Diffuse Axonal Injury Research Articles

Primary injuries of corpus callosum vessels in craniocerebral injuries

The aim of the scientific work is to establish morphological characteristics of hemorrhages in the corpus callosum as a marker of primary vascular injuries in diffuse axonal injury (DAI) in relation to the goals and objectives of forensic examination. Changes in the structures of corpus callosum were analyzed in 45 corpses of persons with traumatic brain injury who died in hospital from DAI diagnosed according to clinical and instrumental data within 24 hours after the trauma. The changes were characterized by rectic hemorrhages (haemorrhagia per rhexin) in combination with successively developing vascular, tissue, and cellular post-traumatic reactions. These changes were not observed in the control group. The following morphological characteristics of hemorrhages were established: small focal, elongated, clearly contoured hemorrhages of different sizes, up to 4 mm long, up to 0.8 mm wide, unidirectional at an angle from the lower to upper surface of the sagittal corpus callosum section, at least three, grouped in limited areas sized up to 1.5 × 1.0 cm without clear borders. The detected hemorrhages and the course of changes give reason to consider them the result of primary traumatic effects, making them a diagnostic marker of DAI.

Serum Albumin as Independent Predictor In Determining The Outcome Of Traumatic Brain Injury

Context: Serum albumin is the major protein of the human plasma, accounting for about 60% of the total plasma protein. Serum albumin levels tend to decline in the plasma due to injury or infection independent of nutritional status. Serum albumin consumption increases in a state of stress. Reduction in serum albumin occurs with intracranial haemorrhages. In a patient with severe head injury, there is a significant decline in serum albumin leading to hypoalbuminemia. Serum albumin can be used as an outcome marker in various critical illnesses, including traumatic brain injury. Aim: To determine that serum albumin is an independent predictor affecting the outcome of patients with severe traumatic brain injury over a 6-month duration Settings and design: This was conducted as prospective cohort study in two neurosurgical centres in the East Coast of Malaysia from June 2020 to June 2021 Subjects and methods: A total of fifty-five patients were admitted to our emergency intensive care, or high dependency unit with varying degrees of severe head injuries. Forty patients fulfilled the inclusion criteria of our study and were recruited for data collection and further analysis. Their serum albumin levels were drawn, analysed, and recorded. Statistical analysis used: Descriptive, univariate and multivariate analyses using Multiple Logistic Regression model were done using SPSS version 26.0. Results: Average age for patients in this study was 42 years old. 87.5% of patients involved in this study were male, while the remaining 12.5% were female. The ethnicity of the majority of patients were Malays (77.5%) and the other ethnicities involved were Chinese, Indians and Bangladeshi, with a total of 22.5%. Multiple intracranial injuries were suffered by 57.5% of our study population, Subdural Hemorrhage, Extradural Hemorrhage, Contusional bleed, and Diffuse Axonal Injury were seen respectively in 20%, 10% 7.5% and 5% of the study population. At six months, the unfavourable outcome for serial serum albumin in patients with severe head injury patients was 62.5%, while the favourable outcome was 37.5%. Serum albumin of 30 g/L or less than 30g/L at day 1,3 and 5 post-trauma was noted to have unfavourable outcomes compared to serum albumin level of more than 30g/L. Conclusion: Serum albumin is an independent predictor of outcome in severe TBI patients. However, larger prospective studies are required to verify these findings.

