Phase II Clinical Trial of Atorvastatin in Mild Traumatic Brain Injury

The protective effects of statins in traumatic brain injury

Traumatic brain injury (TBI), often referred to as the "silent epidemic", is the most common cause of mortality and morbidity worldwide among all trauma-related injuries. It is associated with considerable personal, medical, and economic consequences. Although remarkable advances in therapeutic approaches have been made, current treatments and clinical management for TBI recovery still remain to be improved. One of the factors that may contribute to this gap is that existing therapies target only a single event or pathology. However, brain injury after TBI involves various pathological mechanisms, including inflammation, oxidative stress, blood-brain barrier (BBB) disruption, ionic disturbance, excitotoxicity, mitochondrial dysfunction, neuronal necrosis, and apoptosis. Statins have several beneficial pleiotropic effects (anti-excitotoxicity, anti-inflammatory, anti-oxidant, anti-thrombotic, immunomodulatory activity, endothelial and vasoactive properties) in addition to promoting angiogenesis, neurogenesis, and synaptogenesis in TBI. Supposedly, using agents such as statins that target numerous and diverse pathological mechanisms, may be more effective than a single-target approach in TBI management. The current review was undertaken to investigate and summarize the protective mechanisms of statins against TBI. The limitations of conducted studies and directions for future research on this potential therapeutic application of statins are also discussed.

Early intervention treatment in the first 2 weeks following concussion in adults: A systematic review of randomised controlled trials

OBJECTIVE

International guidelines support a repertoire of therapeutic interventions that may assist recovery following concussion. We aimed to systematically review the efficacy of early pharmacological and non-pharmacological interventions initiated within two weeks of injury on symptoms and functional recovery of adults with concussion.

METHODS

We conducted a Systematic Review (SR) of Randomised Controlled Trials (RCTs) without meta-analysis utilising the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search was performed of four databases. Study inclusion criteria were adult participants diagnosed with concussion and commencing active intervention within 14 days of injury.

RESULTS AND CONCLUSIONS

Of 7531 studies identified, 11 were included in the final review. Six studies were rated as high-risk of bias, three with some concerns and two as low-risk of bias. We found no evidence to support specific pharmacotherapeutic management to hasten the natural recovery time-course. Two studies reported significant improvement in selected concussion symptoms following manual therapy (at 48-72 hours post-treatment) or telephone counselling interventions (at 6 months post-injury). No high quality RCTs demonstrate superior effects of early therapeutic interventions on concussion recovery in the first 2 weeks. We advocate future research to examine impacts of health-clinician contact points aligned with symptom-specific interventions.

HMG-CoA Reductase Inhibitors for Traumatic Brain Injury

Traumatic brain injuries (TBIs) are associated with high morbidity and mortality due to both the original insult as well as the destructive biological response that follows. Medical management aims to slow or even halt secondary neurological injury while simultaneously laying the groundwork for recovery. Statins are one class of medications that is showing increased promise in the management of TBI. Used extensively in cardiovascular disease, these drugs were originally developed as competitive inhibitors within the cholesterol production pipeline. They are now used in diverse disease states due to their pleiotropic effects on other biological processes such as inflammation and angiogenesis. Preclinical studies, retrospective reviews, and randomized clinical trials have shown a variety of benefits in the management of TBI, but to date, no large-scale randomized clinical trial has been performed. Despite this limitation, statins' early promise and well-tolerated side effect profile make them a promising new tool in the management of TBIs. More bench and clinical studies are needed to delineate proper treatment regimens as well as understand their true potential.

