Spectrum of Traumatic Brain Injury from Mild to Severe

Head Injury Evaluation and Ambulance Diagnosis (HOME) Study protocol: a feasibility study assessing the implementation of the Canadian CT Head Rule in the prehospital setting

INTRODUCTION

Traumatic brain injury (TBI) is a common presentation in the prehospital environment. At present, paramedics do not routinely use tools to identify low-risk patients who could be left at scene or taken to a local hospital rather than a major trauma centre. The Canadian CT Head Rule (CCHR) was developed to guide the use of CT imaging in hospital. It has not been evaluated in the prehospital setting. We aim to address this gap by evaluating the feasibility and acceptability of implementing the CCHR to patients and paramedics, and the feasibility of conducting a full-scale clinical trial of its use.

METHODS AND ANALYSIS

We will recruit adult patients who are being transported to an emergency department (ED) by ambulance after suffering a mild TBI. Paramedics will prospectively collect data for the CCHR. All patients will be transported to the ED, where deferred consent will be taken and the treating clinician will reassess the CCHR, blinded to paramedic interpretation. The primary clinical outcome will be neurosurgically significant TBI. Feasibility outcomes include recruitment and attrition rates. We will assess acceptability of the CCHR to paramedics using the Ottawa Acceptability of Decision Rules Instrument. Interobserver reliability of the CCHR will be assessed between paramedics and the treating clinician in the ED. Participating paramedics and patients will be invited to participate in semistructured interviews to explore the acceptability of trial processes and facilitators and barriers to the use of the CCHR in practice. Data will be analysed thematically. We anticipate recruiting approximately 100 patients over 6 months.

ETHICS AND DISSEMINATION

This study was approved by the Health Research Authority and the Research Ethics Committee (REC reference: 22/NW/0358). The results will be published in a peer-reviewed journal, presented at conferences and will be incorporated into a doctoral thesis.

TRIAL REGISTRATION NUMBER

ISRCTN92566288.

Traumatic Brain Injury in the Long-COVID Era

Major determinants of the biological background or reserve, such as age, biological sex, comorbidities (diabetes, hypertension, obesity, etc.), and medications (e.g., anticoagulants), are known to affect outcome after traumatic brain injury (TBI). With the unparalleled data richness of coronavirus disease 2019 (COVID-19; ∼375,000 and counting!) as well as the chronic form, long-COVID, also called post-acute sequelae SARS-CoV-2 infection (PASC), publications (∼30,000 and counting) covering virtually every aspect of the diseases, pathomechanisms, biomarkers, disease phases, symptomatology, etc., have provided a unique opportunity to better understand and appreciate the holistic nature of diseases, interconnectivity between organ systems, and importance of biological background in modifying disease trajectories and affecting outcomes. Such a holistic approach is badly needed to better understand TBI-induced conditions in their totality. Here, I briefly review what is known about long-COVID/PASC, its underlying-suspected-pathologies, the pathobiological changes induced by TBI, in other words, the TBI endophenotypes, discuss the intersection of long-COVID/PASC and TBI-induced pathobiologies, and how by considering some of the known factors affecting the person's biological background and the inclusion of mechanistic molecular biomarkers can help to improve the clinical management of TBI patients.

A Machine Learning-Based Prognostic Model for the Prediction of Early Death After Traumatic Brain Injury: Comparison with the Corticosteroid Randomization After Significant Head Injury (CRASH) Model

BACKGROUND

Machine learning (ML) has been used to predict the outcomes of traumatic brain injury. However, few studies have reported the use of ML models to predict early death. This study aimed to develop ML models for early death prediction and to compare performance with the corticosteroid randomization after significant head injury (CRASH) model.

METHODS

We retrospectively reviewed traumatic brain injury patients between February 2017 and August 2021. The patients were randomly assigned to a training set and a test set. Predictive variables included clinical findings, laboratory values, and computed tomography findings. The ML models (random forest, support vector machine [SVM], logistic regression) were developed with the training set. The CRASH model is a prognostic model that was developed based on 10,008 patients included in the CRASH trial. The ML and CRASH models were applied to the test set to evaluate the performance.

