Therapeutic hypothermia: Applications in adults with acute ischemic stroke

Natural product P57 induces hypothermia through targeting pyridoxal kinase

Induction of hypothermia during hibernation/torpor enables certain mammals to survive under extreme environmental conditions. However, pharmacological induction of hypothermia in most mammals remains a huge challenge. Here we show that a natural product P57 promptly induces hypothermia and decreases energy expenditure in mice. Mechanistically, P57 inhibits the kinase activity of pyridoxal kinase (PDXK), a key metabolic enzyme of vitamin B6 catalyzing phosphorylation of pyridoxal (PL), resulting in the accumulation of PL in hypothalamus to cause hypothermia. The hypothermia induced by P57 is significantly blunted in the mice with knockout of PDXK in the preoptic area (POA) of hypothalamus. We further found that P57 and PL have consistent effects on gene expression regulation in hypothalamus, and they may activate medial preoptic area (MPA) neurons in POA to induce hypothermia. Taken together, our findings demonstrate that P57 has a potential application in therapeutic hypothermia through regulation of vitamin B6 metabolism and PDXK serves as a previously unknown target of P57 in thermoregulation. In addition, P57 may serve as a chemical probe for exploring the neuron circuitry related to hypothermia state in mice.

Integrative Approaches in Acute Ischemic Stroke: From Symptom Recognition to Future Innovations

Among the high prevalence of cerebrovascular diseases nowadays, acute ischemic stroke stands out, representing a significant worldwide health issue with important socio-economic implications. Prompt diagnosis and intervention are important milestones for the management of this multifaceted pathology, making understanding the various stroke-onset symptoms crucial. A key role in acute ischemic stroke management is emphasizing the essential role of a multi-disciplinary team, therefore, increasing the efficiency of recognition and treatment. Neuroimaging and neuroradiology have evolved dramatically over the years, with multiple approaches that provide a higher understanding of the morphological aspects as well as timely recognition of cerebral artery occlusions for effective therapy planning. Regarding the treatment matter, the pharmacological approach, particularly fibrinolytic therapy, has its merits and challenges. Endovascular thrombectomy, a game-changer in stroke management, has witnessed significant advances, with technologies like stent retrievers and aspiration catheters playing pivotal roles. For select patients, combining pharmacological and endovascular strategies offers evidence-backed benefits. The aim of our comprehensive study on acute ischemic stroke is to efficiently compare the current therapies, recognize novel possibilities from the literature, and describe the state of the art in the interdisciplinary approach to acute ischemic stroke. As we aspire for holistic patient management, the emphasis is not just on medical intervention but also on physical therapy, mental health, and community engagement. The future holds promising innovations, with artificial intelligence poised to reshape stroke diagnostics and treatments. Bridging the gap between groundbreaking research and clinical practice remains a challenge, urging continuous collaboration and research.

The safety and efficacy of hypothermia combining mechanical thrombectomy or thrombolysis in the treatment of ischemic stroke: A systematic meta-analysis

BACKGROUND

Stroke is a major global public health problem, affecting 13.7 million people worldwide. Previous studies have found a neuroprotective effect of hypothermia therapy and the efficacy and safety of combined hypothermia and mechanical thrombectomy or thrombolysis in the treatment of ischemic stroke have also attracted attention.

OBJECTIVE

In the present research, the authors conducted a meta-analysis to comprehensively assess the safety and efficacy of hypothermia combining mechanical thrombectomy or thrombolysis in the treatment of ischemic stroke.

METHODS

Articles published from January 2001 to May 2022 were searched from Google Scholar, Baidu Scholar and PubMed to evaluate the clinical significance of hypothermia treatment in ischemic stroke. Complications, short-term mortality, and the modified Rankin Scale (mRS) in the full text was extracted.

RESULTS

89 publications were selected and 9 among them were included in this study with sample size of 643. All selected studies are in accordance with the inclusion criteria. Forest plot of clinical characteristics was as follows: complications (RR = 1.132, 95% CI 0.942‒1.361, p = 0.186, I² = 37.2%), mortality within 3 months (RR = 1.076, 95% CI 0.694‒1.669, p = 0.744, I² = 0.00%), mRS ≤ 1 at 3 months (RR = 1.138, 95% CI 0.829‒1.563, p = 0.423, I² = 26.0%), mRS ≤ 2 at 3 months (RR = 1.672, 95% CI 1.236‒2.263, p = 0.001, I²=49.6%) and mRS ≤ 3 at 3 months (RR = 1.518, 95% CI 1.128‒2.043, p = 0.006, I² = 0.00%). The funnel plot suggested that there was no significant publication bias in the meta-analysis on complications, mortality within 3 months, mRS ≤ 1 at 3 months and mRS ≤ 2 at 3 months.