Atlanto-occipital dislocation with concomitant severe traumatic brain injury: A retrospective study at a level 1 trauma center

BackgroundTraumatic atlanto-occipital dislocation (AOD) is a life-threatening injury. Although traumatic brain injury (TBI) is associated with increased mortality in AOD patients, a detailed individual analysis of these patients is lacking in the literature. MethodsPatients ≥16 years old who were diagnosed of AOD with concomitant severe TBI from 2010 to 2020 were included in this retrospective study. We examined the epidemiology, injury mechanisms, associated injuries, and outcomes of these patients. ResultsEight patients were included. Six patients died before any intervention could be performed, and two patients underwent an occipito-cervical fixation, showing a notorious neurologic improvement on follow-up. Cardiorespiratory arrest (CRA) was a strong predictor of subsequent death. CT signs of diffuse axonal injury (DAI) were present in most patients and were confirmed by magnetic resonance imaging (MRI) in survivors. Although TBI was not the main cause of death, it was responsible for the delayed neurological improvement and deferred stabilization. The average sensitivity of the different used methodologies for AOD diagnosis ranged from 0.50 to 1.00, being the Basion Dens Interval (BDI) and the Condyle-C1 interval (CCI) sum the most reliable criteria. Non-survivors tended to show greater distraction measurements. The high incidence of condylar avulsion fractures suggests that their visualization on the initial CT study should heighten the suspicion for AOD. ConclusionsOur data suggest that patients with AOD and concomitant severe TBI might be salvageable patients. In those who survive beyond the first hospital days and show neurological improvement, surgical treatment should be performed as they can achieve an important neurologic recovery.

Supine Posterior Hoop Plating of Bicondylar Posterior Coronal Shear Tibial Plateau Fractures Without Fibular Osteotomy.

Tibial plateau posterolateral fragments, especially those associated with articular depression, are difficult to capture and support with anteriorly or lateral based implants. Applying implants to the posterior plateau has traditionally involved a prone approach or fibular osteotomy, especially when access to both the medial and lateral sides is necessary, such as a bicondylar posterior coronal shear fracture pattern. By combining two previously described techniques for posterolateral rim plating and bicondylar hoop plating, we describe a novel technique to apply a posterior bicondylar hoop implant in the supine position without fibular osteotomy for bicondylar posterior coronal shear injuries.

Case Report and Review: An Unusual Case of Fetal Traumatic Brain Injury

We herein report an unusual case of maternal road traffic accident with blunt trauma to the abdomen at 34 weeks of gestation followed by delivery of severely encephalopathic baby and also a brief review of similar previous reports.The baby had near normal transition, then progressively developed severe encephalopathy and multiple organ dysfunction attributed mainly to the intrauterine traumatic injury. The baby had multiple intra and extra axial bleeds,cerebral edema and diffuse axonal injury, as revealed by the CT scan. The baby was managed conservatively with various neuroprotective strategies similar to management in older children and thus cerebral edema/ hematomas subsided. The baby required ventilatory support, prolonged assisted ventilation/oxygen and the metabolic derangements were managed accordingly. The baby was discharged on oral Levetiracetam, multivitamins and nasogastric tube feeds. Baby was followed up sequentially till day 74 and on physical examination had poor head growth and increased muscle tone of the extremities. Neuroimaging revealed diffuse multicystic leukoencephalomalacia, hydrocephalus ex vacuo with cortical thinning. Intrauterine fetal brain injury is an uncommon incidence which causes mortality and significant morbidity in the child. Neuroimaging of the fetus after trauma to the mother can lead to early diagnosis and anticipation. Early vigorous neuroprotective measures and management may prevent mortality and reduce further brain insult in theseneonates. There is paucity of information on management of such cases thus they should be reported in detail forstudy and future references.

Role of integrin and its potential as a novel postmortem biomarker in traumatic axonal injury.

Traumatic axonal injury (TAI) accounts for a large proportion of the mortality of traumatic brain injury (TBI). The diagnosis of TAI is currently of limited use for medicolegal purposes. It is known that axons in TAI are diffusely damaged by secondary processes other than direct head injury. However, the physiopathological mechanism of TAI is still elusive. The present study used RGD peptide, an antagonist of the mechanotransduction protein integrin, to explore the role of integrin-transmitted mechanical signalling in the pathogenesis of rat TAI. The rats were subjected to a linearly accelerating load, and changes in beta-amyloid precursor protein (β-APP) expression, skeleton ultrastructure, skeleton protein neurofilament light (NF-L), and α-tubulin in the brainstem were observed, indicating that RGD could relieve the severity of axonal injury in TAI rats. In addition, the expression of β-integrin was stronger and centralized in the brainstem of the deceased died from TAI compared to other nonviolent causes. This study examined the pathophysiology and biomechanics of TAI and assessed the role of integrin in the injury of microtubules and neurofilaments in TAI. Thus, we propose that integrin-mediated cytoskeletal injury plays an important role in TAI and that integrin has the potential as a biomarker for TAI.

