Neurological Deficit Scale Scores Research Articles

No Benefit of 3% Hypertonic Saline Following Experimental Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a stroke subtype with a high mortality rate (~ 40%). After ICH, the mass effect of the hematoma and edema contribute to raised intracranial pressure (ICP) and poor outcome. Endogenous compensatory mechanisms that blunt ICP elevations include redirection of venous blood and cerebrospinal fluid, along with brain tissue compliance (e.g., decreased cell volume, increased cell density); however, these limited reserves can be exhausted after severe stroke, resulting in decompensated ICP that requires careful clinical management. Management strategies can include administration of hypertonic saline (HTS), an osmotic agent that putatively attenuates edema, and thereby ICP elevations. Evidence regarding the efficacy of HTS treatment following ICH remains limited. In this study, adult male rats were given a collagenase-induced striatal ICH and a bolus of either 3% HTS or 0.9% saline vehicle at 2- and 14-hours post-stroke onset. Neurological deficits, edema, ipsilateral cell volume and density (in areas S1 and CA1), and contralateral CA1 ultrastructural morphology were assessed 24 h post-ICH. Animals had large bleeds (median 108.2 µL), extensive edema (median 83.9% brain water content in ipsilateral striatum), and evident behavioural deficits (median 5.4 neurological deficit scale score). However, HTS did not affect edema (p ≥ 0.4797), behaviour (p = 0.6479), cell volume (p ≥ 0.1079), or cell density (p ≥ 0.0983). Qualitative ultrastructural assessment of contralateral area CA1 suggested that HTS administration was associated with paradoxical cellular swelling in ICH animals. Overall, there was no benefit with administering 3% HTS after ICH.

Colchicine pre-treatment and post-treatment does not worsen bleeding or functional outcome after collagenase-induced intracerebral hemorrhage.

Patients with intracerebral hemorrhage (ICH) are at increased risk for major ischemic cardiovascular and cerebrovascular events. However, the use of preventative antithrombotic therapy can increase the risk of ICH recurrence and worsen ICH-related outcomes. Colchicine, an anti-inflammatory agent, has the potential to mitigate inflammation-related atherothrombosis and reduce the risk of ischemic vascular events. Here we investigated the safety and efficacy of colchicine when used both before and acutely after ICH. We predicted that daily colchicine administration would not impact our safety measures but would reduce brain injury and improve functional outcomes associated with inflammation reduction. To test this, 0.05 mg/kg colchicine was given orally once daily to rats either before or after they were given a collagenase-induced striatal ICH. We assessed neurological impairments, intra-parenchymal bleeding, Perls positive cells, and brain injury to gauge the therapeutic impact of colchicine on brain injury. Colchicine did not significantly affect bleeding (average = 40.7 μL) at 48 hrs, lesion volume (average = 24.5 mm3) at 14 days, or functional outcome (median neurological deficit scale score at 2 days post-ICH = 4, i.e., modest deficits) from 1-14 days after ICH. Colchicine reduced the volume of Perls positive cells in the perihematomal zone, indicating a reduction in inflammation. Safety measures (body weight, food consumption, water consumption, hydration, body temperature, activity, and pain) were not affected by colchicine. Although colchicine did not confer neuroprotection or functional benefit, it was able to reduce perihematomal inflammation after ICH without increasing bleeding. Thus, our findings suggest that colchicine treatment is safe, unlikely to worsen bleeding, and is unlikely but may reduce secondary injury after an ICH if initiated early post ICH to reduce the risk of ischemic vascular events. These results are informative for the ongoing CoVasc-ICH phase II randomized trial (NCT05159219).

