NXY-059 for acute ischemic stroke

Tetramethylpyrazine nitrone exerts neuroprotection via activation of PGC-1α/Nrf2 pathway in Parkinson's disease models

INTRODUCTION

Parkinson's disease (PD) is common neurodegenerative disease where oxidative stress and mitochondrial dysfunction play important roles in its progression. Tetramethylpyrazine nitrone (TBN), a potent free radical scavenger, has shown protective effects in various neurological conditions. However, the neuroprotective mechanisms of TBN in PD models remain unclear.

OBJECTIVES

We aimed to investigate TBN's neuroprotective effects and mechanisms in PD models.

METHODS

TBN's neuroprotection was initially measured in MPP+/MPTP-induced PD models. Subsequently, a luciferase reporter assay was used to detect peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) promoter activity. Effects of TBN on antioxidant damage and the PGC-1α/Nuclear factor erythroid-2-related factor 2 (Nrf2) pathway were thoroughly investigated.

RESULTS

In MPP+-induced cell model, TBN (30-300 μM) increased cell survival by 9.95 % (P < 0.05), 16.63 % (P < 0.001), and 24.09 % (P < 0.001), respectively. TBN enhanced oxidative phosphorylation (P < 0.05) and restored PGC-1α transcriptional activity suppressed by MPP+ (84.30 % vs 59.03 %, P < 0.01). In MPTP-treated mice, TBN (30 mg/kg) ameliorated motor impairment, increased striatal dopamine levels (16.75 %, P < 0.001), dopaminergic neurons survival (27.12 %, P < 0.001), and tyrosine hydroxylase expression (28.07 %, P < 0.01). Selegiline, a positive control, increased dopamine levels (15.35 %, P < 0.001) and dopaminergic neurons survival (25.34 %, P < 0.001). Additionally, TBN reduced oxidative products and activated the PGC-1α/Nrf2 pathway. PGC-1α knockdown diminished TBN's neuroprotective effects, decreasing cell viability from 73.65 % to 56.87 % (P < 0.001).

CONCLUSION

TBN has demonstrated consistent effectiveness in MPP+-induced midbrain neurons and MPTP-induced mice. Notably, the therapeutic effect of TBN in mitigating motor deficits and neurodegeneration is superior to selegiline. The neuroprotective mechanisms of TBN are associated with activation of the PGC-1α/Nrf2 pathway, thereby reducing oxidative stress and maintaining mitochondrial function. These findings suggest that TBN may be a promising therapeutic candidate for PD, warranting further development and investigation.

Tongxinluo and Functional Outcomes Among Patients With Acute Ischemic Stroke: A Randomized Clinical Trial

Importance

Previous studies revealed limited effectiveness of neuroprotective agents in treating acute ischemic stroke (AIS). Tongxinluo, developed from traditional Chinese medicines, has been recognized as a novel neuroprotective agent with anti-inflammatory properties that stabilize vulnerable plaques in animal models and patients with myocardial infarction.

Objective

To assess the efficacy and safety of Tongxinluo in patients with acute ischemic stroke (AIS).

Design, Setting, and Participants

This multicenter, open-label, double-blind, randomized clinical trial included 2007 patients with AIS and a National Institutes of Health Stroke Scale score between 4 and 22 at admission. The trial was conducted at 50 hospitals in China from March 1, 2014, to October 31, 2016. Data were analyzed from November 14, 2016, to November 16, 2017.

Interventions

Eligible patients were randomized within 72 hours of symptom onset to the Tongxinluo group or the control group. Participants received 4 oral capsules of Tongxinluo or placebo, 3 times a day for 90 days. Other treatment was administrated according to guidelines.

Main Outcomes and Measure

The primary outcome was a favorable functional outcome at day 90 after randomization, defined as a modified Rankin Scale (mRS) score of 0 to 1 (on a scale of 0 [no neurologic deficit, no symptoms, or completely recovered] to 6 [death]). All statistical analyses were performed in a modified intention-to-treat population, defined as all patients who underwent randomization, were given any treatment, and underwent any posttreatment assessment.

Results

Among 2007 patients with AIS who were randomized, 1946 (96.5%) were included in the modified intention-to-treat analysis (973 in the Tongxinluo group and 973 in the control group, with mean [SD] age of 60.5 [9.2] years and 1342 [69.0%] male). Patients in the Tongxinluo group had a significantly higher proportion of favorable functional outcomes at day 90 compared with those in the control group (mRS score of 0-1, 640 [65.8%] vs 575 [59.1%]; odds ratio, 1.33 [95% CI, 1.11-1.60]; P = .002). The prespecified subgroup analyses indicated that, among all subgroups, additional Tongxinluo treatment had similar outcomes.

Conclusions and Relevance

Among patients with ischemic stroke within 72 hours after symptom onset, those additionally receiving Tongxinluo were more likely to have a favorable functional outcome, compared with a placebo group. Further research in patients with thrombolysis and endovascular treatment are needed to explore these outcomes.

Trial registration

ClinicalTrials.gov Identifier: NCT01919671.

Effects of edaravone dexborneol on functional outcome and inflammatory response in patients with acute ischemic stroke

BACKGROUND

Edaravone dexborneol has been reported as an effective neuroprotective agent in the treatment of acute ischemic stroke (AIS). This study aimed at investigating the impact of edaravone dexborneol on functional outcomes and systematic inflammatory response in AIS patient.

METHODS

All participants were recruited from the AISRNA study (registered 21/11/2019, NCT04175691 [ClinicalTrials.gov]) between January 2022 and December 2022. The AIS patients were divided into two groups based on whether they received the treatment of edaravone dexborneol (37.5 mg/12 hours, IV) within 48 h after stroke onset. Inflammatory response was determined by detecting levels of cytokines (interleukin-2 [IL-2], IL-4, IL-5, IL-8, IL-6, IL-10, IL-12p70, IL-17, tumor necrosis factor-α [TNF-α], interferon-γ [IFN-γ], IFN-α, and IL-1β) within 14 days after stroke onset.

RESULTS

Eighty-five AIS patients were included from the AISRNA study. Patients treated with edaravone dexborneol showed a significantly higher proportion of modified Rankin Scale score < 2 compared to those who did not receive this treatment (70.7% versus 47.8%; P = 0.031). Furthermore, individuals receiving edaravone dexborneol injection exhibited lower expression levels of interleukin (IL)-1β, IL-6, and IL-17, along with higher levels of IL-4 and IL-10 expression during the acute phase of ischemic stroke (P < 0.05). These trends were not observed for IL-2, IL-5, IL-8, IL-12p70, tumor necrosis factor-α, interferon-γ [IFN-γ], and IFN-α (P > 0.05).

CONCLUSIONS

Treatment with edaravone dexborneol resulted in a favorable functional outcome at 90 days post-stroke onset when compared to patients without this intervention; it also suppressed proinflammatory factors expression while increasing anti-inflammatory factors levels.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04175691. Registered November 21, 2019, https://www.

CLINICALTRIALS

gov/ct2/show/NCT04175691 .

Clinical pharmacology and tolerability of REC-994, a redox-cycling nitroxide compound, in randomized phase 1 dose-finding studies

Cerebral cavernous malformation (CCM) has variable clinical symptoms, including potentially fatal hemorrhagic stroke. Treatment options are very limited, presenting a large unmet need. REC-994 (also known as tempol), identified as a potential treatment through an unbiased drug discovery platform, is hypothesized to treat CCMs through a reduction in superoxide, a reactive oxygen species. We investigated the safety, tolerability, and pharmacokinetic profile of REC-994 in healthy volunteers. Single- and multiple-ascending dose (SAD and MAD, respectively) studies were conducted in adult volunteers (ages 18-55). SAD study participants received an oral dose of REC-994 or placebo. MAD study participants were randomized 3:1 to oral doses of REC-994 or matching placebo, once daily for 10 days. Thirty-two healthy volunteers participated in the SAD study and 52 in the MAD study. Systemic exposure increased in proportion to REC-994 dose after single doses of 50-800 mg and after 10 days of dosing over the 16-fold dose range of 50-800 mg. Median Tmax and mean t1/2 were independent of dose in both studies, and the solution formulation was more rapidly absorbed. REC-994 was well tolerated. Treatment-emergent adverse effects across both studies were mild and transient and resolved by the end of the study. REC-994 has a favorable safety profile and was well tolerated in single and multiple doses up to 800 mg with no dose-limiting adverse effects identified. Data support conducting a phase 2 clinical trial in patients with symptomatic CCM.

