Neuroprotective effects of magnesium-sulfate on ischemic injury mediated by modulating the release of glutamate and reduced of hyperreperfusion

Antenatal Magnesium Sulfate Benefits Female Preterm Infants but Results in Poor Male Outcomes

Magnesium sulfate (MagSul) is used clinically to prevent eclamptic seizures during pregnancy and as a tocolytic for preterm labor. More recently, it has been implicated as offering neural protection in utero for at-risk infants. However, evidence is mixed. Some studies found that MagSul reduced the incidence of cerebral palsy (CP) but did not improve other measures of neurologic function. Others did not find any improvement in outcomes. Inconsistencies in the literature may reflect the fact that sex effects are largely ignored, despite evidence that MagSul shows sex effects in animal models of neonatal brain injury. The current study used retrospective infant data to assess differences in developmental outcomes as a function of sex and MagSul treatment. We found that on 18-month neurodevelopmental cognitive and language measures, preterm males treated with MagSul (n = 209) had significantly worse scores than their untreated counterparts (n = 135; p < 0.05). Female preterm infants treated with MagSul (n = 220), on the other hand, showed a cognitive benefit relative to untreated females (n = 123; p < 0.05). No significant effects of MagSul were seen among females on language (p > 0.05). These results have tremendous implications for risk-benefit considerations in the ongoing use of MagSul and may explain why benefits have been hard to identify in clinical trials when sex is not considered.

Treatment of refractory obsessive-compulsive disorder with nutraceuticals (TRON): a 20-week, open label pilot study

BACKGROUND

Obsessive-compulsive disorder (OCD) is often challenging to treat and resistant to psychological interventions and prescribed medications. The adjunctive use of nutraceuticals with potential neuromodulatory effects on underpinning pathways such as the glutamatergic and serotonergic systems is one novel approach.

OBJECTIVE

To assess the effectiveness and safety of a purpose-formulated combination of nutraceuticals in treating OCD: N-acetyl cysteine, L-theanine, zinc, magnesium, pyridoxal-5' phosphate, and selenium.

METHODS

A 20-week open label proof-of-concept study was undertaken involving 28 participants with treatment-resistant DSM-5-diagnosed OCD, during 2017 to 2020. The primary outcome measure was the Yale-Brown Obsessive-Compulsive Scale (YBOCS), administered every 4 weeks.

RESULTS

An intention-to-treat analysis revealed an estimated mean reduction across time (baseline to week-20) on the YBOCS total score of -7.13 (95% confidence interval = -9.24, -5.01), with a mean reduction of -1.21 points per post-baseline visit (P ≤ .001). At 20-weeks, 23% of the participants were considered "responders" (YBOCS ≥35% reduction and "very much" or "much improved" on the Clinical Global Impression-Improvement scale). Statistically significant improvements were also revealed on all secondary outcomes (eg, mood, anxiety, and quality of life). Notably, treatment response on OCD outcome scales (eg, YBOCS) was greatest in those with lower baseline symptom levels, while response was limited in those with relatively more severe OCD.

CONCLUSIONS

While this pilot study lacks placebo-control, the significant time effect in this treatment-resistant OCD population is encouraging and suggests potential utility especially for those with lower symptom levels. Our findings need to be confirmed or refuted via a follow-up placebo-controlled study.

Differential Gene Expression in Cord Blood of Infants Diagnosed with Cerebral Palsy: A Pilot Analysis of the Beneficial Effects of Antenatal Magnesium Cohort

The Beneficial Effects of Antenatal Magnesium clinical trial was conducted between 1997 and 2007, and demonstrated a significant reduction in cerebral palsy (CP) in preterm infants who were exposed to peripartum magnesium sulfate (MgSO4). However, the mechanism by which MgSO4 confers neuroprotection remains incompletely understood. Cord blood samples from this study were interrogated during an era when next-generation sequencing was not widely accessible and few gene expression differences or biomarkers were identified between treatment groups. Our goal was to use bulk RNA deep sequencing to identify differentially expressed genes comparing the following four groups: newborns who ultimately developed CP treated with MgSO4 or placebo, and controls (newborns who ultimately did not develop CP) treated with MgSO4 or placebo. Those who died after birth were excluded. We found that MgSO4 upregulated expression of SCN5A only in the control group, with no change in gene expression in cord blood of newborns who ultimately developed CP. Regardless of MgSO4 exposure, expression of NPBWR1 and FTO was upregulated in cord blood of newborns who ultimately developed CP compared with controls. These data support that MgSO4 may not exert its neuroprotective effect through changes in gene expression. Moreover, NPBWR1 and FTO may be useful as biomarkers and may suggest new mechanistic pathways to pursue in understanding the pathogenesis of CP. The small number of cases ultimately available for this secondary analysis, with male predominance and mild CP phenotype, is a limitation of the study. In addition, differentially expressed genes were not validated by qRT-PCR.