RESULTS

A total of 423 patients were included; 317 and 106 patients were randomly assigned to the training and test sets, respectively. The area under the curve was highest in the SVM (0.952, 95% confidence interval = 0.906-0.990) and lowest in the CRASH model (0.942, 95% confidence interval = 0.886-0.999). There were no significant differences between the area under the curves of the ML and CRASH models (P = 0.899 for random forest vs. the CRASH model, P = 0.760 for SVM vs. the CRASH model, P = 0.806 for logistic regression vs. the CRASH model).

CONCLUSIONS

The ML models may have comparable performances compared to the CRASH model despite being developed with a smaller sample size.

Role of Diffusion Tensor Imaging in the Diagnosis of Traumatic Axonal Injury in Individual Patients with a Concussion or Mild Traumatic Brain Injury: A Mini-Review

Present review paper aims to understand role of diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in diagnosis of traumatic axonal injury (TAI), induced by head trauma, in individual patients with a concussion or mild traumatic brain injury (mTBI). Precise information on presence and severity of TAI in brain is necessary for determining appropriate therapeutic strategies. Several hundred DTI-based studies have reported TAI in concussion or mTBI. Majority of these DTI-based studies have been performed in a group of patients, whereas case studies that have reported TAI in individual patients with a concussion or mTBI are fewer. Summary of these DTI-based studies for individual patients is as follows: DTI can be used as a non-invasive tool for determining presence and severity of TAI in individual patients with concussion or mTBI. However, for diagnosis of TAI in an individual patient, several conditions are required to be met: no past history of head trauma, presence of possible conditions for TAI occurrence during head trauma, development of new clinical features after head trauma, and DTI observed abnormality of a neural structure that coincides with a newly developed clinical feature. However, further studies for a more precise diagnosis of TAI in individual patients should be encouraged.

Delayed Neurosurgical Intervention in Traumatic Brain Injury Patients Referred From Primary Hospitals Is Not Associated With an Unfavorable Outcome

Background: Secondary transports of patients suffering from traumatic brain injury (TBI) may result in a delayed management and neurosurgical intervention, which is potentially detrimental. The aim of this study was to study the effect of triaging and delayed transfers on outcome, specifically studying time to diagnostics and neurosurgical management.

Methods: This was a retrospective observational cohort study of TBI patients in need of neurosurgical care, 15 years and older, in the Stockholm Region, Sweden, from 2008 throughout 2014. Data were collected from pre-hospital and in-hospital charts. Known TBI outcome predictors, including the protein biomarker of brain injury S100B, were used to assess injury severity. Characteristics and outcomes of direct trauma center (TC) and those of secondary transfers were evaluated and compared. Functional outcome, using the Glasgow Outcome Scale, was assessed in survivors at 6–12 months after trauma. Regression models, including propensity score balanced models, were used for endpoint assessment.

Results: A total of n = 457 TBI patients were included; n = 320 (70%) patients were direct TC transfers, whereas n = 137 (30%) were secondary referrals. In all, n = 295 required neurosurgery for the first 24 h after trauma (about 75% of each subgroup). Direct TC transfers were more severely injured (median Glasgow Coma Scale 8 vs. 13) and more often suffered a high energy trauma (31 vs. 2.9%) than secondary referrals. Admission S100B was higher in the TC transfer group, though S100B levels 12–36 h after trauma were similar between cohorts. Direct or indirect TC transfer could be predicted using propensity scoring. The secondary referrals had a shorter distance to the primary hospital, but had later radiology and surgery than the TC group (all p < 0.001). In adjusted multivariable analyses with and without propensity matching, direct or secondary transfers were not found to be significantly related to outcome. Time from trauma to surgery did not affect outcome.

Conclusions: TBI patients secondary transported to a TC had surgical intervention performed hours later, though this did not affect outcome, presumably demonstrating that accurate pre-hospital triaging was performed. This indicates that for selected patients, a wait-and-see approach with delayed neurosurgical intervention is not necessarily detrimental, but warrants further research.