CONCLUSION

In summary, the results showed that hypothermia treatment was correlated with mRS ≤ 2 at 3 months, but not linked with complications and mortality within 3 months.

Research progress of selective brain cooling methods in the prehospital care for stroke patients: A narrative review

Over the past four decades, therapeutic hypothermia (TH) has long been suggested as a promising neuroprotective treatment of acute ischemic stroke (AIS). Much attention has focus on keeping the hypothermic benefits and removing side effects of systemic hypothermia. In the past few years, the advent of intravenous thrombolysis and endovascular thrombectomy has taken us into a reperfusion era of AIS treatment. With recent research emphasizing ways to plus neuroprotective treatments to reperfusion therapy, the spotlight is now shifting toward the study of how selective brain hypothermia can offset the drawbacks of systemic hypothermia and be applied in prehospital condition. This mini-review summarizes current brain cooling methods that can be used for inducing selective hypothermia in prehospital care. It will guide the future development of selective cooling methods, extend the application of TH in prehospital care, and provide insights into the prospects of selective hypothermia in AIS.

Selective brain hypothermia attenuates focal cerebral ischemic injury and improves long-term neurological outcome in aged female mice

AIMS

This study aimed to investigate the effects of mild selective brain hypothermia on aged female ischemic mice.

METHODS

A distal middle cerebral artery occlusion (dMCAO) model was established in aged female mice, who were then subjected to mild selective brain hypothermia immediately after the dMCAO procedure. Neurological behavioral examinations were conducted prior to and up to 35 days post-ischemia. Infarct volume, brain atrophy, pro-inflammation, and anti-inflammation microglia/macrophages phenotype and white matter injury were evaluated by immunofluorescence staining. Correlations between neurological behaviors and histological parameters were evaluated by Pearson product linear regression analysis.

RESULTS

Sensorimotor and cognitive function tests confirmed the protective effect of mild selective brain hypothermia in elderly female ischemic mice. In addition, hypothermia decreased the infarct volume and brain atrophy induced by focal cerebral ischemia. Furthermore, hypothermia alleviated ischemia-induced short-term and long-term white matter injury, which was correlated with behavioral deficits. Finally, hypothermia suppressed the harmful immunological response by promoting the transformation of pro-inflammatory microglia/macrophages to anti-inflammatory phenotype. This polarization was negatively correlated with neuronal loss and white matter injury.

CONCLUSION

Mild selective brain hypothermia promoted long-term functional recovery by alleviating white matter damage in an aged female mouse model of ischemia.

The BE COOL Treatments (Batroxobin, oxygEn, Conditioning, and cOOLing): Emerging Adjunct Therapies for Ischemic Cerebrovascular Disease

Ischemic cerebrovascular disease (ICD), the most common neurological disease worldwide, can be classified based on the onset time (acute/chronic) and the type of cerebral blood vessel involved (artery or venous sinus). Classifications include acute ischemic stroke (AIS)/transient ischemic attack (TIA), chronic cerebral circulation insufficiency (CCCI), acute cerebral venous sinus thrombosis (CVST), and chronic cerebrospinal venous insufficiency (CCSVI). The pathogenesis of cerebral arterial ischemia may be correlated with cerebral venous ischemia through decreased cerebral perfusion. The core treatment goals for both arterial and venous ICDs include perfusion recovery, reduction of cerebral ischemic injury, and preservation of the neuronal integrity of the involved region as soon as possible; however, therapy based on the current guidelines for either acute ischemic events or chronic cerebral ischemia is not ideal because the recurrence rate of AIS or CVST is still very high. Therefore, this review discusses the neuroprotective effects of four novel potential ICD treatments with high translation rates, known as the BE COOL treatments (Batroxobin, oxygEn, Conditioning, and cOOLing), and subsequently analyzes how BE COOL treatments are used in clinical settings. The combination of batroxobin, oxygen, conditioning, and cooling may be a promising intervention for preserving ischemic tissues.