Tetramethylpyrazine Nitrone Promotes the Clearance of Alpha-Synuclein via Nrf2-Mediated Ubiquitin-Proteasome System Activation

Aggregation of α-synuclein (α-syn) and α-syn cytotoxicity are hallmarks of sporadic and familial Parkinson's disease (PD). Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-dependent enhancement of the expression of the 20S proteasome core particles (20S CPs) and regulatory particles (RPs) increases proteasome activity, which can promote α-syn clearance in PD. Activation of peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) may reduce oxidative stress by strongly inducing Nrf2 gene expression. In the present study, tetramethylpyrazine nitrone (TBN), a potent-free radical scavenger, promoted α-syn clearance by the ubiquitin-proteasome system (UPS) in cell models overexpressing the human A53T mutant α-syn. In the α-syn transgenic mice model, TBN improved motor impairment, decreased the products of oxidative damage, and down-regulated the α-syn level in the serum. TBN consistently up-regulated PGC-1α and Nrf2 expression in tested models of PD. Additionally, TBN similarly enhanced the proteasome 20S subunit beta 8 (Psmb8) expression, which is linked to chymotrypsin-like proteasome activity. Furthermore, TBN increased the mRNA levels of both the 11S RPs subunits Pa28αβ and a proteasome chaperone, known as the proteasome maturation protein (Pomp). Interestingly, specific siRNA targeting of Nrf2 blocked TBN's effects on Psmb8, Pa28αβ, Pomp expression, and α-syn clearance. In conclusion, TBN promotes the clearance of α-syn via Nrf2-mediated UPS activation, and it may serve as a potentially disease-modifying therapeutic agent for PD.

Update on Antioxidant Therapy with Edaravone: Expanding Applications in Neurodegenerative Diseases

The brain is susceptible to oxidative stress, which is associated with various neurological diseases. Edaravone (MCI-186, 3-methyl-1 pheny-2-pyrazolin-5-one), a free radical scavenger, has promising effects by quenching hydroxyl radicals (∙OH) and inhibiting both ∙OH-dependent and ∙OH-independent lipid peroxidation. Edaravone was initially developed in Japan as a neuroprotective agent for acute cerebral infarction and was later applied clinically to treat amyotrophic lateral sclerosis (ALS), a neurodegenerative disease. There is accumulating evidence for the therapeutic effects of edaravone in a wide range of diseases related to oxidative stress, including ischemic stroke, ALS, Alzheimer's disease, and placental ischemia. These neuroprotective effects have expanded the potential applications of edaravone. Data from experimental animal models support its safety for long-term use, implying broader applications in various neurodegenerative diseases. In this review, we explain the unique characteristics of edaravone, summarize recent findings for specific diseases, and discuss its prospects for future therapeutic applications.

Brain FADE syndrome: the final common pathway of chronic inflammation in neurological disease

Importance

While the understanding of inflammation in the pathogenesis of many neurological diseases is now accepted, this special commentary addresses the need to study chronic inflammation in the propagation of cognitive Fog, Asthenia, and Depression Related to Inflammation which we name Brain FADE syndrome. Patients with Brain FADE syndrome fall in the void between neurology and psychiatry because the depression, fatigue, and fog seen in these patients are not idiopathic, but instead due to organic, inflammation involved in neurological disease initiation.

Observations

A review of randomized clinical trials in stroke, multiple sclerosis, Parkinson's disease, COVID, traumatic brain injury, and Alzheimer's disease reveal a paucity of studies with any component of Brain FADE syndrome as a primary endpoint. Furthermore, despite the relatively well-accepted notion that inflammation is a critical driving factor in these disease pathologies, none have connected chronic inflammation to depression, fatigue, or fog despite over half of the patients suffering from them.

Conclusions and relevance

Brain FADE Syndrome is important and prevalent in the neurological diseases we examined. Classical "psychiatric medications" are insufficient to address Brain FADE Syndrome and a novel approach that utilizes sequential targeting of innate and adaptive immune responses should be studied.

Evolving Clinical-Translational Investigations of Cerebroprotection in Ischemic Stroke

Ischemic stroke is a highly morbid disease, with over 50% of large vessel stroke (middle cerebral artery or internal carotid artery terminus occlusion) patients suffering disability despite maximal acute reperfusion therapy with thrombolysis and thrombectomy. The discovery of the ischemic penumbra in the 1980s laid the foundation for a salvageable territory in ischemic stroke. Since then, the concept of neuroprotection has been a focus of post-stroke care to (1) minimize the conversion from penumbra to core irreversible infarct, (2) limit secondary damage from ischemia-reperfusion injury, inflammation, and excitotoxicity and (3) to encourage tissue repair. However, despite multiple studies, the preclinical-clinical research enterprise has not yet created an agent that mitigates post-stroke outcomes beyond thrombolysis and mechanical clot retrieval. These translational gaps have not deterred the scientific community as agents are under continuous investigation. The NIH has recently promoted the concept of cerebroprotection to consider the whole brain post-stroke rather than just the neurons. This review will briefly outline the translational science of past, current, and emerging breakthroughs in cerebroprotection and use of these foundational ideas to develop a novel paradigm for optimizing stroke outcomes.

Efficacy and Safety of Butylphthalide in Patients With Acute Ischemic Stroke: A Randomized Clinical Trial

Importance

DL-3-n-butylphthalide (NBP) is a drug for treating acute ischemic stroke and may play a neuroprotective role by acting on multiple active targets. The efficacy of NBP in patients with acute ischemic stroke receiving reperfusion therapy remains unknown.

Objective

To assess the efficacy and safety of NBP in patients with acute ischemic stroke receiving reperfusion therapy of intravenous thrombolysis and/or endovascular treatment.

Design, Setting, and Participants

This multicenter, double-blind, placebo-controlled, parallel randomized clinical trial was conducted in 59 centers in China with 90-day follow-up. Of 1236 patients with acute ischemic stroke, 1216 patients 18 years and older diagnosed with acute ischemic stroke with a National Institutes of Health Stroke Scale score ranging from 4 to 25 who could start the trial drug within 6 hours from symptom onset and received either intravenous recombinant tissue plasminogen activator (rt-PA) or endovascular treatment or intravenous rt-PA bridging to endovascular treatment were enrolled, after excluding 20 patients who declined to participate or did not meet eligibility criteria. Data were collected from July 1, 2018, to May 22, 2022.

Interventions

Within 6 hours after symptom onset, patients were randomized to receive NBP or placebo in a 1:1 ratio.

Main Outcomes and Measures

The primary efficacy outcome was the proportion of patients with a favorable outcome based on 90-day modified Rankin Scale score (a global stroke disability scale ranging from 0 [no symptoms or completely recovered] to 6 [death]) thresholds of 0 to 2 points, depending on baseline stroke severity.

Results

Of 1216 enrolled patients, 827 (68.0%) were men, and the median (IQR) age was 66 (56-72) years. A total of 607 were randomly assigned to the butylphthalide group and 609 to the placebo group. A favorable functional outcome at 90 days occurred in 344 patients (56.7%) in the butylphthalide group and 268 patients (44.0%) in the placebo group (odds ratio, 1.70; 95% CI, 1.35-2.14; P < .001). Serious adverse events within 90 days occurred in 61 patients (10.1%) in the butylphthalide group and 73 patients (12.0%) in the placebo group.

Conclusions and Relevance

Among patients with acute ischemic stroke receiving intravenous thrombolysis and/or endovascular treatment, NBP was associated with a higher proportion of patients achieving a favorable functional outcome at 90 days compared with placebo.

