Thrombolysis for acute stroke:

Hemoglobin A1c predicts hemorrhagic transformation and poor outcomes after acute anterior stroke

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) is a major complication of acute ischaemic stroke that is potentially related to clinical deterioration. The objective of this study was to assess whether chronic hyperglycemia is a predictive factor of HT in patients with acute anterior stroke.

METHODS

Patients with acute anterior stroke were included in this study. Hemoglobin A1c (HbA1c) was measured in the morning after hospitalization. HT was detected by computed tomography scans or gradient echo magnetic resonance imaging performed 4 (±2) days after onset. Univariate and multivariate logistic regression analyses were used to assess the risks for HT and short-term outcomes.

RESULTS

Of the 426 patients included, 93 (21.8%) had HT: 61 (14.3%) presented with hemorrhagic infarction and 32 (7.5%) presented with parenchymal hematoma. A total of 54 patients received thrombolytic treatment and 18 (33.3%) were found to have HT. In the multivariate analysis, HbA1c [odds ratio (OR), 1.294; 95% confidence interval (CI), 1.097-1.528], infarction size (OR, 3.358; 95% CI, 1.748-6.449) and thrombolytic therapy (OR, 3.469; 95% CI, 1.757-6.847) were predictors of HT. The predictive effect of HbA1c on HT was still observed in both groups when patients were stratified according to the levels of fasting blood glucose. HbA1c was found to be a predictor of poor outcomes in the multilogistic regression analysis (OR, 1.482; 95% CI, 1.228-1.788).

CONCLUSIONS

Higher HbA1c was independently related to HT and poor neurological outcomes in patients with ischaemic stroke. These findings have significant implications for the treatment of diabetes and glucose management in patients with diabetes mellitus and/or acute ischaemic stroke.

Benefits of occupational therapy in stroke rehabilitation

Stroke is the largest single cause of severe physical disability and rehabilitation to reduce functional deficits is the most effective treatment. Occupational therapists play a central role in rehabilitation as members of a multidisciplinary team. Occupational therapy is a client-centered profession that uses meaningful activities across the spectrum of physical and mental domains to reduce limitations after stroke. Where remediation is not possible, occupational therapists implement compensatory strategies to promote independence. Rehabilitation is based on the concept of brain plasticity, which implies that it is possible to modulate or facilitate cerebral reorganization by external inputs. Occupational therapy activities are specifically geared to promote this re-education process and encourage the development of lost skills while accommodating for specific physical, cognitive or affective impairments. Principles of motor, sensory, cognitive and affective rehabilitation are incorporated into effective task-specific activities and environments are adapted to create the optimum conditions for successful rehabilitation. Several promising new rehabilitation approaches, based on neuropsychology and technological advances, have been developed to complement therapy inputs and exploit the brain's capacity to recover from stroke.

Glycosylated hemoglobin A1 predicts risk for symptomatic hemorrhage after thrombolysis for acute stroke

BACKGROUND AND PURPOSE

Symptomatic intracerebral hemorrhage (sICH) is the most feared acute complication after intravenous thrombolysis. The aim of this study was to determine the predictive value of parameters of glycosylated hemoglobin A1 (HbA1c) on sICH.

METHODS

In a retrospective single center series, 1112 consecutive patients treated with thrombolysis were studied. Baseline blood glucose was obtained at admission. HbA1c was determined within hospital stay. A second head computed tomography was obtained after 24 hours or when neurological worsening occurred. Modified Rankin Scale was used to assess outcome at 90 days.

RESULTS

A total of 222 patients (19.9%) had any hemorrhage; 43 of those had sICH (3.9%) per Safe Implementation of Treatments in Stroke definition and 95 (8.5%) per National Institute of Neurological Disorders and Stroke definition; 33.2% of patients had a dependent outcome (modified Rankin Scale score 3-5). In univariate analysis history of diabetes mellitus, HbA1c, blood glucose, and National Institute of Health Stroke Scale score on admission were associated with any hemorrhage and sICH. In multivariate analysis National Institute of Health Stroke Scale score, a history of diabetes mellitus, and HbA1c were predictors of sICH per National Institute of Neurological Disorders and Stroke, and only HbA1c when Safe Implementation of Treatments in Stroke criteria were used.