Research progress on pleiotropic neuroprotective drugs for traumatic brain injury

Traumatic brain injury (TBI) has become one of the most important causes of death and disability worldwide. A series of neuroinflammatory responses induced after TBI are key factors for persistent neuronal damage, but at the same time, such inflammatory responses can also promote debris removal and tissue repair after TBI. The concept of pleiotropic neuroprotection delves beyond the single-target treatment approach, considering the multifaceted impacts following TBI. This notion embarks deeper into the research-oriented treatment paradigm, focusing on multi-target interventions that inhibit post-TBI neuroinflammation with enhanced therapeutic efficacy. With an enriched comprehension of TBI's physiological mechanisms, this review dissects the advancements in developing pleiotropic neuroprotective pharmaceuticals to mitigate TBI. The aim is to provide insights that may contribute to the early clinical management of the condition.

A Systematic Review of Treatments of Post-Concussion Symptoms

Approximately 10−20% of patients who have sustained a mild Traumatic Brain Injury (mTBI) show persistent post-concussion symptoms (PCS). This review aims to summarize the level of evidence concerning interventions for PCS. Following the PRISMA guidelines, we conducted a systematic review regarding interventions for PCS post-mTBI until August 2021 using the Medline, Cochrane, and Embase databases. Inclusion criteria were the following: (1) intervention focusing on PCS after mTBI, (2) presence of a control group, and (3) adult patients (≥18 y.o). Quality assessment was determined using the Incog recommendation level, and the risk of bias was assessed using the revised Cochrane risk-of-bias tool. We first selected 104 full-text articles. Finally, 55 studies were retained, including 35 that obtained the highest level of evidence. The risk of bias was high in 22 out of 55 studies. Cognitive training, psycho-education, cognitive behavioral therapy, and graded return to physical activity demonstrated some effectiveness on persistent PCS. However, there is limited evidence of the beneficial effect of Methylphenidate. Oculomotor rehabilitation, light therapy, and headache management using repetitive transcranial magnetic stimulation seem effective regarding somatic complaints and sleep disorders. The preventive effect of early (<3 months) interventions remains up for debate. Despite its limitations, the results of the present review should encourage clinicians to propose a tailored treatment to patients according to the type and severity of PCS and could encourage further research with larger groups.

The effects of statin monotherapy on depressive symptoms: A systematic review and meta-analysis

INTRODUCTION

Statins have been proposed as a strategy for treating depression, but their benefit in the absence of concurrent antidepressant treatment is unclear. This meta-analysis investigated the antidepressant effects of statin monotherapy in the general population.

METHODS

We conducted a literature search of randomised controlled trials using any statin monotherapy versus any control condition for depressive symptoms. Our primary efficacy outcome was the mean value on any standardised scale for depression at study endpoint. We also measured efficacy at three further timepoints (<6 months, 6-12 months, >12 months), as well as acceptability, tolerability, and safety. Respectively, continuous and dichotomous outcomes were computed using standardised mean difference (SMD) or relative risk (RR) with 95% confidence intervals (CI) using a random-effect model.

RESULTS

Pooled analyses did not show that statin monotherapy improves depressive symptoms at endpoint (N = 2712 SMD = -0.18; 95% CI = -0.41 to 0.04), nor at any other specific timepoint. No difference between statins and control was identified for any of the other outcome measures.

DISCUSSION

These results differ from those of previous meta-analyses and, compounded by more recently available evidence, suggest that statins may not have intrinsic antidepressant properties, but may be useful for the management of depression in add-on to antidepressants.

LIMITATIONS

Data from heterogeneous populations and using different statins were pooled, though several sensitivity and subgroup analyses were performed to account for that. PROSPERO registration: CRD42022306653. https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=306653.

Metabolic disorders on cognitive dysfunction after traumatic brain injury

Cognitive dysfunction is a common adverse consequence of traumatic brain injury (TBI). After brain injury, the brain and other organs trigger a series of complex metabolic changes, including reduced glucose metabolism, enhanced lipid peroxidation, disordered neurotransmitter secretion, and imbalanced trace element synthesis. In recent years, several research and clinical studies have demonstrated that brain metabolism directly or indirectly affects cognitive dysfunction after TBI, but the mechanisms remain unclear. Drugs that improve the symptoms of cognitive dysfunction caused by TBI are under investigation and treatments that target metabolic processes are expected to improve cognitive function in the future. This review explores the impact of metabolic disorders on cognitive dysfunction after TBI and provides new strategies for the treatment of metabolic disorders.

