Traumatic brain injury: an enduring challenge

[Current Aspects of Intensive Medical Care for Traumatic Brain Injury - Part 2 - Secondary Treatment Strategies, Long-term Outcome, Neuroprognostics and Chronification]

This two-part article deals with the intensive medical care of traumatic brain injury. Part 1 addresses the primary treatment strategy, haemodynamic management and multimodal monitoring, Part 2 secondary treatment strategies, long-term outcome, neuroprognostics and chronification. Traumatic brain injury is a complex clinical entity with a high mortality rate. The primary aim is to maintain homeostasis based on physiological targeted values. In addition, further therapy must be geared towards intracranial pressure. In addition to this, there are other monitoring options that appear sensible from a pathophysiological point of view with appropriate therapy adjustment. However, there is still a lack of data on their effectiveness. A further aspect is the inflammation of the cerebrum with the "cross-talk" of the organs, which has a significant influence on further intensive medical care.

Polysaccharides from Polygonatum cyrtonema Hua prevent post-traumatic stress disorder behaviors in mice: Mechanisms from the perspective of synaptic injury, oxidative stress, and neuroinflammation

ETHNOPHARMACOLOGICAL RELEVANCE

According to traditional Chinese medicine (TCM) theory, post-traumatic stress disorder (PTSD) is a kind of depression syndrome, and its occurrence is related to deficiencies of the heart and kidney. Polygonatum cyrtonema Hua replenishes Qi and blood and tonifies the five zang organs, so it is widely used in TCM as a prescription for the treatment of depression syndrome. The polysaccharides in P. cyrtonema Hua (PSP) are the main active components of the herb, but the effects of PSP on PTSD and the mechanisms remain unclear.

AIM OF THE STUDY

To investigate the preventive effect of PSP on PTSD-like behaviors and to determine the mechanisms.

METHODS

We used behavioral tests to evaluate PTSD-like behaviors in mice. Synaptic changes were assessed by transmission electron microscopy. Hematoxylin-eosin staining was used to assess pathological changes to the hippocampus, and immunofluorescence staining was used to observe changes in astrocytes. Serum corticosterone (CORT), cytokine, and hippocampal oxidation-related indicator levels were evaluated by ELISA. We detected the expression levels of synaptic, oxidative, and inflammation-related proteins in the hippocampus by western blotting.

RESULTS

Single prolonged stress (SPS)-modeled mice exhibited significant PTSD-like phenotypes, including increased fear memory acquisition and anxiety-like behaviors. These behavioral changes were prevented by PSP administration. Compared to controls, SPS modeling increased serum CORT, cytokine, and hippocampal malondialdehyde levels; decreased superoxide dismutase activity; and caused losses in pyramidal neurons, astrocytes, and synapses in the CA1 region. At the molecular level, the expression of brain-derived neurotrophic factor, postsynaptic density protein 95, nuclear factor erythroid 2-related factor 2 (Nrf2), phospho-tyrosine kinase receptor B, activity-regulated cytoskeleton-associated protein, heme oxygenase-1 (HO-1), and GluA1 decreased in SPS mice compared with the control group, while the expression of NOD-like receptor protein 3 (NLRP3), GluN2B, and apoptosis-associated speck-like protein increased in SPS mice. Treatment with PSP counteracted these abnormal changes. Importantly, ML385, an Nrf2 inhibitor, blocked PSP's ability to ameliorate PTSD behaviors and abnormal protein expression. The NLRP3 inhibitor MCC950 reduced the PTSD-like behaviors and normalized protein expression in SPS mice.

CONCLUSION

PSP prevents SPS-induced PTSD-like behaviors and synaptic damage by regulating oxidative stress and NLRP3-mediated inflammation, probably in an Nrf2/HO-1 signaling pathway-dependent manner.

Neurological Symptoms and Their Associations With Inflammatory Biomarkers in the Chronic Phase Following Traumatic Brain Injuries

BACKGROUND

The underlying biological mechanisms for neurological symptoms following a traumatic brain injury (TBI) remain poorly understood. This study investigated the associations between serum inflammatory biomarkers and neurological symptoms in the chronic phase following moderate to severe TBI.

METHODS

The serum interleukin [IL]-1β, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, and the tumor necrosis factor [TNF]-α in 72 TBI patients 6 months to 2 years post injury were measured. Neurological symptoms including depression, chronic headache, sleep disturbance, irritability, anxiety, and global neurological disability was assessed. The associations between the biomarkers and the neurological symptoms were assessed using correlation and regression analysis.

RESULTS

It was found that the most common post-injury symptom was sleep disturbance (84.7%), followed by chronic headaches (59.7%), irritability (55.6%), and depression (54.2%). TNF-α was a protective factor for chronic headache (OR = 0.473, 95% CI = 0.235-0.952). IL-6 was positively associated with sleep disturbance (r = 0.274, p = 0.021), while IL-5 and IL-12p70 were negatively associated with the degree of global neurological disability (r = -0.325, p = 0.006; r = -0.319, p = 0.007).

CONCLUSION

This study provides preliminary evidence for the association between chronic inflammation with neurological symptoms following a TBI, which suggests that anti-inflammatory could be a potential target for post-TBI neurological rehabilitation. Further research with larger sample sizes and more related biomarkers are still needed, however, to elucidate the inflammatory mechanisms for this association.

