Understanding Traumatic Brain Injury in Females: A State-of-the-Art Summary and Future Directions.

In this report, we identify existing issues and challenges related to research on traumatic brain injury (TBI) in females and provide future directions for research. In 2017, the National Institutes of Health, in partnership with the Center for Neuroscience and Regenerative Medicine and the Defense and Veterans Brain Injury Center, hosted a workshop that focused on the unique challenges facing researchers, clinicians, patients, and other stakeholders regarding TBI in women. The goal of this "Understanding TBI in Women" workshop was to bring together researchers and clinicians to identify knowledge gaps, best practices, and target populations in research on females and/or sex differences within the field of TBI. The workshop, and the current literature, clearly highlighted that females have been underrepresented in TBI studies and clinical trials and have often been excluded (or ovariectomized) in preclinical studies. Such an absence in research on females has led to an incomplete, and perhaps inaccurate, understanding of TBI in females. The presentations and discussions centered on the existing knowledge regarding sex differences in TBI research and how these differences could be incorporated in preclinical and clinical efforts going forward. Now, a little over 2 years later, we summarize the issues and state of the science that emerged from the "Understanding TBI in Women" workshop while incorporating updates where they exist. Overall, despite some progress, there remains an abundance of research focused on males and relatively little explicitly on females.

Resuscitation with macromolecular superoxide dismutase/catalase mimetic polynitroxylated PEGylated hemoglobin offers neuroprotection in guinea pigs after traumatic brain injury combined with hemorrhage shock.

BACKGROUND: Polynitroxylated PEGylated hemoglobin (PNPH, aka SanFlow) possesses superoxide dismutase/catalase mimetic activities that may directly protect the brain from oxidative stress. Stabilization of PNPH with bound carbon monoxide prevents methemoglobin formation during storage and permits it to serve as a carbon monoxide donor. We determined whether small volume transfusion of hyperoncotic PNPH is neuroprotective in a polytrauma model of traumatic brain injury (TBI) plus hemorrhagic shock. Guinea pigs were used because, like humans, they do not synthesize their own ascorbic acid, which is important in reducing methemoglobin. RESULTS: TBI was produced by controlled cortical impact and was followed by 20 mL/kg hemorrhage to a mean arterial pressure (MAP) of 40 mmHg. At 90 min, animals were resuscitated with 20 mL/kg lactated Ringer's solution or 10 mL/kg PNPH. Resuscitation with PNPH significantly augmented the early recovery of MAP after hemorrhagic shock by 10-18 mmHg; whole blood methemoglobin was only 1% higher and carboxyhemoglobin was 2% higher. At 9 days of recovery, unbiased stereology analysis revealed that, compared to animals resuscitated with lactated Ringer's solution, those treated with PNPH had significantly more viable neurons in the hippocampus CA1 + 2 region (59 ± 10% versus 87 ± 18% of sham and naïve mean value) and in the dentate gyrus (70 ± 21% versus 96 ± 24%; n = 12 per group). CONCLUSION: PNPH may serve as a small-volume resuscitation fluid for polytrauma involving TBI and hemorrhagic shock. The neuroprotection afforded by PNPH seen in other species was sustained in a species without endogenous ascorbic acid synthesis, thereby supporting potential translatability for human use.

Global Consortium Study of Neurological Dysfunction in COVID-19 (GCS-NeuroCOVID): Study Design and Rationale.