Hypoxia and Alpha-Synuclein: Inextricable Link Underlying the Pathologic Progression of Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease, with typical motor symptoms as the main clinical manifestations. At present, there are about 10 million patients with PD in the world, and its comorbidities and complications are numerous and incurable. Therefore, it is particularly important to explore the pathogenesis of PD and find possible therapeutic targets. Because the etiology of PD is complex, involving genes, environment, and aging, finding common factors is the key to identifying intervention targets. Hypoxia is ubiquitous in the natural environment and disease states, and it is considered to be closely related to the etiology of PD. Despite research showing that hypoxia increases the expression and aggregation of alpha-synuclein (α-syn), the most important pathogenic protein, there is still a lack of systematic studies on the role of hypoxia in α-syn pathology and PD pathogenesis. Considering that hypoxia is inextricably linked with various causes of PD, hypoxia may be a co-participant in many aspects of the PD pathologic process. In this review, we describe the risk factors for PD, and we discuss the possible role of hypoxia in inducing PD pathology by these risk factors. Furthermore, we attribute the pathological changes caused by PD etiology to oxygen uptake disorder and oxygen utilization disorder, thus emphasizing the possibility of hypoxia as a critical link in initiating or promoting α-syn pathology and PD pathogenesis. Our study provides novel insight for exploring the pathogenesis and therapeutic targets of PD.

Chlorpromazine and Promethazine (C+P) Reduce Brain Injury after Ischemic Stroke through the PKC-δ/NOX/MnSOD Pathway

Cerebral ischemia-reperfusion (I/R) incites neurologic damage through a myriad of complex pathophysiological mechanisms, most notably, inflammation and oxidative stress. In I/R injury, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) produces reactive oxygen species (ROS), which promote inflammatory and apoptotic pathways, augmenting ROS production and promoting cell death. Inhibiting ischemia-induced oxidative stress would be beneficial for reducing neuroinflammation and promoting neuronal cell survival. Studies have demonstrated that chlorpromazine and promethazine (C+P) induce neuroprotection. This study investigated how C+P minimizes oxidative stress triggered by ischemic injury. Adult male Sprague-Dawley rats were subject to middle cerebral artery occlusion (MCAO) and subsequent reperfusion. 8 mg/kg of C+P was injected into the rats when reperfusion was initiated. Neurologic damage was evaluated using infarct volumes, neurological deficit scoring, and TUNEL assays. NOX enzymatic activity, ROS production, protein expression of NOX subunits, manganese superoxide dismutase (MnSOD), and phosphorylation of PKC-δ were assessed. Neural SHSY5Y cells underwent oxygen-glucose deprivation (OGD) and subsequent reoxygenation and C+P treatment. We also evaluated ROS levels and NOX protein subunit expression, MnSOD, and p-PKC-δ/PKC-δ. Additionally, we measured PKC-δ membrane translocation and the level of interaction between NOX subunit (p47^phox) and PKC-δ via coimmunoprecipitation. As hypothesized, treatment with C+P therapy decreased levels of neurologic damage. ROS production, NOX subunit expression, NOX activity, and p-PKC-δ/PKC-δ were all significantly decreased in subjects treated with C+P. C+P decreased membrane translocation of PKC-δ and lowered the level of interaction between p47^phox and PKC-δ. This study suggests that C+P induces neuroprotective effects in ischemic stroke through inhibiting oxidative stress. Our findings also indicate that PKC-δ, NOX, and MnSOD are vital regulators of oxidative processes, suggesting that C+P may serve as an antioxidant.

Neuroprotective Effects of Pharmacological Hypothermia on Hyperglycolysis and Gluconeogenesis in Rats after Ischemic Stroke