Pharmacotherapy for mild traumatic brain injury: an overview of the current treatment options

INTRODUCTION

Accounting for 90% of all traumatic brain injuries (TBIs), mild traumatic brain injury (mTBI) is currently the most frequently seen type of TBI. Although most patients can recover from mTBI, some may suffer from prolonged symptoms for months to years after injury. Growing evidence indicates that mTBI is associated with neurodegenerative diseases including dementias and Parkinson's disease (PD). Pharmacological interventions are necessary to address the symptoms and avoid the adverse consequences of mTBI.

AREAS COVERED

To provide an overview of the current treatment options, the authors herein review the potential drugs to reduce the secondary damage and symptom-targeted therapy as well as the ongoing clinical trials about pharmacotherapy for mTBI.

EXPERT OPINION

There has been no consensus on the pharmacotherapy for mTBI. Several candidates including n-3 PUFAs, melatonin, NAC and statins show potential benefits in lessening the secondary injury and improving neurological deficits in pre-clinic studies, which, however, still need further investigation in clinical trials. The current pharmacotherapy for mTBI is empirical in nature and mainly targets to mitigate the symptoms. Well-designed clinical trials are now warranted to provide high level evidence.

Antioxidant therapies in traumatic brain injury

Oxidative stress plays a crucial role in traumatic brain injury (TBI) pathogenesis. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) formed in excess after TBI synergistically contribute to secondary brain damage together with lipid peroxidation products (reactive aldehydes) and inflammatory mediators. Furthermore, oxidative stress, endoplasmic reticulum stress and inflammation potentiate each other. Following TBI, excessive oxidative stress overloads the endogenous cellular antioxidant system leading to cell death. To combat oxidative stress, several antioxidant therapies were tested in preclinical animal models of TBI. These include free radical scavengers, activators of antioxidant systems, Inhibitors of free radical generating enzymes and antioxidant enzymes. Many of these therapies showed promising outcomes including reduced edema, blood-brain barrier (BBB) protection, smaller contusion volume, and less inflammation. In addition, many antioxidant therapies also promoted better sensory, motor, and cognitive functional recovery after TBI. Overall, preventing oxidative stress is a viable therapeutic option to minimize the secondary damage and to improve the quality of life after TBI.

Evaluation of the Effect of Atorvastatin Administration on the Outcomes of Patients with Traumatic Brain Injury: A Double-blinded Randomized Clinical Trial

Background

Traumatic brain injury (TBI) is one of the common causes of long-term disabilities and mortality. This study aimed to evaluate the effect of atorvastatin administration on the Glasgow Coma Scale (GCS), Glasgow Outcome Scale (GOS), and Disability Rating Scale (DRS) in patients with TBI.

Methods

This double-blinded randomized clinical trial included 60 patients with TBI in Golestan Hospital of Ahvaz, Iran. After obtaining an informed consent from all patients, the patients were randomly assigned into two groups. For the intervention group, atorvastatin with a daily dose of 20 mg was used. The control group was administered the same amount of placebo for 10 days. Changes in the level of consciousness were measured using the GCS, and functional recovery rate in patients was measured by GOS and DRS in the third follow-up month.

Results

According to the obtained results, compared with the control group, the atorvastatin administration significantly increased the level of GCS and DRS within 2 - 3 months post-intervention and improved GOS since the tenth day after the study (P < 0.05).

Conclusions

The results revealed the positive effect of atorvastatin on the improvement of outcomes measurements such as GCS, DRS, and GOS in patients after moderate and severe TBI.