Local Application of Magnesium Sulfate Solution Suppressed Cortical Spreading Ischemia and Reduced Brain Damage in a Rat Subarachnoid Hemorrhage-Mimicking Model

OBJECTIVE

Cortical spreading depolarization (CSD), cortical spreading ischemia (CSI), and early brain injury are involved in the occurrence of delayed brain ischemia after subarachnoid hemorrhage (SAH). We tested whether local application of magnesium (Mg) sulfate solution suppressed CSD and CSI, and decreased brain damage in a rat SAH-mimicking model.

METHODS

Nitric oxide synthase inhibitor L-NG-nitroarginine methyl ester (L-NAME) and high concentration potassium solution were topically applied to simulate the environment after SAH. We irrigated the parietal cortex with artificial cerebrospinal fluid (ACSF), containing L-NAME (1 mM), K⁺ (35 mM), and Mg²⁺ (5 mM). Forty-five rats were divided into 3 groups: sham surgery (sham group), L-NAME + [K⁺]_ACSF (control group), and L-NAME + [K⁺]_ACSF + [Mg²⁺] (Mg group). CSD was induced by topical application with 1 M KCl solution in 3 groups. The effects of Mg administration on CSD and cerebral blood flow were evaluated. Histological brain tissue damage, body weight, and neurological score were assessed at 2 days after insult.

RESULTS

Mg solution significantly shortened the total depolarization time, and reduced CSI, histological brain damage, and brain edema compared with those of the control group (P < 0.05). Body weight loss was significantly suppressed in the Mg group (P < 0.05), but neurological score did not improve.

CONCLUSIONS

Local application of Mg suppressed CSI and reduced brain damage in a rat SAH-mimicking model. Mg irrigation therapy may be beneficial to suppress brain damage due to CSI after SAH.

Fetal Neuroprotective Strategies: Therapeutic Agents and Their Underlying Synaptic Pathways

Synaptic signaling is integral for proper brain function. During fetal development, exposure to inflammation or mild hypoxic-ischemic insult may lead to synaptic changes and neurological damage that impairs future brain function. Preterm neonates are most susceptible to these deleterious outcomes. Evaluating clinically used and novel fetal neuroprotective measures is essential for expanding treatment options to mitigate the short and long-term consequences of fetal brain injury. Magnesium sulfate is a clinical fetal neuroprotective agent utilized in cases of imminent preterm birth. By blocking N-methyl-D-aspartate receptors, magnesium sulfate reduces glutamatergic signaling, which alters calcium influx, leading to a decrease in excitotoxicity. Emerging evidence suggests that melatonin and N-acetyl-L-cysteine (NAC) may also serve as novel putative fetal neuroprotective candidates. Melatonin has important anti-inflammatory and antioxidant properties and is a known mediator of synaptic plasticity and neuronal generation. While NAC acts as an antioxidant and a precursor to glutathione, it also modulates the glutamate system. Glutamate excitotoxicity and dysregulation can induce perinatal preterm brain injury through damage to maturing oligodendrocytes and neurons. The improved drug efficacy and delivery of the dendrimer-bound NAC conjugate provides an opportunity for enhanced pharmacological intervention. Here, we review recent literature on the synaptic pathways underlying these therapeutic strategies, discuss the current gaps in knowledge, and propose future directions for the field of fetal neuroprotective agents.

