Long-term outcome after severe traumatic brain injury: a systematic literature review

Long-term survival of traumatic brain injury and intra-cerebral haemorrhage patients: A multicentric observational cohort

PURPOSE

Mortality is often assessed during ICU stay and early after, but rarely at later stage. We aimed to compare the long-term mortality between TBI and ICH patients.

MATERIALS AND METHODS

From an observational cohort, we studied 580 TBI patients and 435 ICH patients, admitted from January 2013 to February 2021 in 3 ICUs and alive at 7-days post-ICU discharge. We performed a Lasso-penalized Cox survival analysis.

RESULTS

We estimated 7-year survival rates at 72.8% (95%CI from 67.3% to 78.7%) for ICH patients and at 84.9% (95%CI from 80.9% to 89.1%) for TBI patients: ICH patients presenting a higher mortality risk than TBI patients. Additionally, we identified variables associated with higher mortality risk (age, ICU length of stay, tracheostomy, low GCS, absence of intracranial pressure monitoring). We also observed anisocoria related with the mortality risk in the early stage after ICU stay.

CONCLUSIONS

In this ICU survivor population with a prolonged follow-up, we highlight an acute risk of death after ICU stay, which seems to last longer in ICH patients. Several variables characteristic of disease severity appeared associated with long-term mortality, raising the hypothesis that the most severe patients deserve closer follow-up after ICU stay.

Long-term life expectancy in severe traumatic brain injury: a systematic review

INTRODUCTION

Traumatic brain injuries (TBIs) pose significant challenges to public health, medicine, and society due to their substantial impact on victims, caregivers, and the community. While indicators like life expectancy or death rates provide insights into mortality and long-term outcomes, they fail to address how TBIs affect aging, neurological sequelae, cognitive impairment, and psychological or psychiatric disorders. Moreover, most studies are limited to North America, limiting the generalizability of findings across different social welfare systems. As a result, clinicians face difficulties in providing optimal care and prognosis, hindering the improvement of life quality for victims and caregivers and efficient public health service planning. This study aims to address these limitations by examining life expectancy, mortality rates, and long-term outcomes in severely injured individuals.

EVIDENCE ACQUISITION

PubMed/Medline, Web of Science, Cochrane Library, Google Scholar, and PEDro search engines were systematically searched for studies investigating life expectancy and long-term outcomes in severe traumatic brain injuries. The final search date for all sources/databases was July 31, 2023. We conducted a systematic review, and only original research articles published in English were eligible for inclusion. After the screening process, data were extracted about life expectancy, follow-up, and conclusions.

EVIDENCE SYNTHESIS

This study analyzed 24 studies out of 343 identified. Life expectancy in the TBI population is lower than that of the general population. Older age and severity of functional impairments are major risk factors for mortality. Mortality rates are particularly high in the first two months. Mortality trends suggest a bimodal distribution, with a peak in the first five years followed by no further deaths until nine years after injury. The most influential factors include age, sex, trauma severity, independence in walking and feeding, time since injury, ventilator dependence, and cognitive and communication impairments. Respiratory and circulatory complications are among the leading causes of TBI-related deaths, followed by epilepsy, suicide, and respiratory infections.

CONCLUSIONS

Further research is required, considering the different long-term outcomes after TBI and their impact on families and society, to accurately estimate the life expectancy necessary for clinicians, caregivers, national health institutions, and medico-legal settlements.

Identification and Validation of Endoplasmic Reticulum Stress-Related Gene in Traumatic Brain Injury

Endoplasmic reticulum stress (ERS) plays an essential role in the development of traumatic brain injury (TBI). We aimed to identify and validate the potential ERS-related genes of TBI through bioinformatics analysis and in vitro cell experiment. A total of 19 TBI and ERS-related genes were obtained from the GeneCards database and Comparative Toxicogenomics Database (CTD). Enrichment analysis primarily enriched in apoptosis. NFE2L2 was identified as a hub gene based on the protein-protein interactions (PPI) network that combined seven ranked methods included in cytoHubba. To further explore the effect of Nrf2, the protein encoded by NFE2L2, on ERS-induced apoptosis, we conducted cell experiments with tert-butylhydroquinone (tBHQ), the classical inducer of Nrf2. Western blot suggested tBHQ pretreatment could diminish ERS and reduce the protein expressions of apoptosis in the primary cultured neuron injury model. These data may establish some theoretical basis for the treatment of TBI and provide inspiration and innovative ideas for clinicians and pathologists to understand TBI comprehensively.