The Relation Between Loss of Consciousness, Severity of Traumatic Brain Injury, and Injury of Ascending Reticular Activating System in Patients With Traumatic Brain Injury

OBJECTIVE

Loss of consciousness is an indicator of the severity of traumatic brain injury and the ascending reticular activating system has been considered as a main structure for consciousness. However, no study on the relation between loss of consciousness and ascending reticular activating system injury in traumatic brain injury has been reported. We investigated the relation between loss of consciousness, severity of traumatic brain injury, and ascending reticular activating system injury using diffusion tensor tractography.

DESIGN

One hundred twenty patients were recruited. Three components of ascending reticular activating system, fractional anisotropy, and tract volume were measured.

RESULTS

In lower dorsal and ventral ascending reticular activating system, fractional anisotropy and tract volume value in mild group were higher than those of moderate and severe groups, and there was no difference between moderate and severe groups. In upper ascending reticular activating system, fractional anisotropy value in mild group was higher than in moderate group, and it was higher than in moderate group than in severe group. Tract volume value in mild group was higher than in severe group. Loss of consciousness showed moderate negative correlations with tract volume value of lower dorsal ascending reticular activating system (r = -0.348), fractional anisotropy value of lower ventral ascending reticular activating system (r = -0.343), and fractional anisotropy value of upper ascending reticular activating system (r = -0.416).

CONCLUSIONS

Injury severity was different among the three traumatic brain injury groups in upper ascending reticular activating system but did not differ between moderate and severe groups in lower dorsal and ventral ascending reticular activating system.

Association of COMT Val158Met Polymorphism With Delirium Risk and Outcomes After Traumatic Brain Injury

OBJECTIVE

The authors investigated the association of the catechol-o-methyltransferase (COMT) gene Val¹⁵⁸Met polymorphism with delirium risk and functional and cognitive outcomes among patients with complicated mild to moderate traumatic brain injury (TBI).

METHODS

In a prospective observational cohort study, patients were monitored for occurrence of delirium during the first 4 days of admission by using the Confusion Assessment Method. Functional and cognitive outcomes were evaluated with the Glasgow Outcome on Discharge Scale and the Montreal Cognitive Assessment test, respectively. Eighty-nine patients were included in the study; of these, 17 (19%) were diagnosed with delirium.

RESULTS

The COMT Val¹⁵⁸/Val¹⁵⁸ polymorphism was associated with increased risk of delirium in multivariable regression analyses adjusted for alcohol misuse, history of neurological disorder, age, and admission Glasgow Coma Scale score (odds ratio=4.57, 95% CI=1.11, 18.9, p=0.036). The COMT Met¹⁵⁸ allele was associated with better functional outcomes in univariate analysis (odds ratio=2.82, 95% CI=1.10, 7.27, p=0.031) but not in multivariable analysis (odds ratio=2.33, 95% CI=0.89, 6.12, p=0.085). Cognitive outcomes were not associated with the COMT Val¹⁵⁸Met polymorphism in univariate regression analysis (p=0.390). Delirium was a significant predictor of worse functional and cognitive outcomes in multivariable regression analyses adjusted for other risk factors (odds ratio=0.04, 95% CI=0.01, 0.16, p<0.001, and β=-3.889, 95% CI=-7.55, -0.23, p=0.038, respectively).

CONCLUSIONS

The COMT genotype is important in delirium risk and functional outcomes of patients with mild to moderate TBI. Whether the COMT genotype is associated with outcomes through incident delirium remains to be determined in larger studies.

Default mode network functional connectivity after multiple concussions in children and adolescents

Objective

This cross-sectional study aims to elucidate if children and adolescents with multiple concussions demonstrate long-term alterations in DMN functional connectivity (FC).

Method

Participants (N = 57, 27 girls and 30 boys; 8-19 years old, M age = 14.7, SD = 2.8) were divided into three groups (orthopedic injury [OI] n = 20; one concussion n = 16; multiple concussions n = 21, M = 3.2 concussions, SD = 1.7) and seen on average 31.6 months post-injury (range 4.3-130.7 months; SD = 19.4). They underwent a resting-state functional magnetic resonance imaging scan. Parents completed the ADHD rating scale-5 for children and adolescents. Children and parents completed the post-concussion symptom inventory (PCSI).