Effect of Neuroprotective Magnesium Sulfate Treatment on Brain Transcription Response to Hypoxia Ischemia in Neonate Mice

MgSO₄ is widely used in the prevention of preterm neurological disabilities but its modes of action remain poorly established. We used a co-hybridization approach using the transcriptome in 5-day old mice treated with a single dose of MgSO₄ (600 mg/kg), and/or exposed to hypoxia-ischemia (HI). The transcription of hundreds of genes was altered in all the groups. MgSO₄ mainly produced repressions culminating 6 h after injection. Bio-statistical analysis revealed the repression of synaptogenesis and axonal development. The putative targets of MgSO₄ were Mnk1 and Frm1. A behavioral study of adults did not detect lasting effects of neonatal MgSO₄ and precluded NMDA-receptor-mediated side effects. The effects of MgSO₄ plus HI exceeded the sum of the effects of separate treatments. MgSO₄ prior to HI reduced inflammation and the innate immune response probably as a result of cytokine inhibition (Ccl2, Ifng, interleukins). Conversely, MgSO₄ had little effect on HI-induced transcription by RNA-polymerase II. De novo MgSO₄-HI affected mitochondrial function through the repression of genes of oxidative phosphorylation and many NAD-dehydrogenases. It also likely reduced protein translation by the repression of many ribosomal proteins, essentially located in synapses. All these effects appeared under the putative regulatory MgSO₄ induction of the mTORC2 Rictor coding gene. Lasting effects through Sirt1 and Frm1 could account for this epigenetic footprint.

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.

Quantification of Trace Elements in Different Dokha and Shisha Tobacco Products using EDXRF

The present study aims to quantify trace metals in different dokha (medwakh) and shisha tobacco products available in local markets. Recent research has shown that these products have higher amounts of nicotine and tar compared to various other tobacco products. No specific data are available on the concentration of trace elements in dokha (medwakh) and shisha tobacco products in the Middle East and North Africa (MENA) region. Harmful health effects due to the toxicity of these elements in tobacco and its smoke have not been adequately emphasized. Concentrations of trace elements were extensively studied using HORIBA XGT-7200 EDXRF fluorescence absorption spectroscopy. The mean concentrations of aluminum, calcium, chromium, copper, iron, magnesium, manganese, nickel, potassium, strontium and zinc in 13 dokha products in μg/g were 406.92 ± 41.72, 14703.27 ± 271.73, 11.73 ± 2.12, 25.58 ± 2.63, 753.85 ± 14.87, 5306.54 ± 134.94, 82.31 ± 4.55, 25.58 ± 2.50, 2212.12 ± 39.04, 816.92 ± 15.26 and 35.96 ± 2.63, respectively; and those in the three shisha products in μg/g were 244.83 ± 25.11, 8235.77 ± 144.51, 3.40 ± 0.38, 22.77 ± 4.50, 569.13 ± 10.22, 2096.20 ± 130.69, 72.13 ± 7.13, 27.67 ± 5.31, 4467.50 ± 168.06, 320.20 ± 6.03 and 36.40 ± 3.57, respectively. In our study, the quantified trace metal concentrations in dokha and shisha tobacco using the EDXRF method were ten times higher than the LODs. The percentage of RSD was <10%, validating the precision of the method. Tobacco smoking is a major source of consumption of toxic elements, not only in the smoker but also in non-smokers through passive smoking. In dokha (medwakh) and shisha tobacco products, compared with cigarettes, Ni levels were significantly higher, Cr, Cu and Zn levels were higher, and Fe levels were similar, while Al and Mn levels were lower. The dokha and shisha tobacco products have no filters; many toxic metals can quickly enter the lungs and cause different pulmonary diseases and oral infections. Tobacco smoking causes lung and oral cancers, chronic obstructive pulmonary disease and cardiovascular diseases.

Effect of magnesium and lignocaine on post-craniotomy pain: A comparative, randomized, double blind, placebo-controlled study

Background:

Lignocaine and Magnesium have an analgesic action and reduce perioperative opioid requirements. We carried out this study to evaluate the effect of magnesium and lignocaine on postoperative pain as assessed using the visual analog scale (VAS) and fentanyl consumption. We also measured S-100 B levels and noted the side effect of drugs if any.

Materials and Methods:

In this prospective preliminary study, 45 patients undergoing supratentorial craniotomy for tumor surgery were randomized to receive either lignocaine (group I-1.5 mg/kg bolus followed by 2 mg/kg/h infusion), saline (Group II) or magnesium (group III: bolus of 50 mg/kg followed by 25 mg/kg/hr) intraoperatively. The amount of fentanyl required, VAS over first 24 hours and any side effects were noted. S100 B levels were also measured to assess brain protective effect of these drugs, if any. Appropriate statistical tests were applied for analysis of data and a P value < 0.05 was considered statistically significant.