Trial Registration

ClinicalTrials.gov Identifier: NCT03539445.

Key design elements of successful acute ischemic stroke treatment trials

PURPOSE

We review key design elements of positive randomized controlled trials (RCTs) in acute ischemic stroke (AIS) treatment and summarize their main characteristics.

METHOD

We searched Medline, Pubmed and Cochrane databases for positive RCTs in AIS treatment. Trials were included if (1) they had a randomized controlled design, with (at least partial) blinding for endpoints, (2) they tested against placebo (or on top of standard therapy in a superiority design) or against approved therapy; (3) the protocol was registered and/or published before trial termination and unblinding (if required at study commencement); (4) the primary endpoint was positive in the intention to treat analysis; and (5) the study findings led to approval of the investigational product and/or high ranked recommendations. A topical approach was used, therefore the findings were summarized as a narrative review.

FINDINGS

Seventeen positive RCTs met the inclusion criteria. The majority of trials included less than 1000 patients (n = 15), had highly selective inclusion criteria (n = 16), used the modified Rankin score as a primary endpoint (n = 15) and had a frequentist design (n = 16). Trials tended to be national (n = 12), investigator-initiated and performed with public funding (n = 11).

DISCUSSION

Smaller but selective trials are useful to identify efficacy in a particular subgroup of stroke patients. It may also be of advantage to limit the number of participating countries and centers to avoid heterogeneity in stroke management and bureaucratic burden.

CONCLUSION

The key characteristics of positive RCTs in AIS treatment described here may assist in the design of further trials investigating a single intervention with a potentially high effect size.

Nelonemdaz for Patients With Acute Ischemic Stroke Undergoing Endovascular Reperfusion Therapy: A Randomized Phase II Trial

BACKGROUND

Nelonemdaz is a multitarget neuroprotectant that selectively blocks N-methyl-D-aspartate receptors and scavenges free radicals, as proven in preclinical ischemia-reperfusion studies. We aimed to evaluate the safety and efficacy of nelonemdaz in patients with acute ischemic stroke receiving endovascular reperfusion therapy.

METHODS

This phase II randomized trial involved participants with large-artery occlusion in the anterior circulation at baseline who received endovascular reperfusion therapy <8 hours from symptom onset at 7 referral stroke centers in South Korea between October 29, 2016, and June 1, 2020. Two hundred thirteen patients were screened and 209 patients were randomly assigned at a 1:1:1 ratio using a computer-generated randomization system. Patients were divided into 3 groups based on the medication received-placebo, low-dose (2750 mg) nelonemdaz, and high-dose (5250 mg) nelonemdaz. The primary outcome was the proportion of patients with modified Rankin Scale scores of 0-2 at 12 weeks.

RESULTS

Two hundred eight patients were assigned to the placebo (n=70), low-dose (n=71), and high-dose (n=67) groups. The groups had similar baseline characteristics. The primary outcome was achieved in 183 patients, and it did not differ among the groups (33/61 [54.1%], 40/65 [61.5%], and 36/57 [63.2%] patients; P=0.5578). The common odds ratio (90% CI) indicating a favorable shift in the modified Rankin Scale scores at 12 weeks was 1.55 (0.92-2.60) between the placebo and low-dose groups and 1.61 (0.94-2.76) between the placebo and high-dose groups. No serious adverse events were reported.

CONCLUSIONS

The study arms showed no significant difference in the proportion of patients achieving modified Rankin Scale scores of 0-2 at 12 weeks. Nevertheless, nelonemdaz-treated patients showed a favorable tendency toward achieving these scores at 12 weeks, without serious adverse effects. Thus, a large-scale phase III trial is warranted.

REGISTRATION

URL: https://clinicaltrials.gov; Unique identifier: NCT02831088.

Cost-effectiveness of edaravone dexborneol versus edaravone for the treatment of acute ischemic stroke in China: Based on the TASTE study

Background and purpose: The TASTE trial indicated that patients with acute ischemic stroke (AIS) using edaravone dexborneol have a significantly higher proportion of 90-day good functional outcomes (mRS 0–1) than those using edaravone. This study compared the cost-effectiveness of the aforementioned interventions in treating AIS in the Chinese setting, aiming to inform treatment decisions in clinical practice.

Methods: A model combining a decision tree and a Markov model was developed to assess the cost-effectiveness of edaravone dexborneol versus edaravone for AIS over a 30-year time horizon from the Chinese healthcare system’s perspective. Both efficacy and safety data were extracted from the TASTE study. Local costs and utilities were derived from publications and open-access databases; both cost and effectiveness were discounted at a rate of 5% per year. Sensitivity analyses were conducted to ensure robustness and identify the main drivers of the result.

Results: Compared with edaravone, edaravone dexborneol for AIS was found to be cost-effective in the first year and highly cost-effective as the study time horizons extended. In the long term (30 years), edaravone dexborneol yielded a lifetime gain of 0.25 (0.07–0.45) quality-adjusted life years (QALYs) at an additional cost of CNY 2201.07 (-3,445.24–6,637.23), yielding an ICER of CNY 8823.41 per QALY gained under the willingness-to-pay (WTP) of 1.5 times per capita GDP (121,464 CNY). The result is robust in both deterministic and probabilistic sensitivity analysis (PSA) methods, with the advantage of the edaravone dexborneol strategy increasing over time. Specifically, the probability of edaravone dexborneol dominant dexborneol is 76.30%, 98.90%, and 99.50% over 1-, 5-, and 30-year time horizons.

Conclusion: Both short- and long-term economic analyses suggest that edaravone dexborneol is highly likely to be a cost-effective alternative to treat AIS compared with edaravone in China.

Neuroprotective efficacy of N-t-butylhydroxylamine (NtBHA) in transient focal ischemia in rats

The pharmacological or toxicological activities of the degradation products of drug candidates have been unaddressed during the drug development process. Ischemic stroke accounts for 80% of all strokes and is responsible for considerable mortality and disability worldwide. Despite decades of research on neuroprotective agents, tissue plasminogen activators (t-PA), a thrombolytic agent, remains the only approved acute stroke pharmacological therapy. NXY-059, a free radical scavenger, exhibited striking neuroprotective properties in preclinical models and met all the criteria established by the Stroke Academic Industry Roundtable (STAIR) for a neuroprotective agent. In phase 3 clinical trials, NXY-059 exhibited significant neuroprotective effects in one trial (SAINT-I), but not in the second (SAINT-II). Some have hypothesized that N-t-butyl hydroxylamine (NtBHA), a breakdown product of NXY-059 was the actual neuroprotective agent in SAINT-I and that changes to the formulation of NXY-059 to prevent its breakdown to NtBHA in SAINT -II was the reason for the lack of efficacy. We evaluated the neuroprotective effect of NtBHA in N-methyl-D-aspartate (NMDA)-treated primary neurons and in rat focal cerebral ischemia. NtBHA significantly attenuated infarct volume in rat transient focal ischemia, and attenuated NMDA-induced cytotoxicity in primary cortical neurons. NtBHA also reduced free radical generation and exhibited mitochondrial protection.

Remote ischemic conditioning for acute ischemic stroke part 2: Study protocol for a randomized controlled trial

Background

Remote ischemic conditioning (RIC) refers to the application of repeated short periods of ischemia intended to protect remote areas against tissue damage during and after prolonged ischemia.

Aim

We aim to evaluate the efficacy of RIC, determined by the modified Rankin Scale (mRS) score at 90 days after stroke onset.

Design and methods

This study is an investigator-initiated, multicenter, prospective, randomized, open-label, parallel-group clinical trial. The sample size is 400, comprising 200 patients who will receive RIC and 200 controls. The patients will be divided into three groups according to their National Institutes of Health Stroke Scale score at enrollment: 5–9, mild; 10–14, moderate; 15–20, severe. The RIC protocol will be comprised of four cycles, each consisting of 5 min of blood pressure cuff inflation (at 200 mmHg or 50 mmHg above the systolic blood pressure) followed by 5 min of reperfusion, with the cuff placed on the thigh on the unaffected side. The control group will only undergo blood pressure measurements before and after the intervention period. This trial is registered with the UMIN Clinical Trial Registry (https://www.umin.ac.jp/: UMIN000046225).