CONCLUSIONS

In our study, HbA1c turns out to be an important predictor of sICH after thrombolysis for acute stroke. These results suggest that hemorrhage after thrombolysis may be a consequence of long-term vascular injury rather than of acute hyperglycemia, and that HbA1c may be a better predictor than acute blood glucose or a history of diabetes mellitus.

Systematic review of descriptive cohort studies on the dynamics of glycaemia among adults admitted to hospital with acute stroke

AIM

This article presents the results of a systematic review of descriptive cohort studies on the dynamics of glycaemia among adults admitted to hospital with acute stroke.

BACKGROUND

Hyperglycaemia is common among adults admitted to hospital with stroke.

DESIGN

Systematic review.

DATA SOURCES

A search for descriptive cohort studies published between January 1996-June 2011, was conducted in MEDLINE, PubMed and Embase electronic databases. The search was performed using the terms 'stroke', 'hyperglycaemia' and/or 'glucose' combined and limited to adults and English language publications. Searching of citations from identified studies supplemented the electronic searches.

REVIEW METHODS

A systematic review was conducted of eight studies, meeting the criteria of: (1) descriptive cohort studies; (2) adults admitted to hospital with acute stroke; and (3) glycaemic status monitored over at least two consecutive days from admission to hospital. The review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis standards.

RESULTS

The dynamics of glycaemia after stroke has been investigated in seven prospective cohort studies and one retrospective study. The patterns that emerged were persisting normoglycaemia, transient hyperglycaemia, persisting hyperglycaemia and delayed hyperglycaemia. Surges in glycaemia are likely on days 2 and 3 and some adults will not exhibit hyperglycaemia till day 7.

CONCLUSION

Further large cohort studies are required to explore the dynamic of glycaemia after stroke for at least 1 week duration. The timing of formal screening for diabetes mellitus is important, as early screening may overestimate detection rates.

Hyperglycaemia and neurological injury

PURPOSE OF REVIEW

Clinical and experimental data suggest that hypergylcaemia lowers the ischaemic neuronal threshold and worsens outcome in the presence of neurological injury from trauma, stroke and subarachnoid haemorrhage. This review aims to appraise the evidence for tight glycaemic control in patients with neurological injury.

RECENT FINDINGS

Hyperglycaemia can adversely affect outcome in critically ill patients. Intensive insulin therapy with tight glycaemic control has been advocated for improving outcome in these patients. However, the extent to which intensive insulin therapy and tight control of blood glucose improve outcome after ischaemic neurological insults remains unclear. The benefit of such treatment regimes may be negated by the increased frequency of hypoglycaemic episodes, which may aggravate neurological injury. Although it seems sensible to control hyperglycaemia in patients with neurological injury, the treatment must account for potential hypoglycaemic episodes.

SUMMARY

Clinical and experimental data suggest that hyperglycaemia lowers the ischaemic neuronal threshold in the presence of neurological injury. Tight glycaemic control may result in hypoglycaemia, which in itself can be detrimental. Therefore, it seems sensible that we should accept slightly less tight blood glucose control than in the critically ill patient without neurological injury.

Mast Cell Stabilization Reduces Hemorrhage Formation and Mortality After Administration of Thrombolytics in Experimental Ischemic Stroke

Background— Thrombolysis with tissue plasminogen activator (tPA) improves stroke outcome, but hemorrhagic complications and reperfusion injury occasionally impede favorable prognosis after vessel recanalization. Perivascularly located cerebral mast cells (MCs) release on degranulation potent vasoactive, proteolytic, and fibrinolytic substances. We previously found MCs to increase ischemic and hemorrhagic brain edema and neutrophil accumulation. This study examined the role of MCs in tPA-mediated hemorrhage formation (HF) and reperfusion injury.