Results:

None of the patient experienced any adverse hemodynamic effect intraoperatively secondary to the study drugs. The amount of intraoperative fentanyl consumption was comparable among the three groups. The mean VAS score was significantly less in group I and III [Group I (15.3 ± 6.0), Group II (24.8 ± 6.7), Group III (17.9 ± 7.6); (P < 0.01)]. The fentanyl consumed in first 24 hours was significantly less in those patients who received lignocaine and magnesium [Group I (204.4 ± 136.4), Group II (383 ± 168.2), Group III (194 ± 148.9); (P = 0.01)]. S100 value did not differ in the lignocaine and the saline group during the perioperative period. However, a significant decline was noted in the levels of S100 B in the magnesium group.

Conclusion:

Intraoperative infusion of lignocaine and magnesium results in lower VAS score and decreases the postoperative opioid requirement in patients undergoing craniotomy for excision of supratentorial tumors.

Biochemical Characterization of the Brain Hippocampal Areas after Cerebral Ischemia-Reperfusion Using Raman Spectroscopy

Cerebral ischemic stroke is one of the most common neurodegenerative conditions characterized by cerebral infarction, death of the brain tissue, and loss of brain function. Cerebral ischemia-reperfusion injury is the tissue damage caused when blood supply begins to the tissue after a period of ischemia or poor oxygen supply. In this study, we preliminarily investigated the biochemical changes in the brain hippocampal area, CA1, resulting from ischemia reperfusion and neuronal nitric oxide synthase (nNOS) inhibitor treatment in rats using Raman spectroscopy. A drastic spectral change was observed in the ischemia-reperfusion brain tissue; a strong dependency between the intensity of certain Raman bands was observed at the amide positions of 1276 and 1658 cm^-1 and at the lipid positions of 1300 and 1438 cm^-1. The spectrum of nNOS inhibitor-treated brain tissue was similar to that of the normal brain tissue, indicating that the nNOS inhibitor could protect the brain against excessive production of NO and biochemical processes dependent on it. Principal component analysis (PCA) precisely identified three classes of tissues: normal; ischemic; and nNOS inhibitor-treated. Therefore, we suggest that quantitative analysis of the changes in the brain tissue by using Raman spectroscopy with multivariate statistical technique could be effective for evaluating neuronal injury and drug effects.

Fetal Neuroprotection by Magnesium Sulfate: From Translational Research to Clinical Application

Despite improvements in perinatal care, preterm birth still occurs regularly and the associated brain injury and adverse neurological outcomes remain a persistent challenge. Antenatal magnesium sulfate administration is an intervention with demonstrated neuroprotective effects for preterm births before 32 weeks of gestation (WG). Owing to its biological properties, including its action as an N-methyl-d-aspartate receptor blocker and its anti-inflammatory effects, magnesium is a good candidate for neuroprotection. In hypoxia models, including hypoxia-ischemia, inflammation, and excitotoxicity in various species (mice, rats, pigs), magnesium sulfate preconditioning decreased the induced lesions’ sizes and inflammatory cytokine levels, prevented cell death, and improved long-term behavior. In humans, some observational studies have demonstrated reduced risks of cerebral palsy after antenatal magnesium sulfate therapy. Meta-analyses of five randomized controlled trials using magnesium sulfate as a neuroprotectant showed amelioration of cerebral palsy at 2 years. A meta-analysis of individual participant data from these trials showed an equally strong decrease in cerebral palsy and the combined risk of fetal/infant death and cerebral palsy at 2 years. The benefit remained similar regardless of gestational age, cause of prematurity, and total dose received. These data support the use of a minimal dose (e.g., 4 g loading dose ± 1 g/h maintenance dose over 12 h) to avoid potential deleterious effects. Antenatal magnesium sulfate is now recommended by the World Health Organization and many pediatric and obstetrical societies, and it is requisite to maximize its administration among women at risk of preterm delivery before 32 WG.

Magnesium sulfate and fetal neuroprotection: overview of clinical evidence

Antenatal administration of magnesium sulfate is an important part of the neuroprotective strategy for preterm infants. Strong evidence from five randomized controlled trials and five meta-analyses has demonstrated that magnesium sulfate, when administered before preterm delivery, significantly reduces the risk of cerebral palsy at two years. Through secondary analyses of randomized controlled trials and other original clinical studies, this state-of-the-art review highlights the absence of serious adverse effects in both pregnant women and neonates, as well as the impact of maternal body mass index and preeclamptic status on the maternal and neonatal magnesium levels, which could influence the magnitude of the neuroprotective effect. Although antenatal magnesium sulfate is a cost-effective strategy, some practice surveys have demonstrated that the use of magnesium sulfate is not sufficient and that its use is heterogeneous, differing among different maternity wards. Since 2010, an increasing number of obstetrical societies have recommended its use to improve the neurological outcomes of preterm infants, especially the International Federation of Gynecology and Obstetrics and World Health Organization in 2015, and France in 2017. Considering the neuroprotective impact of magnesium sulfate when administered before delivery, postnatal administration should be considered, and its effects should be assessed using randomized controlled trials.

