Considerations in the design of clinical trials of neuroprotective therapy in acute stroke

Study on the Effect of Prehospital Emergency Nursing Model Based on Network Information Sharing Platform in Acute Ischemic Stroke

Background

Acute ischemic stroke is one of the most common emergencies in clinical medicine. Prehospital first aid of ischemic stroke has become the focus and focus of the global medical community. The combination of network information technology and prehospital first aid can better serve the treatment of ischemic stroke.

Objective

To explore the effect of prehospital emergency nursing model based on network information sharing platform in acute ischemic stroke.

Methods

78 patients with acute ischemic stroke from February 2020 to October 2021 were studied. Patients were randomly divided into study group (n = 39) and control group (n = 39). The control group was given routine first aid nursing. Prehospital first aid nursing based on network information sharing platform was used in the study group. Alarm response time, on-site first aid response time, hospital handover time, National Institutes of Health Stroke scale (NIHSS) at 12 and 24 hours after admission, Glasgow coma scale (GCS) at 12 and 24 hours after admission, incidence of poor prognosis, and nursing satisfaction score at 24 hours after admission were recorded.

Results

The emergency response time and hospital handover time in the study group were significantly shorter than those in the control group (P < 0.05). The NIHSS score and the incidence of poor prognosis at 12 and 24 hours after admission in the study group were lower than those in the control group (P < 0.05). The GCS scores at 12 hours and 24 hours after admission in the study group were higher than those in the control group (P < 0.05). The NSNS score of the study group was higher than that of the control group.

Conclusion

Prehospital first aid nursing based on network information sharing platform has great application value in patients with acute ischemic stroke. It can shorten the time of first aid, improve patients' consciousness, and reduce the incidence of poor prognosis.

Evaluating the Neuroprotective Effect of Melatonin on Patients with Hemorrhagic Stroke Using Serum S100B Protein as a Prognostic Marker

Background: Intracerebral hemorrhage (ICH) is one of the most debilitating kinds of stroke. Recent evidence shows that the proper initiation of neuroprotective agents might save at risk neurons and improve the outcome. Objectives: The focus of this study is to evaluate the neuroprotective effect of melatonin on patients with hemorrhagic stroke. Methods: Forty adult patients with confirmed nontraumatic ICH, who were admitted to the ICU within 24 hours of the stroke onset were enrolled in this study. Subjects in the melatonin group received 30 mg of melatonin every night for 5 consecutive nights. In order to evaluate the intensity of the neuronal injury, S100B was assessed once on day 1 and, day 5 post ICU admission. Additionally, the length of ICU stay, mortality, and the duration of mechanical ventilation were also recorded. Results: Forty patients completed the study. In both groups the plasma concentrations of S100B decreased after 5 days compared with their baseline values. However, this reduction was more significant in the melatonin compared to the control group (P-value < 0.05). The duration of mechanical ventilation and length of ICU stay was shorter in the melatonin group, and this difference was statistically significant for the length of ICU stay (P-value < 0.05), and marginally significant for the duration of mechanical ventilation (P-value = 0.065). The in-ICU mortality rate of the melatonin group was 15%, almost half of that of the control group (30%). However, this difference was not statistically significant. Conclusions: In conclusion, melatonin can be considered as a harmless and effective nueroprotective agent with some unique features which has made it an appropriate adjunctive medicine for critically ill intubated patients.

Melatonin Supplementation May Improve the Outcome of Patients with Hemorrhagic Stroke in the Intensive Care Unit

Objective:

Although mechanical ventilation is frequently a life-saving therapy, its use can result in unwanted side effects. It has been well documented that the choice of sedating agent may influence the duration of mechanical ventilation. Melatonin is a sedative and analgesic agent without any respiratory depressant effect which makes it an attractive adjuvant for sedation in the intubated patients. The aim of this study is to evaluate the effect of melatonin on the duration of mechanical ventilation in patients with hemorrhagic stroke.