Study outcome

The primary outcome will be a good functional outcome as determined by the mRS score at 90 days after stroke onset, with a target mRS score of 0–1 in the mild group, 0–2 in the moderate group, and 0–3 in the severe group.

Discussion

This trial may help determine whether RIC should be recommended as a routine clinical strategy for patients with ischemic stroke.

Cognitive-motor dissociation and time to functional recovery in patients with acute brain injury in the USA: a prospective observational cohort study

BACKGROUND

Recovery trajectories of clinically unresponsive patients with acute brain injury are largely uncertain. Brain activation in the absence of a behavioural response to spoken motor commands can be detected by EEG, also known as cognitive-motor dissociation. We aimed to explore the role of cognitive-motor dissociation in predicting time to recovery in patients with acute brain injury.

METHODS

In this observational cohort study, we prospectively studied two independent cohorts of clinically unresponsive patients (aged ≥18 years) with acute brain injury. Machine learning was applied to EEG recordings to diagnose cognitive-motor dissociation by detecting brain activation in response to verbal commands. Survival statistics and shift analyses were applied to the data to identify an association between cognitive-motor dissociation and time to and magnitude of recovery. The prediction accuracy of the model that was built using the derivation cohort was assessed using the validation cohort. Functional outcomes of all patients were assessed with the Glasgow Outcome Scale-Extended (GOS-E) at hospital discharge and at 3, 6, and 12 months after injury. Patients who underwent withdrawal of life-sustaining therapies were censored, and death was treated as a competing risk.

FINDINGS

Between July 1, 2014, and Sept 30, 2021, we screened 598 patients with acute brain injury and included 193 (32%) patients, of whom 100 were in the derivation cohort and 93 were in the validation cohort. At 12 months, 28 (15%) of 193 unresponsive patients had a GOS-E score of 4 or above. Cognitive-motor dissociation was seen in 27 (14%) patients and was an independent predictor of shorter time to good recovery (hazard ratio 5·6 [95% CI 2·5-12·5]), as was underlying traumatic brain injury or subdural haematoma (4·4 [1·4-14·0]), a Glasgow Coma Scale score on admission of greater than or equal to 8 (2·2 [1·0-4·7]), and younger age (1·0 [1·0-1·1]). Among patients discharged home or to a rehabilitation setting, those diagnosed with cognitive-motor dissociation consistently had higher scores on GOS-E indicating better functional recovery compared with those without cognitive-motor dissociation, which was seen as early as 3 months after the injury (odds ratio 4·5 [95% CI 2·0-33·6]).

INTERPRETATION

Recovery trajectories of clinically unresponsive patients diagnosed with cognitive-motor dissociation early after brain injury are distinctly different from those without cognitive-motor dissociation. A diagnosis of cognitive-motor dissociation could inform the counselling of families of clinically unresponsive patients, and it could help clinicians to identify patients who will benefit from rehabilitation.

FUNDING

US National Institutes of Health.

Hearing loss drug discovery and medicinal chemistry: Current status, challenges, and opportunities

Hearing loss is a severe high unmet need condition affecting more than 1.5 billion people globally. There are no licensed medicines for the prevention, treatment or restoration of hearing. Prosthetic devices, such as hearing aids and cochlear implants, do not restore natural hearing and users struggle with speech in the presence of background noise. Hearing loss drug discovery is immature, and small molecule approaches include repurposing existing drugs, combination therapeutics, late-stage discovery optimisation of known chemotypes for identified molecular targets of interest, phenotypic tissue screening and high-throughput cell-based screening. Hearing loss drug discovery requires the integration of specialist therapeutic area biology and otology clinical expertise. Small molecule drug discovery projects in the global clinical portfolio for hearing loss are here collated and reviewed. An overview is provided of human hearing, inner ear anatomy, inner ear delivery, types of hearing loss and hearing measurement. Small molecule experimental drugs in clinical development for hearing loss are reviewed, including their underpinning biology, discovery strategy and activities, medicinal chemistry, calculated physicochemical properties, pharmacokinetics and clinical trial status. SwissADME BOILED-Egg permeability modelling is applied to the molecules reviewed, and these results are considered. Non-small molecule hearing loss assets in clinical development are briefly noted in this review. Future opportunities in hearing loss drug discovery for human genomics and targeted protein degradation are highlighted.

Neuroprotection in Acute Ischemic Stroke: A Battle Against the Biology of Nature

Stroke is the second most common cause of global death following coronary artery disease. Time is crucial in managing stroke to reduce the rapidly progressing insult of the ischemic penumbra and the serious neurologic deficits that might follow it. Strokes are mainly either hemorrhagic or ischemic, with ischemic being the most common of all types of strokes. Thrombolytic therapy with recombinant tissue plasminogen activator and endovascular thrombectomy are the main types of management of acute ischemic stroke (AIS). In addition, there is a vital need for neuroprotection in the setting of AIS. Neuroprotective agents are important to investigate as they may reduce mortality, lessen disability, and improve quality of life after AIS. In our review, we will discuss the main types of management and the different modalities of neuroprotection, their mechanisms of action, and evidence of their effectiveness after ischemic stroke.

A Historical Review of Brain Drug Delivery

The history of brain drug delivery is reviewed beginning with the first demonstration, in 1914, that a drug for syphilis, salvarsan, did not enter the brain, due to the presence of a blood-brain barrier (BBB). Owing to restricted transport across the BBB, FDA-approved drugs for the CNS have been generally limited to lipid-soluble small molecules. Drugs that do not cross the BBB can be re-engineered for transport on endogenous BBB carrier-mediated transport and receptor-mediated transport systems, which were identified during the 1970s-1980s. By the 1990s, a multitude of brain drug delivery technologies emerged, including trans-cranial delivery, CSF delivery, BBB disruption, lipid carriers, prodrugs, stem cells, exosomes, nanoparticles, gene therapy, and biologics. The advantages and limitations of each of these brain drug delivery technologies are critically reviewed.

Oxidative Stress in Ischemia/Reperfusion Injuries following Acute Ischemic Stroke

Recanalization therapy is increasingly used in the treatment of acute ischemic stroke. However, in about one third of these patients, recanalization is followed by ischemia/reperfusion injuries, and clinically to worsening of the neurological status. Much research has focused on unraveling the involved mechanisms in order to prevent or efficiently treat these injuries. What we know so far is that oxidative stress and mitochondrial dysfunction are significantly involved in the pathogenesis of ischemia/reperfusion injury. However, despite promising results obtained in experimental research, clinical studies trying to interfere with the oxidative pathways have mostly failed. The current article discusses the main mechanisms leading to ischemia/reperfusion injuries, such as mitochondrial dysfunction, excitotoxicity, and oxidative stress, and reviews the clinical trials with antioxidant molecules highlighting recent developments and future strategies.

NIHSS score at admission can predict functional outcomes in patients with ischemic stroke undergoing carotid endarterectomy

OBJECTIVE

The aim of present study was to evaluate the prognostic impact of National Institutes of Health Stroke Scale (NIHSS) score in patients undergoing acute CEA, and to assess clinical and morphological factors that could predict worse outcomes.

METHODS

The data of 183 consecutive patients who have undergone CEA after ischemic stroke was analyzed from January 2015 to January 2021. Patients were divided into two groups using the NIHSS cut off point of 4. Functional dependence was assessed on hospital discharge and 90 days after.