BACKGROUND: As the COVID-19 pandemic developed, reports of neurological dysfunctions spanning the central and peripheral nervous systems have emerged. The spectrum of acute neurological dysfunctions may implicate direct viral invasion, para-infectious complications, neurological manifestations of systemic diseases, or co-incident neurological dysfunction in the context of high SARS-CoV-2 prevalence. A rapid and pragmatic approach to understanding the prevalence, phenotypes, pathophysiology and prognostic implications of COVID-19 neurological syndromes is urgently needed. METHODS: The Global Consortium to Study Neurological dysfunction in COVID-19 (GCS-NeuroCOVID), endorsed by the Neurocritical Care Society (NCS), was rapidly established to address this need in a tiered approach. Tier-1 consists of focused, pragmatic, low-cost, observational common data element (CDE) collection, which can be launched immediately at many sites in the first phase of this pandemic and is designed for expedited ethical board review with waiver-of-consent. Tier 2 consists of prospective functional and cognitive outcomes assessments with more detailed clinical, laboratory and radiographic data collection that would require informed consent. Tier 3 overlays Tiers 1 and 2 with experimental molecular, electrophysiology, pathology and imaging studies with longitudinal outcomes assessment and would require centers with specific resources. A multicenter pediatrics core has developed and launched a parallel study focusing on patients ages <18 years. Study sites are eligible for participation if they provide clinical care to COVID-19 patients and are able to conduct patient-oriented research under approval of an internal or global ethics committee. Hospitalized pediatric and adult patients with SARS-CoV-2 and with acute neurological signs or symptoms are eligible to participate. The primary study outcome is the overall prevalence of neurological complications among hospitalized COVID-19 patients, which will be calculated by pooled estimates of each neurological finding divided by the average census of COVID-19 positive patients over the study period. Secondary outcomes include: in-hospital, 30 and 90-day morality, discharge modified Rankin score, ventilator-free survival, ventilator days, discharge disposition, and hospital length of stay. RESULTS: In a one-month period (3/27/20-4/27/20) the GCS-NeuroCOVID consortium was able to recruit 71 adult study sites, representing 17 countries and 5 continents and 34 pediatrics study sites. CONCLUSIONS: This is one of the first large-scale global research collaboratives urgently assembled to evaluate acute neurological events in the context of a pandemic. The innovative and pragmatic tiered study approach has allowed for rapid recruitment and activation of numerous sites across the world-an approach essential to capture real-time critical neurological data to inform treatment strategies in this pandemic crisis.

The Global Consortium Study of Neurological Dysfunction in COVID-19 (GCS-NeuroCOVID): Development of Case Report Forms for Global Use.

Since its original report in January 2020, the coronavirus disease 2019 (COVID-19) due to Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection has rapidly become one of the deadliest global pandemics. Early reports indicate possible neurological manifestations associated with COVID-19, with symptoms ranging from mild to severe, highly variable prevalence rates, and uncertainty regarding causal or coincidental occurrence of symptoms. As neurological involvement of any systemic disease is frequently associated with adverse effects on morbidity and mortality, obtaining accurate and consistent global data on the extent to which COVID-19 may impact the nervous system is urgently needed. To address this need, investigators from the Neurocritical Care Society launched the Global Consortium Study of Neurological Dysfunction in COVID-19 (GCS-NeuroCOVID). The GCS-NeuroCOVID consortium rapidly implemented a Tier 1, pragmatic study to establish phenotypes and prevalence of neurological manifestations of COVID-19. A key component of this global collaboration is development and application of common data elements (CDEs) and definitions to facilitate rigorous and systematic data collection across resource settings. Integration of these elements is critical to reduce heterogeneity of data and allow for future high-quality meta-analyses. The GCS-NeuroCOVID consortium specifically designed these elements to be feasible for clinician investigators during a global pandemic when healthcare systems are likely overwhelmed and resources for research may be limited. Elements include pediatric components and translated versions to facilitate collaboration and data capture in Latin America, one of the epicenters of this global outbreak. In this manuscript, we share the specific data elements, definitions, and rationale for the adult and pediatric CDEs for Tier 1 of the GCS-NeuroCOVID consortium, as well as the translated versions adapted for use in Latin America. Global efforts are underway to further harmonize CDEs with other large consortia studying neurological and general aspects of COVID-19 infections. Ultimately, the GCS-NeuroCOVID consortium network provides a critical infrastructure to systematically capture data in current and future unanticipated disasters and disease outbreaks.

The epilepsy bioinformatics study for anti-epileptogenic therapy (EpiBioS4Rx) clinical biomarker: Study design and protocol.

The Epilepsy Bioinformatics Study for Anti-epileptogenic Therapy (EpiBioS4Rx) is a longitudinal prospective observational study funded by the National Institute of Health (NIH) to discover and validate observational biomarkers of epileptogenesis after traumatic brain injury (TBI). A multidisciplinary approach has been incorporated to investigate acute electrical, neuroanatomical, and blood biomarkers after TBI that may predict the development of post-traumatic epilepsy (PTE). We plan to enroll 300 moderate-severe TBI patients with a frontal and/or temporal lobe hemorrhagic contusion. Acute evaluation with blood, imaging and electroencephalographic monitoring will be performed and then patients will be tracked for 2 years to determine the incidence of PTE. Validation of selected biomarkers that are discovered in planned animal models will be a principal feature of this work. Specific hypotheses regarding the discovery of biomarkers have been set forth in this study. An international cohort of 13 centers spanning 2 continents will be developed to facilitate this study, and for future interventional studies.