Results

Anterior and posterior DMN components were extracted from the fMRI data for each participant using FSL’s MELODIC and dual regression. We tested for pairwise group differences within each DMN component in FSL’s Randomize (5000 permutations) using threshold-free cluster enhancement to estimate cluster activation, controlling for age, sex, and symptoms of inattention. FC of the anterior DMN was significantly reduced in the group with multiple concussions compared to the two other groups, whereas there were no significant group differences on FC of the posterior DMN. There were no significant associations between DMN FC and PCSI scores.

Conclusions

These results suggest reduced FC in the anterior DMN in youth with multiple concussions, but no linear association with post-concussive symptoms.

Difference between injuries of the corticospinal tract and corticoreticulospinal tract in patients with diffuse axonal injury: a diffusion tensor tractography study

Objectives: No studies have investigated differences in injury of the corticospinal tract (CST) and corticoreticulospinal tract (CRT) following diffuse axonal injury (DAI) to date. Therefore, we investigated differences in injury of the CST and CRT in patients with DAI using diffusion tensor tractography (DTT).Methods: Twenty consecutive patients with DAI and 20 control subjects were recruited. CST and CRT were reconstructed. Each part of the CST and CRT was analyzed in terms of DTT parameters and configuration.Results: Upon group analysis, decreased FA and TV values were observed in both the CST and CRT in the patient group compared with the control group (%) (p < .05). In the individual analysis in terms of the TV, significantly higher injury incidence was observed for the CRT (47.5%) than the CST (25.0%) (p < .05). Evaluation of the DTT configuration revealed significantly higher injury incidence for the CRT (50.0%) than the CST (17.5%) (p < .05). Specifically, the incidence of discontinuation was significantly higher for the CRT (40.0%) than the CST (10.0%) (p < .05).Conclusions: Injury of the CST and CRT was detected in patients with DAI using DTT. In terms of the incidence and severity of neural injury, the CRT appeared to be more vulnerable to DAI than the CST.

Mild, moderate and severe: terminology implications for clinical and experimental traumatic brain injury

PURPOSE OF REVIEW

When describing clinical or experimental traumatic brain injury (TBI), the adjectives 'mild,' 'moderate' and 'severe' are misleading. 'Mild' clinical TBI frequently results in long-term disability. 'Severe' rodent TBI actually resembles mild or complicated mild clinical TBI.

RECENT FINDINGS

Many mild TBI patients appear to have recovered completely but have postconcussive symptoms, deficits in cognitive and executive function and reduced cerebral blood flow. After moderate TBI, 31.8% of patients died or were discharged to skilled nursing or hospice. Among survivors of moderate and severe TBI, 44% were unable to return to work. On MRI, 88% of mild TBI patients have evidence of white matter damage, based on measurements of fractional anisotropy and mean diffusivity/apparent diffusion coefficient. After sports concussion, clinically recovered patients have abnormalities in functional connectivity on functional MRI. Methylphenidate improved fatigue and cognitive impairment and, combined with cognitive rehabilitation, improved memory and executive functioning. In comparison to clinical TB, because the entire spectrum of experimental rodent TBI, although defined as moderate or severe, more closely resembles mild or complicated mild clinical TBI.

SUMMARY

Many patients after mild or moderate TBI suffer long-term sequelae and should be considered a major target for translational research. Treatments that improve outcome in rodent TBI, even when the experimental injuries are defined as severe, might be most applicable to mild or moderate TBI.

Headache due to spinothalamic tract injury in patients with mild traumatic brain injury: Two case reports

RATIONALE

Headache is the most common physical complaint reported by the following traumatic brain injury (TBI). Several studies using diffusion tensor tractography (DTT) have demonstrated that injury of the spinothalamic tract (STT) is a pathogenetic mechanism of central pain following TBI. However, no study of headache due to injury of the STT has been reported.