RESULTS

In total, 102 patients (55.7%) had a minor stroke (Group A: NIHSS ≤ 4), whereas 81 patients (44.3%) had a moderate-major stroke (Group B: NIHSS > 4). Group A and group B showed significant differences in their intracranial anatomic features: presence of incomplete Circle of Willis (7.8% vs 17.3%; p=.05), volume of Cerebral ischemic lesion volume ≥4000 mm³ (5.9 % vs 24.7%; p=<.001), and high ASPECTS of 8 to 10 (75.5% vs 44.4%; p=<.001). The overall rate of combined perioperative stroke/myocardial infarction/death was 1.1%, with no strokes recorded during the waiting time to carotid endarterectomy (CEA). Patients in group A had a lower rate of functional dependence at discharge (4.9% vs. 35.8%; p = <.001) and at 90 days after index stroke event (2.5% vs. 19.6%; p = <.001) versus those in group B. Using multivariate binary logistic regression, admission NIHSS>4 was significantly associated with higher odds of functional dependence at discharge (OR= 7.9, 95%CI= 2.7-18.5, p = <.001) and at 90 days (OR= 10.4, 95%CI= 2.7-19.3, p = .002).

CONCLUSIONS

NIHSS>4 at admission will increase the risk of having higher mRS scores both at hospital discharge and at 90 days after index stroke event. acute CEA was safe and feasible in patients with ischemic stroke, even if they had previously undergone intravenous thrombolysis.

Using the Barthel Index and modified Rankin Scale as Outcome Measures for Stroke Rehabilitation Trials; A Comparison of Minimum Sample Size Requirements

OBJECTIVES

Underpowered trials risk inaccurate results. Recruitment to stroke rehabilitation randomised controlled trials (RCTs) is often a challenge. Statistical simulations offer an important opportunity to explore the adequacy of sample sizes in the context of specific outcome measures. We aimed to examine and compare the adequacy of stroke rehabilitation RCT sample sizes using the Barthel Index (BI) or modified Rankin Scale (mRS) as primary outcomes.

METHODS

We conducted computer simulations using typical experimental event rates (EER) and control event rates (CER) based on individual participant data (IPD) from stroke rehabilitation RCTs. Event rates are the proportion of participants who experienced clinically relevant improvements in the RCT experimental and control groups. We examined minimum sample size requirements and estimated the number of participants required to achieve a number needed to treat within clinically acceptable boundaries for the BI and mRS.

RESULTS

We secured 2350 IPD (18 RCTs). For a 90% chance of statistical accuracy on the BI a rehabilitation RCT would require 273 participants per randomised group. Accurate interpretation of effect sizes would require 1000s of participants per group. Simulations for the mRS were not possible as a clinically relevant improvement was not detected when using this outcome measure.

CONCLUSIONS

Stroke rehabilitation RCTs with large sample sizes are required for accurate interpretation of effect sizes based on the BI. The mRS lacked sensitivity to detect change and thus may be unsuitable as a primary outcome in stroke rehabilitation trials.

Adjunctive cytoprotective therapies in acute ischemic stroke: a systematic review

With the introduction of endovascular thrombectomy (EVT), a new era for treatment of acute ischemic stroke (AIS) has arrived. However, despite the much larger recanalization rate as compared to thrombolysis alone, final outcome remains far from ideal. This raises the question if some of the previously tested neuroprotective drugs warrant re-evaluation, since these compounds were all tested in studies where large-vessel recanalization was rarely achieved in the acute phase. This review provides an overview of compounds tested in clinical AIS trials and gives insight into which of these drugs warrant a re-evaluation as an add-on therapy for AIS in the era of EVT. A literature search was performed using the search terms "ischemic stroke brain" in title/abstract, and additional filters. After exclusion of papers using pre-defined selection criteria, a total of 89 trials were eligible for review which reported on 56 unique compounds. Trial compounds were divided into 6 categories based on their perceived mode of action: systemic haemodynamics, excitotoxicity, neuro-inflammation, blood-brain barrier and vasogenic edema, oxidative and nitrosative stress, neurogenesis/-regeneration and -recovery. Main trial outcomes and safety issues are summarized and promising compounds for re-evaluation are highlighted. Looking at group effect, drugs intervening with oxidative and nitrosative stress and neurogenesis/-regeneration and -recovery appear to have a favourable safety profile and show the most promising results regarding efficacy. Finally, possible theories behind individual and group effects are discussed and recommendation for promising treatment strategies are described.

Nephroprotective Effects of Tetramethylpyrazine Nitrone TBN in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of end-stage renal failure, but therapeutic options for nephroprotection are limited. Oxidative stress plays a key role in the pathogenesis of DKD. Our previous studies demonstrated that tetramethylpyrazine nitrone (TBN), a novel nitrone derivative of tetramethylpyrazine with potent free radical-scavenging activity, exerted multifunctional neuroprotection in neurological diseases. However, the effect of TBN on DKD and its underlying mechanisms of action are not yet clear. Herein, we performed streptozotocin-induced rat models of DKD and found that TBN administrated orally twice daily for 6 weeks significantly lowered urinary albumin, N-acetyl-β-D-glycosaminidase, cystatin C, malonaldehyde, and 8-hydroxy-2′-deoxyguanosine levels. TBN also ameliorated renal histopathological changes. More importantly, in a nonhuman primate model of spontaneous stage III DKD, TBN increased the estimated glomerular filtration rate, decreased serum 3-nitrotyrosine, malonaldehyde and 8-hydroxy-2′-deoxyguanosine levels, and improved metabolic abnormalities. In HK-2 cells, TBN increased glycolytic and mitochondrial functions. The protective mechanism of TBN might involve the activation of AMPK/PGC-1α-mediated downstream signaling pathways, thereby improving mitochondrial function and reducing oxidative stress in the kidneys of DKD rodent models. These results support the clinical development of TBN for the treatment of DKD.

Translational Block in Stroke: A Constructive and "Out-of-the-Box" Reappraisal

Why can we still not translate preclinical research to clinical treatments for acute strokes? Despite > 1000 successful preclinical studies, drugs, and concepts for acute stroke, only two have reached clinical translation. This is the translational block. Yet, we continue to routinely model strokes using almost the same concepts we have used for over 30 years. Methodological improvements and criteria from the last decade have shed some light but have not solved the problem. In this conceptual analysis, we review the current status and reappraise it by thinking "out-of-the-box" and over the edges. As such, we query why other scientific fields have also faced the same translational failures, to find common denominators. In parallel, we query how migraine, multiple sclerosis, and hypothermia in hypoxic encephalopathy have achieved significant translation successes. Should we view ischemic stroke as a "chronic, relapsing, vascular" disease, then secondary prevention strategies are also a successful translation. Finally, based on the lessons learned, we propose how stroke should be modeled, and how preclinical and clinical scientists, editors, grant reviewers, and industry should reconsider their routine way of conducting research. Translational success for stroke treatments may eventually require a bold change with solutions that are outside of the box.

Confidence interval estimation for treatment effects in cluster randomization trials based on ranks

A cluster randomization trial is one in which clusters of individuals are randomly allocated to different intervention arms. This design has become the standard for the evaluation of health care and educational strategies. To assess treatment effect, many cluster randomization trials involve outcomes that are lack meaningful units, making interpretation difficult. This difficulty may be dealt with by estimating the Mann-Whitney probability, which quantifies the probability that a typical response from one treatment arm is larger (or smaller) than a typical response from the other arm. In this work, we propose procedures for estimating this probability in cluster randomization trials. Primary emphasis is given to confidence interval estimation in trials with a small number of large clusters. The essence of the procedures is to obtain placement values based on overall ranks and arm-specific ranks prior to application of the ratio estimator, cluster-size-weighted means and mixed models for adjusting clustering effects. Nine confidence intervals were developed by applying three interval methods each based on the three variance estimators. The proposed methods can be applied to studies with binary, ordinal or continuous outcomes without making parametric assumptions. Simulation results demonstrated that the three variance estimators performed equally well, with the confidence interval procedures based on logit and inverse hyperbolic sine transformations performing better in terms of coverage and average interval width, even when the numbers of clusters are as small as 3 to 5 clusters per arm. The methods are illustrated using data from three published cluster randomization trials with SAS code provided.