Effect of magnesium sulfate and thyroxine on inflammatory markers in a rat model of hypothyroidism

Inflammation is a major risk factor for cardiovascular complications. Magnesium sulfate (MgSO4) has anti-inflammatory actions. Therefore we investigated the effects of levothyroxine and MgSO4 on inflammatory markers as C-reactive protein (CRP), interleukin-6, tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in hypothyroid rats. Sixty male rats were divided into 6 groups; normal, normal + MgSO4, hypothyroidism, hypothyroidism + levothyroxine, hypothyroidism + MgSO4, and hypothyroidism + levothyroxine + MgSO4. Thyroxine, triiodothyronine, and thyroid-stimulating hormone (TSH), CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 were measured in all rats. Hypothyroidism significantly increased TSH, CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 and decreased triiodothronine and thyroxine. Treatment of hypothyroid rats with levothyroxine or MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1. Combined therapy of hypothyroid rats with levothyroxine and MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 compared with hypothyroid rats either untreated or treated with levothyroxine or MgSO4. This study demonstrates that hypothyroid rats have chronic low grade inflammation, which may account for increased risk of cardiovascular diseases. Combined levothyroxine and MgSO4 is better than levothyroxine or MgSO4 alone in alleviating the chronic low grade inflammatory status and therefore reducing the risk of cardiovascular diseases in hypothyroid animals.

Effect of magnesium on functional outcome and paraclinical parameters of patients undergoing supratentorial craniotomy for brain tumors: a randomized controlled trial

BACKGROUND

Several studies have demonstrated that magnesium (Mg) plays an important role in the prevention and treatment of central nervous system (CNS) insults. In this study, we tested the effect of intravenous magnesium sulfate (MgSO4) on the outcome of patients with brain tumors who underwent craniotomy. The outcome was defined clinically as the Barthel index score and paraclinically as blood levels of NSE (neuron-specific enloase) and S100Β protein.

METHODS

Sixty patients were randomly divided into two groups of 30 patients: the treatment and control groups. In the treatment group, 5 g of MgSO4 in normal saline was infused in 6 h 2 days before surgery, and the same dosage was repeated the day before and during surgery. The control group received placebo. Serum S100Β and NSE concentrations were measured at baseline before administration of magnesium, before surgery, and on the 2nd postoperative day. The Barthel index score was evaluated and registered before surgery, 3, and 6 months after the operation.

RESULTS

The study results showed a significant change in S100Β protein levels before and after surgery (p < 0.05), but we could not find similar results for NSE protein and the Barthel index score. There was a correlation between NSE protein and the Barthel index.

CONCLUSIONS

The results of this study revealed that administration of intravenous MgSO4 before and during surgery is safe and effective in reducing S100B protein levels in patients undergoing supratentorial craniotomy for brain tumors. Further studies to elucidate the pathophysiology of brain injuries and role of magnesium are warranted.

Evaluation of the anti-inflammatory effects of peri-operative infusion of magnesium sulfate on the microsurgical procedures for intracranial tumors

Background:

The anti-inflammatory properties of magnesium sulfate have never been discussed in brain tumor surgeries.

Objectives:

This study is aimed to find anti-inflammatory aspects of high dose magnesium sulfate infusion during perioperative period of neurosurgical patients through checking the serial C-reactive protein (CRP) blood levels as a biomarker of inflammation.

Patients and Methods:

Sixty patients who were candidate for elective craniotomy were enrolled randomly into two equal groups to receive either magnesium sulfate or normal saline during their perioperative period. Infusion of magnesium was performed three times during the study and a summation of 15 grams was administered: 1- two days before surgery, 2- one day before surgery, 3- from the beginning of surgery (five grams was infused within six hours in each session). Serum level of CRP was checked just before commencement of magnesium infusion and on the first and second day after surgery as primary outcome. Hemodynamic parameters, total propofol requirement and total blood loss were recorded as well.