PATIENT CONCERNS

Patient 1 was a 52-year-old female who suffered head trauma resulting from an in-car traffic crash. While sitting in a passenger seat in a moving vehicle, another vehicle suddenly hit the car from the right side. Her head hit the door and she suffered a flexion-hyperextension-rotation injury. She began to feel headaches in both fronto-parieto-occipital areas approximately 2 weeks after the crash. The characteristics and severity of pain were as follows: constant tingling and intermittent stabbing pain without allodynia or hyperalgesia (visual analogue scale score: 7). Patient 2 was a 50-year-old male who suffered head trauma from a flexion-hyperextension injury that occurred after being hit from behind by a vehicle while driving his car. He began to feel headache in both fronto-parieto-occipital areas the day after the crash: constant tingling pain without allodynia or hyperalgesia (visual analogue scale score: 6).

DIAGNOSES

The patient 1 was diagnosed as mild TBI due to head flexion-hyperextension-rotation injury. The patient 2 was diagnosed as mild TBI due to head flexion-hyperextension injury.

INTERVENTIONS

Clinical assessment and DTT were performed at 5 months (patient 1) and 10 months (patient 2) after the initial injury.

OUTCOMES

On DTTs of patient 1 and 2, the STTs showed narrowing in both hemispheres. In addition, discontinuations at the subcortical white matter were observed in both hemispheres in patient 2.

LESSONS

Headache due to injury of the STT was diagnosed in patients with mild TBI. Precise diagnosis of central pain from other types of pain is clinically important because the management of central pain is quite different from those for other types of pain. Our results suggest that headache might be ascribed to the injury of the STT in patients with mild TBI. Therefore, we recommend evaluation of the STT using DTT in patients with mild TBI who complain of headache having the characteristics of neuropathic pain.

Neuropsychological assessment of traumatic brain injury: Current ethical challenges and recommendations for future practice

Numerous ethical challenges may arise over the course of neuropsychological assessment. This paper highlights the ethical considerations associated with neuropsychological assessment of individuals with traumatic brain injury. Issues regarding professional competency, providing and obtaining informed consent, neuropsychological test selection and administration, effectively communicating assessment results, and working as part of a multidisciplinary team are discussed with practical recommendations. Ultimately, a comprehensive understanding of these issues as well as an integration of resources to guide clinical practice will contribute to ethical decision-making and strong professional practice.

Is Computerized Cognitive Testing Useful in Children and Adolescents with Moderate-to-Severe Traumatic Brain Injury?

OBJECTIVES

Children and adolescents with moderate-to-severe traumatic brain injury (TBI) present with short and long-term neuropsychological deficits following their injury. The aim of this study was to investigate the utility of a brief computerized test battery for evaluating cognitive functioning sub-acutely following a TBI.

METHODS

Participants (n=33) sustained a moderate-to-severe TBI, were between 8 and 18 years old, and were assessed using CNS Vital Signs (CNSVS) within 6 months post-injury (median=0.6 month). Participants with TBI were matched to 33 healthy controls based on age, sex, and handedness to compare their cognitive functioning on the CNSVS battery.

RESULTS

Children and adolescents with moderate-to-severe TBI had significantly lower scores and large effect sizes on Reaction Time, Complex Attention, and Cognitive Flexibility domains, as well as medium effect sizes on two Visual Memory test scores and one Psychomotor Speed test score. A significantly higher percentage of participants with TBI had cognitive impairment on Reaction Time domain score compared to the control group. Finally, CNSVS domain scores correctly categorized 76% of participants as either group with TBI or control group.

CONCLUSIONS

CNSVS may be a useful tool for screening cognitive abilities in children and adolescents who are early in their recovery from a moderate-to-severe TBI, particularly when a rapid screening evaluation can help guide management, interventions, and track recovery. (JINS, 2017, 23, 304-313).

Neurologic Emergencies in the Elderly

Neurologic diseases are a major cause of death and disability in elderly patients. Due to the physiologic changes and increased comorbidities that occur as people age, neurologic diseases are more common in geriatric patients and a major cause of death and disability in this population. This article discusses the elderly patient presenting to the emergency department with acute ischemic stroke, transient ischemic attack, intracerebral hemorrhage, subarachnoid hemorrhage, chronic subdural hematoma, traumatic brain injury, seizures, and central nervous system infections. This article reviews the subtle presentations, difficult workups, and complicated treatment decisions as they pertain to our older patients."