Survival and predictive factors of clinical outcome in patients with severe acquired brain injury

BACKGROUND

Despite the many tools available to modern medicine, predicting the neurological and functional status of patients after severe brain injury remains difficult.

AIM

This analysis evaluates the outcomes of patients with the most severe degree of cerebral function impairment.

DESIGN

Retrospective cohort study.

SETTING

Patients hospitalized in the long-term Intensive Care Unit (ICU) department in the Military University Hospital in Prague between 2015-2022.

POPULATION

We analyzed patients with severe acquired brain damage from five distinct etiologies whose initial Glasgow Coma Scale (GCS) score was eight or less upon admission to ICU due to neurological damage.

METHODS

Several parameters reflecting the patients' clinical status were evaluated. Overall survival after discharge from the ICU was calculated according to the Kaplan-Meier model with comparison between traumatic (TR) and non-traumatic (non-TR) etiologies.

RESULTS

The analyzed cohort of 221 patients consisted of 116 patients of TR and 105 of non-TR etiology. There was no significant difference in overall survival between TR and non-TR groups. The length of hospitalization in the ICU was similar in both groups with a median of 94 days. The majority of patients had an improvement of GCS during the hospitalization with a median improvement of five points. GCS improvement occurred in the vast majority of patients regardless of TR or non-TR etiology.

CONCLUSIONS

We did not observe a statistically significant difference in mortality or log-term neurological status between patients with severe brain injury of traumatic or non-traumatic etiology for the duration of our follow-up. The majority of patients had improved GCS, were successfully decannulated, but remained disabled with severe limitations of functional independence.

CLINICAL REHABILITATION IMPACT

The return of the patient to normal life is a rehabilitation challenge, regardless of the etiology of brain injury, and is extremely influenced by the level of development of neurorehabilitation programs in individual institutions, the severity of brain injury, and the individual motivation of the patient.

Bradykinin 2 Receptors Mediate Long-Term Neurocognitive Deficits After Experimental Traumatic Brain Injury

The kallikrein-kinin system is one of the first inflammatory pathways to be activated following traumatic brain injury (TBI) and has been shown to exacerbate brain edema formation in the acute phase through activation of bradykinin 2 receptors (B2R). However, the influence of B2R on chronic post-traumatic damage and outcome is unclear. In the current study, we assessed long-term effects of B2R-knockout (KO) after experimental TBI. B2R KO mice (heterozygous, homozygous) and wild-type (WT) littermates (n = 10/group) were subjected to controlled cortical impact (CCI) TBI. Lesion size was evaluated by magnetic resonance imaging up to 90 days after CCI. Motor and memory function were regularly assessed by Neurological Severity Score, Beam Walk, and Barnes maze test. Ninety days after TBI, brains were harvested for immunohistochemical analysis. There was no difference in cortical lesion size between B2R-deficient and WT animals 3 months after injury; however, hippocampal damage was reduced in B2R KO mice (p = 0.03). Protection of hippocampal tissue was accompanied by a significant improvement of learning and memory function 3 months after TBI (p = 0.02 WT vs. KO), whereas motor function was not influenced. Scar formation and astrogliosis were unaffected, but B2R deficiency led to a gene-dose-dependent attenuation of microglial activation and a reduction of CD45+ cells 3 months after TBI in cortex (p = 0.0003) and hippocampus (p < 0.0001). These results suggest that chronic hippocampal neurodegeneration and subsequent cognitive impairment are mediated by prolonged neuroinflammation and B2R. Inhibition of B2R may therefore represent a novel strategy to reduce long-term neurocognitive deficits after TBI.