Methods:

Forty adult intubated patients with hemorrhagic stroke, who were admitted to the Intensive Care Unit (ICU) within 24 h of onset, were enrolled in this randomized double-blind study. Subjects in the melatonin group received 30 mg of melatonin every night throughout the nasogastric tube. Length of ICU stay, mortality, and duration of mechanical ventilation were recorded for all patients.

Findings:

The duration of mechanical ventilation and length of ICU stay were shorter in patients who received melatonin in comparison with the control group, and this difference was statistically significant for the length of ICU stay and marginally significant for the duration of mechanical ventilation. Although not statistically significant, the mortality rate of the control group was 30%, almost double that of the study group (15%).

Conclusion:

Melatonin possesses hypnotic, analgesic, anti-inflammatory, and anti-oxidative properties that distinguish it as an attractive adjuvant in patients under mechanical ventilation. In conclusion, the administration of melatonin may facilitate the weaning process through decreasing the consumption of sedatives with respiratory depressant properties as well as preventing ventilator-associated lung injury.

Medical Management of Patients with an Acute Stroke: Treatment and Prevention

Stroke is a common and serious disorder and will probably occur with increasing frequency due to an aging of the population. Acute therapies aimed at reversing the effects of acute ischemic stroke are limited to recombinant tissue plasminogen activator administered intravenously within 3 hours of stroke onset. Neuroprotective agents and acute anticoagulation with agents such as heparinoids and heparin are not effective in most cases. Poststroke medical complications such as infection and venous thromboembolism are common but are largely preventable. A variety of medical therapies such as antiplatelet agents, warfarin, statins, and ACE inhibitors can reduce the risk of a recurrent stroke. A key aspect of management for stroke is selection of the proper treatment regimen for each patient.

Intravenous transplantation of mesenchymal stem cells preconditioned with early phase stroke serum: current evidence and study protocol for a randomized trial

Background

Recovery after a major stroke is usually limited, but cell therapy for patients with fixed neurologic deficits is emerging. Several recent clinical trials have investigated mesenchymal stem cell (MSC) therapy for patients with ischemic stroke. We previously reported the results of a controlled trial on the application of autologous MSCs in patients with ischemic stroke with a long-term follow-up of up to 5 years (the 'STem cell Application Researches and Trials In NeuroloGy’ (STARTING) study). The results from this pilot trial are challenging, but also raise important issues. In addition, there have been recent efforts to improve the safety and efficacy of MSC therapy for stroke.

Methods and design

The clinical and preclinical background and the STARTING-2 study protocol are provided. The trial is a prospective, randomized, open-label, blinded-endpoint (PROBE) clinical trial. Both acute and chronic stroke patients will be selected based on clinical and radiological features and followed for 3 months after MSC treatment. The subjects will be randomized into one of two groups: (A) a MSC group (n = 40) or (B) a control group (n = 20). Autologous MSCs will be intravenously administered after ex vivo culture expansion with autologous ischemic serum obtained as early as possible, to enhance the therapeutic efficacy (ischemic preconditioning). Objective outcome measurements will be performed using multimodal MRI and detailed functional assessments by blinded observers.

Discussion

This trial is the first to evaluate the efficacy of MSCs in patients with ischemic stroke. The results may provide better evidence for the effectiveness of MSC therapy in patients with ischemic stroke.

Trial registration

This trial was registered with ClinicalTrials.gov, number NCT01716481.

Nonhuman primate models of stroke for translational neuroprotection research

Despite the discovery of several promising neuroprotective therapies in rodent models of stroke, no therapy other than the fibrinolytics has been found to be effective in human clinical trials. To address potential discrepancies between rodent and human studies, the Stroke Therapy Academic Industry Roundtable (STAIR) committee suggested that nonhuman primates (NHPs) be used for preclinical, translational stroke studies. Due to the paucity of stroke studies in NHPs, few experimental models have been described. Critical factors in designing NHP stroke models include the choice of species, the method of inducing the stroke and the choice of outcome measures. In this review, we describe established NHP models of stroke and discuss factors that may influence model development with a focus on models that may be useful in preclinical studies for neuroprotective drug screening prior to clinical trials.