Central pain due to spinothalamic tract injury caused by indirect head trauma following a pratfall

OBJECTIVES

This study reports on patients who showed central pain due to injury of the spinothalamic tract (STT) caused by fall without direct head trauma.

DESIGN

Prospective study.

PARTICIPANTS

Two patients with mild traumatic brain injury (TBI) resulting from a fall were enrolled. Patient 1 was a 21-year-old female who had suffered a pratfall with no history of direct head trauma. She had begun to feel pain in both upper trunk and lower back and the left leg since ~ 5 days after onset: constant tingling and throbbing sensation with allodynia. Patient 2 was a 39-year-old male who had suffered a pratfall without direct head trauma. He had begun to feel pain in both arms and legs since ~ 4 days after the fall: constant tingling and pricking sensation without allodynia or hyperalgesia.

RESULTS

On diffusion tensor tractograhpy (DTT) of patient 1, partial tearing of the right STT was observed at the subcortical white matter. On DTT of patient 2, partial tearing at the subcortical white matter was observed in the right STT and partial narrowing at the subcortical white matter was observed in the left STT.

CONCLUSIONS

This study demonstrated injury of the STT in patients who suffered from central pain following a fall. The results suggest that minor indirect head trauma can cause traumatic axonal injury of the brain.

Understanding the pathology and treatment of traumatic brain injury and posttraumatic stress disorder: a therapeutic role for hyperbaric oxygen therapy

Traumatic brain injury (TBI) is an intracranial injury caused by external trauma leading to different degrees of brain damage. TBI can cause a wide array of symptoms and range in severity from concussion to coma and death. The link between TBI and posttraumatic stress disorder (PTSD) has received increasing attention due to the high incidence of these conditions in soldiers returning from recent conflicts. TBI has been associated with an increased risk of PTSD. Additionally, TBI and PTSD often demonstrate overlapping symptoms. In this article, we discuss the different forms of TBI and their links to PTSD. We also discuss current therapies for TBI and PTSD, in particular detailing the therapeutic potential of hyperbaric oxygen therapy in the management of these conditions.

Cognitive Rehabilitation After Traumatic Brain Injury: A Reference for Occupational Therapists

Nearly 1.7 million Americans sustain a traumatic brain injury (TBI) each year. These injuries can result in physical, emotional, and cognitive consequences. While many individuals receive cognitive rehabilitation from occupational therapists (OTs), the interdisciplinary nature of TBI research makes it difficult to remain up-to-date on relevant findings. We conducted a literature review to identify and summarize interdisciplinary evidence-based practice targeting cognitive rehabilitation for civilian adults with TBI. Our review summarizes TBI background, and our cognitive remediation section focuses on the findings from 37 recent (since 2006) empirical articles directly related to cognitive rehabilitation for individuals (i.e., excluding special populations such as veterans or athletes). This manuscript is offered as a tool for OTs engaged in cognitive rehabilitation and as a means to highlight arenas where more empirical, interdisciplinary research is needed.

Transocular ultrasound measurement of the optic nerve sheath diameter can identify elevated intracranial pressure in trauma patients

Background

Prompt identification of elevated intracranial pressure (eICP) is life-saving. Physical exam alone often fails to identify this problem and invasive monitoring is not always utilized appropriately. A non-invasive, rapid, reliable technique to detect eICP is needed and optic nerve sheath diameter (ONSD) is known to be a valid surrogate. Historically, ONSD in patients with eICP above 20 mmHg varied from 0.5 to 0.7 cm. Receiver operator curves predict that diameters below 0.5 to 0.58 cm correspond to normal pressures. Interobserver variability is low (0.01--0.03 cm). The learning curve was 25 and 10 procedures for novice and experienced sonographers, respectively. We report our initial experience using ultrasound to measure ONSD during initial trauma evaluation.

Study design

Transocular ultrasound was used to determine ONSD after traumatic brain injury. Data were correlated with CT and exam findings or measured ICP. Measurements were performed by a single trauma surgeon. Time to perform the measurement was recorded. Relevant literature from the past 15 years was reviewed.