Administration of a 20-Hydroxyeicosatetraenoic Acid Synthesis Inhibitor Improves Outcome in a Rat Model of Pediatric Traumatic Brain Injury.

The arachidonic acid pathway metabolite 20-hydroxyeicosatetraenoic acid (20-HETE) contributes to ischemia/reperfusion brain injury. Inhibition of 20-HETE formation can protect the developing brain from global ischemia. Here, we examined whether treatment with the 20-HETE synthesis inhibitor N-hydroxy-N-4-butyl-2-methylphenylformamidine (HET0016) can protect the immature brain from traumatic brain injury (TBI). Male rats at postnatal day 9-10 underwent controlled cortical impact followed by intraperitoneal injection with vehicle or HET0016 (1 mg/kg, 5 min and 3 h post-injury). HET0016 decreased the lesion volume by over 50% at 3 days of recovery, and this effect persisted at 30 days as the brain matured. HET0016 decreased peri-lesion gene expression of proinflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-1ß [IL-1ß]) at 1 day and increased reparative cytokine (IL-4, IL-10) expression at 3 days. It also partially preserved microglial ramified processes, consistent with less activation. HET0016 decreased contralateral hindlimb foot faults and improved outcome on the novel object recognition memory task 30 days after TBI. In cultured BV2 microglia, HET0016 attenuated the lipopolysaccharide-evoked increase in release of TNF-α. Our data show that HET0016 improves acute and long-term histologic and functional outcomes, in association with an attenuated neuroinflammatory response after contusion of an immature rat brain.

Trauma Bay Disposition of Infants and Young Children With Mild Traumatic Brain Injury and Positive Head Imaging.

OBJECTIVES: To describe the disposition of infants and young children with isolated mild traumatic brain injury and neuroimaging findings evaluated at a level 1 pediatric trauma center, and identify factors associated with their need for ICU admission. DESIGN: Retrospective cohort. SETTING: Single center. PATIENTS: Children less than or equal to 4 years old with mild traumatic brain injury (Glasgow Coma Scale 13-15) and neuroimaging findings evaluated between January 1, 2013, and December 31, 2015. Polytrauma victims and patients requiring intubation or vasoactive infusions preadmission were excluded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Two-hundred ten children (median age/weight/Glasgow Coma Scale: 6 mo/7.5 kg/15) met inclusion criteria. Most neuroimaging showed skull fractures with extra-axial hemorrhage/no midline shift (30%), nondisplaced skull fractures (28%), and intracranial hemorrhage without fractures/midline shift (19%). Trauma bay disposition included ICU (48%), ward (38%), intermediate care unit and home (7% each). Overall, 1% required intubation, 4.3% seizure management, and 4.3% neurosurgical procedures; 15% were diagnosed with nonaccidental trauma. None of the ward/intermediate care unit patients were transferred to ICU. Median ICU/hospital length of stay was 2 days. Most patients (99%) were discharged home without neurologic deficits. The ICU subgroup included all patients with midline shift, 62% patients with intracranial hemorrhage, and 20% patients with skull fractures. Across these imaging subtypes, the only clinical predictor of ICU admission was trauma bay Glasgow Coma Scale less than 15 (p = 0.018 for intracranial hemorrhage; p < 0.001 for skull fractures). A minority of ICU patients (18/100) required neurocritical care and/or neurosurgical interventions; risk factors included neurologic deficit, loss of consciousness/seizures, and extra-axial hemorrhage (especially epidural hematoma). CONCLUSIONS: Nearly half of our cohort was briefly monitored in the ICU (with disposition mostly explained by trauma bay imaging, rather than clinical findings); however, less than 10% required ICU-specific interventions. Although ICU could be used for close neuromonitoring to prevent further neurologic injury, additional research should explore if less conservative approaches may preserve patient safety while optimizing healthcare resource utilization.

Progesterone protects mitochondrial function in a rat model of pediatric traumatic brain injury.