Preclinical Stroke Research and Translational Failure: A Bird's Eye View on Preventable Variables

Despite achieving remarkable success in understanding the cellular, molecular and pathophysiological aspects of stroke, translation from preclinical research has always remained an area of debate. Although thousands of experimental compounds have been reported to be neuro-protective, their failures in clinical setting have left the researchers and stakeholders in doldrums. Though the failures described have been excruciating, they also give us a chance to refocus on the shortcomings. For better translational value, evidences from preclinical studies should be robust and reliable. Preclinical study design has a plethora of variables affecting the study outcome. Hence, this review focusses on the factors to be considered for a well-planned preclinical study while adhering to guidelines with emphasis on the study design, commonly used animal models, their limitations with special attention on various preventable attritions including comorbidities, aged animals, time of dosing, outcome measures and physiological variables along with the concept of multicentric preclinical randomized controlled trials. Here, we provide an overview of a panorama of practical aspects, which could be implemented, so that a well-defined preclinical study would result in a neuro-protectant with better translational value.

Factors Contributing to an Efficacious Endovascular Treatment for Acute Ischemic Stroke in Asian Population

Although randomized control trials about endovascular treatment (EVT) of emergent large vessel occlusion (LVO) have demonstrated the success of mechanical thrombectomy as the choice of treatment, a wide range of caveats remain unaddressed. Asian patients were rarely included in the trials, thereby raising the question of whether the treatment could be generalized. In addition, there remains a concern on the feasibility of the method with respect to its application against intracranial atherosclerosis (ICAS)-related LVO, frequently observed in the Asian population. It is important to include evidence on ICAS LVO from Asian countries in the future for a comprehensive understanding of LVO etiology. Besides the issues with EVT, prognostic concerns in diabetes patients, acute kidney injury following EVT, neuroprotective management against reperfusion injury, and other peri-EVT issues should be considered in clinical practice. In the current article, we present an in-depth review of the literature that revises information pertaining to such concerns.

Neuroprotective effect of magnesium supplementation on cerebral ischemic diseases

Ischemic encephalopathy is associated with a high mortality and rate of disability. The most common type of ischemic encephalopathy, ischemic stroke, is the second leading cause of death in the world. At present, the main treatment for ischemic stroke is to reopen blocked blood vessels. However, despite revascularization, many patients are not able to achieve good functional results. At the same time, the strict time window (<4.5 h) of thrombolytic therapy limits clinical application. Therefore, it is important to explore effective neuroprotective drugs for the treatment of ischemic stroke. Magnesium is a natural calcium antagonist, which exerts neuroprotective effects through various mechanisms. However, while most basic studies have shown that magnesium supplementation can help treat cerebral ischemia, intravenous magnesium supplementation in large clinical trials has failed to improve prognosis of ischemic patients. Therefore, we review the basic and clinical studies of magnesium supplementation for cerebral ischemia. According to the route of administration, treatment can be divided into intraperitoneal magnesium supplementation, intravenous magnesium supplementation, arterial magnesium supplementation and intracranial magnesium supplementation. We also summarized the potential influencing factors of magnesium ion intervention in cerebral ischemia injury. Finally, in combination with influencing factors derived from basic research, this article proposes three future research directions, including magnesium supplementation into the circulatory system combined with magnesium supplementation in the lateral ventricle, magnesium supplementation in the lateral ventricle combined with hypothermia therapy, and lateral ventricle magnesium supplementation combined with intracarotid magnesium supplementation combined with selective hypothermia.

Edaravone Dexborneol Versus Edaravone Alone for the Treatment of Acute Ischemic Stroke: A Phase III, Randomized, Double-Blind, Comparative Trial

BACKGROUND AND PURPOSE

Edaravone dexborneol, comprised of 2 active ingredients, edaravone and (+)-borneol, has been developed as a novel neuroprotective agent with synergistic effects of antioxidant and anti-inflammatory in animal models. The present clinical trial aimed at testing the effects of edaravone dexborneol versus edaravone on 90-day functional outcome in patients with acute ischemic stroke (AIS).

METHODS

A multicenter, randomized, double-blind, comparative, phase III clinical trial was conducted at 48 hospitals in China between May 2015 and December 2016. Inclusion criteria included patients diagnosed as AIS, 35 to 80 years of age, National Institutes of Health Stroke Scale Score between 4 and 24, and within 48 hours of AIS onset. AIS patients were randomized in 1:1 ratio into 2 treatment arms: 14-day infusion of edaravone dexborneol or edaravone injection. The primary end point was the proportion of patients with modified Rankin Scale score ≤1 on day 90 after randomization.

RESULTS

One thousand one hundred sixty-five AIS patients were randomly allocated to the edaravone dexborneol group (n=585) or the edaravone group (n=580). The edaravone dexborneol group showed significantly higher proportion of patients experiencing good functional outcomes on day 90 after randomization, compared with the edaravone group (modified Rankin Scale score ≤1, 67.18% versus 58.97%; odds ratio, 1.42 [95% CI, 1.12-1.81]; P=0.004). The prespecified subgroup analyses indicated that a greater benefit was observed in female patients than their male counterparts (2.26, 1.49-3.43 versus 1.14, 0.85-1.52).

CONCLUSIONS

When edaravone dexborneol versus edaravone was administered within 48 hours after AIS, 90-day good functional outcomes favored the edaravone dexborneol group, especially in female patients. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02430350.

Demystifying Oxidative Stress

The hypothesis that reactive oxygen species (ROS) can be not just associated with but causally implicated in disease was first made in 1956, but so far, the oxidative stress theory of disease has not led to major therapeutic breakthrough, and the use of antioxidant is now confined to the field of complementary medicine. This chapter reviews the lack of high-level clinical evidence for the effectiveness of antioxidants in preventing disease and the epistemological problems of the oxidative stress theory of disease. We conclude on possible ways forward to test this hypothesis with approaches that take into account personalized medicine. The previous oxidative stress model has helped neither to diagnose nor to treat possibly ROS-related or ROS-dependent diseases. The redox balance concept that low ROS levels are beneficial or tolerable and high levels are disease triggers and best reduced is apparently wrong. Physiological ROS signalling may become dysfunctional or a disease trigger by at least five mechanisms: a physiological source may appear at an unphysiological site, a physiological source may be underactivated (less common) or overactivated (more common), a new source may appear, a physiological source may be overactivated or underactivated, and a toxifying enzyme may convert an ROS signal molecule into a more reactive molecule. The latter three mechanisms may reach a physiological or nonphysiological target. All of these dysregulations may be the direct and essential cause of a disease (rarely the case) or just a secondary epiphenomenon, which will disappear once the non-ROS-related cause of the disease is cured (much more common). Importantly, these mechanisms are the same for almost every signalling system. Causal target validation (sources, toxifiers and targets) is essential in order to identify effective drugs and therapies for ROSopathies.

Targeting the Immune System for Ischemic Stroke

Stroke is responsible for almost 6 million deaths and more than 10% of all mortalities each year, and two-thirds of stroke survivors remain disabled. With treatments for ischemic stroke still limited to clot lysis and/or mechanical removal, new therapeutic targets are desperately needed. In this review, we provide an overview of the complex mechanisms of innate and adaptive immune cell-mediated inflammatory injury, that exacerbates infarct development for several days after stroke. We also highlight the features of poststroke systemic immunodepression that commonly leads to infections and some mortalities, and argue that safe and effective therapies will need to balance pro- and anti-inflammatory mechanisms in a time-sensitive manner, to maximize the likelihood of an improved long-term outcome.

Pathophysiology and Treatment of Stroke: Present Status and Future Perspectives

Stroke is the second leading cause of death and a major contributor to disability worldwide. The prevalence of stroke is highest in developing countries, with ischemic stroke being the most common type. Considerable progress has been made in our understanding of the pathophysiology of stroke and the underlying mechanisms leading to ischemic insult. Stroke therapy primarily focuses on restoring blood flow to the brain and treating stroke-induced neurological damage. Lack of success in recent clinical trials has led to significant refinement of animal models, focus-driven study design and use of new technologies in stroke research. Simultaneously, despite progress in stroke management, post-stroke care exerts a substantial impact on families, the healthcare system and the economy. Improvements in pre-clinical and clinical care are likely to underpin successful stroke treatment, recovery, rehabilitation and prevention. In this review, we focus on the pathophysiology of stroke, major advances in the identification of therapeutic targets and recent trends in stroke research.

