 2019 and 630 in 2020. The majority of patients were male (71.33% in 2019; 68.57% in 2020) and Caucasian (78.67% in 2019; 75.4% in 2020). Patients presented with cGSWs more frequently in 2020 (n = 49, 7.78%) than in 2019 (n = 25, 4.48%). The odds of suffering a cGSW in 2020 was 73.6% higher than those in 2019 (95% confidence interval = [1.0871, 2.7722]; P = 0.0209). The etiology of such injury was most commonly assault (n = 16, 21.62% in 2019; n = 34, 45.95% in 2020), followed by self-inflicted injury (n = 4, 5.41% in 2019; 12, 16.22% in 2020). CONCLUSIONS: Despite the government-mandated shutdown, we observed an increase in the number of neurotrauma cases in 2020. There was a significant increase in the incidence cGSWs in 2020, with an increase in assaults and self-inflicted injuries. Further investigation into socioeconomic factors for the observed increase in cGSWs is warranted.

An independent, external validation and component analysis of the Surviving Penetrating Injury to the Brain score for civilian cranial gunshot injuries.

OBJECTIVE: The Surviving Penetrating Injury to the Brain (SPIN) score utilizes clinical variables to estimate in-hospital and 6-month mortality for patients with civilian cranial gunshot wounds (cGSWs) and demonstrated good discrimination (area under the receiver operating characteristic curve [AUC] 0.880) in an initial validation study. The goal of this study was to provide an external, independent validation of the SPIN score for in-hospital and 6-month mortality. METHODS: To accomplish this, the authors retrospectively reviewed 6 years of data from their institutional trauma registry. Variables used to determine SPIN score were collected, including sex, transfer status, injury motive, pupillary reactivity, motor component of the Glasgow Coma Scale (mGCS), Injury Severity Score (ISS), and international normalized ratio (INR) at admission. Multivariable logistic regression analysis identified variables associated with mortality. The authors compared AUC between models by using a nonparametric test for equality. RESULTS: Of the 108 patients who met the inclusion criteria, 101 had all SPIN score components available. The SPIN model had an AUC of 0.962. The AUC for continuous mGCS score alone (0.932) did not differ significantly from the AUC for the full SPIN model (p = 0.26). The AUC for continuous mGCS score (0.932) was significantly higher compared to categorical mGCS score (0.891, p = 0.005). Use of only mGCS score resulted in fewer exclusions due to missing data. No additional variable included in the predictive model alongside continuous mGCS score was a significant predictor of inpatient mortality, 6-month mortality, or increased model discrimination. CONCLUSIONS: Given these findings, continuous 6-point mGCS score may be sufficient as a generalizable predictor of inpatient and 6-month mortality in patients with cGSW, demonstrating excellent discrimination and reduced bias due to missing data.

The Relationship Between Seizures and Spreading Depolarizations in Patients with Severe Traumatic Brain Injury.

BACKGROUND: Both seizures and spreading depolarizations (SDs) are commonly detected using electrocorticography (ECoG) after severe traumatic brain injury (TBI). A close relationship between seizures and SDs has been described, but the implications of detecting either or both remain unclear. We sought to characterize the relationship between these two phenomena and their clinical significance. METHODS: We performed a post hoc analysis of a prospective observational clinical study of patients with severe TBI requiring neurosurgery at five academic neurotrauma centers. A subdural electrode array was placed intraoperatively and ECoG was recorded during intensive care. SDs, seizures, and high-frequency background characteristics were quantified offline using published standards and terminology. The primary outcome was the Glasgow Outcome Scale-Extended score at 6 months post injury. RESULTS: There were 138 patients with valid ECoG recordings; the mean age was 47 ± 19 years, and 104 (75%) were men. Overall, 2,219 ECoG-detected seizures occurred in 38 of 138 (28%) patients in a bimodal pattern, with peak incidences at 1.7-1.8 days and 3.8-4.0 days post injury. Seizures detected on scalp electroencephalography (EEG) were diagnosed by standard clinical care in only 18 of 138 (13%). Of 15 patients with ECoG-detected seizures and contemporaneous scalp EEG, seven (47%) had no definite scalp EEG correlate. ECoG-detected seizures were significantly associated with the severity and number of SDs, which occurred in 83 of 138 (60%) of patients. Temporal interactions were observed in 17 of 24 (70.8%) patients with both ECoG-detected seizures and SDs. After controlling for known prognostic covariates and the presence of SDs, seizures detected on either ECoG or scalp EEG did not have an independent association with 6-month functional outcome but portended worse outcome among those with clustered or isoelectric SDs. CONCLUSIONS: In patients with severe TBI requiring neurosurgery, seizures were half as common as SDs. Seizures would have gone undetected without ECoG monitoring in 20% of patients. Although seizures alone did not influence 6-month functional outcomes in this cohort, they were independently associated with electrographic worsening and a lack of motor improvement following surgery. Temporal interactions between ECoG-detected seizures and SDs were common and held prognostic implications. Together, seizures and SDs may occur along a dynamic continuum of factors critical to the development of secondary brain injury. ECoG provides information integral to the clinical management of patients with TBI.