Cortical Anoxic Spreading Depolarization During Cardiac Arrest is Associated with Remote Effects on Peripheral Blood Pressure and Postresuscitation Neurological Outcome

BackgroundSpreading depolarizations (SDs) are self-propagating waves of neuronal and glial depolarizations often seen in neurological conditions in both humans and animal models. Because SD is thought to worsen neurological injury, the role of SD in a variety of cerebral insults has garnered significant investigation. Anoxic SD is a type of SD that occurs because of anoxia or asphyxia. Although asphyxia leading to a severe drop in blood pressure may affect cerebral hemodynamics and is widely known to cause anoxic SD, the effect of anoxic SD on peripheral blood pressure in the extremities has not been investigated. This relationship is especially important to understand for conditions such as circulatory shock and cardiac arrest that directly affect both peripheral and cerebral perfusion in addition to producing anoxic SD in the brain.MethodsIn this study, we used a rat model of asphyxial cardiac arrest to investigate the role of anoxic SD on cerebral hemodynamics and metabolism, peripheral blood pressure, and the relationship between these variables in 8- to 12-week-old male rats. We incorporated a multimodal monitoring platform measuring cortical direct current simultaneously with optical imaging.ResultsWe found that during anoxic SD, there is decoupling of peripheral blood pressure from cerebral blood flow and metabolism. We also observed that anoxic SD may modify cerebrovascular resistance. Furthermore, shorter time difference between anoxic SDs measured at different locations in the same rat was associated with better neurological outcome on the basis of the recovery of electrocorticography activity (bursting) immediately post resuscitation and the neurological deficit scale score 24 h post resuscitation.ConclusionsTo our knowledge, this is the first study to quantify the relationship between peripheral blood pressure, cerebral hemodynamics and metabolism, and neurological outcome in anoxic SD. These results indicate that the characteristics of SD may not be limited to cerebral hemodynamics and metabolism but rather may also encompass changes in peripheral blood flow, possibly through a brain–heart connection, providing new insights into the role of anoxic SD in global ischemia and recovery.

Metformin prevents brain injury after cardiopulmonary resuscitation by inhibiting the endoplasmic reticulum stress response and activating AMPK-mediated autophagy.

The neurological damage caused by cardiac arrest (CA) can seriously affect quality of life. We investigated the effect of metformin pretreatment on brain injury and survival in a rat CA/cardiopulmonary resuscitation (CPR) model. After 14 days of pretreatment with metformin, rats underwent 9 minutes of asphyxia CA/CPR. Survival was evaluated 7 days after restoration of spontaneous circulation; neurological deficit scale (NDS) score was evaluated at days 1, 3, and 7. Proteins related to the endoplasmic reticulum (ER) stress response and autophagy were measured using immunoblotting. Seven-day survival was significantly improved and NDS score was significantly improved in rats pretreated with metformin. Metformin enhanced AMPK-induced autophagy activation. AMPK and autophagy inhibitors removed the metformin neuroprotective effect. Although metformin inhibited the ER stress response, its inhibitory effect was weaker than 4-PBA. In a CA/CPR rat model, 14-day pretreatment with metformin has a neuroprotective effect. This effect is closely related to the activation of AMPK-induced autophagy and inhibition of the ER stress response. Long-term use of metformin can reduce brain damage following CA/CPR.

Intravenous Transplants of Human Adipose-Derived Stem Cell Protect the Rat Brain From Ischemia-Induced Damage

Background: Survival following cardiac arrest (CA) and subsequent cardiopulmonary resuscitation (CPR), to a great extent, depends on brain damage. Adipose-derived stem cells (ADSCs), as a source of paracrine growth factors and the capacity of neural differentiation may reduce this brain damage. Objective: The purpose of this study is to evaluate the protection of ADSCs to brain damage following CPR. Methods: Rats were divided into 3 groups, sham, CA, and ADSCs group. Rats in sham group went through sham surgery. Rats in CA group went through CA, CPR, and injection PBS (phosphate buffer saline). Rats in ADSCs group went through CA, CPR, and intravenous injection of ADSCs. Rats in sham group were sacrificed immediately after operation. At 24, 72, and 168 hours after return of spontaneous circulation operation, rats in CA and ADSCs group were randomly selected and sacrificed. Brain damage was evaluated by using Neurological Deficit Scale (NDS) score, hippocampal pathology, serum level of S100β, and apoptosis ratio of hippocampal neurons. Protein of brain derived neurotrophic factor (BDNF) and IL-6 (interleukin-6) in the hippocampus were detected. Results: Compared with sham group, CA and ADSCs group showed a decrease in NDS score, an increased apoptosis ratio of hippocampal nerve cells, increased serum level of S100-β, and a significant increase in neuroprotective IL-6 and BDNF. In comparison to CA group, ADSCs group had a mild degree of brain damage and higher expression of IL-6 and BDNF. Conclusions: In the acute stage of cerebral injury following CA, ADSCs might improve the prognosis of brain damage by stimulating the expression of neuroprotective IL-6 and BDNF.