Progesterone has been studied extensively in preclinical models of adult traumatic brain injury (TBI), and has advanced to clinical trials in adults with TBI. However, there are very few preclinical studies in pediatric TBI models investigating progesterone for neuroprotection. Immature male and female rats (postnatal day, PND 17-21) underwent controlled cortical impact (CCI) to the left parietal cortex. Rats received either progesterone (10 mg/kg) at 1 h (i.p.) and 6 h (s.c.) after TBI or vehicle (22.5 % cyclohexdrin), and were compared to naïve, age-matched littermates. At 24 h after CCI, brain mitochondria were isolated from the ipsilateral hemisphere. Active (State 3) and resting (State 4) mitochondrial respiration were measured, and mitochondrial respiratory control ratio (RCR, State 3/State 4) was determined. Total mitochonidral glutathione content was measured. A separate group of rats were studied for histology, and received progesterone or vehicle every 24 h (s.c.) for 7 days. In male rats, TBI reduced mitochondrial RCR, and progesterone preserved mitochondrial RCR. This improvement of RCR was predominantly through significant decreases in State 4 respiratory rates. In female rats, post-injury treatment with progesterone did not significantly improve mitochondrial RCR. Normal (uninjured) male rats had lower mitochondrial glutathione content than normal female rats. After TBI, progesterone prevented loss of mitochondrial glutathione in male rats only. Tissue loss was reduced in progesterone treated female rats at 7d after CCI. Future studies will be directed at correlation with neurologic outcome testing. These preclinical studies could provide information for planning future clinical trials of progesterone treatment in children with TBI.

Metabolic Alterations in Developing Brain After Injury: Knowns and Unknowns.

Brain development is a highly orchestrated complex process. The developing brain utilizes many substrates including glucose, ketone bodies, lactate, fatty acids and amino acids for energy, cell division and the biosynthesis of nucleotides, proteins and lipids. Metabolism is crucial to provide energy for all cellular processes required for brain development and function including ATP formation, synaptogenesis, synthesis, release and uptake of neurotransmitters, maintaining ionic gradients and redox status, and myelination. The rapidly growing population of infants and children with neurodevelopmental and cognitive impairments and life-long disability resulting from developmental brain injury is a significant public health concern. Brain injury in infants and children can have devastating effects because the injury is superimposed on the high metabolic demands of the developing brain. Acute injury in the pediatric brain can derail, halt or lead to dysregulation of the complex and highly regulated normal developmental processes. This paper provides a brief review of metabolism in developing brain and alterations found clinically and in animal models of developmental brain injury. The metabolic changes observed in three major categories of injury that can result in life-long cognitive and neurological disabilities, including neonatal hypoxia-ischemia, pediatric traumatic brain injury, and brain injury secondary to prematurity are reviewed.

Progesterone for neuroprotection in pediatric traumatic brain injury.

OBJECTIVE: To provide an overview of the preclinical literature on progesterone for neuroprotection after traumatic brain injury and to describe unique features of developmental brain injury that should be considered when evaluating the therapeutic potential for progesterone treatment after pediatric traumatic brain injury. DATA SOURCES: National Library of Medicine PubMed literature review. STUDY SELECTION: The mechanisms of neuroprotection by progesterone are reviewed, and the preclinical literature using progesterone treatment in adult animal models of traumatic brain injury is summarized. Unique features of the developing brain that could either enhance or limit the efficacy of neuroprotection by progesterone are discussed, and the limited preclinical literature using progesterone after acute injury to the developing brain is described. Finally, the current status of clinical trials of progesterone for adult traumatic brain injury is reviewed. DATA EXTRACTION AND DATA SYNTHESIS: Progesterone is a pleiotropic agent with beneficial effects on secondary injury cascades that occur after traumatic brain injury, including cerebral edema, neuroinflammation, oxidative stress, and excitotoxicity. More than 40 studies have used progesterone for treatment after traumatic brain injury in adult animal models, with results summarized in tabular form. However, very few studies have evaluated progesterone in pediatric animal models of brain injury. To date, two human phase II trials of progesterone for adult traumatic brain injury have been published, and two multicenter phase III trials are underway. CONCLUSIONS: The unique features of the developing brain from that of a mature adult brain make it necessary to independently study progesterone in clinically relevant, immature animal models of traumatic brain injury. Additional preclinical studies could lead to the development of a novel neuroprotective therapy that could reduce the long-term disability in head-injured children and could potentially provide benefit in other forms of pediatric brain injury (global ischemia, stroke, and statue epilepticus).