Stroke is a leading threat to human life. Metabolic dysfunction of glucose may play a key role in stroke pathophysiology. Pharmacological hypothermia (PH) is a potential neuroprotective strategy for stroke, in which the temperature is decreased safely. The present study determined whether neuroprotective PH with chlorpromazine and promethazine (C + P), plus dihydrocapsaicin (DHC) improved glucose metabolism in acute ischemic stroke. A total of 208 adult male Sprague Dawley rats were randomly divided into the following groups: sham, stroke, and stroke with various treatments including C + P, DHC, C + P + DHC, phloretin (glucose transporter (GLUT)-1 inhibitor), cytochalasin B (GLUT-3 inhibitor), TZD (thiazolidinedione, phosphoenolpyruvate carboxykinase (PCK) inhibitor), and apocynin (nicotinamide adenine dinucleotide phosphate oxidase (NOX) inhibitor). Stroke was induced by middle cerebral artery occlusion (MCAO) for 2 h followed by 6 or 24 h of reperfusion. Rectal temperature was monitored before, during, and after PH. Infarct volume and neurological deficits were measured to assess the neuroprotective effects. Reactive oxygen species (ROS), NOX activity, lactate, apoptotic cell death, glucose, and ATP levels were measured. Protein expression of GLUT-1, GLUT-3, phosphofructokinase (PFK), lactate dehydrogenase (LDH), PCK1, PCK2, and NOX subunit gp91 was measured with Western blotting. PH with a combination of C + P and DHC induced faster, longer, and deeper hypothermia, as compared to each alone. PH significantly improved every measured outcome as compared to stroke and monotherapy. PH reduced brain infarction, neurological deficits, protein levels of glycolytic enzymes (GLUT-1, GLUT-3, PFK and LDH), gluconeogenic enzymes (PCK1 and PCK2), NOX activity and its subunit gp91, ROS, apoptotic cell death, glucose, and lactate, while raising ATP levels. In conclusion, stroke impaired glucose metabolism by enhancing hyperglycolysis and gluconeogenesis, which led to ischemic injury, all of which were reversed by PH induced by a combination of C + P and DHC.

Perspectives on benefit of early and prereperfusion hypothermia by pharmacological approach in stroke

Stroke kills or disables approximately 15 million people worldwide each year. It is the leading cause of brain injury, resulting in persistent neurological deficits and profound physical handicaps. In spite of over 100 clinical trials, stroke treatment modalities are limited in applicability and efficacy, and therefore, identification of new therapeutic modalities is required to combat this growing problem. Poststroke oxidative damage and lactic acidosis are widely-recognized forms of brain ischemia/reperfusion injury. However, treatments directed at these injury mechanisms have not been effective. In this review, we offer a novel approach combining these well-established damage mechanisms with new insights into brain glucose handling. Specifically, emerging evidence of brain gluconeogenesis provides a missing link for understanding oxidative injury and lactate toxicity after ischemia. Therefore, dysfunctional gluconeogenesis may substantially contribute to oxidative and lactate damage. We further review that hypothermia initiated early in ischemia and before reperfusion may ameliorate gluconeogenic dysfunction and subsequently provide an important mechanism of hypothermic protection. We will focus on the efficacy of pharmacologically assisted hypothermia and suggest a combination that minimizes side effects. Together, this study will advance our knowledge of basic mechanisms of ischemic damage and apply this knowledge to develop new therapeutic strategies that are desperately needed in the clinical treatment of stroke.

Cellular and Molecular Targets for Non-Invasive, Non-Pharmacological Therapeutic/Rehabilitative Interventions in Acute Ischemic Stroke

BACKGROUND

Cerebral circulation delivers the blood flow to the brain through a dedicated network of sanguine vessels. A healthy human brain can regulate cerebral blood flow (CBF) according to any physiological or pathological challenges. The brain is protected by its self-regulatory mechanisms, which are dependent on neuronal and support cellular populations, including endothelial ones, as well as metabolic, and even myogenic factors.

OBJECTIVES

Accumulating data suggest that "non-pharmacological" approaches might provide new opportunities for stroke therapy, such as electro-/acupuncture, hyperbaric oxygen therapy, hypothermia/cooling, photobiomodulation, therapeutic gases, transcranial direct current stimulations, or transcranial magnetic stimulations. We reviewed the recent data on the mechanisms and clinical implications of these non-pharmaceutical treatments.

METHODS

To present the state-of-the-art for currently available non-invasive, non-pharmacological-related interventions in acute ischemic stroke, we accomplished this synthetic and systematic literature review based on the Preferred Reporting Items for Systematic Principles Reviews and Meta-Analyses (PRISMA).

RESULTS

The initial number of obtained articles was 313. After fulfilling the five steps in the filtering/selection methodology, 54 fully eligible papers were selected for synthetic review. We enhanced our documentation with other bibliographic resources connected to our subject, identified in the literature within a non-standardized search, to fill the knowledge gaps. Fifteen clinical trials were also identified.

DISCUSSION

Non-invasive, non-pharmacological therapeutic/rehabilitative interventions for acute ischemic stroke are mainly holistic therapies. Therefore, most of them are not yet routinely used in clinical practice, despite some possible beneficial effects, which have yet to be supplementarily proven in more related studies. Moreover, few of the identified clinical trials are already completed and most do not have final results.