Translating promising preclinical neuroprotective therapies to human stroke trials

Stroke is the third leading cause of mortality and carries the greatest socioeconomic burden of disease in North America. Despite several promising therapies discovered in the preclinical setting, there have been no positive results in human stroke clinical trials to date. In this article, we review the potential causes for failure and discuss strategies that have been proposed to overcome the barrier to translation of stroke therapies. To improve the chance of success in future human stroke trials, we propose that therapies be tested in stroke models that closely resemble the human condition with molecular, imaging and functional outcomes that relate to outcomes utilized in clinical trials. These strategies include higher-order, old-world, nonhuman primate models of stroke with clinically relevant outcome measures. Although stroke neuroprotection has been looked upon pessimistically given the many failures in clinical trials to date, we propose that neuroprotection in humans is feasible and will be realized with rigorous translational science.

Current status of cell therapies in stroke

Stroke is a leading cause of death and disability in adults. Recovery after stroke is usually limited as there is no definite therapy to restore lost brain function. Cell therapy is an emerging paradigm in stroke therapy for patients with fixed neurologic deficits. Cell therapy for stroke may be greatly different from cell therapy for other disease conditions; the complexity of central nervous system structures and functions may limit its effectiveness. Recently, there have been several clinical trials of cell therapy for patients with ischemic stroke. In this review, the current status and limitations of cell therapy for stroke will be discussed. In addition, recent efforts and perspectives to improve therapeutic efficacy and safety of cell therapy will be summarized.

Pre-hospital and in-hospital delays after onset of acute ischemic stroke: a hospital-based study in southern Taiwan

The biggest hurdle for early hospital presentation is the narrow therapeutic window after stroke. The aims of our study were to investigate the time lags and the factors causing pre-hospital and emergency department (ED) delay during acute ischemic stroke attack. Between June 2004 and October 2005, we prospectively studied 129 acute ischemic stroke patients who presented to the ED of the study hospital within 4 hours after symptom onset. Chi-square testing for trend, univariate and multiple logistic regression analyses was performed to evaluate the factors influencing delays in the ED presentation of acute ischemic stroke patients. The median time from symptom onset to ED arrival was 71 (mean +/- SD, 82.7 +/- 57.7) minutes. The median times from ED arrival to neurologic consultation, computed tomography scan, electrocardiogram, and laboratory data completion were 10 (11.3 +/- 9.9) minutes, 17 (9.6 +/- 11.3) minutes, 14 (23.3 +/- 55) minutes, and 39 (44.4 +/- 24.5) minutes, respectively. Univariate and multiple logistic regression models revealed that age < 65 years, illiteracy and awakening with symptoms were the most significant factors related to a delay in ED presentation. This study indicates that 2 hours of pre-hospital delay is the cutoff point for thrombolytic therapy. Organization of a stroke team and standardized stroke pathways may help to shorten in-hospital time consumption. Educational efforts should not only focus on the public, but also on the training of ED physicians and other medical personnel.

Measurement of Upper-Extremity Function Early After Stroke: Properties of the Action Research Arm Test

OBJECTIVE

To examine the responsiveness and validity of the Action Research Arm Test (ARAT) in a population of subjects with mild-to-moderate hemiparesis within the first few months after stroke.

DESIGN

Data were collected as part of the Very Early Constraint-Induced Therapy for Recovery from Stroke trial, an acute, single-blind randomized controlled trial of constraint-induced movement therapy. Subjects were studied at baseline (day 0), after treatment (day 14), and after 90 days (day 90) poststroke.

SETTING

Inpatient rehabilitation hospital; follow-up 3 months poststroke.