Effects of various statins on depressive symptoms: A network meta-analysis

BACKGROUND

Previous studies have indicated that statins can reduce the severity of depressive symptoms. However, the optimal choice of statin remains unclear. Therefore, we conducted a network meta-analysis to determine the optimal statin for treating depression.

METHOD

We performed a pairwise and network meta-analysis by searching the PubMed, Embase, and Cochrane Library databases on October 29th, 2020. Eligible studies were randomized controlled trials that reported on changes in depressive symptoms. The Cochrane Collaboration tool was used to assess risk of bias. We tested for possible inconsistency globally by using a χ²-test and locally by calculating inconsistency factors for each comparison in closed loops. The ranking probabilities of being at each possible rank for each intervention were estimated. Comparison-adjusted funnel plots were obtained to assess publication bias. Sensitivity analysis was also performed.

RESULTS

We identified 13 studies that matched our inclusion criteria. The risks of bias were mostly low. None of the global or local tests found significance. Compared with placebo, atorvastatin significantly reduced the severity of depressive symptoms (mean difference -3.46, 95% confidence interval -5.26 to -1.67). Atorvastatin had the first and second rank with probabilities of 44.9% and 39.0%, respectively. Comparison-adjusted funnel plots revealed no significant publication bias.

LIMITATIONS

Low similarity of included studies and a relative large treatment effect of a single study were observed.

CONCLUSIONS

In this first network meta-analysis, atorvastatin, with high intensity and a lipophilic effect, was identified as the optimal choice of statin for treating depression.

Statins in Depression: An Evidence-Based Overview of Mechanisms and Clinical Studies

Background: Depression is a leading cause of disability, burdened by high levels of non-response to conventional antidepressants. Novel therapeutic strategies targeting non-monoaminergic pathways are sorely needed. The widely available and safe statins have several putative mechanisms of action, especially anti-inflammatory, which make them ideal candidates for repurposing in the treatment of depression. A large number of articles has been published on this topic. The aim of this study is to assess this literature according to evidence-based medicine principles to inform clinical practise and research. Methods: We performed a systematic review of the electronic databases MEDLINE, CENTRAL, Web of Science, CINAHL, and ClinicalTrials.gov, and an unstructured Google Scholar and manual search, until the 9th of April 2021, for all types of clinical studies assessing the effects of statins in depression. Results: Seventy-two studies were retrieved that investigated the effects of statins on the risk of developing depression or on depressive symptoms in both depressed and non-depressed populations. Fifteen studies specifically addressed the effects of statins on inflammatory-related symptoms of anhedonia, psychomotor retardation, anxiety, and sleep disturbances in depression. Most studies suggested a positive effect of statins on the occurrence and severity of depression, with fewer studies showing no effect, while a minority indicated some negative effects. Limitations: We provide a narrative report on all the included studies but did not perform any quantitative analysis, which limits the strength of our conclusions. Conclusions: Robust evidence indicates that statins are unlikely to lead to depressive symptoms in the general population. Promising data suggest a potential role for statins in the treatment of depression. Further clinical studies are needed, especially in specific subgroups of patients identified by pre-treatment assessments of inflammatory and lipid profiles.

A 3-month-delayed treatment with anatabine improves chronic outcomes in two different models of repetitive mild traumatic brain injury in hTau mice

To date, an overwhelming number of preclinical studies have addressed acute treatment in mild TBI (mTBI) and repetitive mTBI (r-mTBI), whereas, in humans, there often exists a significant time gap between the injury and the first medical intervention. Our study focused on a delayed treatment with anatabine, an anti-inflammatory compound, in hTau mice using two different models of r-mTBI. The rationale for using two models of the same impact but different frequencies (5 hit mTBI over 9 days and 24 hit mTBI over 90 days) was chosen to address the heterogeneity of r-mTBI in clinical population. Following the last injury in each model, three months elapsed before the initiation of treatment. Anatabine was administered in drinking water for 3 months thereafter. Our data demonstrated that a 3-month delayed treatment with anatabine mitigated astrogliosis in both TBI paradigms but improved cognitive functions only in more-frequently-injured mice (24 hit mTBI). We also found that anatabine decreased the phosphorylation of tau protein and NFκB, which were increased after r-mTBI in both models. The ability of anatabine to suppress these mechanisms suggests that delayed treatment can be effective for clinical population of r-mTBI. The discrepancy between the two models with regard to changes in cognitive performance suggests that r-mTBI heterogeneity may influence treatment efficiency and should be considered in therapeutic development.