Abstract 21321: Heart Rate During Pulseless Electrical Activity as a Marker for Successful Resuscitation and Neurological Outcome in a Rodent Model of Cardiac Arrest

Introduction: During cardiac arrest (CA), a major goal of responders is to ascertain the likelihood of successful cardiopulmonary resuscitation (CPR) and optimize efforts accordingly to achieve return of spontaneous circulation (ROSC). Pulseless electrical activity (PEA), a common form of CA in inpatient settings, often allows monitoring of heart rate (HR) immediately preceding cardiopulmonary resuscitation (CPR). We were interested in assessing the role of HR during PEA in outcome of CPR. To evaluate this in a controlled setting, we used a rodent model of asphyxial CA with electrocardiogram (ECG) recordings and neurological testing. We hypothesized that more severe bradycardia may be associated with failure to achieve ROSC and worse neurological outcome if ROSC is achieved. Methods: Adult male Wistar rats (n=25) were anesthetized, intubated, and placed under mechanical ventilation. Needle electrodes were inserted into the rats to obtain continuous ECG data. Rats then underwent 8 minutes of asphyxial CA followed by CPR accompanied with intravenous epinephrine and bicarbonate injections. Neurological deficit scale (NDS) testing was conducted at 24hrs post-ROSC. Results: Of 25 rats that underwent CA, 4 failed to achieve ROSC. HR was measured after 7.5 minutes of asphyxia (i.e. 30 sec. prior to CPR), when the systolic blood pressure was <10-20mmHg, which is presumed to be a “pulseless” equivalent in humans. Rats failing to achieve ROSC had a significantly lower HR in comparison to rats achieving ROSC (26.6±8.4 vs. 46.2±16.9; p< 0.05). Interestingly, among survivors, HR immediately pre-CPR was inversely correlated with NDS scores (r=-0.655, p< 0.05). No association was found between groups in pre-CA arterial blood gas measurements (e.g. pH, CO2, electrolytes). Conclusions: In a rodent asphyxial model of CA mimicking a PEA state, rats failing to achieve ROSC had lower HR immediately prior to CPR. However, in rats achieving ROSC, slower pre-CPR HR is associated with better neurological outcome. These findings appear to be independent of respiratory acidosis. We propose a model and future experimentation that may help define underlying mechanisms. Validation is needed in human studies to assess potential translational implications in a clinical setting.

Abstract 21158: Ultra-Short Caloric Restriction Prior to Cardiac Arrest and Resuscitation Leads to Improved Survival and Neurological Outcome in a Rodent Model