Post-discharge outcomes of hospitalized children diagnosed with acute SARS-CoV-2 or MIS-C.

Introduction: Hospitalized children diagnosed with SARS-CoV-2-related conditions are at risk for new or persistent symptoms and functional impairments. Our objective was to analyze post-hospital symptoms, healthcare utilization, and outcomes of children previously hospitalized and diagnosed with acute SARS-CoV-2 infection or Multisystem Inflammatory Syndrome in Children (MIS-C). Methods: Prospective, multicenter electronic survey of parents of children <18 years of age surviving hospitalization from 12 U.S. centers between January 2020 and July 2021. The primary outcome was a parent report of child recovery status at the time of the survey (recovered vs. not recovered). Secondary outcomes included new or persistent symptoms, readmissions, and health-related quality of life. Multivariable backward stepwise logistic regression was performed for the association of patient, disease, laboratory, and treatment variables with recovered status. Results: The children [n = 79; 30 (38.0%) female] with acute SARS-CoV-2 (75.7%) or MIS-C (24.3%) had a median age of 6.5 years (interquartile range 2.0-13.0) and 51 (64.6%) had a preexisting condition. Fifty children (63.3%) required critical care. One-third [23/79 (29.1%)] were not recovered at follow-up [43 (31, 54) months post-discharge]. Admission C-reactive protein levels were higher in children not recovered vs. recovered [5.7 (1.3, 25.1) vs. 1.3 (0.4, 6.3) mg/dl, p = 0.02]. At follow-up, 67% overall had new or persistent symptoms. The most common symptoms were fatigue (37%), weakness (25%), and headache (24%), all with frequencies higher in children not recovered. Forty percent had at least one return emergency visit and 24% had a hospital readmission. Recovered status was associated with better total HRQOL [87 (77, 95) vs. 77 (51, 83), p = 0.01]. In multivariable analysis, lower admission C-reactive protein [odds ratio 0.90 (95% confidence interval 0.82, 0.99)] and higher admission lymphocyte count [1.001 (1.0002, 1.002)] were associated with recovered status. Conclusions: Children considered recovered by their parents following hospitalization with SARS-CoV-2-related conditions had less symptom frequency and better HRQOL than those reported as not recovered. Increased inflammation and lower lymphocyte count on hospital admission may help to identify children needing longitudinal, multidisciplinary care. Clinical Trial Registration: ClinicalTrials.gov (NCT04379089).

Severe Pediatric Neurological Manifestations With SARS-CoV-2 or MIS-C Hospitalization and New Morbidity.

Importance: Neurological manifestations during acute SARS-CoV-2-related multisystem inflammatory syndrome in children (MIS-C) are common in hospitalized patients younger than 18 years and may increase risk of new neurocognitive or functional morbidity. Objective: To assess the association of severe neurological manifestations during a SARS-CoV-2-related hospital admission with new neurocognitive or functional morbidities at discharge. Design, Setting, and Participants: This prospective cohort study from 46 centers in 10 countries included patients younger than 18 years who were hospitalized for acute SARS-CoV-2 or MIS-C between January 2, 2020, and July 31, 2021. Exposure: Severe neurological manifestations, which included acute encephalopathy, seizures or status epilepticus, meningitis or encephalitis, sympathetic storming or dysautonomia, cardiac arrest, coma, delirium, and stroke. Main Outcomes and Measures: The primary outcome was new neurocognitive (based on the Pediatric Cerebral Performance Category scale) and/or functional (based on the Functional Status Scale) morbidity at hospital discharge. Multivariable logistic regression analyses were performed to examine the association of severe neurological manifestations with new morbidity in each SARS-CoV-2-related condition. Results: Overall, 3568 patients younger than 18 years (median age, 8 years [IQR, 1-14 years]; 54.3% male) were included in this study. Most (2980 [83.5%]) had acute SARS-CoV-2; the remainder (588 [16.5%]) had MIS-C. Among the patients with acute SARS-CoV-2, 536 (18.0%) had a severe neurological manifestation during hospitalization, as did 146 patients with MIS-C (24.8%). Among survivors with acute SARS-CoV-2, those with severe neurological manifestations were more likely to have new neurocognitive or functional morbidity at hospital discharge compared with those without severe neurological manifestations (27.7% [n = 142] vs 14.6% [n = 356]; P < .001). For survivors with MIS-C, 28.0% (n = 39) with severe neurological manifestations had new neurocognitive and/or functional morbidity at hospital discharge compared with 15.5% (n = 68) of those without severe neurological manifestations (P = .002). When adjusting for risk factors in those with severe neurological manifestations, both patients with acute SARS-CoV-2 (odds ratio, 1.85 [95% CI, 1.27-2.70]; P = .001) and those with MIS-C (odds ratio, 2.18 [95% CI, 1.22-3.89]; P = .009) had higher odds of having new neurocognitive and/or functional morbidity at hospital discharge. Conclusions and Relevance: The results of this study suggest that children and adolescents with acute SARS-CoV-2 or MIS-C and severe neurological manifestations may be at high risk for long-term impairment and may benefit from screening and early intervention to assist recovery.