PARTICIPANTS

Fifty hemiparetic subjects.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

At each time point, subjects were tested on: (1) the ARAT, (2) clinical measures of sensorimotor impairments, (3) in the kinematics laboratory where they performed reach and grasp movements, and (4) clinical measures of disability. Blinded raters performed all evaluations. Analyses at each time point included calculating effect size as indicators of responsiveness, and correlation and regression analyses to examine relationships between ARAT scores and other measures.

RESULTS

The ARAT is responsive to change, with effect sizes greater than 1.0 and responsiveness ratios of 7.0 at 3 months poststroke. ARAT scores were related to sensorimotor impairment measures, 3-dimensional kinematic measures of movement performance, and disability measures at all 3 time points.

CONCLUSIONS

The ARAT is a responsive and valid measure of upper-extremity functional limitation and therefore may be an appropriate measure for use in acute upper-extremity rehabilitation trials.

Predicting the Long-Term Outcome after Subacute Stroke within the Middle Cerebral Artery Territory

BACKGROUND AND PURPOSE

The National Institutes of Health Stroke Scale (NIHSS) score is known to be effective in predicting the likelihood of recovery after stroke. However, the baseline NIHSS score predicts long-term outcomes rather crudely because early changes in stroke scores may influence the stroke outcomes. Therefore, a precise prognostic algorithm or a cutoff point for predicting long-term outcomes based on data from serial NIHSS scores is needed.

METHODS

We serially assessed 437 patients with acute symptomatic ischemic stroke within the middle cerebral artery territory who presented with nonlacunar stroke and were followed-up for at least 6 months after symptom onset. The NIHSS score was serially checked at 0, 1, 3, 7, and 14 days after admission. In all patients, the Barthel index (BI) and the modified Rankin Scale (mRS) score were checked, with a poor outcome defined as any of the following endpoints: death, modified mRS score of >3, or BI of <60.

RESULTS

A marked neurological improvement or worsening (i.e., a change in the NIHSS score of at least 4) was seen in 13.5% or 5.5% of the patients, respectively, during the first 7 days after admission. About 25% of the 437 patients had poor long-term outcomes. Analysis of receiver operating characteristic curves showed that the NIHSS score at day 7 after admission was better for predicting poor long-term outcomes than was the baseline score (P=0.003). In addition, we analyzed the cutoff point of the 7th-day NIHSS score for predicting a poor outcome at 6 months after symptom onset. An NIHSS score of at least 6 at day 7 after admission predicted poor long-term outcomes with a sensitivity of 84% [95% confidence interval (CI), 76-90%], a specificity of 92% (95% CI, 88-94%), and positive and negative predictive values of 77% and 95%, respectively. A logistic regression analysis revealed that age, diffusion-weighted imaging lesion volume, stroke history, and 7th-day NIHSS score were independently associated with poor outcome. However, no score used in addition to the 7th-day NIHSS score improved the prediction of a poor outcome.

CONCLUSIONS

An NIHSS score of at least 6 on day 7 after admission accurately forecasts a poor long-term outcome after stroke. Our data may be helpful in predicting the long-term prognosis as well as in making decisions regarding novel therapeutic applications in subacute-stroke trials.

Traumatic Cerebral Vascular Injury: The Effects of Concussive Brain Injury on the Cerebral Vasculature

In terms of human suffering, medical expenses, and lost productivity, head injury is one of the major health care problems in the United States, and inadequate cerebral blood flow is an important contributor to mortality and morbidity after traumatic brain injury. Despite the importance of cerebral vascular dysfunction in the pathophysiology of traumatic brain injury, the effects of trauma on the cerebral circulation have been less well studied than the effects of trauma on the brain. Recent research has led to a better understanding of the physiologic, cellular, and molecular components and causes of traumatic cerebral vascular injury. A more thorough understanding of the direct and indirect effects of trauma on the cerebral vasculature will lead to improvements in current treatments of brain trauma as well as to the development of novel and, hopefully, more effective therapeutic strategies.