Introduction: Caloric restriction (CR) has been widely shown to have both cardioprotective and neuroprotective properties. However, nearly all studies have investigated chronic CR with mechanisms linked to the upregulation of SIRT-1 and BDNF. Minimal to no focus has been placed on the potential benefits of transient CR in models of brain injury, including stroke. Furthermore, the effects of transient CR in cardiac arrest-induced global cerebral ischemia have not been evaluated. We investigated the effects of overnight (~14-hour) CR on survival and neurological outcome in a rodent model of cardiac arrest (CA). Methods: Adult male Wistar rats (n=28) were divided into 75% CR (n=14) and non-CR (n=14) groups 14hrs prior to rats undergoing intubation, mechanical ventilation, cannulation of femoral vessels, and 8 minutes of asphyxial CA followed by cardiopulmonary resuscitation (CPR). Blood glucose was measured before CA. We conducted neurological deficit scale (NDS) behavioral testing at 4hrs, 24hrs, 48hrs, and 72hrs post-CA. The NDS score ranges from 0 (dead) to 80 (normal). Rats were euthanized after 72hrs and tissue was collected for protein analysis via Western blot. Results: CR, in comparison to no-CR, resulted in significant reduction of mortality (0% vs. 28.6%; Kaplan-Meier log-rank test, p< 0.05). Of those that survived, NDS scores improved significantly in the CR group at 4hrs (32.8±6.1 vs. 24.5±3.3; p<0.05), 24hrs (66.5±8.4 vs. 57.0±7.9; p< 0.05), 48hrs (73.1±4.7 vs. 61.3±12.5; p< 0.05), and 72hrs (76.3±3.3 vs. 73.14±12.2; p< 0.05). CR also significantly lowered pre-CA glucose levels (151.0±22.1 vs. 220.7±17.5; p< 0.05). Western blot analysis yielded no significant difference in BDNF and SIRT-1 expression in brain regions of CR vs. non-CR rats. Conclusions: Our results demonstrate that ultra-short CR (~14 hours) significantly improves survival and neurological outcome after CA/CPR. Interestingly, these improvements appear to be independent of BDNF or SIRT-1 pathways, commonly linked to chronic CR. While ultra-short CR improved glycemic control in rats, further investigation into the underlying molecular mechanisms are imperative to explore potential translational and therapeutic implications, including for patients at high risk of CA.

Therapeutic effects of various methods of MSC transplantation on cerebral resuscitation following cardiac arrest in rats.

In the present study, mesenchymal stem cells (MSCs) were transplanted into the brain of rats following cardiopulmonary resuscitation (CPR) by three different methods: Direct stereotaxic injection into the lateral cerebral ventricle (LV), intra-carotid administration (A), and femoral venous infusion (V). The three different methods were compared by observing the effects of MSCs on neurological function following global cerebral hypoxia-ischemia, in order to determine the optimum method for MSC transplantation. MSCs were transplanted in groups A, V and LV following the restoration of spontaneous circulation. Neurological deficit scale scores were higher in the transplantation groups, as compared with the control group. Neuronal damage, brain water content and serum levels of S100 calcium-binding protein B were reduced in the hippo-campus and temporal cortex of the transplantation groups, as compared with the control rats following resuscitation. MSCs were able to migrate inside the brain tissue following transplantation, and were predominantly distributed in the hippocampus and temporal cortex where the neurons were vulnerable during global cerebral ischemia. These results suggest that transplantation of MSCs may notably improve neurological function following CPR in a rat model. Of the three different methods of MSC transplantation tested in the present study, LV induced the highest concentration of MSCs in brain areas vulnerable to global cerebral ischemia, and therefore, produced the best neurological outcome.

Protective effect of ulinastatin on cerebral tissue in septic rats

Objective To explore the effect of Ulinastatin on blood brain barrier (BBB) and apoptosis of neural cells in septic rats.Methods Fifty-two clean level male Sprague-Dawley rats were randomly (random number table) divided into six groups:Sham groups at 6 h and 24 h,each group with six rats.Sepsis groups (CLP) and Ulinastatin treated groups (UTI) at 6 h and 24 h,each group with ten rats.In CLP and UTI groups,cecal ligation and puncture (CLP) were performed to induce sepsis.Sham group was only opened and closed abdomen.Ulinastatin (50 000 U/kg) was administered via femoral vein 1 h after CLP.The same volume of saline instead of Ulinastatin was administered in Sham and CLP groups.The neurological status was assessed by Neurological Deficit Scale Scores (NDSS) at 6 h and 24 h after CLP.Then the brain was harvested for HE staining and weighing water content.The BBB permeability was assayed by Evans Blue dye extravasations.Apoptosis of neural cells were detected by TUNEL immune fluorescence.Statistical analysis was performed with SPSS version 13.0,ANOVA was used for multiple groups comparison and t-test for paired comparison.Results The Neurological Deficit Scale Scores of UTI group was lower than Sham group (P ＜ 0.05) but higher than that of CLP group (P ＜ 0.05).Swelling,degeneration and edema were observed in cerebral cortex and hippocampal neurons in CLP group through light microscope,and were more serious than those in UTI group.Compared with UTI 24 h group,BBB permeability of CLP 24 h group significantly rose (P ＜ 0.05).The number of apoptosis of neural cells increased more in CLP group than it did in UTI group (P ＜ 0.05).Conclusions Ulinastatin could protect the cerebral tissue in septic rats by alleviating the damage of BBB and reducing the apoptosis of neural cells. Key words: Sepsis; Cerebral injury; Cecal ligation and puncture; Ulinastatin; Evans blue; Blood brain barrier; Immune fluorescence; Apoptosis