The role of bioactive lipids in attenuating the neuroinflammatory cascade in traumatic brain injury

Traumatic brain injury (TBI) is a major cause of morbidity, mortality, and economic burden. Despite this, there are no proven medical therapies in the pharmacologic management of TBI. A better understanding of disease pathophysiology might lead to novel approaches. In one area of increasing interest, bioactive lipids known to attenuate inflammation might serve as an important biomarker and mediator of disease after TBI. In this review, we describe the pathophysiology of inflammation following TBI, the actions of endogenous bioactive lipids in attenuating neuroinflammation, and their possible therapeutic role in the management of TBI. In particular, specialized pro‐resolving lipid mediators (SPMs) of inflammation represent endogenous compounds that might serve as important biomarkers of disease and potential therapeutic targets. We aim to discuss the current literature from animal models of TBI and limited human experiences that suggest that bioactive lipids and SPMs are mechanistically important to TBI recovery, and by doing so, aim to highlight the need for further clinical and translational research. Early investigations of dietary and parenteral supplementation of pro‐resolving bioactive lipids have been promising. Given the high morbidity and mortality that occurs with TBI, novel approaches are needed.

The Effect of Low-Dose Atorvastatin on Inflammatory Factors in Patients with Traumatic Brain Injury: A Randomized Clinical Trial

Background: Traumatic brain injury (TBI) is the leading cause of morbidity and mortality. Each year near 1.5 million Americans experience a TBI. Of which about 235,000 are hospitalized. Also, TBI claims 50 000 American lives each year. TBI causes mechanical damage to the blood-brain barrier and white blood cells (WBCs) entry to the brain. Objectives: The current study aimed to evaluate the efficacy of low-dose Atorvastatin on inflammatory factors in patients with traumatic brain injury (TBI). Methods: This double-blind, randomized clinical trial study was conducted in the ICU ward of Golestan Hospital in the city of Ahvaz (Iran) from April 2019-May 2020. Sixty patients with moderate to severe TBI were studied. Patients were randomly assigned into two groups of Atorvastatin and control. The main outcomes included the amount of CRP and ESR as well as white blood cells in the first 14 days of hospitalization. Glasgow Coma Score, the length of ICU stay, and the duration of mechanical ventilation were secondary outcomes. Results: The amount of CRP in the Atorvastatin group on the 14th day of hospitalization was significantly lower than those in the control group (31.99 ± 8.38 vs 59.65 ± 10.43) (P < 0.0001). On the same day, the Atorvastatin group had lower levels of ESR than the control group (14.28 ± 4.18 vs 25.57 ± 5.18) (P < 0.0001). The Atorvastatin group had significantly lower levels of white blood cells than the control group (5247.53 ± 751.93 vs 7143.94 ± 907.64, P < 0.0001). Glasgow Coma Score at the time of discharge from the ICU in the Atorvastatin group was more than control (14.06 ± 1.45 and 11.85 ± 0.75, respectively) (P < 0.05). A significant difference was found concerning the ICU stay between the two groups (P = 0.03). Conclusions: This study demonstrated that Atorvastatin could reduce the rate of inflammatory factors in TBI patients. The inflammatory condition of TBI patients heavily determines their prognosis. Inflammation leads to several reactions as well as interactions between different cells and chemical mediators. The Atorvastatin could reduce the rate of inflammatory factors and improved GCS in TBI patients.