Methods and Results— Exposure to tPA in vitro induced strong MC degranulation. In vivo experiments in a focal cerebral ischemia/reperfusion model in rats showed 70- to 100-fold increase in HF after postischemic tPA administration ( P <0.001). Pharmacological MC stabilization with cromoglycate led to significant reduction in tPA-mediated HF at 3 (97%), 6 (76%), and 24 hours (96%) compared with controls ( P <0.01, P <0.001, and P <0.01, respectively). Furthermore, genetically modified MC-deficient rats showed similarly robust reduction of tPA-mediated HF at 6 (92%) and 24 (89%) hours compared with wild-type littermates ( P <0.01 and P <0.001, respectively). MC stabilization and MC deficiency also significantly reduced other hallmarks of reperfusion injury, such as brain swelling and neutrophil infiltration. These effects of cromoglycate and MC deficiency translated into significantly better neurological outcome ( P <0.01 and P <0.05, respectively) and lower mortality ( P <0.05 and P <0.05, respectively) after 24 hours.

Conclusions— MCs appear to play an important role in HF and reperfusion injury after tPA administration. Pharmacological stabilization of MCs could offer a novel type of therapy to improve the safety of administration of thrombolytics.

Anti-high mobility group box 1 monoclonal antibody ameliorates brain infarction induced by transient ischemia in rats

The high mobility group box-1 (HMGB1), originally identified as an architectural nuclear protein, exhibits an inflammatory cytokine-like activity in the extracellular space. Here we show that treatment with neutralizing anti-HMGB1 monoclonal antibody (mAb; 200 microg, twice) remarkably ameliorated brain infarction induced by 2-h occlusion of the middle cerebral artery in rats, even when the mAb was administered after the start of reperfusion. Consistent with the 90% reduction in infarct size, the accompanying neurological deficits in locomotor function were significantly improved. Anti-HMGB1 mAb inhibited the increased permeability of the blood-brain barrier, the activation of microglia, the expression of TNF-alpha and iNOS, and suppressed the activity of MMP-9, whereas it had little effect on blood flow. Intracerebroventricular injection of HMGB1 increased the severity of infarction. Immunohistochemical study revealed that HMGB1 immunoreactivity in the cell nuclei decreased or disappeared in the affected areas, suggesting the release of HMGB1 into the extracellular space. These results indicate that HMGB1 plays a critical role in the development of brain infarction through the amplification of plural inflammatory responses in the ischemic region and could be an outstandingly suitable target for the treatment. Intravenous injection of neutralizing anti-HMGB1 mAb provides a novel therapeutic strategy for ischemic stroke.

Evidence, education and practice

Stroke causes greater loss of quality-adjusted life years than any other disease and is also one of the most expensive disorders. The burden of stroke will increase in the future due to change in the age structure of populations. We have a vast body of evidence on how to prevent stroke and how to treat stroke patients. Good examples are treatment of hypertension, antithrombotic agents and carotid surgery in stroke prevention, thrombolysis in ischaemic stroke and stroke unit care for all stroke patients. We only have to translate scientific evidence into daily practice. If some pieces are missing, it is our duty to generate them through research. While taking part in randomized clinical trials (RCTs), the discipline, an essential part of RCTs, will improve the daily care of all stroke patients. Besides RCTs there are many other sources of scientific evidence for stroke management, one of which is the European Stroke Initiative (EUSI). The mission of the EUSI is to improve and optimize stroke management in Europe through education and by offering best practice guidelines. Also national and international societies and organizations play an important role in providing education. The human factor is one obstacle to more successful stroke management because to be more effective we must change our own clinical routine. We can make a difference by applying available evidence to our daily practice.

Directed use of the Cincinnati Prehospital Stroke Scale by laypersons

BACKGROUND

The Cincinnati Prehospital Stroke Scale (CPSS) is a three-item examination that has been effective in the identification of stroke victims by health care professionals. However, assessment of the patient earlier in the chain of care, specifically by a 9-1-1 telecommunicator, may improve stroke outcomes.