Results

Physical exam was not a reliable indicator of eICP. In patients with eICP requiring surgery, ONSD averaged 0.62 cm. Normal pressures were ensured if the ONDS was <0.50 cm (95% CI 0.469–0.540 cm, p < 0.001). Intraobserver variability was low (0.01--0.02 cm). Average time to perform the exam was less than 2 min.

Conclusions

Determining ONSD with ultrasound is easy to learn, precise, and inexpensive. An ONSD of less than 5 mm ensures no eICP. This procedure can be added to the evaluation of trauma patients with no delay in care. Future prospective studies may validate and incorporate this technique into the trauma surgeon's armamentarium.

The role of cell-free DNA measured by a fluorescent test in the management of isolated traumatic head injuries

Background

Traumatic brain injury (TBI) is a major cause of death and disability. In this study a new method to measure cell free DNA (CFD) for the management of TBI is tested. Our hypothesis was that CFD concentrations correlate to the magnitude of brain damage, and may predict the outcome of injured patients.

Methods

Twenty eight patients with isolated head injury were enrolled. Their demographic and clinical data were recorded. CFD levels were determined in patients' sera samples by a direct fluorescence method developed in our laboratory.

Results

Mean admission CFD values were lower in patients with mild TBI compared to severe injury (760 ± 340 ng/ml vs. 1600 ± 2100 ng/ml, p = 0.03), and in patients with complete recovery upon discharge compared to patients with disabilities (680 ± 260 ng/ml vs. 2000 ± 2300 ng/ml, p = 0.003). Patients with high CFD values had a relative risk to require surgery of 1.5 (95% CI 0.83 to 2.9) a relative risk to have impaired outcome on discharge of 2.8 (95% CI 0.75 – 10), and a longer length of stay (12 ± 13 days vs. 3.4 ± 4.8 days, p = 0.02). CFD values did not correlate with CT scan based grading.

Conclusions

CFD levels may be used as a marker to assess the severity of TBI and to predict the prognosis. Its use should be considered as an additional tool along with currently used methods or as a surrogate for them in limited resources environment.

Assessment of dietary adequacy for important brain micronutrients in patients presenting to a traumatic brain injury clinic for evaluation

OBJECTIVE

To evaluate dietary adequacy of patients presenting for evaluation at an outpatient traumatic brain injury (TBI) clinic.

METHODS

We identified 14 key micronutrients with defined dietary intake reference ranges that are considered important for brain health. Adult patients completed the Brief NutritionQuest Food Frequency Questionnaire (FFQ) to calculate estimated nutrient intake. Medical records were abstracted for diagnoses, body mass index, and neurobehavioral subscale scores. Nutrients were assessed individually and were also summarized into a summary score. Associations between individual nutrients, summary nutrient intake, and neurobehavioral scores were assessed.

RESULTS

A total of 39 FFQs were completed by subjects, and 25 (64%) had recorded neurobehavioral scores. No subjects met the recommended dietary allowances (RDAs) for all 14 micronutrients. Ten (26%) met the RDAs for 6 or fewer nutrients, and 10 met the RDAs for 11-12 nutrients. Of 12 nutrients with sufficient sample size for analysis, 11 (92%) were associated with worse mean somatic scores, 9 (75%) were associated with worse cognitive scores, and 8 (67%) were linked with worse affective scores for those with the lowest nutrient intake compared with those who had the highest intake. However, only four nutrients were statistically associated with the somatic mean score: folate (P = 0.010), magnesium (P = 0.082), vitamin C (P = 0.021), and vitamin K (P = 0.024). None were linked with cognitive or affective scores.

DISCUSSION

Diets failing to meet RDAs for important brain nutrients were common in an outpatient TBI clinic, with the worst mean neurobehavioral scores for those patients not meeting the estimated average requirements.