Excitatory amino acid antagonists for acute stroke

BACKGROUND

Focal cerebral ischaemia causes release of excitatory amino acid (EAA) neurotransmitters, principally glutamate, with resultant over-stimulation of EAA receptors and downstream pathways. Excess glutamate release is a pivotal event in the evolution of irreversible ischaemic damage in animal models of ischaemia, and drugs that modulate glutamate action either by inhibiting its release, or blocking post-synaptic receptors, are potent neuroprotective agents. Many clinical trials with EAA modulating drugs have been conducted, none individually demonstrating efficacy.

OBJECTIVES

To synthesise all the available data on all different classes of EAA modulators and to evaluate evidence of effects on outcome systematically.

SEARCH STRATEGY

Relevant trials were identified in the Specialised Register of Controlled Trials (last searched May 2001). In addition, MEDLINE and EMBASE online searches for the terms "neuroprotection" (and its variants), "neuroprotective agent", for all individual drugs and drug classes included in the review, hand searches of conference proceedings from European, International, American Heart Association and Princeton conferences on Stroke, American Neurological Association and American Academy of Neurology meetings from 1992-2001, and direct contact with individual investigators and pharmaceutical companies.

SELECTION CRITERIA

Trials were included if they were randomised, controlled studies giving agents with pharmacological properties that included modification of release of EAAs, or blockade of EAA receptors, in stroke within 24h of onset. Efficacy analysis was restricted to trials with a parallel group design: dose escalation studies were excluded. Intention-to-treat analyses were performed on all data. Outcome had to be reported in terms of death or dependence 1-12 months after the acute event.

DATA COLLECTION AND ANALYSIS

Data were available for 36 of 41 relevant trials identified, involving 11,209 subjects. Data were unavailable for 632 participants (517 in trials fulfilling criteria for efficacy analysis). Seven trials did not report disability data, which were available for 29 trials involving 10,802 subjects. Twenty one of these trials, involving 10,342 subjects, were parallel group studies included in the primary efficacy analysis. Efficacy analysis included data derived from 9 trials not primarily designed to assess efficacy (1022 subjects). The primary (efficacy) end-point was the proportion of patients dead or disabled at final follow-up (defined by Barthel Index<60 at 3 months by preference). Mortality was a secondary end-point. Drugs were considered as individual agents, and also grouped principally into categories of ion channel modulators (glutamate release inhibition) and NMDA antagonists.

MAIN RESULTS

There was no significant heterogeneity of outcome amongst individual drugs, or of drug classes either for the primary efficacy analysis (death or dependence) or for mortality at final follow-up. For the primary efficacy analysis, odds of death or dependence were 1.03 [95% confidence interval 0.96-1.12], and for mortality 1.02 [0.92-1.12]. Neither ion channel modulators (death or dependence 1.02 [0.90-1.16]) nor NMDA antagonists (death or dependence 1.05 [0.95-1.16]) differed from the principal analysis including all compounds. Trends for increased mortality with three NMDA antagonists were seen - selfotel (OR 1.19 [0.81-1.74]), aptiganel (OR 1.32 [0.91-1.93]) and gavestinel (OR 1.12 [0.95-1.32]) - but this did not achieve significance for the NMDA antagonists considered as a class (1.09 [0.96-1.23]). Aptiganel was also associated with a trend towards worse functional outcome (OR 1.20 [0.88-1.65]) although this was not the case for either of the other two compounds. No statistically significant detriment of psychotomimetic NMDA antagonists was found, although a trend towards higher mortality in this sub-group was seen (OR 1.25 [0.96-1.64]).

REVIEWER'S CONCLUSIONS

There was no evidence of significant benefit or harm from drugs modulating excitatory amino acid action. Reductio]).