Results:

No significant difference was found between groups in terms of serum CRP levels. The mean arterial blood pressure, heart rate, blood loss and total anesthetic requirement were significantly lower in magnesium group in comparison to the control group.

Conclusions:

We did not find conclusive evidence for anti-inflammatory effects of magnesium in craniotomy for microsurgery of intracranial tumors using CRP level changes. However, high dose magnesium might be suggested as a safe anesthetic adjuvant in neurosurgery.

School-age outcomes following a randomized controlled trial of magnesium sulfate for neuroprotection of preterm infants

In a French randomized trial, children at school-age demonstrated no evidence of harm from fetal exposure to MgSO4 before very preterm birth. Motor dysfunction/death, qualitative behavioral disorders, cognitive difficulties, school grade repetition, and education services were decreased in the children exposed to MgSO4, although the differences were not significant.

MMP-9 inhibitor SB-3CT attenuates behavioral impairments and hippocampal loss after traumatic brain injury in rat

The aim of this study was to evaluate the potential efficacy of SB-3CT, a matrix metallopeptidase 9 inhibitor, on behavioral and histological outcomes after traumatic brain injury (TBI) in rats. Adult male Sprague-Dawley rats were randomly divided into three groups (n=15/group): TBI with SB-3CT treatment, TBI with saline, and sham injury. The TBI model was induced by a fluid percussion TBI device. SB-3CT (50 mg/kg in 10% dimethyl sulfoxide) was administered intraperitoneally at 30 min, 6 h, and 12 h after the TBI. Motor function (beam-balance/beam-walk tests) and spatial learning/memory (Morris water maze) were assessed on post-operative Days 1-5 and 11-15, respectively. Fluoro-Jade staining, immunofluorescence, and cresyl violet-staining were carried out for histopathological evaluation at 24 h, 72 h, and 15 days after TBI, respectively. It was shown that TBI can result in significant behavioral deficit induced by acute neurodegeneration, increased expression of cleaved caspase-3, and long-term neuronal loss. SB-3CT intervention via the current regime provides robust behavioral protection and hippocampal neurons preservation from the deleterious effects of TBI. Hence, the efficacy of SB-3CT on TBI prognosis could be ascertained. It is believed that the current study adds to the growing literature in identifying SB-3CT as a potential therapy for human brain injury.

Levosimendan limits reperfusion injury in a rat middle cerebral artery occlusion (MCAO) model

Background

Neuroprotective strategies in ischemic stroke are an important challenge in clinical and experimental research as an adjunct to reperfusion therapy that may reduce neurologic injury and improve outcome. The neuroprotective properties of levosimendan in traumatic brain injury in vitro, transient global brain ischemia and focal spinal cord ischemia suggest the potential for similar effects in transient brain ischemia.

Methods

Transient brain ischemia was induced for 60 min by intraluminal occlusion of the middle cerebral artery in 40 male Wistar rats under general anesthesia with s-ketamine and xylazine and with continuous monitoring of their blood pressure and cerebral perfusion. Five minutes before inducing reperfusion, a levosimendan bolus (24 μg kg ^-1) was administered over a 20 minute period. Infarct size, brain swelling, neurological function and the expression of inflammatory markers were quantified 24 hours after reperfusion.

Results

Although levosimendan limited the infarct size and brain swelling by 40% and 53%, respectively, no effect on neurological outcome or mortality could be demonstrated. Upregulation of tumor necrosis factor α and intercellular adhesion molecule 1 was significantly impeded. Cerebral blood flow during reperfusion was significantly reduced as a consequence of sustained autoregulation.

Conclusions

Levosimendan demonstrated significant neuroprotective properties in a rat model of transient brain ischemia by reducing reperfusion injury.

Neuroprotective therapies after perinatal hypoxic-ischemic brain injury

Hypoxic-ischemic (HI) brain injury is one of the main causes of disabilities in term-born infants. It is the result of a deprivation of oxygen and glucose in the neural tissue. As one of the most important causes of brain damage in the newborn period, the neonatal HI event is a devastating condition that can lead to long-term neurological deficits or even death. The pattern of this injury occurs in two phases, the first one is a primary energy failure related to the HI event and the second phase is an energy failure that takes place some hours later. Injuries that occur in response to these events are often manifested as severe cognitive and motor disturbances over time. Due to difficulties regarding the early diagnosis and treatment of HI injury, there is an increasing need to find effective therapies as new opportunities for the reduction of brain damage and its long term effects. Some of these therapies are focused on prevention of the production of reactive oxygen species, anti-inflammatory effects, anti-apoptotic interventions and in a later stage, the stimulation of neurotrophic properties in the neonatal brain which could be targeted to promote neuronal and oligodendrocyte regeneration.