Anti-inflammatory and Neuroprotective Agents in Clinical Trials for CNS Disease and Injury: Where Do We Go From Here?

Neurological disorders are major contributors to death and disability worldwide. The pathology of injuries and disease processes includes a cascade of events that often involve molecular and cellular components of the immune system and their interaction with cells and structures within the central nervous system. Because of this, there has been great interest in developing neuroprotective therapeutic approaches that target neuroinflammatory pathways. Several neuroprotective anti-inflammatory agents have been investigated in clinical trials for a variety of neurological diseases and injuries, but to date the results from the great majority of these trials has been disappointing. There nevertheless remains great interest in the development of neuroprotective strategies in this arena. With this in mind, the complement system is being increasingly discussed as an attractive therapeutic target for treating brain injury and neurodegenerative conditions, due to emerging data supporting a pivotal role for complement in promoting multiple downstream activities that promote neuroinflammation and degeneration. As we move forward in testing additional neuroprotective and immune-modulating agents, we believe it will be useful to review past trials and discuss potential factors that may have contributed to failure, which will assist with future agent selection and trial design, including for complement inhibitors. In this context, we also discuss inhibition of the complement system as a potential neuroprotective strategy for neuropathologies of the central nervous system.

Do statins have an effect on depressive symptoms? A systematic review and meta-analysis

BACKGROUND

Clinical trials of the effects of statins in people with and without depressive symptoms at baseline have yielded conflicting results with studies reporting both an increase and decrease in depressive symptoms. To address these inconsistences, a systematic review and meta-analysis has been conducted to determine the effects of statins on depression in those with or without clinical major depression.

METHODS

A comprehensive literature search was conducted in MEDLINE, EMBASE and PsychINFO to identify relevant articles that met predefined inclusion and exclusion criteria. The primary outcome measure was the mean difference in depression scores at endpoint between the statin and placebo groups which was computed using random effects model.

RESULTS

10 articles were found and used to determine the effects of statins on depressive symptoms. Subgroup analyses were performed to determine the effects of statins in patients with and without depression at baseline. Overall, statin use was associated with significantly lower scores on depression rating scales compared with the placebo use (SMD: -0.309, CI: -0.525, -0.094; p = 0.005). The subgroup analysis showed significant effects in the depressed population (SMD: -0.796, CI: -1.107, -0.486, p = 0.001) but not in the non-depressed population (SMD: -0.153, CI: -0.353, 0.047, p = 0.113).

LIMITATIONS

There was high heterogeneity in the studies included and only two studies had low risk of bias.

CONCLUSION

The results suggest that statins are effective in improving depressive symptoms, particularly in those with clinical depression and that they do not worsen depression in non-depressed subjects.

Preinjury Statins Are Associated With Improved Survival in Patients With Traumatic Brain Injury

BACKGROUND

Statins have been shown to improve outcomes in traumatic brain injury (TBI) in animal models. The aim of our study was to determine the effect of preinjury statins on outcomes in TBI patients.

METHODS

We performed a 4-y (2014-2017) review of our TBI database and included all patients aged ≥18 y with severe isolated TBI. Patients were stratified into those who were on statins and those who were not and were matched (1:2 ratio) using propensity score matching. The primary outcome was in-hospital mortality. The secondary outcomes were skilled nursing facility disposition, Glasgow Outcome Scale-extended score, and hospital and intensive care unit length of stay (LOS).