Translational Medicine in Acute Ischemic Stroke and Traumatic Brain Injury-NeuroAiD Trials, from Traditional Beliefs to Evidence-Based Therapy

Acute ischemic stroke (AIS) and traumatic brain injury (TBI) are two severe neurological events, both being major causes of death and prolonged impairment. Their incidence continues to rise due to the global increase in the number of people at risk, representing a significant burden on those remaining impaired, their families, and society. These molecular and cellular mechanisms of both stroke and TBI present similarities that can be targeted by treatments with a multimodal mode of action, such as traditional Chinese medicine. Therefore, we performed a detailed review of the preclinical and clinical development of MLC901 (NeuroAiDTMII), a natural multi-herbal formulation targeting several biological pathways at the origin of the clinical deficits. The endogenous neurobiological processes of self-repair initiated by the brain in response to the onset of brain injury are often insufficient to achieve complete recovery of impaired functions. This review of MLC901 and its parent formulation MLC601 confirms that it amplifies the natural self-repair process of brain tissue after AIS or TBI. Following AIS and TBI where "time is brain", many patients enter the post-acute phase with their functions still impaired, a period when "the brain needs time to repair itself". The treatment goal must be to accelerate recovery as much as possible. MLC901/601 demonstrated a significant reduction by 18 months of recovery time compared to a placebo, indicating strong potential for facilitating the improvement of health outcomes and the more efficient use of healthcare resources.

Transcutaneous Cervical Vagus Nerve Magnetic Stimulation in Patients With Traumatic Brain Injury: A Feasibility Study

OBJECTIVES

Transcutaneous vagus nerve stimulation has shown promising results in improving cognitive and motor function after stroke. However, to our knowledge, there have been no studies in the modulation of the cervical vagus nerve using repetitive transcranial magnetic stimulation (rTMS) in patients with traumatic brain injury (TBI) with cognitive dysfunction. Thus, we conducted a single-arm feasibility trial to assess the safety and effectiveness of rTMS of the vagus nerve in patients with TBI.

MATERIALS AND METHODS

We enrolled ten patients with TBI and administered half-hour vagus nerve magnetic stimulation (VNMS) sessions for ten days to evaluate the feasibility of the treatment. The Montreal cognitive assessment-Beijing (MoCA-B), the Digit Span Test, and the Auditory Verbal Learning Test (AVLT) were used to measure cognitive function before and after the VNMS treatment. Physiological parameters of all subjects were assessed by electrocardiogram.

RESULTS

The findings showed that daily half-hour VNMS for ten days was feasible in patients with TBI, with minimal side effects and no clinically significant effects on physiological parameters. Eight patients showed improvement in MoCA-B, and five patients showed improvement in immediate memory as measured by AVLT.

CONCLUSIONS

We conclude that VNMS is a safe and feasible treatment option for patients with TBI with cognitive dysfunction. However, further controlled studies are necessary to establish the efficacy of VNMS in promoting cognitive recovery after TBI.

SIGNIFICANCE

This study is, to our knowledge, the first study to investigate the feasibility of VNMS for cognitive dysfunction in patients with TBI. Our findings offer the possibility of rTMS applied to the vagus nerve in clinical practice.

The Australian Traumatic Brain Injury Initiative: Review and Recommendations for Outcome Measures for Use With Adults and Children After Moderate-to-Severe Traumatic Brain Injury

The Australian Traumatic Brain Injury Initiative (AUS-TBI) aims to select a set of measures to comprehensively predict and assess outcomes following moderate-to-severe traumatic brain injury (TBI) across Australia. The aim of this article was to report on the implementation and findings of an evidence-based consensus approach to develop AUS-TBI recommendations for outcome measures following adult and pediatric moderate-to-severe TBI. Following consultation with a panel of expert clinicians, Aboriginal and Torres Strait Islander representatives and a Living Experience group, and preliminary literature searches with a broader focus, a decision was made to focus on measures of mortality, everyday functional outcomes, and quality of life. Standardized searches of bibliographic databases were conducted through March 2022. Characteristics of 75 outcome measures were extracted from 1485 primary studies. Consensus meetings among the AUS-TBI Steering Committee, an expert panel of clinicians and researchers and a group of individuals with lived experience of TBI resulted in the production of a final list of 11 core outcome measures: the Functional Independence Measure (FIM); Glasgow Outcome Scale-Extended (GOS-E); Satisfaction With Life Scale (SWLS) (adult); mortality; EuroQol-5 Dimensions (EQ5D); Mayo-Portland Adaptability Inventory (MPAI); Return to Work /Study (adult and pediatric); Functional Independence Measure for Children (WEEFIM); Glasgow Outcome Scale Modified for Children (GOS-E PEDS); Paediatric Quality of Life Scale (PEDS-QL); and Strengths and Difficulties Questionnaire (pediatric). These 11 outcome measures will be included as common data elements in the AUS-TBI data dictionary. Review Registration PROSPERO (CRD42022290954).