Minimally invasive surgery technique for unstable pelvic ring fractures with severe vertical shear displacement: A retrospective study

BackgroundUnstable pelvic fractures, especially vertical shear fractures, require surgery for correct reduction, rigid fixation, and improved postoperative outcomes. Herein, we assess the effectiveness of our minimally invasive procedure for the management of unstable pelvic fractures. HypothesisWe hypothesized that this procedure would be useful for the management of unstable pelvic fractures. Patients and methodsThis study included 28 patients with unstable pelvic fractures (vertical shear injuries; AO types C1–3) treated using minimally invasive surgery for spinopelvic fixation (MIS-SP) between 2014 and 2020 (mean follow-up time, 15 months). The MIS-SP requires four percutaneous pedicle screws and four iliac screw insertions. Subsequently, reduction and fixation are performed. ResultsThe mean preoperative displacement of the posterior pelvic elements in craniocaudal correction was 17.6 (range, 9.0–32.2) mm. The mean length of the craniocaudal reduction was 16.5 (8.1–30.1) mm, with a mean reduction rate of 93.5% (78%–100%). The mean length of the mediolateral reduction was 11.3 (3.9–19.6) mm, with a mean reduction rate of 87.3% (76%–100%). DiscussionOur novel reduction and fixation procedure is a powerful, minimally invasive option for the treatment of unstable pelvic ring fractures. Level of evidenceIII.

1316: BLOOD PRESSURE VARIABILITY AND OUTCOME FOR PATIENTS WITH TRAUMATIC DIFFUSE AXONAL INJURY BY MRI

Introduction: Patients with high impact trauma can sustain Diffuse Axonal Injury (DAI) and may have poor prognosis. Blood pressure variability (BPV) has been shown to be associated with poor prognosis in TBI patients but it has not been studied among patients with DAI. Our study investigated whether 24-hour BPV after injury and other clinical factors would be associated with patients’ outcomes. Methods: This is a retrospective study involving all adult patients who presented to a Regional Quaternary Trauma Center between 01/01/2017-12/31/2021. Patients who were radiologically classified as having DAI and received MRI were eligible, as presence of DAI on Magnetic Resonance Imaging (MRI) is also associated with poor outcome. Outcomes were hospital dispositions (ranking from Being discharged home, Rehabilitation facility, Dead) and Glasgow Coma Scale on hospital day 5 (HD5GCS ranking from 3-8, 9-12, 13-14, 15), which also correlated with patients’ 90-day neurocognitive function. We performed ordinal logistic regression to measure association between clinical factors and outcome. Results: We identified and analyzed 154 patients. Mean age was 49 (± 20) years and 114 (74%) were male. Median [IQR] GCS at admission and 24-hour, hospital day 5 were 5 [3-11], 5 [7-10], 8 [6-11], respectively. Most common lesion location was Corpus (89/154, 58%), brain stem (68/154, 44%). Seventy-one (46%) patients had highest Adam score of 3. Ordinal regression showed that BPV components were not associated with DAI patients’ outcome. However, increased age (Coeff. -0.04, OR 0.95, 95%CI 0.92-0.99), Brainstem lesion (Coeff -3.1, OR 0.04, 95%CI 0.001-0.36), requiring anti-hypertensive infusion (Ceff -1.9, OR 0.15, 95%CI 0.03-0.891), blood transfusion (coeff -2.4, OR 0.08, 95%CI 0.01-0.51 were associated with higher mortality, while only high GCS at 24 hours was associated with high HD5GCS (Coeff -01.6, OR 0.85, 95%CI 0.74-0.99) Conclusions: Blood pressure variability was not associated with outcome among patients with DAI. However, increased age, having brainstem lesion, requiring anti-hypertensive infusion and blood products were associated with poor outcome, while high GCS on 24 hour after admission was associated with high GCS on hospital day 5.