[Use of magnesium sulfate in obstetrics]

Magnesium sulfate (MgSO(4)) is the best treatment of eclampsia, reduces the risk of recurrence better than other anticonvulsants and is recommended as first line in cases of eclampsia. In cases of severe pre-eclampsia and especially when prodromes are present, MgSO(4) reduces better than conventional anticonvulsants the risk of eclampsia. More recently, MgSO(4) was used in cases of preterm delivery to reduce the risk of cerebral palsy in premature infants. Three large randomized trials have obtained convergent results which all tended to show a neuroprotective effect of MgSO(4). These trials were included in three meta-analyzes that showed a 30% reduction in the incidence of cerebral palsy before 32 weeks gestation suggesting that this drug should be used in cases of preterm birth. A protocol using low doses associated with a well-conducted maternal surveillance reduces of maternal hypermagnesemia and the risk of maternal toxicity.

The effects of levosimendan on brain metabolism during initial recovery from global transient ischaemia/hypoxia

BACKGROUND

Neuroprotective strategies after cardiopulmonary resuscitation are currently the focus of experimental and clinical research. Levosimendan has been proposed as a promising drug candidate because of its cardioprotective properties, improved haemodynamic effects in vivo and reduced traumatic brain injury in vitro. The effects of levosimendan on brain metabolism during and after ischaemia/hypoxia are unknown.

METHODS

Transient cerebral ischaemia/hypoxia was induced in 30 male Wistar rats by bilateral common carotid artery clamping for 15 min and concomitant ventilation with 6% O2 during general anaesthesia with urethane. After 10 min of global ischaemia/hypoxia, the rats were treated with an i.v. bolus of 24 μg kg-1 levosimendan followed by a continuous infusion of 0.2 μg kg-1 min-1. The changes in the energy-related metabolites lactate, the lactate/pyruvate ratio, glucose and glutamate were monitored by microdialysis. In addition, the effects on global haemodynamics, cerebral perfusion and autoregulation, oedema and expression of proinflammatory genes in the neocortex were assessed.

RESULTS

Levosimendan reduced blood pressure during initial reperfusion (72 ± 14 vs. 109 ± 2 mmHg, p = 0.03) and delayed flow maximum by 5 minutes (p = 0.002). Whereas no effects on time course of lactate, glucose, pyruvate and glutamate concentrations in the dialysate could be observed, the lactate/pyruvate ratio during initial reperfusion (144 ± 31 vs. 77 ± 8, p = 0.017) and the glutamate release during 90 minutes of reperfusion (75 ± 19 vs. 24 ± 28 μmol·L-1) were higher in the levosimendan group. The increased expression of IL-6, IL-1ß TNFα and ICAM-1, extend of cerebral edema and cerebral autoregulation was not influenced by levosimendan.

CONCLUSION

Although levosimendan has neuroprotective actions in vitro and on the spinal cord in vivo and has been shown to cross the blood-brain barrier, the present results showed that levosimendan did not reduce the initial neuronal injury after transient ischaemia/hypoxia.

Concussions: What a neurosurgeon should know about current scientific evidence and management strategies

BACKGROUND

There has been a tremendous amount of interest focused on the topic of concussions over the past few decades. Neurosurgeons are frequently consulted to manage patients with mild traumatic brain injuries (mTBI) that have radiographic evidence of cerebral injury. These injuries share significant overlap with concussions, injuries that typically do not reveal radiographic evidence of structural injury, in the realms of epidemiology, pathophysiology, outcomes, and management. Further, neurosurgeons often manage patients with extracranial injuries that have concomitant concussions. In these cases, neurosurgeons are often the only "concussion experts" that patients encounter.

RESULTS

The literature has been reviewed and data have been synthesized on the topic including sections on historical background, epidemiology, pathophysiology, diagnostic advances, clinical sequelae, and treatment suggestions, with neurosurgeons as the intended target audience.

CONCLUSIONS

Neurosurgeons should have a fundamental knowledge of the scientific evidence that has developed regarding concussions and be prepared to guide patients with treatment plans.