Predictors of outcomes 3 to 12 months after traumatic brain injury: a systematic review and meta-analysis

The exact factors predicting outcomes following traumatic brain injury (TBI) remain elusive. In this systematic review and meta-analysis, we examined factors influencing outcomes in adult patients with TBI, from 3 months to 1 year after injury. A search of four electronic databases-PubMed, Scopus, Web of Science, and ScienceDirect-yielded 29 studies for review and 16 for meta-analysis, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. In patients with TBI of any severity, mean differences were observed in age (8.72 years; 95% confidence interval [CI], 4.77-12.66 years), lymphocyte count (-0.15 109/L; 95% CI, -0.18 to -0.11), glucose levels (1.20 mmol/L; 95% CI, 0.73-1.68), and haemoglobin levels (-0.91 g/dL; 95% CI, -1.49 to -0.33) between those with favourable and unfavourable outcomes. The prevalence rates of unfavourable outcomes were as follows: abnormal cisterns, 65.7%; intracranial pressure above 20 mmHg, 52.9%; midline shift of 5 mm or more, 63%; hypotension, 71%; hypoxia, 86.8%; blood transfusion, 70.3%; and mechanical ventilation, 90%. Several predictors were strongly associated with outcome. Specifically, age, lymphocyte count, glucose level, haemoglobin level, severity of TBI, pupillary reaction, and type of injury were identified as potential predictors of long-term outcomes.

Treating social cognition impairment with the online therapy 'SoCoBo': A randomized controlled trial including traumatic brain injury patients

OBJECTIVE

Acquired brain injuries (ABIs), such as traumatic brain injuries (TBIs), often entail impairments of general cognition (e.g., memory, attention or executive functions) and social cognition (e.g. emotion recognition, theory of mind [ToM], social problem-solving). The availability of fully computerized interventions targeting sociocognitive deficits specifically in neurologically impaired patients is extremely limited. Therefore, the Treatment Program for Deficits in Social Cognition and Social Competencies of the Ruhr University Bochum (SoCoBo), a fully computerized online therapy designed for ABI patients was evaluated in a randomized controlled trial involving TBI patients.

METHOD

Sixty-four patients with TBI were randomly assigned to two groups with 43 patients fully completing either SoCoBo (N = 27) or a commercially available computerized program for cognitive rehabilitation (RehaCom®, N = 16). All participants underwent comprehensive pre-post online neuropsychological assessment and worked with their respective rehabilitation programs for four days a week during a scheduled period of 12 weeks.

RESULTS

After treatment, the SoCoBo group, but not the RehaCom® group showed significant improvements in facial emotion recognition and self-rated empathy. Moreover, in the SoCoBo group, an increase in empathy was also associated with increased life satisfaction after treatment. There were no improvements in ToM and social problem-solving. Furthermore, general cognition did not improve in any of the groups.

CONCLUSIONS

SoCoBo represents an effective new online therapy for the amelioration of deficits in key domains of social cognition. Its implementation in clinical practice will serve as a meaningful addition to the existing fully computerized approaches specifically in neurological patient groups.

Early-Stage Application of Agomir-137 Promotes Locomotor Recovery in a Mouse Model of Motor Cortex Injury

Traumatic brain injury (TBI) is a significant risk factor for neurodegenerative disorders, and patients often experience varying degrees of motor impairment. MiR-137, a broadly conserved and brain-enriched miRNA, is a key regulator in neural development and in various neurological diseases. Following TBI, the expression of miR-137 is dramatically downregulated. However, whether miR-137 is a therapeutic target for TBI still remains unknown. Here, for the first time, we demonstrate that intranasal administration of miR-137 agomir (a mimic) in the early stage (0-7 days) of TBI effectively inhibits glial scar formation and improves neuronal survival, while early-stage administration of miR-137 antagomir (an inhibitor) deteriorates motor impairment. This study elucidates the therapeutic potential of miR-137 mimics in improving locomotor recovery following motor cortex injury.