RESULTS

We identified 1359 patients, of which 270 were matched (statin: 90, no-statin: 180). Mean age was 55 ± 8y, median Glasgow Coma Scale was 10 (8-12), and median head-abbreviated injury scale was 3 (3-5). Matched groups were similar in age, mechanism of injury, Glasgow Coma Scale, Injury Severity Score, neurosurgical intervention, type and size of intracranial hemorrhage, and preinjury anticoagulant or antiplatelet use. The overall in-hospital mortality rate was 18%. Patients who received statins had lower rates of in-hospital mortality (11% versus 21%, P = 0.01), skilled nursing facility disposition (19% versus 28%; P = 0.04), and a higher median Glasgow Outcome Scale-extended (11 [9-13] versus 9 [8-10]; P = 0.04). No differences were found between the two groups in terms of hospital LOS (6 [4-9] versus 5 [3-8]; P = 0.34) and intensive care unit LOS (3 [3-6] versus 4 [3-5]; P = 0.09).

CONCLUSIONS

Preinjury statin use in isolated traumatic brain injury patients is associated with improved outcomes. This finding warrants further investigations to evaluate the potential beneficial role of statins as a therapeutic drug in a TBI.

LEVEL OF EVIDENCE

Level III Therapeutic.

Association Between Statin Use and Risk of Dementia After a Concussion

Importance

Concussions are an acute injury that may lead to chronic disability, while statin use might improve neurologic recovery.

Objective

To test whether statin use is associated with an increased or decreased risk of subsequent dementia after a concussion.

Design, Setting, and Participants

Large extended population-based double cohort study in Ontario, Canada, from April 1, 1993, to April 1, 2013 (enrollment), and continued until March 31, 2016 (follow-up). Dates of analysis were April 28, 2014, through March 21, 2019. Participants were older adults diagnosed as having a concussion, excluding severe cases resulting in hospitalization, individuals with a prior diagnosis of dementia or delirium, and those who died within 90 days.

Exposure

Statin prescription within 90 days after a concussion.

Main Outcome and Measure

Long-term incidence of dementia.

Results

This study identified 28 815 patients diagnosed as having a concussion (median age, 76 years; 61.3% female), of whom 7058 (24.5%) received a statin, and 21 757 (75.5%) did not receive a statin. A total of 4727 patients subsequently developed dementia over a mean follow-up of 3.9 years, equal to an incidence of 1 case per 6 patients. Patients who received a statin had a 13% reduced risk of dementia compared with patients who did not receive a statin (relative risk, 0.87; 95% CI, 0.81-0.93; P < .001). The decreased risk of dementia associated with statin use applied to diverse patient groups, remained independent of other cardiovascular medication use, intensified over time, was distinct from the risk of subsequent depression, and was not observed in patients after an ankle sprain.

Conclusions and Relevance

In this study, older adults had a substantial long-term risk of dementia after a concussion, which was associated with a modest reduction among patients receiving a statin.

Metabolism and inflammation: implications for traumatic brain injury therapeutics

INTRODUCTION

Traumatic Brain Injury (TBI) is a leading cause of death and disability in young people, affecting 69 million people annually, worldwide. The initial trauma disrupts brain homeostasis resulting in metabolic dysfunction and an inflammatory cascade, which can then promote further neurodegenerative effects for months or years, as a 'secondary' injury. Effective targeting of the cerebral inflammatory system is challenging due to its complex, pleiotropic nature. Cell metabolism plays a key role in many diseases, and increased disturbance in the TBI metabolic state is associated with poorer patient outcomes. Investigating critical metabolic pathways, and their links to inflammation, can potentially identify supplements which alter the brain's long-term response to TBI and improve recovery. Areas covered: The authors provide an overview of literature on metabolism and inflammation following TBI, and from relevant pre-clinical and clinical studies, propose therapeutic strategies. Expert opinion: There is still no specific active drug treatment for TBI. Changes in metabolic and inflammatory states have been reported after TBI and appear linked. Understanding more about abnormal cerebral metabolism following TBI, and its relationship with cerebral inflammation, will provide essential information for designing therapies, with implications for neurocritical care and for alleviating long-term disability and neurodegeneration in post-TBI patients.