REVIEWER'S CONCLUSIONS

There was no evidence of significant benefit or harm from drugs modulating excitatory amino acid action. Reduction of death or dependence by 8% or more has been excluded for gavestinel and lubeluzole, which contribute most of the data for this review. However, mechanistic understanding of neuroprotection is too poor to extrapolate from these two failed development plans to all glutamate modulators. Further clinical trials of neuroprotective agents remain justified, since confidence limits around estimates of effect remain wide for most agents, and cannot reliably exclude benefit. Although numbers of patients are too small to confirm or refute a trend towards increased mortality with some NMDA antagonists, further commercial development of these agents is exceedingly unlikely.

Nitrous oxide modulator: lubeluzole

Lubeluzole was developed as a neuroprotective substance for use in acute ischaemic stroke. Its biological function is related to its ability to alter the biochemical cascade that leads to irreversible neural damage in the penumbra by preventing an increase in extracellular glutamate and normalizing neuronal excitability in the peri-infarct region. Phase II and early phase III trials indicated an improvement in neurological outcome, whereas a final large randomized and placebo controlled trial did not show superiority versus placebo.

Lubeluzole for acute ischaemic stroke

BACKGROUND

Experimental studies have shown that ischaemic insults cause excess release of excitatory amino acid (EAA) neurotransmitters, particularly glutamate. Glutamate re-uptake is impaired under ischaemic conditions. In preclinical models of stroke, antagonists of excitatory amino acids or of glutamate release protect against ischaemic injury, even when administered after the ischaemic insult. Lubeluzole is a benzothiazole derivative that has shown neuroprotective properties in different experimental models inhibiting glutamate release, nitric oxide (NO) synthesis and blocking voltage-gated Na+ and Ca2+ ion channels.

OBJECTIVES

The objective of this review is to assess the effectiveness and safety of lubeluzole given in the acute phase of acute ischaemic stroke.

SEARCH STRATEGY

The Cochrane Stroke Group trials register was searched. Additional searches of Cochrane Controlled Trials Register (CENTRAL/CCTR), Medline, Embase, Pascal BioMed (1996-2001) and Current Contents CCSearch reg 7 Editions (1996-2001) were made to supplement the Stroke Group general strategy. We contacted Janssen Research Foundation to identify further studies.

SELECTION CRITERIA

All randomised unconfounded trials comparing intravenous lubeluzole with placebo or open control in patients with a clinical syndrome definitely considered as an acute stroke in whom CT scanning showed an infarct or was normal.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Five trials involving a total of 3,510 patients were included. The quality of the trials did not vary considerably. Sensitivity/subgroups analysis was not completely performed because of lack of data. Lubeluzole given at the doses of 5, 10 and 20 mg/day for 5 days was tested against a placebo-control group. There was no evidence that Lubeluzole given at any dose either reduced the odds of death from all causes (OR=0.93, 95% CI 0.79-1.09) or reduced the odds of being dead or dependent at the end of follow-up (OR=1.04, 95% CI 0.91-1.19). On the other hand, given at any dose, Lubeluzole was associated with a significant excess of heart-conduction disorders (Q-T prolonged > 450 msec) at the end of follow-up (OR=1.43, 95% CI 1.09-1.87).

REVIEWER'S CONCLUSIONS

Lubeluzole, given in the acute phase of ischaemic stroke, is not associated with a significant reduction of death or dependency at the end of scheduled follow-up period but seems to be associated with a significant increase of heart-conduction disorders (Q-T prolonged >450 msec).

Neuroprotection for ischaemic stroke: an unattainable goal?

Neuroprotective therapies for acute ischaemic stroke have yet to be realised despite the determined efforts of basic science and clinical investigators. Progressive elucidation of the complex pathophysiology involved in the ischaemic cascade has led to the development of numerous candidate interventions. Preliminary efficacy in animal models has repeatedly resulted in frustration after extensive clinical testing. Failure in the translation of results from animal models to humans implicates potential limitations of the current drug development process. Reflection on prior studies suggests possible flaws at several stages. Incorporation of standardised guidelines for preclinical testing of putative neuroprotective therapies and modification of clinical trial design, methodology and reporting may improve chances for success. The future of neuroprotection for stroke remains bright in spite of previous disappointments.