OBJECTIVES

To modify the CPSS for over-the-phone administration and to assess whether untrained adults can follow the CPSS instructions, identify deficits in stroke survivors, and return these findings to an investigator.

METHODS

One hundred nonpatient visitors to an academic tertiary care emergency department were recruited. Each participant was brought to a room with a stroke survivor possessing unresolved symptoms from a previous stroke. The participant was telephoned by an investigator and led through administering the CPSS to the stroke survivor. The investigator noted whether the participant accurately administered CPSS instructions and whether normal or abnormal findings were returned.

RESULTS

Participants correctly administered CPSS directions 98% of the time. For facial weakness, the sensitivity of the participants' assessments was 74% and the specificity was 94%. For arm weakness, the sensitivity was 97% and the specificity was 72%. For speech deficits, the sensitivity was 96% and the specificity was 96%.

CONCLUSIONS

Untrained adults can use the CPSS to accurately identify stroke symptoms and can relay these findings to an investigator. Telecommunicator administration of the CPSS may allow for expedited prehospital triage of the stroke patient and delivery of resources in a timely manner and, given the limited time window for efficacious treatment, may lead to improved patient outcome.

Assessing acute middle cerebral artery ischemic stroke by quantitative electric tomography

This paper focuses on the application of quantitative electric tomography (qEEGT) to map changes in EEG generators for detection of early signs of ischemia in patients with acute middle cerebral artery stroke. Thirty-two patients were studied with the diagnosis of acute ischemic stroke of the left middle cerebral artery territory, within the first 24 hours of their clinical evolution. Variable Resolution Electrical Tomography was used for estimating EEG source generators. High resolution source Z-spectra and 3- dimensional images of Z values for all the sources at each frequency were obtained for all cases. To estimate statistically significant increments and decrements of brain electric activity within the frequency spectra, the t-Student vs. Zero test was performed. A significant increment of delta activity was observed on the affected vascular territory, and a more extensive increment of theta activity was detected. A significant alpha decrement was found in the parieto-occipital region of the affected cerebral hemisphere (left), and in the medial and posterior region of the right hemisphere. These findings suggest that qEEGT Z delta images are probably related to the main ischemic core within the affected arterial territory; penumbra, diaschisis, edema, might explain those observed theta and alpha abnormalities. It was concluded that qEEGT is useful for the detection of early signs of ischemia in acute ischemic stroke.

Community-based thrombolytic therapy of acute ischemic stroke in Helsinki

BACKGROUND AND PURPOSE

Thrombolysis with alteplase is used in acute ischemic stroke within 3 hours after symptom onset in many stroke centers, but experience remains limited in Europe.

METHODS

Using eligibility and management criteria similar to those published by the American Heart Association, we treated 75 consecutive patients aged 21 to 83 years (mean age, 63.6 years; median Scandinavian Stroke Scale score, 32/58) with hemispheric infarction with alteplase in 1998-2001. Their neuroradiological findings (ischemic and hemorrhagic changes) and functional outcome at 3 months were evaluated.

RESULTS

Sixty-one percent of the patients had recovered functional independence (Barthel Index 95 to 100) at the 3-month follow-up. On the modified Rankin Scale (mRS), 37% (28/75) of patients had no or minimal symptoms (mRS 0 to 1), while 17% (13/75) remained dependent (mRS 4 to 5) and 5% (4/75) died. Cerebral parenchymal hematomas occurred in 8% (6/75) and hemorrhagic transformation in 8% (6/75) of the patients. Low initial diastolic blood pressure and administration of intravenous antihypertensive medication were associated with unfavorable outcome (mRS 3 to 6).

CONCLUSIONS

We conclude that our management protocol for thrombolytic therapy is safe. These rates of functional outcome, case fatality, and hemorrhagic cerebral events compare favorably with those of other published series of stroke thrombolysis with similar time windows and management guidelines. Associations between blood pressure and its treatment during thrombolysis with functional outcome deserve further analysis.