The Rehabilitation Potential of Neurostimulation for Mild Traumatic Brain Injury in Animal and Human Studies

Neurostimulation carries high therapeutic potential, accompanied by an excellent safety profile. In this review, we argue that an arena in which these tools could provide breakthrough benefits is traumatic brain injury (TBI). TBI is a major health problem worldwide, with the majority of cases identified as mild TBI (mTBI). MTBI is of concern because it is a modifiable risk factor for dementia. A major challenge in studying mTBI is its inherent heterogeneity across a large feature space (e.g., etiology, age of injury, sex, treatment, initial health status, etc.). Parallel lines of research in human and rodent mTBI can be collated to take advantage of the full suite of neuroscience tools, from neuroimaging (electroencephalography: EEG; functional magnetic resonance imaging: fMRI; diffusion tensor imaging: DTI) to biochemical assays. Despite these attractive components and the need for effective treatments, there are at least two major challenges to implementation. First, there is insufficient understanding of how neurostimulation alters neural mechanisms. Second, there is insufficient understanding of how mTBI alters neural function. The goal of this review is to assemble interrelated but disparate areas of research to identify important gaps in knowledge impeding the implementation of neurostimulation.

Predicting Outcome in Patients with Brain Injury: Differences between Machine Learning versus Conventional Statistics

Defining reliable tools for early prediction of outcome is the main target for physicians to guide care decisions in patients with brain injury. The application of machine learning (ML) is rapidly increasing in this field of study, but with a poor translation to clinical practice. This is basically dependent on the uncertainty about the advantages of this novel technique with respect to traditional approaches. In this review we address the main differences between ML techniques and traditional statistics (such as logistic regression, LR) applied for predicting outcome in patients with stroke and traumatic brain injury (TBI). Thirteen papers directly addressing the different performance among ML and LR methods were included in this review. Basically, ML algorithms do not outperform traditional regression approaches for outcome prediction in brain injury. Better performance of specific ML algorithms (such as Artificial neural networks) was mainly described in the stroke domain, but the high heterogeneity in features extracted from low-dimensional clinical data reduces the enthusiasm for applying this powerful method in clinical practice. To better capture and predict the dynamic changes in patients with brain injury during intensive care courses ML algorithms should be extended to high-dimensional data extracted from neuroimaging (structural and fMRI), EEG and genetics.

Cognitive Reserve, Early Cognitive Screening, and Relationship to Long-Term Outcome after Severe Traumatic Brain Injury

The objective was to investigate the relationship between early global cognitive functioning using the Barrow Neurological Institute Screen for Higher Cerebral Functions (BNIS) and cognitive flexibility (Trail Making Test (TMT), TMT B-A), with long-term outcome assessed by the Mayo-Portland Adaptability Index (MPAI-4) in severe traumatic brain injury (sTBI) controlling for the influence of cognitive reserve, age, and injury severity. Of 114 patients aged 18–65 with acute Glasgow Coma Scale 3–8, 41 patients were able to complete (BNIS) at 3 months after injury and MPAI-4 5–8 years after injury. Of these, 33 patients also completed TMT at 3 months. Global cognition and cognitive flexibility correlated significantly with long-term outcome measured with MPAI-4 total score (r_BNIS = 0.315; r_TMT = 0.355). Global cognition correlated significantly with the participation subscale (r = 0.388), while cognitive flexibility correlated with the adjustment (r = 0.364) and ability (r = 0.364) subscales. Adjusting for cognitive reserve and acute injury severity did not alter these relationships. The effect size for education on BNIS and TMT scores was large (d ≈ 0.85). Early screenings with BNIS and TMT are related to long-term outcome after sTBI and seem to measure complementary aspects of outcome. As early as 3 months after sTBI, educational level influences the scores on neuropsychological screening instruments.