The assessment of risk factors for brainstem injuries and supratentorial brain injuries in patients with traumatic brain injury

Traumatic brain injury (TBI) is an important cause of death with a significant worldwide percentage. In the United States, there are approximately 2.8 million TBIs yearly with 250,000 hospitalized patients and 50,000 TBI-related deaths. Every year, there are one million hospitalizations in the European Union, resulting in more than 50,000 deaths, most of which occur due to road traffic accidents. Needless to say, these estimations varied based on the different sources of data. The patient’s outcome is determined by the context of the trauma, the type of lesion, as well as other factors. The aim of the study was to assess variables associated with brainstem injury and supra-tentorial brain injury in patients with TBI. This cohort included 70 consecutive TBI-related deaths from the Institute of Legal Medicine Cluj-Napoca. There was a significant difference in brainstem contusion (haemorrhage contusion) in patients younger than 60. According to the computed tomography (CT) data, brain contusion and laceration were observed in association with brainstem contusion in a significant percentage of TBI-related deaths (p=0.016). Neither the meningo-cerebral blood collections nor the intraparenchymal hematomas had a significant occurrence with brainstem contusion. The diffuse axonal injuries were detected on a CT scan in a significant number of cases with brainstem contusion (p=0.011). The mass effect with brain herniation in the posterior fossa was associated with the occurrence of brainstem contusion, possibly as an extensive process (p=0.041). Analyzing the histopathological data, we observed the significant presence of intracranial haemorrhage in association with a hemorrhagic contusion in the brainstem (p=0.004), but not with meningeal haemorrhage. The poor neurological assessment evaluated by GCS was not an independent variable in relation to this brainstem lesion. That was probably caused by the complexity of the TBI. We did not include this variable in a multivariate analysis considering the poor outcome for all patients

Automated detection of axonal damage along white matter tracts in acute severe traumatic brain injury

New techniques for individualized assessment of white matter integrity are needed to detect traumatic axonal injury (TAI) and predict outcomes in critically ill patients with acute severe traumatic brain injury (TBI). Diffusion MRI tractography has the potential to quantify white matter microstructure in vivo and has been used to characterize tract-specific changes following TBI. However, tractography is not routinely used in the clinical setting to assess the extent of TAI, in part because focal lesions reduce the robustness of automated methods. Here, we propose a pipeline that combines automated tractography reconstructions of 40 white matter tracts with multivariate analysis of along-tract diffusion metrics to assess the presence of TAI in individual patients with acute severe TBI. We used the Mahalanobis distance to identify abnormal white matter tracts in each of 18 patients with acute severe TBI as compared to 33 healthy subjects. In all patients for which a FreeSurfer anatomical segmentation could be obtained (17 of 18 patients), including 13 with focal lesions, the automated pipeline successfully reconstructed a mean of 37.5 ± 2.1 white matter tracts without the need for manual intervention. A mean of 2.5 ± 2.1 tracts resulted in partial or failed reconstructions and needed to be reinitialized upon visual inspection. The pipeline detected at least one abnormal tract in all patients (mean: 9.1 ± 7.9) and accurately discriminated between patients and controls (AUC: 0.91). The number and neuroanatomic location of abnormal tracts varied across patients and levels of consciousness. The premotor, temporal, and parietal sections of the corpus callosum were the most commonly damaged tracts (in 10, 9, and 8 patients, respectively), consistent with prior histopathological studies of TAI. TAI measures were not associated with concurrent behavioral measures of consciousness. In summary, we provide proof-of-principle evidence that an automated tractography pipeline has translational potential to detect and quantify TAI in individual patients with acute severe TBI.