Importance of Control Groups for Evaluating Long-Term Behavioral and Cognitive Outcomes of Controlled Cortical Impact in Immature Rats.

Therapies are limited for pediatric traumatic brain injury (TBI), especially for the very young who can experience long-term consequences to learning, memory, and social behavior. Animal models of pediatric TBI have yielded mechanistic insights, but demonstration of clinically relevant long-term behavioral and/or cognitive deficits has been challenging. We characterized short- and long-term outcomes in a controlled cortical impact (CCI) model of pediatric TBI using a panel of tests between 2 weeks and ∼4 months after injury. Male rats with CCI at postnatal Day (PND) 10 were compared with three control groups: Naïve, Anesthesia, and Craniotomy. Motor testing (PND 25-33), novel object recognition (NOR; PND 40-50), and multiple tasks in water maze (WM; PND 65-100) were followed by social interaction tests (PND 120-140). Anesthesia rats performed the same as Naïve rats in all tasks. TBI rats, when compared with Naïve controls, had functional impairments across most tests studied. The most sensitive cognitive processes affected by TBI included those that required fast one-trial learning (NOR, WM), flexibility of acquired memory traces (reversals in WM), response strategies (WM), or recognition memory in the setting of reciprocal social interactions. Both TBI and Craniotomy groups demonstrated increased rates of decision making across several WM tasks, suggesting disinhibition of motor responses. When the TBI group was compared with the Craniotomy group, however, deficits were detected in a limited number of outcomes. The latter included learning speed (WM), cognitive flexibility (WM), and social recognition memory. Notably, effects of craniotomy, when compared with Naïve controls, spanned across multiple tasks, and in some tasks, could reach the effect sizes observed in TBI. These results highlight the importance of appropriate control groups in pediatric CCI models. In addition, the study demonstrates the high sensitivity of comprehensive cognitive testing to detect long-term effects of early-age craniotomy and TBI and provides a template for future testing of experimental therapies.

Bone Turnover Markers Including Undercarboxylated Osteocalcin Are Associated With Mortality Risk in Older Men.

Osteocalcin in its undercarboxylated form (ucOC) may influence diabetes risk; however, its relationship with all-cause and cause-specific mortality is unclear. Whether other bone turnover markers (BTMs) are associated with mortality risk differently from ucOC also remains uncertain. Our aim was to determine associations of serum ucOC with all-cause and cause-specific mortality and compare these with the corresponding associations of serum total osteocalcin (TOC), procollagen type I N-propeptide (PINP), and collagen type 1 C-terminal cross-linked telopeptide (CTX) in older men. We conducted a prospective cohort study of 3871 community-dwelling men, aged 77.0 ± 3.6 years at baseline, followed for a median of 12.3 years. Exposure variables were ucOC, TOC, PINP, and CTX concentrations assayed in serum. Outcomes were incidence of all deaths and deaths due to cardiovascular disease (CVD) or cancer, ascertained using death registry data. Cox regression analyses adjusted for cardiovascular risk factors and prevalent CVD and for prevalent cancer in analyses of cancer-related mortality. Higher concentrations of ucOC, PINP, and CTX were associated with all-cause mortality (hazard ratio [HR] per 1 standard deviation increase: ucOC 1.12, 95% confidence interval [CI] 1.06-1.18, p < 0.001; PINP HR = 1.06, 95% CI 1.01-1.11, p = 0.009; CTX HR = 1.13, 95% CI 1.08-1.19, p < 0.001), but TOC was not associated. Similar results were found after excluding men with an incident fracture during follow-up. Higher ucOC and CTX were associated with CVD mortality (ucOC HR per 1 SD increase 1.13, 95% CI 1.05-1.22, p = 0.001; CTX HR = 1.12, 95% CI 1.04-1.20, p = 0.003), but this result was not significant in competing risks analysis. Higher CTX was also associated with cancer mortality (HR = 1.12, 95% CI 1.01-1.23, p = 0.024). In conclusion, in older men, higher bone turnover, assessed by BTMs including ucOC, is a biomarker for all-cause mortality risk. Undercarboxylated osteocalcin was a more informative biomarker for this outcome than TOC. Higher CTX was associated with all-cause and cancer-related mortality. Further evaluation of causality and potential underlying mechanisms is warranted. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Prevalence and Risk Factors of Neurologic Manifestations in Hospitalized Children Diagnosed with Acute SARS-CoV-2 or MIS-C.