Intranasally administered pitavastatin ameliorates pentylenetetrazol-induced neuroinflammation, oxidative stress and cognitive dysfunction

AIM

The present study aimed to evaluate the neuroprotective potential of intranasally administered pitavastatin in the PTZ-induced kindling model.

MATERIALS AND METHODS

Subconvulsant dose of PTZ (35 mg/kg, i.p) was administered on an alternate day until the development of kindling. Behavioural test, biochemical tests and inflammatory cytokines were estimated. Comparative molecular docking study of sodium valproate (VPA) and pitavastatin was performed to predict the binding affinity with GABA_A and GABA transaminase. Intranasally administered pitavastatin (0.5 mg/kg and 1 mg/kg) and VPA (200 mg/kg) were used to investigate its protective effect.

KEY FINDINGS

Comparative in-silico study showed docking score of -4.56 and -2.86 against GABA_A receptor whereas -5.56 and -1.86, against GABA transaminase. Root mean square deviation (RMSD) of 0.39A and 0.55A was found for pitavastatin and VPA, respectively. The present study showed the dose-dependent protective effect of intranasally administered pitavastatin and oral VPA against PTZ-induced seizure, cognitive impairment, oxidative stress, and neuroinflammation.

SIGNIFICANCE

Our findings suggest that the intranasally administered pitavastatin is potential therapeutic approach to managing PTZ-induced kindling and associated comorbid conditions via its antioxidant, anti-inflammatory, and anticonvulsant potential. Further, pitavastatin can modulate GABA_A receptor and GABA transaminase enzyme to ameliorate seizure. Meanwhile, more extensive studies are required to establish the molecular mechanism underlying the neuroprotective effect of pitavastatin.

Effects of Statin Treatment on Outcomes after Traumatic Brain Injury

Neuroprotective treatments that have shown promise in reducing secondary injury and improving recovery in animal models of traumatic brain injury (TBI) have not been found effective to date in humans. One reason may be the delay after injury in initiating treatment. Statin medications are among the promising neuroprotective agents in animal models, and their presence in the bloodstream of many individuals at the time of injury might optimize their clinical impact. This observational study conducted by a subset of centers participating in the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR)-funded TBI Model System program sought to examine the effects of taking statin medication at the time injury on functional outcomes. Participants >50 years of age were prospectively enrolled during patient rehabilitation. Demographic data, cardiovascular history, and brain injury history were obtained through chart abstraction and interview. Prescription medication use in the year prior to enrollment was determined from a national pharmacy search service. Propensity scoring was used to create 49 pairs of participants who were well matched on demographic and clinical attributes but discordant for statin use. The treated and untreated participants did not differ on initial Glasgow Coma Score, time until commands were followed, duration of post-traumatic amnesia, or Functional Independence Measure (FIM) scores at rehabilitation admission, discharge, or 1 year post-injury, or on acute or rehabilitation hospital lengths of stay. Evidence of greater and lesser statin compliance was not associated with outcome. This study did not provide support for a clinically important benefit of statin use at the time of moderate to severe TBI.

Potential immunotherapies for traumatic brain and spinal cord injury

Traumatic injury of the central nervous system (CNS) including brain and spinal cord remains a leading cause of morbidity and disability in the world. Delineating the mechanisms underlying the secondary and persistent injury versus the primary and transient injury has been drawing extensive attention for study during the past few decades. The sterile neuroinflammation during the secondary phase of injury has been frequently identified substrate underlying CNS injury, but as of now, no conclusive studies have determined whether this is a beneficial or detrimental role in the context of repair. Recent pioneering studies have demonstrated the key roles for the innate and adaptive immune responses in regulating sterile neuroinflammation and CNS repair. Some promising immunotherapeutic strategies have been recently developed for the treatment of CNS injury. This review updates the recent progress on elucidating the roles of the innate and adaptive immune responses in the context of CNS injury, the development and characterization of potential immunotherapeutics, as well as outstanding questions in this field.