Postconditioning improvement effects of ulinastatin on brain injury following cardiopulmonary resuscitation.

The aim of the present study was to determine the effects of ulinastatin (UTI) on brain injury in rats subjected to cardiopulmonary resuscitation (CPR) following asphyxial cardiac arrest (CA) and identify the underlying mechanisms. In total, 100 healthy male Wistar rats were randomly divided into control and treatment groups (n=50). After 4 min of asphyxial CA, all the rats were immediately subjected to CPR. The treatment group animals were administered 15 mg/kg UTI at the onset of resuscitation. The mortality rate in the two groups was recorded at 24 h post-resuscitation. In addition, neurological function was evaluated at 24, 48 and 72 h post-resuscitation using a neurological deficit scale (NDS). Furthermore, the effects of UTI on the Toll-like receptor 4 (TLR4) signaling pathway in brain tissues were determined by assessing TLR4 mRNA expression, nuclear factor (NF)-κB activity and tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels at 1, 3, 6, 12, 24, 48 and 72 h post-resuscitation. After 24 h, the mortality rate significantly decreased in the treatment group when compared with the control animals (10 vs. 30%; P<0.05). Additionally, an overt improvement was observed in the NDS score following UTI treatment when compared with the control (P<0.01). Finally, statistically significant decreases in the levels of TLR4 mRNA expression, NF-κB activity and TNF-α and IL-6 were observed in the treatment group at each time point (P<0.01). Therefore, UTI treatment at the onset of CPR significantly inhibits the TLR4 signaling pathway, thereby alleviating the inflammatory responses following resuscitation and improving neurological function.

Postconditioning improvement effects of ulinastatin on brain injury following cardiopulmonary resuscitation

The aim of the present study was to determine the effects of ulinastatin (UTI) on brain injury in rats subjected to cardiopulmonary resuscitation (CPR) following asphyxial cardiac arrest (CA) and identify the underlying mechanisms. In total, 100 healthy male Wistar rats were randomly divided into control and treatment groups (n=50). After 4 min of asphyxial CA, all the rats were immediately subjected to CPR. The treatment group animals were administered 15 mg/kg UTI at the onset of resuscitation. The mortality rate in the two groups was recorded at 24 h post‑resuscitation. In addition, neurological function was evaluated at 24, 48 and 72 h post‑resuscitation using a neurological deficit scale (NDS). Furthermore, the effects of UTI on the Toll‑like receptor 4 (TLR4) signaling pathway in brain tissues were determined by assessing TLR4 mRNA expression, nuclear factor (NF)‑κB activity and tumor necrosis factor (TNF)‑α and interleukin (IL)‑6 levels at 1, 3, 6, 12, 24, 48 and 72 h post‑resuscitation. After 24 h, the mortality rate significantly decreased in the treatment group when compared with the control animals (10 vs. 30%; P<0.05). Additionally, an overt improvement was observed in the NDS score following UTI treatment when compared with the control (P<0.01). Finally, statistically significant decreases in the levels of TLR4 mRNA expression, NF‑κB activity and TNF‑α and IL‑6 were observed in the treatment group at each time point (P<0.01). Therefore, UTI treatment at the onset of CPR significantly inhibits the TLR4 signaling pathway, thereby alleviating the inflammatory responses following resuscitation and improving neurological function.