Phase I safety, tolerability, and pharmacokinetic studies of tetramethylpyrazine nitrone in healthy Chinese volunteers

BACKGROUND

The purpose of this study was to investigate the safety, tolerability and pharmacokinetics of tetramethylpyrazine nitrone (TBN) in healthy Chinese volunteers.

METHODS

A single-ascending-dose (SAD) study where 68 subjects were randomized to a single dose of placebo or TBN (50, 100, 200, 400, 700, 1,000, 1,400, or 1,800 mg) through IV infusion over 30 min. A multiple-ascending-dose (MAD) study where 24 subjects received TBN twice daily (with 12 hr interval) for total 6.5 days at doses of either 700 or 1,400 mg. Adverse events were recorded and pharmacokinetic samples were collected during the whole study period.

RESULTS

No serious adverse events were found in the study. All of the observed adverse events, including increased white blood cell (4.4% subjects) and neutrophil counts (4.4% subjects), and decreased hemoglobin levels (4.2% subjects), were laboratory test abnormalities. All the adverse events were mild and tolerable, and returned to normal without any intervention. In the SAD study, linear C_max values were observed in the dose interval of 50-1,800 mg. In the MAD study, the average steady-state concentrations (C_avg.ss ) of TBN in the 700 and 1,400 mg dose group were 2,407 and 5,837 ng/ml, respectively. No drug accumulation was observed in this study.

CONCLUSIONS

TBN is well tolerated in healthy volunteers. Linear C_max values were observed in the interval of 50-1,800 mg, and target exposures of TBN were achieved without accumulation after twice daily administration to subjects. (This study has been registered at ChiCTR.org.cn. Identifier: ChiCTR1800016225 and ChiCTR1800019627.).

Natalizumab in acute ischemic stroke (ACTION II): A randomized, placebo-controlled trial

Objective

We evaluated the effect of 2 doses of natalizumab on functional outcomes in patients with acute ischemic stroke (AIS).

Methods

In this double-blind phase 2b trial, patients with AIS aged 18–80 years with NIH Stroke Scale scores of 5–23 from 53 US and European sites were randomized 1:1:1 to receive a single dose of 300 or 600 mg IV natalizumab or placebo, with randomization stratified by treatment window (≤9 or >9 to ≤24 hours from patient's last known normal state). The primary endpoint was a composite measure of excellent outcome (modified Rankin Scale score ≤1 and Barthel Index score ≥95) at day 90 assessed in all patients receiving a full dose. Sample size was estimated from a Bayesian model; p values were not used for hypothesis testing.

Results

An excellent outcome was less likely with natalizumab than with placebo (natalizumab 300 or 600 mg odds ratio 0.60; 95% confidence interval 0.39–0.93). There was no effect modification by time to treatment or use of thrombolysis/thrombectomy. For natalizumab 300 mg, 600 mg, or placebo, there were no differences in incidence of adverse events (90.0%, 92.1%, and 92.3%, respectively), serious adverse events (25.6%, 32.6%, and 20.9%, respectively), or deaths (6.7%, 4.5%, and 5.5%, respectively).

Conclusions

Natalizumab administered ≤24 hours after AIS did not improve patient outcomes.

ClinicalTrials.gov identifier

NCT02730455

Classification of evidence

This study provides Class I evidence that for patients with AIS, an excellent outcome was less likely in patients treated with natalizumab than with placebo.

Targeting Myeloperoxidase (MPO) Mediated Oxidative Stress and Inflammation for Reducing Brain Ischemia Injury: Potential Application of Natural Compounds

Oxidative stress and inflammation are two critical pathological processes of cerebral ischemia-reperfusion injury. Myeloperoxidase (MPO) is a critical inflammatory enzyme and therapeutic target triggering both oxidative stress and neuroinflammation in the pathological process of cerebral ischemia-reperfusion injury. MPO is presented in infiltrated neutrophils, activated microglial cells, neurons, and astrocytes in the ischemic brain. Activation of MPO can catalyze the reaction of chloride and H2O2 to produce HOCl. MPO also mediates oxidative stress by promoting the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), modulating the polarization and inflammation-related signaling pathways in microglia and neutrophils. MPO can be a therapeutic target for attenuating oxidative damage and neuroinflammation in ischemic stroke. Targeting MPO with inhibitors or gene deficiency significantly reduced brain infarction and improved neurological outcomes. This article discusses the important roles of MPO in mediating oxidative stress and neuroinflammation during cerebral ischemia-reperfusion injury and reviews the current understanding of the underlying mechanisms. Furthermore, we summarize the active compounds from medicinal herbs with potential as MPO inhibitors for anti-oxidative stress and anti-inflammation to attenuate cerebral ischemia-reperfusion injury, and as adjunct therapeutic agents for extending the window of thrombolytic treatment. We highlight that targeting MPO could be a promising strategy for alleviating ischemic brain injury, which merits further translational study.

The Future of Stroke Interventions

Mechanical thrombectomy (MT) has revolutionized the treatment of large-vessel occlusion stroke and markedly improved patient outcomes. Unfortunately, there remains a large proportion of patients that do not benefit from this technology. This review takes a look at recent and upcoming technologies that may help to increase the number of MT-treated patients, thereby improving their outcomes. To that end, an overview of digital health solutions, innovative pharmacological treatment, and futuristic robotic endovascular interventions is provided.

Resilience to Injury: A New Approach to Neuroprotection?

Despite thousands of neuroprotectants demonstrating promise in preclinical trials, a neuroprotective therapeutic has yet to be approved for the treatment of acute brain injuries such as stroke or traumatic brain injury. Developing a more detailed understanding of models and populations demonstrating "neurological resilience" in spite of brain injury can give us important insights into new translational therapies. Resilience is the process of active adaptation to a stressor. In the context of neuroprotection, models of preconditioning and unique animal models of extreme physiology (such as hibernating species) reliably demonstrate resilience in the laboratory setting. In the clinical setting, resilience is observed in young patients and can be found in those with specific genetic polymorphisms. These important examples of resilience can help transform and extend the current neuroprotective framework from simply countering the injurious cascade into one that anticipates, monitors, and optimizes patients' physiological responses from the time of injury throughout the process of recovery. This review summarizes the underpinnings of key adaptations common to models of resilience and how this understanding can be applied to new neuroprotective approaches.

The Local and Peripheral Immune Responses to Stroke: Implications for Therapeutic Development

The immune response to stroke is an exciting target for future stroke therapies. Stroke is a leading cause of morbidity and mortality worldwide, and clot removal (mechanical or pharmacological) to achieve tissue reperfusion is the only therapy currently approved for patient use. Due to a short therapeutic window and incomplete effectiveness, however, many patients are left with infarcted tissue that stimulates inflammation. Although this is critical to promote repair, it can also damage surrounding healthy brain tissue. In addition, acute immunodepression and subsequent infections are common and are associated with worse patient outcomes. Thus, the acute immune response is a major focus of researchers attempting to identify ways to amplify its benefits and suppress its negative effects to improve short-term recovery of patients. Here we review what is known about this powerful process. This includes the role of brain resident cells such as microglia, peripherally activated cells such as macrophages and neutrophils, and activated endothelium. The role of systemic immune activation and subsequent immunodepression in the days after stroke is also discussed, as is the chronic immune responses and its effects on cognitive function. The biphasic role of inflammation, as well as complex timelines of cell production, differentiation, and trafficking, suggests that the relationship between the acute and chronic phases of stroke recovery is complex. Gaining a more complete understanding of this intricate process by which inflammation is initiated, propagated, and terminated may potentially lead to therapeutics that can treat a larger population of stroke patients than what is currently available. The immune response plays a critical role in patient recovery in both the acute and chronic phases after stroke. In patients, the immune response can be beneficial by promoting repair and recovery, and also detrimental by propagating a pro-inflammatory microenvironment. Thus, it is critical to understand the mechanisms of immune activation following stroke in order to successfully design therapeutics.