CONCLUSIONS

This review synthesizes the current findings on acute ischemic stroke therapeutic/rehabilitative interventions, described as non-invasive and non-pharmacological.

Phenothiazine Inhibits Neuroinflammation and Inflammasome Activation Independent of Hypothermia After Ischemic Stroke

A depressive or hibernation-like effect of chlorpromazine and promethazine (C + P) on brain activity was reported to induce neuroprotection, with or without induced-hypothermia. However, the underlying mechanisms remain unclear. The current study evaluated the pharmacological function of C + P on the inhibition of neuroinflammatory response and inflammasome activation after ischemia/reperfusion. A total of 72 adult male Sprague-Dawley rats were subjected to 2 h middle cerebral artery occlusion (MCAO) followed by 6 or 24 h reperfusion. At the onset of reperfusion, rats received C + P (8 mg/kg) with temperature control. Brain cell death was detected by measuring CD68 and myeloperoxidase (MPO) levels. Inflammasome activation was measured by mRNA levels of NLRP3, IL-1β, and TXNIP, and protein quantities of NLRP3, IL-1β, TXNIP, cleaved-Caspase-1, and IL-18. Activation of JAK2/STAT3 pathway was detected by the phosphorylation of STAT3 (p-STAT3) and JAK2 (p-JAK2), and the co-localization of p-STAT3 and NLRP3. Activation of the p38 pathway was assessed with the protein levels of p-p38/p38. The mRNA and protein levels of HIF-1α, FoxO1, and p-FoxO1, and the co-localization of p-STAT3 with HIF-1α or FoxO1 were quantitated. As expected, C + P significantly reduced cell death and attenuated the neuroinflammatory response as determined by reduced CD68 and MPO. C + P decreased ischemia-induced inflammasome activation, shown by reduced mRNA and protein expressions of NLRP3, IL-1β, TXNIP, cleaved-Caspase-1, and IL-18. Phosphorylation of JAK2/STAT3 and p38 pathways and the co-localization of p-STAT3 with NLRP3 were also inhibited by C + P. Furthermore, mRNA levels of HIF-1α and FoxO1 were decreased in the C + P group. While C + P inhibited HIF-1α protein expression, it increased FoxO1 phosphorylation, which promoted the exclusion of FoxO1 from the nucleus and inhibited FoxO1 activity. At the same time, C + P reduced the co-localization of p-STAT3 with HIF-1α or FoxO1. In conclusion, C + P treatment conferred neuroprotection in stroke by suppressing neuroinflammation and NLRP3 inflammasome activation. The present study suggests that JAK2/STAT3/p38/HIF-1α/FoxO1 are vital regulators and potential targets for efficacious therapy following ischemic stroke.

Infarct Growth despite Successful Endovascular Reperfusion in Acute Ischemic Stroke: A Meta-analysis

BACKGROUND

Infarct volume inversely correlates with good recovery in stroke. The magnitude and predictors of infarct growth despite successful reperfusion via endovascular treatment are not known.

PURPOSE

We aimed to summarize the extent of infarct growth in patients with acute stroke who achieved successful reperfusion (TICI 2b-3) after endovascular treatment.

DATA SOURCES

We performed a systematic review and meta-analysis by searching MEDLINE and Google Scholar for articles published up to October 31, 2020.

STUDY SELECTION

Studies of >10 patients reporting baseline and post-endovascular treatment infarct volumes on MR imaging were included. Only patients with TICI 2b-3 were included. We calculated infarct growth at a study level as the difference between baseline and follow-up MR imaging infarct volumes.

DATA ANALYSIS

Our search yielded 345 studies, and we included 10 studies reporting on 973 patients having undergone endovascular treatment who achieved successful reperfusion.

DATA SYNTHESIS

The mean baseline infarct volume was 19.5 mL, while the mean final infarct volume was 37.5 mL. A TICI 2b reperfusion grade was achieved in 24% of patients, and TICI 2c or 3 in 76%. The pooled mean infarct growth was 14.8 mL (95% CI, 7.9-21.7 mL). Meta-regression showed higher infarct growth in studies that reported higher baseline infarct volumes, higher rates of incomplete reperfusion (modified TICI 2b), and longer onset-to-reperfusion times.

LIMITATIONS

Significant heterogeneity among studies was noted and might be driven by the difference in infarct growth between early- and late-treatment studies.