Intraventricular orexin-A improves arousal and early EEG entropy in rats after cardiac arrest

The recovery of arousal after cardiac arrest (CA) is associated with evolution from electroencephalographic (EEG) burst-suppression to continuous activity. Orexin-A elicits arousal EEG during anesthetic burst-suppression. We hypothesized that orexin-A would improve arousal and EEG entropy after CA. Eighteen Wistar rats were subjected to 7-minute asphyxial CA and resuscitation. Rats were divided into treatment ( n = 9) and control ( n = 9) groups. Twenty minutes after resuscitation, the treatment group received 0.1 mL of 1 nM orexin-A intraventricularly, while controls received saline. EEG was quantified using Information Quantity (IQ), a measure of entropy validated for detection of burst-suppression and arousal patterns. IQ values range from 0 to 1.0. Arousal was quantified using the neurological deficit scale (NDS). The ischemic neuronal fraction of hippocampus CA1 and cortex was histologically determined. Baseline and post-resuscitation characteristics were similar between the groups. The NDS score (mean ± SD) at 4 h was higher in the orexin-A group compared to controls (57.3 ± 5.8 vs. 40.7 ± 5.9, p < 0.02), but scores were similar at 72 h. Burst frequency was similar in both groups but the orexin-A group demonstrated higher IQ values compared to controls beginning within 10 min. IQ values remained significantly higher in the orexin-A group for the first 120 min ( p = 0.008) and subsequently converged. The ischemic neuronal fraction was similar between groups in cortex ( p = 0.54) and hippocampus CA1 ( p = 0.14). In rats resuscitated from CA, orexin-A transiently increased arousal and EEG entropy without worsening ischemic neuronal injury. The role of orexin-A in recovery of arousal after CA deserves further investigation.

Abstract P108: Orexin-A Improves Arousal and Electroencephalographic Entropy in Rats after Cardiac Arrest

Objective: Cardiac arrest (CA) survivors progress through electroencephalographic (EEG) burst-suppression prior to arousal. Orexin-A, an excitatory neuropeptide, elicits arousal EEG patterns during anesthetic-induced burst-suppression. We hypothesized that intraventricular injection of orexin-A would improve arousal and burst-suppression after CA in rats. Methods: Eighteen Wistar rats were subjected to 7-minute asphyxial CA and resuscitation by external cardiac massage. Rats were divided into treatment (n=9) and control (n=9) groups. Twenty minutes after resuscitation, the treatment group received 0.1 mL of 1nM orexin-A intraven-tricularly, while controls received saline. EEG was continuously monitored and quantified using Information Quantity (IQ), a measure of entropy validated for detection of burst-suppression and arousal patterns. IQ was normalized to baseline prior to CA (range 0 –1.0). Arousal was quantified using the neurological deficit scale (NDS). Stereologic microscopy was used to determine the ischemic neuronal fraction of hippocampus CA1 and cortex. Results: Baseline and post-resuscitation characteristics were similar between the 2 groups. Burst frequency by visual inspection was similar after administration of orexin-A or saline. Rats in the orexin-A group demonstrated higher IQ values (mean±SD) compared to controls beginning 10 minutes after drug injection (0.564±0.098 vs. 0.429±0.116, p=0.024). IQ values remained significantly higher in the orexin-A group for the first 60 minutes after drug injection and subsequently converged. The NDS score (mean±SD) at 4 hours was higher in the orexin-A group compared to controls (57.3±5.8 vs. 40.7±5.9, p&lt;0.02), but scores were similar at 72 hours. The ischemic neuronal fraction was similar between groups in cortex (p=0.54) and hippocampus CA1 (p=0.14). Conclusions: In rats resuscitated from CA, orexin-A hastened improvement of EEG entropy and arousal measures without increasing ischemic neuronal injury. The role of orexin-A in hastening arousal after CA deserves further investigation.