Development of Novel N-hydroxypyridone Derivatives as Potential Anti-Ischemic Stroke Agents

Our previous study had identified ciclopirox (CPX) as a promising lead compound for treatment of ischemic stroke. To find better neuroprotective agents, a series of N-hydroxypyridone derivatives based on CPX were designed, synthesized, and evaluated in this study. Among these derivatives, compound 11 exhibits significant neuroprotection against oxygen glucose deprivation and oxidative stress-induced injuries in neuronal cells. Moreover, compound 11 possesses good blood-brain barrier permeability and superior antioxidant capability. In addition, a complex of compound 11 with olamine-11·Ola possesses good water solubility, negligible hERG inhibition, and superior metabolic stability. The in vivo experiment demonstrates that 11·Ola significantly reduces brain infarction and alleviates neurological deficits in middle cerebral artery occlusion rats. Hence, compound 11·Ola is identified in our research as a prospective prototype in the innovation of stroke treatment.

Neurocognitive and functional impairment in adult and paediatric tuberculous meningitis

In those who survive tuberculous meningitis (TBM), the long-term outcome is uncertain; individuals may suffer neurocognitive, functional and psychiatric impairment, which may significantly affect their ability to lead their lives as they did prior to their diagnosis of TBM. In children who survive, severe illness has occurred at a crucial timepoint in their development, which can lead to behavioural and cognitive delay. The extent and nature of this impairment is poorly understood, particularly in adults. This is in part due to a lack of observational studies in this area but also inconsistent inclusion of outcome measures which can quantify these deficits in clinical studies. This leads to a paucity of appropriate rehabilitative therapies available for these individuals and their caregivers, as well as burden at a socioeconomic level. In this review, we discuss what is known about neurocognitive impairment in TBM, draw on lessons learnt from other neurological infections and discuss currently available and emerging tools to evaluate function and cognition and their value in TBM. We make recommendations on which measures should be used at what timepoints to assess for impairment, with a view to optimising and standardising assessment of neurocognitive and functional impairment in TBM research.

The role of radiologic, clinical and biochemical parameters in prediction of stroke mortality

Objectives:

To assess National Institutes of Health Stroke Scale (NIHSS), stroke volume, biochemical, and blood parameters for the prediction of one-month mortality in stroke patients

Methods:

The study had retrospective design and 75 patients were involved that presented to a hospital Emergency Department between January 2016 and December 2017 in Adiyaman, Turkey diagnosed with acute ischemic cerebral infarction. The patients were divided into 2 groups according to whether mortality occurred within one month. Values for NIHSS, stroke volume, Glasgow Coma Scale, and blood parameters were compared between the groups.

Results:

Values for Glasgow Coma Scale p=0.002, NIHSS p=0.001, stroke volume p=0.003, monocyte/HDL ratio p=0.047, neutrophils p=0.01, white blood cell p=0.007, calcium p=0.016, and albumin p=0.027 were statistically significant for the prediction of one-month mortality. There were no significant differences between the groups for other parameters.

Conclusion:

The clinical, laboratory, and radiological findings individually provide significant support for the short-term prognosis of stroke. The evaluation of these results together can provide a clearer advance understanding of a prognosis to better manage the course of the disease and prevent death.

The role of reactive oxygen species in angiogenesis and preventing tissue injury after brain ischemia

Oxidative stress, which is defined as an imbalance between proxidant and antioxidant systems, is the essential mechanism involving in the ischemic process. During the early stage of brain ischemia, reactive oxygen species (ROS) are increased. Increased ROS are thought of a consequence of brain ischemia and exacerbating disease due to inducing cell death, apoptosis and senescence by oxidative stress. During brain tissue repair, ROS are act as signaling molecules and may be benefical for regulating angiogenesis and preventing tissue injury. New blood vessel formation is essentially required for rescuing tissue from brain ischemia. In ischemic conditions, ROS promotes angiogenesis, either directly or via the generation of active oxidation products. ROS-induced angiogenesis involves several signaling pathways. This paper reviewed current understanding of the role of ROS as a mediator and modulator of angiogenesis in brain ischemia.

Neuroprotective Agents in the Intensive Care Unit: -Neuroprotective Agents in ICU

Neuroprotection or prevention of neuronal loss is a complicated molecular process that is mediated by various cellular pathways. Use of different pharmacological agents as neuroprotectants has been reported especially in the last decades. These neuroprotective agents act through inhibition of inflammatory processes and apoptosis, attenuation of oxidative stress and reduction of free radicals. Control of this injurious molecular process is essential to the reduction of neuronal injuries and is associated with improved functional outcomes and recovery of the patients admitted to the intensive care unit. This study reviews neuroprotective agents and their mechanisms of action against central nervous system damages.

A new era for stroke therapy: Integrating neurovascular protection with optimal reperfusion

Recent advances in stroke reperfusion therapies have led to remarkable improvement in clinical outcomes, but many patients remain severely disabled, due in part to the lack of effective neuroprotective strategies. In this review, we show that 95% of published preclinical studies on "neuroprotectants" (1990-2018) reported positive outcomes in animal models of ischemic stroke, while none translated to successful Phase III trials. There are many complex reasons for this failure in translational research, including that the majority of clinical trials did not test early delivery of neuroprotectants in combination with successful reperfusion. In contrast to the clinical trials, >80% of recent preclinical studies examined the neuroprotectant in animal models of transient ischemia with complete reperfusion. Furthermore, only a small fraction of preclinical studies included long-term functional assessments, aged animals of both genders, and models with stroke comorbidities. Recent clinical trials demonstrate that 70%-80% of patients treated with endovascular thrombectomy achieve successful reperfusion. These successes revive the opportunity to retest previously failed approaches, including cocktail drugs that target multiple injury phases and different cell types. It is our hope that neurovascular protectants can be retested in future stroke research studies with specific criteria outlined in this review to increase translational successes.

Reactive Oxygen Species Formation in the Brain at Different Oxygen Levels: The Role of Hypoxia Inducible Factors

Hypoxia inducible factor (HIF) is the master oxygen sensor within cells and is central to the regulation of cell responses to varying oxygen levels. HIF activation during hypoxia ensures optimum ATP production and cell integrity, and is associated both directly and indirectly with reactive oxygen species (ROS) formation. HIF activation can either reduce ROS formation by suppressing the function of mitochondrial tricarboxylic acid cycle (TCA cycle), or increase ROS formation via NADPH oxidase (NOX), a target gene of HIF pathway. ROS is an unavoidable consequence of aerobic metabolism. In normal conditions (i.e., physioxia), ROS is produced at minimal levels and acts as a signaling molecule subject to the dedicated balance between ROS production and scavenging. Changes in oxygen concentrations affect ROS formation. When ROS levels exceed defense mechanisms, ROS causes oxidative stress. Increased ROS levels can also be a contributing factor to HIF stabilization during hypoxia and reoxygenation. In this review, we systemically review HIF activation and ROS formation in the brain during hypoxia and hypoxia/reoxygenation. We will then explore the literature describing how changes in HIF levels might provide pharmacological targets for effective ischaemic stroke treatment. HIF accumulation in the brain via HIF prolyl hydroxylase (PHD) inhibition is proposed as an effective therapy for ischaemia stroke due to its antioxidation and anti-inflammatory properties in addition to HIF pro-survival signaling. PHD is a key regulator of HIF levels in cells. Pharmacological inhibition of PHD increases HIF levels in normoxia (i.e., at 20.9% O₂ level). Preconditioning with HIF PHD inhibitors show a neuroprotective effect in both in vitro and in vivo ischaemia stroke models, but post-stroke treatment with PHD inhibitors remains debatable. HIF PHD inhibition during reperfusion can reduce ROS formation and activate a number of cellular survival pathways. Given agents targeting individual molecules in the ischaemic cascade (e.g., antioxidants) fail to be translated in the clinic setting, thus far, HIF pathway targeting and thereby impacting entire physiological networks is a promising drug target for reducing the adverse effects of ischaemic stroke.