CONCLUSIONS

These results suggest considerable infarct growth despite successful endovascular treatment reperfusion and call for a faster workflow and the need for specific therapies to limit infarct growth.

New approaches for developing multi-targeted drug combinations for disease modification of complex brain disorders. Does epilepsy prevention become a realistic goal?

Over decades, the prevailing standard in drug discovery was the concept of designing highly selective compounds that act on individual drug targets. However, more recently, multi-target and combinatorial drug therapies have become an important treatment modality in complex diseases, including neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The development of such network-based approaches is facilitated by the significant advance in our understanding of the pathophysiological processes in these and other complex brain diseases and the adoption of modern computational approaches in drug discovery and repurposing. However, although drug combination therapy has become an effective means for the symptomatic treatment of many complex diseases, the holy grail of identifying clinically effective disease-modifying treatments for neurodegenerative and other brain diseases remains elusive. Thus, despite extensive research, there remains an urgent need for novel treatments that will modify the progression of the disease or prevent its development in patients at risk. Here we discuss recent approaches with a focus on multi-targeted drug combinations for prevention or modification of epilepsy. Over the last ~10 years, several novel promising multi-targeted therapeutic approaches have been identified in animal models. We envision that synergistic combinations of repurposed drugs as presented in this review will be demonstrated to prevent epilepsy in patients at risk within the next 5-10 years.

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.

Rapid Intervention of Chlorpromazine and Promethazine for Hibernation-Like Effect in Stroke: Rationale, Design, and Protocol for a Prospective Randomized Controlled Trial

Background: Following an acute ischemic stroke (AIS), rapidly initiated reperfusion therapies [i. e., intravenous thrombolysis (IVT) and endovascular treatment (EVT)] demonstrate robust clinical efficacy. However, only a subset of these patients can benefit from these therapies due to their short treatment windows and potential complications. In addition, many patients despite successful reperfusion still have unfavorable outcomes. Thus, neuroprotection strategies are urgently needed for AIS patients. Chlorpromazine and promethazine (C+P) have been employed in clinical practice for antipsychotic and sedative purposes. A clinical study has also shown a neuroprotective effect of C+P on patients with cerebral hemorrhage and subarachnoid hemorrhage. The safety, feasibility, and preliminary efficacy of intravenous administration of C+P in AIS patients within 24 h of onset will be elucidated.

Methods: A prospective randomized controlled trial is proposed with AIS patients. Participants will be randomly allocated to an intervention group and a control group with a 1:1 ratio (n = 30) and will be treated with standard therapies according to the current stroke guidelines. Participants allocated to the intervention group will receive intravenous administration of C+P (chlorpromazine 50 mg and promethazine 50 mg) within 24 h of symptom onset. The primary outcome is safety (mainly hypotension), while the secondary outcomes include changes in functional outcome and infarction volume.

Discussions: This study on Rapid Intervention of Chlorpromazine and Promethazine for Hibernation-like Effect in Stroke (RICHES) will be the first prospective randomized controlled trial to ascertain the safety, feasibility, and preliminary efficacy of intravenous C+P as a neuroprotection strategy in AIS patients. These results will provide parameters for future studies, provide insights into treatment effects, and neuroprotection with phenothiazine in AIS.

Clinical Trial Registration:www.chictr.org.cn, identifier: ChiCTR2000038727.

DJ-1: A promising therapeutic candidate for ischemia-reperfusion injury

DJ-1 is a multifaceted protein with pleiotropic functions that has been implicated in multiple diseases, ranging from neurodegeneration to cancer and ischemia-reperfusion injury. Ischemia is a complex pathological state arising when tissues and organs do not receive adequate levels of oxygen and nutrients. When the blood flow is restored, significant damage occurs over and above that of ischemia alone and is termed ischemia-reperfusion injury. Despite great efforts in the scientific community to ameliorate this pathology, its complex nature has rendered it challenging to obtain satisfactory treatments that translate to the clinic. In this review, we will describe the recent findings on the participation of the protein DJ-1 in the pathophysiology of ischemia-reperfusion injury, firstly introducing the features and functions of DJ-1 and, successively highlighting the therapeutic potential of the protein.

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DJ-1 has been shown to confer protection in ischemia-reperfusion injury models.

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DJ-1 protection relies on the activation of antioxidant signaling pathways.

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DJ-1 regulates mitochondrial homeostasis during ischemia and reperfusion.