BACKGROUND: Our objective was to characterize the frequency, early impact, and risk factors for neurological manifestations in hospitalized children with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or multisystem inflammatory syndrome in children (MIS-C). METHODS: Multicenter, cross-sectional study of neurological manifestations in children aged <18 years hospitalized with positive SARS-CoV-2 test or clinical diagnosis of a SARS-CoV-2-related condition between January 2020 and April 2021. Multivariable logistic regression to identify risk factors for neurological manifestations was performed. RESULTS: Of 1493 children, 1278 (86%) were diagnosed with acute SARS-CoV-2 and 215 (14%) with MIS-C. Overall, 44% of the cohort (40% acute SARS-CoV-2 and 66% MIS-C) had at least one neurological manifestation. The most common neurological findings in children with acute SARS-CoV-2 and MIS-C diagnosis were headache (16% and 47%) and acute encephalopathy (15% and 22%), both P < 0.05. Children with neurological manifestations were more likely to require intensive care unit (ICU) care (51% vs 22%), P < 0.001. In multivariable logistic regression, children with neurological manifestations were older (odds ratio [OR] 1.1 and 95% confidence interval [CI] 1.07 to 1.13) and more likely to have MIS-C versus acute SARS-CoV-2 (OR 2.16, 95% CI 1.45 to 3.24), pre-existing neurological and metabolic conditions (OR 3.48, 95% CI 2.37 to 5.15; and OR 1.65, 95% CI 1.04 to 2.66, respectively), and pharyngeal (OR 1.74, 95% CI 1.16 to 2.64) or abdominal pain (OR 1.43, 95% CI 1.03 to 2.00); all P < 0.05. CONCLUSIONS: In this multicenter study, 44% of children hospitalized with SARS-CoV-2-related conditions experienced neurological manifestations, which were associated with ICU admission and pre-existing neurological condition. Posthospital assessment for, and support of, functional impairment and neuroprotective strategies are vitally needed.

Sex differences in pediatric traumatic brain injury.

The response of the developing brain to traumatic injury is different from the response of the mature, adult brain. There are critical developmental trajectories in the young brain, whereby injury can lead to long term functional abnormalities. Emerging preclinical and clinical literature supports the presence of significant sex differences in both the response to and the recovery from pediatric traumatic brain injury (TBI). These sex differences are seen at all pediatric ages, including neonates/infants, pre-pubertal children, and adolescents. As importantly, the response to neuroprotective therapies or treatments can differ between male and females subjects. These sex differences can result from several biologic origins, and may manifest differently during the various phases of brain and body development. Recognizing and understanding these potential sex differences is crucial, and should be considered in both preclinical and clinical studies of pediatric TBI.

Early and sustained alterations in cerebral metabolism after traumatic brain injury in immature rats.