External validation of the GCS-Pupils Score as an outcome predictor after traumatic brain injury in adults: a single-center experience

The GCS-Pupils (GCS-P) score is a recently described scoring system to aid outcome prediction in patients with traumatic brain injury (TBI). The aim of this study was to provide the first external validation of the GCS-P score by identifying independent predictors of outcome in TBI patients. Review of prospective adult (≥ 16years) TBI database at a tertiary neurosurgical center with a catchment population of 1.5 million over a 12-month period commencing October 2016. Multivariate logistic regression was used to identify predictors of discharge destination and 30-day mortality. Three hundred and fifty-eight patients were included. The median age was 60years with a male predominance of 64%. The median GCS-P was 14 (interquartile range 12-15) and the commonest GCS-P category was mild (13-15; 238/358, 66%). Discharge destination was home in 69% of patients and rehab services or equivalent in 31%. Multivariate analysis identified age (p = 0.01), CT findings of an acute subdural hematoma (p = 0.01) or diffuse axonal injury (p = 0.02), and a neurosurgical operation (p = 0.02) as independent predictors of discharge destination. The 30-day mortality rate was 11%. Within the category of severe TBI (GCS-P ≤ 8), GCS-P was able to identify patients with a very high likelihood of 30-day mortality (GCS-P ≤ 4; 16/31, 52%). Multivariate analysis revealed the Charlson comorbidity score (p = 0.01), GCS-P (p = 0.02), and traumatic subarachnoid hemorrhage (p = 0.05) as independent predictors of mortality. The GCS-P is a useful predictor of 30-day mortality, although its usefulness for other clinical outcomes remains to be proven.

The Role of Neuroplasticity in the Neuro-Optometric Rehabilitation of Traumatic Brain Injury

Athletic communities have begun to take pre­ cautions to mitigate traumatic brain injury, such as using protective gear, increasing medical oversight, and establishing better return­to­play rules to protect athletes. As awareness increases, there will be a correspondingly higher frequency of people with traumatic brain injury seeking neuro­optometric evaluation and treatment. Therefore, it is imperative for optometrists to understand the signs, symptoms, and treatment of associated visual sequelae of traumatic brain injury. There are many optometric conditions caused by traumatic brain injury, including, but not limited to: convergence insufficiency, accommodative insufficiency, oculomotor dys­ function, visual motion sensitivity and light sensitivity. In particular, the functional vision problems associated with traumatic brain injury can be addressed with neuro­-optometric rehabilitation therapy. They are often due to diffuse axonal injury throughout the brain caused by shearing and tearing of the axons. People with diffuse axonal injury tend to have slower processing speeds due to impaired function at the synapse and longer neuronal pathways. Neuro­-optometric rehabilitation therapy creates an environment to facilitate neuroplastic changes within the brain, such as axonal sprouting or dendritic plasticity. This article explores possible correlation between improved clinical findings in traumatic brain injury after neuro­ optometric rehabilitation therapy and increased neurophysiological changes in brain activity after vision therapy for convergence insufficiency.