Seizures and Cognitive Outcome After Traumatic Brain Injury: A Post Hoc Analysis.

INTRODUCTION: Seizures and abnormal periodic or rhythmic patterns are observed on continuous electroencephalography monitoring (cEEG) in up to half of patients hospitalized with moderate to severe traumatic brain injury (TBI). We aimed to determine the impact of seizures and abnormal periodic or rhythmic patterns on cognitive outcome 3 months following moderate to severe TBI. METHODS: This was a post hoc analysis of the multicenter randomized controlled phase 2 INTREPID2566 clinical trial conducted from 2010 to 2016 across 20 United States Level I trauma centers. Patients with nonpenetrating TBI and postresuscitation Glasgow Coma Scale scores 4-12 were included. Bedside cEEG was initiated per protocol on admission to intensive care, and the burden of ictal-interictal continuum (IIC) patterns, including seizures, was quantified. A summary global cognition score at 3 months following injury was used as the primary outcome. RESULTS: 142 patients (age mean + / - standard deviation 32 + / - 13 years; 131 [92%] men) survived with a mean global cognition score of 81 + / - 15; nearly one third were considered to have poor functional outcome. 89 of 142 (63%) patients underwent cEEG, of whom 13 of 89 (15%) had severe IIC patterns. The quantitative burden of IIC patterns correlated inversely with the global cognition score (r = - 0.57; p = 0.04). In multiple variable analysis, the log-transformed burden of severe IIC patterns was independently associated with the global cognition score after controlling for demographics, premorbid estimated intelligence, injury severity, sedatives, and antiepileptic drugs (odds ratio 0.73, 95% confidence interval 0.60-0.88; p = 0.002). CONCLUSIONS: The burden of seizures and abnormal periodic or rhythmic patterns was independently associated with worse cognition at 3 months following TBI. Their impact on longer-term cognitive endpoints and the potential benefits of seizure detection and treatment in this population warrant prospective study.

Remote and Persistent Alterations in Glutamate Receptor Subunit Composition Induced by Spreading Depolarizations in Rat Brain.

Spreading depolarizations (SDs) are massive breakdowns of ion homeostasis in the brain's gray matter and are a necessary pathologic mechanism for lesion development in various injury models. However, injury-induced SDs also propagate into remote, healthy tissue where they do not cause cell death, yet their functional long-term effects are unknown. Here we induced SDs in uninjured cortex and hippocampus of Sprague-Dawley rats to study their impact on glutamate receptor subunit expression after three days. We find that both cortical and hippocampal tissue exhibit changes in glutamate receptor subunit expression, including GluA1 and GluN2B, suggesting that SDs in healthy brain tissue may have a role in plasticity. This study is the first to show prolonged effects of SDs on glutamate signaling and has implications for neuroprotection strategies aimed at SD suppression.

Lack of Glutamate Receptor Subunit Expression Changes in Hippocampal Dentate Gyrus after Experimental Traumatic Brain Injury in a Rodent Model of Depression.

Traumatic brain injury (TBI) affects over 69 million people annually worldwide, and those with pre-existing depression have worse recovery. The molecular mechanisms that may contribute to poor recovery after TBI with co-morbid depression have not been established. TBI and depression have many commonalities including volume changes, myelin disruption, changes in proliferation, and changes in glutamatergic signaling. We used a well-established animal model of depression, the Wistar Kyoto (WKY) rat, to elucidate changes after TBI that may influence the recovery trajectory. We compared the histological and molecular outcomes in the hippocampal dentate gyrus after experimental TBI using the lateral fluid percussion injury (LFPI) in the WKY and the parent Wistar (WIS) strain. We showed that WKY had exaggerated myelin loss after LFPI and baseline deficits in proliferation. In addition, we showed that while after LFPI WIS rats exhibited glutamate receptor subunit changes, namely increased GluN2B, the WKY rats failed to show such injury-related changes. These differential responses to LFPI helped to elucidate the molecular characteristics that influence poor recovery after TBI in those with pre-existing depression and may lead to targets for future therapeutic interventions.

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.