Although studies have shown alterations in cerebral metabolism after traumatic brain injury (TBI), clinical data in the developing brain is limited. We hypothesized that post-traumatic metabolic changes occur early (<24 h) and persist for up to 1 week. Immature rats underwent TBI to the left parietal cortex. Brains were removed at 4 h, 24 h, and 7 days after injury, and separated into ipsilateral (injured) and contralateral (control) hemispheres. Proton nuclear magnetic resonance (NMR) spectra were obtained, and spectra were analyzed for N-acetyl-aspartate (NAA), lactate (Lac), creatine (Cr), choline, and alanine, with metabolite ratios determined (NAA/Cr, Lac/Cr). There were no metabolic differences at any time in sham controls between cerebral hemispheres. At 4 and 24 h, there was an increase in Lac/Cr, reflecting increased glycolysis and/or decreased oxidative metabolism. At 24 h and 7 days, there was a decrease in NAA/Cr, indicating loss of neuronal integrity. The NAA/Lac ratio was decreased ( approximately 15-20%) at all times (4 h, 24 h, 7 days) in the injured hemisphere of TBI rats. In conclusion, metabolic derangements begin early (<24 h) after TBI in the immature rat and are sustained for up to 7 days. Evaluation of early metabolic alterations after TBI could identify novel targets for neuroprotection in the developing brain.

Normoxic ventilatory resuscitation following controlled cortical impact reduces peroxynitrite-mediated protein nitration in the hippocampus.

OBJECTIVES: Ventilatory resuscitation with 100% O2 after severe traumatic brain injury (TBI) raises concerns about the increased production of reactive oxygen species (ROS). The product of peroxynitrite-meditated tyrosine residue nitration, 3-nitrotyrosine (3-NT), is a marker for oxidative damage to proteins. The authors hypothesized that posttraumatic resuscitation with hyperoxia (100% fraction of inspired oxygen [FiO2] concentration) results in increased ROS-induced damage to proteins compared with resuscitation using normoxia (21% FiO2 concentration). METHODS: Male Sprague-Dawley rats underwent controlled cortical impact (CCI) injury and resuscitation with either normoxic or hyperoxic ventilation for 1 hour (5 rats per group). Twenty-four hours after injury, rat hippocampi were evaluated using 3-NT immunostaining. In a second experiment, animals similarly underwent CCI injury and normoxic or hyperoxic ventilation for 1 hour (4 rats per group). One week after injury, neuronal counts were performed after neuronal nuclei immunostaining. RESULTS: The 3-NT staining was significantly increased in the hippocampi of the hyperoxic group. The normoxic group showed a 51.0% reduction of staining in the CA1 region compared with the hyperoxic group and a 50.8% reduction in the CA3 region (p < 0.05, both regions). There was no significant difference in staining between the injured normoxic group and sham-operated control groups. In the delayed analysis of neuronal survival (neuronal counts), there was no significant difference between the hyperoxic and normoxic groups. CONCLUSIONS: In this clinically relevant model of TBI, normoxic resuscitation significantly reduced oxidative damage to proteins compared with hyperoxic resuscitation. Neuronal counts showed no benefit from hyperoxic resuscitation. These findings indicate that hyperoxic ventilation in the early stages after severe TBI may exacerbate oxidative damage to proteins.

Prospective assessment of guidelines for determining appropriate depth of endotracheal tube placement in children.

OBJECTIVE: To determine whether multiplying the internal diameter of the endotracheal tube (ETT) by 3 (3x ETT size) is a reliable method for determining correct depth of oral ETT placement in the pediatric population. DESIGN: Prospective, observational. SETTING: University-affiliated, 12-bed pediatric intensive care unit. PATIENTS: Orally intubated pediatric intensive care unit patients of < or =12 yrs of age. INTERVENTIONS: Demographics, ETT size, and depth of ETT placement measured from the lip were obtained. Correct placement, defined as the tip of the ETT below the thoracic inlet and > or =0.5 cm above the carina, was determined by chest radiograph. MEASUREMENTS AND MAIN RESULTS: Suggested ETT size based on the Pediatric Advanced Life Support (PALS) age-based formula and the Broselow tape-length-based guidelines were determined. A total of 174 of 226 ETTs (77%) were correctly positioned. If practitioners utilized the 3x ETT size for the actual tubes chosen, 170 of 226 (75%) would have been accurately placed. More accurate were the 3x PALS-based ETT size (81%) and 3x Broselow-suggested ETT size (85%). The use of the Broselow ETTs to determine the depth would have led to a significantly improved ETT position (p = .009) compared with the actual ETT. CONCLUSION: The commonly used formula of 3x tube size for ETT depth in children results in 15-25% malpositioned tubes. Practitioners can improve the reliability of this formula by utilizing the recommended ETT size as suggested by the Broselow tape. A more reliable method is necessary to avoid ETT malposition.