Distinct patterns of neurodegeneration after TBI and in Alzheimer’s disease

AbstractBackgroundTraumatic brain injury (TBI) is an established risk factor for dementia, with Alzheimer’s disease reportedly more prevalent post‐injury. Experimental injury models relate axonal injury to the generation of toxic proteinopathies including amyloid and hyperphosphorylated tau, but epidemiological data relating brain injury and Alzheimer’s disease specifically are inconsistent. Using longitudinal volumetric MRI, it is possible to assess commonalities and differences between chronic post‐traumatic neurodegeneration, Alzheimer’s disease and ageing in vivo, to better understand the long‐term consequences of TBI.MethodSerial volumetric T1‐weighted MRI was performed on two occasions a year apart in 55 patients after moderate‐severe TBI, a group of 23 age‐matched healthy volunteers, a group of 15 older healthy controls (healthy ageing group), as well as 45 patients with Alzheimer’s disease alongside 23 age‐matched controls comprising the MIRIAD dataset. Jacobian determinant (JD) brain atrophy rates in white, grey matter and CSF were quantified, spatial patterns defined and systematically compared between the groups. Diffusion imaging was acquired in TBI patients at baseline, facilitating the generation of the fractional anisotropy metric of axonal integrity via diffusion tensor imaging.ResultAtrophy rates were significantly increased in white matter only after TBI (P<0.01), in contrast to increases in both white matter and grey matter in Alzheimer’s disease (P<0.001). Common subcortical white matter regions showed atrophy in both Alzheimer’s disease and TBI, but deep white matter atrophy was TBI‐specific, and cortical atrophy Alzheimer’s disease‐specific. Post‐TBI atrophy patterns were distinct from ageing, which more closely resembled Alzheimer’s disease, and were predicted by the extent of axonal injury on diffusion tensor imaging at baseline (P<0.05).ConclusionNeurodegeneration after moderate‐severe TBI is distinct in location from both ageing and Alzheimer’s disease, with a characteristic central white matter predominance. This likely reflects the underlying spatial distribution of traumatic axonal injury, and may represent ongoing chronic Wallerian degeneration, and/or toxic proteinopathy‐driven neurodegeneration.

Multi-omics analysis reveals GABAergic dysfunction after traumatic brainstem injury in rats.

Traumatic brainstem injury (TBSI) is one of the forms of brain injury and has a very high mortality rate. Understanding the molecular mechanism of injury can provide additional information for clinical treatment. In this study, we detected transcriptome, proteomics, and metabolome expression changes in the brainstem of TBSI rats, and comprehensively analyzed the underlying mechanisms of TBSI. After TBSI, there was significant diffuse axonal injury (DAI) in the brainstem of rats. A total of 579 genes, 70 proteins, and 183 metabolites showed significant changes in brainstem tissue. Through molecular function and pathway analysis, the differentially expressed genes, proteins, and metabolites of TBSI were mainly attributed to neural signal regulation, inflammation, neuroprotection, and immune system. In addition, a comprehensive analysis of transcripts, proteins, and metabolites showed that the genes, proteins, and metabolic pathways regulated in the brainstem after TBSI were involved in neuroactive ligand-receptor interaction. A variety of GCPR-regulated pathways were affected, especially GAGA's corresponding receptors GABAA, GABAB, GABAC, and transporter GAT that were inhibited to varying degrees. This study provides insights into the development of a rapid diagnostic kit and making treatment strategies for TBSI.

Estrogen can improve the prognosis of patients with diffuse axonal injury due to severe traumatic brain injury: A Randomized Triple-blind Placebo-controlled Trial

Objective: To evaluate the effects of estrogen on the prognosis of patients with diffuse axonal injury due to severe traumatic brain injury. Design: Triple-blind placebo-controlled randomized clinical trial study Setting: The study was conducted at the Neurosurgery Department of Imam Reza Hospital of Tabriz University of Medical Sciences Patients: A total of 200 patients were enrolled in the study Methods: Two hundred patients were randomly allocated into two cases, with a control group of 100 each. The case group daily received 8μg/kg of estrogen by nasogastric for three days and the control group only received a placebo. The Glasgow Coma Scale (GCS) at discharge, Glasgow Outcome Score (GOS) at discharge, and the GOS three months later were investigated to evaluate the effect of estrogen on patients with diffuse axonal injury (DAI) following traumatic brain injury (TBI) in the case and control group. Results: It was shown that there is a significant difference between the case and control groups based on GCS at discharge (p-value = 0.007), GOS at discharge (p-value = 0.02), and GOS at a 3-months follow-up period (p-value = 0.025). Ten patients (5 patients in each group) died during the study. Conclusion: This study indicated the efficacy of estrogen in patients with Diffuse Axonal Injury (DAI) following TBI.