Characterisation of SB-221420-A - a neuronal Ca(2+) and Na(+) channel antagonist in experimental models of stroke

For progression to clinical trials in stroke, putative neuroprotective compounds should show robust efficacy post-ischaemia in several experimental models of stroke. This paper describes the characterisation of (+)(1S, 2R)-cis-1-[4-(1-methyl-1-phenylethyl)phenoxy]-2-methylamino indane hydrochloride (SB-221420-A), a Ca(2+) and Na(+) channel antagonist. SB-221420-A inhibited (IC(50)=2.2 microM) N-type voltage-operated Ca(2+) channel currents in cultured superior cervical ganglion neurons, which were pretreated with 10 microM nimodipine to block L-type voltage-operated Ca(2+) channel currents. In dorsal root ganglion neurons pretreated with 1 microM omega-conotoxin GVIA to block N-type voltage-operated Ca(2+) channel currents, SB-221420-A inhibited the residual Ca(2+) current with an IC(50) of 7 microM. SB-221420-A also inhibited Na(+) currents in dorsal root ganglion neurons with an IC(50) of 8 microM. In rats, the pharmacokinetic profile of SB-221420-A shows that it has a half-life of 6.4 h, a high volume of distribution, is highly brain penetrating, and has no persistent metabolites. Following bilateral carotid artery occlusion in gerbils, SB-221420-A significantly reduced the level of ischaemia-induced hyperlocomotor activity and the extent of hippocampal CA1 cell loss compared to the ischaemic vehicle-treated group. SB-221420-A was also effective in focal models of ischaemia. In the mouse permanent middle cerebral artery occlusion model, SB-221420-A (10 mg/kg) administered intravenously, post-ischaemia significantly (P<0.05) reduced lesion volume compared to the ischaemic vehicle-treated group. In the normotensive rat permanent middle cerebral artery occlusion model, SB-221420-A (10 mg/kg) administered intravenously over 1 h, beginning 30 min postmiddle cerebral artery occlusion, significantly (P<0.05) reduced lesion volume from 291+/-16 to 153+/-30 mm(3), compared to ischaemic vehicle-treated controls when measured 24 h postmiddle cerebral artery occlusion. Efficacy was maintained when the same total dose of SB-221420-A was infused over a 6-h period, beginning 30 min postmiddle cerebral artery occlusion. SB-221420-A also significantly (P<0.05) reduced lesion volume following transient middle cerebral artery occlusion in normotensive rats and permanent middle cerebral artery occlusion in spontaneously hypertensive rats (SHR). Investigation of the side effect profile using the Irwin screen in mice revealed that, at neuroprotective doses, there were no overt behavioural or cardiovascular changes. These data demonstrate that robust neuroprotection can be seen post-ischaemia with SB-221420-A in both global and focal ischaemia with no adverse effects at neuroprotective doses, and indicate the potential utility of a mixed cation blocker to improve outcome in cerebral ischaemia.

Neuroprotection in acute ischaemic stroke. II: Clinical potential

In the 4 years since our first article, there has been considerable progress in our understanding of the pathophysiology of acute ischaemic stroke, and the results of well-conducted trials have at last begun to change everyday clinical practice. The timing of the various processes of the ischaemic cascade and the potential time windows for different interventions are better understood. Furthermore, the importance of maintaining cerebral perfusion and optimizing systemic physiological and biochemical factors in order to prevent neurological deterioration ('progressing stroke') is increasingly being realized. Numerous antithrombotic and neuroprotective drugs have been evaluated in clinical trials, and while none has shown unequivocal benefits on its own, prospects for successful intervention are still good. This will probably involve different combinations of treatments targeted on different pathophysiological stroke types, so that the management of acute stroke will offer a considerable challenge to the stroke physicians of the future.