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DJ-1 seems to modulate ion homeostasis during ischemia and reperfusion.

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DJ-1 may represent a promising therapeutic target for ischemia-reperfusion injury.

Acute Injection of Omega-3 Triglyceride Emulsion Provides Very Similar Protection as Hypothermia in a Neonatal Mouse Model of Hypoxic-Ischemic Brain Injury

Therapeutic hypothermia (HT) is a currently accepted treatment for neonatal asphyxia and is a promising strategy in adult stroke therapy. We previously reported that acute administration of docosahexaenoic acid (DHA) triglyceride emulsion (tri-DHA) protects against hypoxic-ischemic (HI) injury in neonatal mice. We questioned if co-treatment with HT and tri-DHA would achieve synergic effects in protecting the brain from HI injury. Neonatal mice (10-day old) subjected to HI injury were placed in temperature-controlled chambers for 4 h of either HT (rectal temperature 31–32°C) or normothermia (NT, rectal temperature 37°C). Mice were treated with tri-DHA (0.375 g tri-DHA/kg bw, two injections) before and 1 h after initiation of HT. We observed that HT, beginning immediately after HI injury, reduced brain infarct volume similarly to tri-DHA treatment (~50%). Further, HT delayed 2 h post-HI injury provided neuroprotection (% infarct volume: 31.4 ± 4.1 vs. 18.8 ± 4.6 HT), while 4 h delayed HT did not protect against HI insult (% infarct volume: 30.7 ± 5.0 vs. 31.3 ± 5.6 HT). HT plus tri-DHA combination treatment beginning at 0 or 2 h after HI injury did not further reduce infarct volumes compared to HT alone. Our results indicate that HT offers similar degrees of neuroprotection against HI injury compared to tri-DHA treatment. HT can only be provided in tertiary care centers, requires intense monitoring and can have adverse effects. In contrast, tri-DHA treatment may be advantageous in providing a feasible and effective strategy in patients after HI injury.

Therapeutic Hypothermia in Acute Ischemic Stroke-a Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

Therapeutic hypothermia (TH) in stroke demonstrates robust neuroprotection in animals but clinical applications remain controversial. We assessed current literature on the efficacy of TH in ischemic stroke.

RECENT FINDINGS

We conducted a meta-analysis comparing TH versus controls in studies published until June 2019. Controlled studies reporting on ≥ 10 adults with acute ischemic stroke were included. Primary outcome was functional independence (modified Rankin Scale [mRS] ≤ 2). Twelve studies (n = 351 TH, n = 427 controls) were included. Functional independence did not differ between groups (RR 1.17, 95% CI 0.93-1.46, random-effects p = 0.2). Five studies reported individual mRS outcomes and demonstrated a shift toward better outcome with TH (unadjusted cOR 1.57, 95% CI 1.01-2.44, p = 0.05). Overall complications were higher with TH (RR 1.18, 95% CI 1.06-1.32, p < 0.01). We did not observe an overall beneficial effect of TH in this analysis although some studies showed a shift toward better outcome. TH was associated with increased complications.

Hypothermic neuroprotection against acute ischemic stroke: The 2019 update

Acute ischemic stroke is a leading cause of death and disability worldwide. Therapeutic hypothermia has long been considered as one of the most robust neuroprotective strategies. Although the neuroprotective effects of hypothermia have only been confirmed in patients with global cerebral ischemia after cardiac arrest and in neonatal hypoxic ischemic encephalopathy, establishing standardized protocols and strictly controlling the key parameters may extend its application in other brain injuries, such as acute ischemic stroke. In this review, we discuss the potential neuroprotective effects of hypothermia, its drawbacks evidenced in previous studies, and its potential clinical application for acute ischemic stroke especially in the era of reperfusion. Based on the different conditions between bench and bedside settings, we demonstrate the importance of vascular recanalization for neuroprotection of hypothermia by analyzing numerous literatures regarding hypothermia in focal cerebral ischemia. Then, we make a thorough analysis of key parameters of hypothermia and introduce novel hypothermic therapies. We advocate in favor of the process of clinical translation of intra-arterial selective cooling infusion in the era of reperfusion and provide insights into the prospects of hypothermia in acute ischemic stroke.