Periodontal ligaments enhance neurite outgrowth in trigeminal ganglion neurons through Wnt5a production induced by mechanical stimulation.

The peripheral sensory nerve must be maintained to perceive environmental changes. Daily physiological mechanical stimulations, like gravity, floor reaction force, and occlusal force, influence the nerve homeostasis directly or indirectly. Although the direct axonal membrane stretch enhances axon outgrowth via mechanosensitive channel activation, the indirect mechanisms remain to be elucidated. In this study, we identified the indirect pathways where Wnt5a was a molecular cue released by mechanically stimulated rat periodontal ligament (rPDL) cells. qRT-PCR and ELISA showed that mechanically stimulated rPDL cells enhanced Wnt5a expression level and Wnt5a protein in a Ca2+-dependent manner. The inhibitors of PI3K (LY294002) and MEK1/2 (U0126) suppressed the Akt/PKB and ERK1/2 phosphorylation, respectively, in Western blotting analysis and consequently abolished the increase in Wnt5a expression. Similarly, PF573228, a focal adhesion kinase inhibitor, attenuated Akt- and ERK1/2-phosphorylation and Wnt5a expression. Importantly, the culture medium of stretched PDL cells enhanced neurite elongation, sprouting, and branching in trigeminal ganglion neurons that project to PDL. Moreover, treatment with an anti-Wnt5a antibody (to neutralize Wnt5a activity), AP7677a (anti-Ryk antibody, to block Ryk receptor activity), or strictinin (Ror1 inhibitor) suppressed the morphological changes. These findings reveal the indirect mechanisms that Wnt5a, released from the connective tissues in response to mechanical stimulation, enhances the outgrowth of the peripheral nerves. Our study suggests that the peripheral connective tissues regulate peripheral nerve homeostasis and that Wnt5a signaling could be targeted for the treatment of peripheral nerve disorders.

Erratum. Increased sensitivity to traumatic axonal injury on postconcussion diffusion tensor imaging scans in National Football League players by using premorbid baseline scans.

"Erratum. Increased sensitivity to traumatic axonal injury on postconcussion diffusion tensor imaging scans in National Football League players by using premorbid baseline scans" published on 01 Jul 2022 by American Association of Neurological Surgeons.

Glymphatic system evaluation using diffusion tensor imaging in patients with traumatic brain injury.

Glymphatic system dysfunction has been reported in animal models of traumatic brain injury (TBI). This study aimed to evaluate the activity of the human glymphatic system using the non-invasive Diffusion Tensor Image-Analysis aLong the Perivascular Space (DTI-ALPS) method in patients with TBI. A total of 89 patients with TBI (June 2018 to May 2020) were retrospectively enrolled, and 34 healthy volunteers were included who had no previous medical or neurological disease. Magnetic resonance imaging (MRI) with DTI was performed, and the ALPS index was calculated to evaluate the glymphatic system's activity. Wilcoxon rank-sum test was used to compare the ALPS index between patients with TBI and healthy controls. ANOVA was done to compare the ALPS index among controls and patients with mild/moderate-to-severe TBI. Multivariate logistic regression analyses were used to identify independent clinical and radiological factors associated with the ALPS index. The correlation between Glasgow Coma Scale (GCS) score and the ALPS index was also assessed. The ALPS index was significantly lower in patients with TBI than in healthy controls (median, 1.317 vs. 1.456, P < 0.0001). There were significant differences in the ALPS index between healthy controls and patients with mild/moderate-to-severe TBI (ANOVA, P < 0.001). The presence of subarachnoid hemorrhage (P = 0.004) and diffuse axonal injury (P = 0.001) was correlated with a lower ALPS index in the multivariate analysis. There was a weak positive correlation between the ALPS index and GCS scores (r = 0.242, P = 0.023). The DTI-ALPS method is useful for evaluating glymphatic system impairment and quantifying its activity in patients with TBI.