Delays in emergency department intervention for patients with traumatic brain injury in Uganda

Background

In Sub-Saharan African countries, the incidence of traumatic brain injury (TBI) is estimated to be many folds higher than the global average and outcome is hugely impacted by access to healthcare services and quality of care. We conducted an analysis of the TBI registry data to determine the disparities and delays in treatment for patients presenting at a tertiary care hospital in Uganda and to identify factors predictive of delayed treatment initiation.

Methods

The study was conducted at the Mulago National Referral Hospital, Kampala. The study included all patients presenting to the emergency department (ED) with suspected or documented TBI. Early treatment was defined as first intervention within 4 hours of ED presentation-a cut-off determined using sensitivity analysis to injury severity. Descriptive statistics were generated and Pearson's χ² test was used to assess the sample distribution between treatment time categories. Univariable and multivariable logistic regression models with <0.05 level of significance were used to derive the associations between patient characteristics and early intervention for TBI.

Results

Of 3944 patients, only 4.6% (n=182) received an intervention for TBI management within 1 hour of ED presentation, whereas 17.4% of patients (n=708) received some treatment within 4 hours of presentation. 19% of those with one or more serious injuries and 18% of those with moderate to severe head injury received care within 4 hours of arrival. Factors independently associated with early treatment included young age, severe head injury, and no known pre-existing conditions, whereas older or female patients had significantly less odds of receiving early treatment.

Discussion

With the increasing number of patients with TBI, ensuring early and appropriate management must be a priority for Ugandan hospitals. Delay in initiation of treatment may impact survival and functional outcome. Gender-related and age-related disparities in care should receive attention and targeted interventions.

Level of evidence

Prognostic and epidemiological study; level II evidence.

Suggesting 7,8-dihydroxyflavone as a promising nutraceutical against CNS disorders

7,8-dihydroxyflavone (DHF), a naturally-occurring plant-based flavone, is a high-affinity tyrosine kinase receptor B (TrkB) agonist and a bioactive molecule of therapeutic interest for neuronal survival, differentiation, synaptic plasticity and neurogenesis. In the family of neurotrophic factors, this small BDNF-mimetic molecule has attracted considerable attention due to its oral bioavailability and ability to cross the blood-brain barrier. Recent evidences have shed light on the neuroprotective role of this pleiotropic flavone against several neurological disorders, including Alzheimer's disease, Parkinson's disease, cerebral ischemia, Huntington's disease, and other CNS disorders. DHF also elicits potent protective actions against toxins-induced insults to brain and neuronal cells. DHF shows promising anti-oxidant and anti-inflammatory properties in ameliorating the neurodegenerative processes affecting the CNS. This review provides an overview of the significant neuroprotective potentials of DHF and discusses how it exerts its multitudinous beneficial effects by modulating different pathways linked with the pathophysiology of CNS disorders, and thus proposes it to be a nutraceutical against a broad spectrum of neurological disorders.

Prelude to the special issue on novel neurocircuit, cellular and molecular targets for developing functional rehabilitation therapies of neurotrauma

The poor endogenous recovery capacity and other impediments to reinstating sensorimotor or autonomic function after adult neurotrauma have perplexed modern neuroscientists, bioengineers, and physicians for over a century. However, despite limited improvement in options to mitigate acute pathophysiological sequalae, the past 20 years have witnessed marked progresses in developing efficacious rehabilitation strategies for chronic spinal cord and brain injuries. The achievement is mainly attributable to research advancements in elucidating neuroplastic mechanisms for the potential to enhance clinical prognosis. Innovative cross-disciplinary studies have established novel therapeutic targets, theoretical frameworks, and regiments to attain treatment efficacy. This Special Issue contained eight papers that described experimental and human data along with literature reviews regarding the essential roles of the conventionally undervalued factors in neural repair: systemic inflammation, neural-respiratory inflammasome axis, modulation of glutamatergic and monoaminergic neurotransmission, neurogenesis, nerve transfer, recovery neurobiology components, and the spinal cord learning, respiration and central pattern generator neurocircuits. The focus of this work was on how to induce functional recovery from manipulating these underpinnings through their interactions with secondary injury events, peripheral and supraspinal inputs, neuromusculoskeletal network, and interventions (i.e., activity training, pharmacological adjuncts, electrical stimulation, and multimodal neuromechanical, brain-computer interface [BCI] and robotic assistance [RA] devices). The evidence suggested that if key neurocircuits are therapeutically reactivated, rebuilt, and/or modulated under proper sensory feedback, neurological function (e.g., cognition, respiration, limb movement, locomotion, etc.) will likely be reanimated after neurotrauma. The efficacy can be optimized by individualizing multimodal rehabilitation treatments via BCI/RA-integrated drug administration and neuromechanical protheses.

Concussions in Sports

Although concussions are common, they are complex, variable, and not entirely understood in terms of pathophysiology and treatment. The incidence of concussion is expected to continue to rise with the increased participation of youth in sports and improved awareness. The role of orthopedic surgeons in concussion management is murky. However, the existing literature does provide a foundation from which orthopedic surgeons who are exposed to concussed patients can function. [Orthopedics. 2019; 42(1):12-21.].