The neuroethics and neurolaw of brain injury

Neuroethics and neurolaw are fields of study that involve the interface of neuroscience with clinical and legal decision-making. The past two decades have seen increasing attention being paid to both fields, in large part because of the advances in neuroimaging techniques and improved ability to visualize and measure brain structure and function. Traumatic brain injury (TBI), along with its acute and chronic sequelae, has emerged as a focus of neuroethical issues, such as informed consent for treatment and research, diagnostic and prognostic uncertainties, and the subjectivity of interpretation of data. The law has also more frequently considered TBI in criminal settings for exculpation, mitigation and sentencing purposes and in tort and administrative law for personal injury, disability and worker's compensation cases. This article provides an overview of these topics with an emphasis on the current challenges that the neuroscience of TBI faces in the medicolegal arena.

Comparison of the safety and efficacy of propofol with midazolam for sedation of patients with severe traumatic brain injury: a meta-analysis

OBJECTIVE

To perform a meta-analysis to compare the safety and efficacy of propofol with midazolam for sedation of patients with severe traumatic brain injury.

MATERIALS AND METHODS

Studies were included in the meta-analysis if they met the following criteria: randomized controlled trial of sedative-hypnotic agents including propofol and midazolam; patients had severe traumatic brain injury; the primary outcome was the Glasgow Outcome Scale score; secondary outcomes included mortality, therapeutic failure, intracranial pressure, and cerebral perfusion pressure. The data were analyzed using software for meta-analysis.

RESULTS

Seven relevant studies were identified. Three of these studies were excluded: one was a single-arm study, one compared morphine and propofol, and for one the full text article could not be obtained. The remaining 4 studies were included in the meta-analysis. The results of the meta-analysis showed that propofol and midazolam have similar effects on the Glasgow Outcome Scale score, mortality, intracranial pressure, and cerebral perfusion pressure.

CONCLUSION

Our meta-analysis of 4 studies showed that there are no important differences between propofol and midazolam when administered to provide sedation for patients with severe traumatic brain injury. Further randomized, controlled trials comparing propofol with midazolam for sedation of such patients are needed.

Traumatic brain injury: pathophysiology, monitoring, and mechanism-based care

Traumatic brain injury, which may be blunt or penetrating, begins altering intracranial physiology at the moment of impact as primary brain trauma. This article differentiates blunt versus penetrating brain trauma, primary versus secondary brain injury, and subsequent intracranial pathophysiology. Discussion and case study correlate intracranial pathophysiology and multisystem influences on evolving brain injury with mechanism-based interventions to modulate brain components (brain, blood, and cerebrospinal fluid volumes). The discussion also explores the effects of controlled ventilation, cardiopulmonary physiology, and global physiologic state on secondary injury, control of intracranial pressure, and recovery.

The liver X receptor agonist GW3965 improves recovery from mild repetitive traumatic brain injury in mice partly through apolipoprotein E

Traumatic brain injury (TBI) increases Alzheimer’s disease (AD) risk and leads to the deposition of neurofibrillary tangles and amyloid deposits similar to those found in AD. Agonists of Liver X receptors (LXRs), which regulate the expression of many genes involved in lipid homeostasis and inflammation, improve cognition and reduce neuropathology in AD mice. One pathway by which LXR agonists exert their beneficial effects is through ATP-binding cassette transporter A1 (ABCA1)-mediated lipid transport onto apolipoprotein E (apoE). To test the therapeutic utility of this pathway for TBI, we subjected male wild-type (WT) and apoE−/− mice to mild repetitive traumatic brain injury (mrTBI) followed by treatment with vehicle or the LXR agonist GW3965 at 15 mg/kg/day. GW3965 treatment restored impaired novel object recognition memory in WT but not apoE−/− mice. GW3965 did not significantly enhance the spontaneous recovery of motor deficits observed in all groups. Total soluble Aβ₄₀ and Aβ₄₂ levels were significantly elevated in WT and apoE−/− mice after injury, a response that was suppressed by GW3965 in both genotypes. WT mice showed mild but significant axonal damage at 2 d post-mrTBI, which was suppressed by GW3965. In contrast, apoE−/− mice showed severe axonal damage from 2 to 14 d after mrTBI that was unresponsive to GW3965. Because our mrTBI model does not produce significant inflammation, the beneficial effects of GW3965 we observed are unlikely to be related to reduced inflammation. Rather, our results suggest that both apoE-dependent and apoE-independent pathways contribute to the ability of GW3965 to promote recovery from mrTBI.