Serum vitamin E level and functional prognosis after traumatic brain injury with intracranial injury: A multicenter prospective study.

Traumatic brain injury (TBI) is a major public health problem with high mortality and disability. Vitamin E, one of the antioxidants for treatment of TBI, has not been sufficiently evaluated for predicting prognosis of TBI. This study aimed to evaluate the prognostic value of vitamin E on functional outcomes of TBI patients with intracranial injury. A multi-center prospective cohort study was conducted in five university hospitals between 2018 and 2020. Adult TBI patients who visited the emergency department (ED) with intracranial hemorrhage or diffuse axonal injury confirmed by radiological examination were eligible. Serum vitamin E levels (mg/dL) were categorized into 4 groups: low (0.0-5.4), low-normal (5.5-10.9), high-normal (11.0-16.9), and high (17.0-). Study outcomes were set as 1- and 6-month disability (Glasgow outcome scale (GOS) 1-4). Multilevel logistic regression analysis was conducted to calculate the adjusted odds ratios (AORs) of vitamin E for related outcomes. Among 550 eligible TBI patients with intracranial injury, the median (IQR) of serum vitamin E was 10.0 (8.0-12.3) mg/dL; 204/550 (37.1%) had 1-month disability and 197/544 (36.1%) had 6-month disability of GOS 1-4. Compared with the high-normal group, the odds of 1-month disability and 6-month disability increased in the low and low-normal group (AORs (95% CIs): 3.66 (1.62-8.27) and 2.60 (1.15-5.85) for the low group and 1.63 (1.08-2.48) and 1.60 (1.04-2.43) for the low-normal group, respectively). Low serum vitamin E level was associated with poor prognosis at 1 and 6 months after TBI with intracranial injury.

ICU management of Traumatic Brain Injury

Traumatic brain injury (TBI) can be defined as the disruption in brain function, or other evidence of brain pathology, caused by an external physical force. Management of TBI depends on, if the injury is focal or diffuse. Focal can be epidural or intra cerebral and diffuse lesions can present as multiple contusions/DAI. A basic understanding of anatomy of central nervous system and some working knowledge of physiology of brain help in management of TBI. According to severity there are three types of TBI patients. They are: mild (GCS 13-15), moderate (GCS 9-12) and severe (GCS 3-8). TBI may be primary or secondary. Primary injuries include contusion, hematoma, subarachnoid hemorrhage, diffuse axonal injury etc. Secondary injuries can manifest as cerebral oedema, raised intra cranial pressure etc. Airway management and cervical spine immobilization are important early steps in management. Hypoxia and hypercarbia must be avoided and attention is always paid to ventilation status of patients. Mean arterial pressure (MAP) should be monitored and maintained at 80-90 mm of Hg. Intracranial pressure (ICP) should be checked whenever feasible and monitored so raised ICP can be controlled. Adequate pain control and sedation, using mannitol, hypertonic saline should be used as needed to control raised ICP. Invasive ICP monitoring and cerebrospinal fluid diversion should be used in patient who decompensate and decision to do decompressive craniectomy is often made by neurosurgeons. Body temperature in TBI patients should be maintained under 37o C. Neurologic conditions like brainstem dysfunction, intracranial hypertension, altered level of consciousness etc. and respiratory conditions like ARDS, hypoxaemia , neurogenic pulmonary oedema etc. warrants endotracheal intubation and mechanical ventilation. TBI patients requiring haemo dialysis usually need special modification in protocol to avoid pulmonary oedema and fluctuation in blood pressure. Monitoring TBI patients is done by routine assessment of GCS, pupillary size and reaction, motor responses. ICP monitoring is to be done if feasible. By aggressive monitoring secondary brain injuries can be avoided or managed. Outcome of management of TBI patients in ICU depends on severity of primary and secondary injuries of brain, status of GCS on presentation, advanced age (&gt;65yrs), presence or absence of co morbidities and severity of associated injuries. Bangladesh Crit Care J September 2022; 10(2): 135-141