Therapeutic Hypothermia Protects Against Heat Stroke-Induced Arterial Hypotension via Promoting Left Ventricular Performance in Rats

We aimed to ascertain whether therapeutic hypothermia (TH) acts as cardioprotective management for heat stroke (HS). Adult male rats under general anesthesia were exposed to whole-body heating (43°C for 70 min) to induce HS. Rats with HS displayed hyperthermia (core body temperature 42°C vs. 36°C); hypotension (30 mmHg vs. 90 mmHg mean arterial blood pressure); suppressed left ventricular (LV) performance (stroke volume 52 μl/min vs. 125 μl/min), ejection fraction (0.29% vs. 0.69%), relaxation factor (72 ms vs. 12 ms), and arterial elastance (0.31 mmHg/ μl vs. 10 mmHg/ μl); increased myocardial injury markers (e.g., creatine kinase-MB: 86 U/L vs. 24 U/L, cardiac troponin I: 3.08 ng/ml vs. 0.57 ng/ml); increased myocardial oxidative stress markers (e.g., malondialdehyde: 6.52 nmol/mg vs. 1.06 nmol/mg, thiobarbituric acid-reactive substances: 29 nmol/g vs. 2 nmol/g); decreased myocardial antioxidants (e.g., superoxide dismutase: 6 unit/mg vs. 17 unit/mg, reduced glutathione: 0.64 nmol/mg vs. 2.53 nmol/mg); increased myocardial proinflammatory cytokines (e.g., tumor necrosis factor-α 3200 pg/ml vs. 1000 pg/ml, interleukin-6: 668 pg/ml vs. 102 pg/ml); and increased cardiac damage scores (2.2 vs. 0.3). TH therapy significantly reversed the following conditions: HS-induced hyperthermia (37.5°C core body temperature), hypotension (71 mmHg), suppressed LV performance (stroke volume: 97 μl/min, ejection fraction: 0.65%, relaxation factor: 39 ms, and arterial elastance: 0.99 mmHg/μl), increased myocardial injury markers (e.g., creatine kinase-MB: 37 U/L, cardiac troponin I: 1.06 ng/ml), increased myocardial oxidative stress markers (e.g., malondialdehyde: 2.68 nmol/mg, thiobarbituric acid-reactive substances: 12.3 nmol/g), decreased myocardial antioxidants (e.g., superoxide dismutase: 13.3 unit/mg, reduced glutathione: 2.71 mmol/mg), increased myocardial proinflammatory cytokines (e.g., tumor necrosis factor-α 1500 pg/ml, interleukin-6: 108 ng/ml); and increased cardiac damage scores (0.9). We thus conclude that TH protects against HS-induced arterial hypotension by promoting LV performance in rats. These results add to the literature regarding the use of TH as cardioprotective management for HS.

Effect of Therapeutic Hypothermia on Liver Enzymes in Patients With Stroke

Introduction:

A promising strategy that can lead to longer brain cell survival after an acute stroke is therapeutic hypothermia. It represents a controlled decrease in body temperature for therapeutic reasons. It is increasingly represented as a therapeutic option and is one of the most challenging treatments that improves neurological recovery and treatment outcome in patients with acute stroke.

Aim:

To examine the effect of therapeutic hypothermia on liver enzymes in patients with diagnosis of stroke.

Methods:

A total of 101 patients diagnosed with acute stroke were treated. The first group (n=40) were treated with conventional treatment and therapeutic hypothermia, while the second group (n=61) only with conventional treatment. Cooling of the body to a target body temperature of 34°C to 35°C was performed for up to 24 hours. Outcome (survival or death) of treatment was monitored, degree of disability was determined by National Institutes of Health Stroke Scale (NIHSS) and assessment of consciousness using the Glasgow Coma Scale (GCS). Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were taken at admission, after 24 hours, and were monitored upon discharge.

Results:

There was a significant difference in AST values at admission relative to disease outcome (p = 0.002), as well as for ALT (p = 0.008). In patients treated with therapeutic hypothermia, mean AST values decreased after 24 hours (32.50 to 31.00 IU/mL) as well as ALT values (27.50 to 26.50 IU/mL), without statistical significance. In the group of subjects who survived with sequela, AST values correlated with GCS (rho = -0.489; p = 0.002) and NIHSS (rho = 0.492; p = 0.003), ALT values correlated with GCS (rho = -0.356; p = 0.03) but not with NIHSS.

Conclusion:

AST and ALT values at admission correlate with the severity of the clinical picture. Therapeutic hypothermia is hepatoprotective and lowers AST and ALT values.