Recent advances in the acute management of ischaemic stroke

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Drug therapy for acute ischaemic stroke: risks versus benefits

Stroke is a very common medical emergency that, until recently, had no specific treatment. Following the results of several major trials (including 2 'mega-trials'), aspirin (acetylsalicylic acid) can be recommended for the majority of patients with acute ischaemic stroke. While the benefit of aspirin is only modest, i.e. an increase of 11 per 1000 long term independent survivors, the public health benefit in the world will be substantial as this treatment could be given to millions of patients with acute ischaemic stroke each year. Heparin is associated with a reduction in early recurrent ischaemic stroke, but there is no net benefit because of a similar sized excess of recurrent haemorrhagic stroke (even for those in atrial fibrillation). Thrombolytic therapy has not been so widely tested and the results of the small trials to date have yielded conflicting results. The only positive publication to date (comprised of 2 related trials) evaluated the recombinant tissue plasminogen activator alteplase, but such treatment is probably only indicated for highly selected patients. Further trials are almost certainly required and it would be unwise to change clinical practice based on the current evidence. No other stroke treatments have been shown to be beneficial, and much larger trials will be required to confirm or refute possible moderate benefits of treatment. A well organised stroke service and participation in clinical trials will improve the future care of patients with acute ischaemic stroke.

Knowledge of stroke in rehabilitation and community samples

This study examined the stroke knowledge of 60 stroke rehabilitation patients, 46 spouses, 25 family members, and 103 people in the general community. Changes in stroke knowledge with time, and determinants of stroke knowledge, were also examined. Clinical participants were assessed on acute admission, admission to and discharge from rehabilitation, and 6 and 12 months after discharge. Community participants were assessed once. Instruments used were the Stroke Care Information Test, Australian ADL Index, Frenchay Activities Index, Illness Behaviour Questionnaire and Zung Self-rating Depression Scale. The stroke knowledge of all participants, particularly patients, was poor, but improved with time. Better-informed patients were younger, had milder strokes, were less depressed, were less likely to develop abnormal illness behaviour, and made a better functional recovery than patients with poorer knowledge. Structured information programmes are needed for stroke patients and their families. Improved community awareness of stroke may help the prospects for recovery and quality of life for people who have strokes.

Effects of isradipine, an L-type calcium channel blocker on permanent and transient focal cerebral ischemia in spontaneously hypertensive rats

Permanent or transient focal cerebral ischemia was induced in spontaneously hypertensive rats (SHR) using the intraluminal filament method. Successful occlusion of the middle cerebral artery (MCA) was achieved using 4/O filaments (terminal diameter 0.20-0.25 mm) coated with poly-L-lysine. The L-type calcium channel blocker isradipine (2.5 mg/kg) administered subcutaneously 30 min following permanent MCA occlusion significantly reduced the volume of ischemic brain damage in the cerebral hemisphere (25%; P = 0.0001), cerebral cortex (18%; P = 0.0034), and caudate nucleus (33%; P = 0.0002) when assessed at 24 h post-MCA occlusion. Isradipine did not affect the functional deficit (measured using a subjective neurological scoring system) induced by MCA occlusion. In SHR undergoing transient (2 h) MCA occlusion isradipine administered 30 min post-MCA occlusion produced a significant reduction (47%; P = 0.001) in hemispheric infarct volume, whereas isradipine administered at the onset of reperfusion did not confer any significant neuroprotection. No change in functional deficit was seen with isradipine with either dosing paradigm at 24 h post-MCA occlusion. These results demonstrate that the intraluminal filament method of MCA occlusion can be used in the SHR strain and also substantiates the neuroprotective efficacy of isradipine in SHR models of permanent and transient focal cerebral ischemia.