The Greater Cincinnati/Northern Kentucky Stroke Study: preliminary first-ever and total incidence rates of stroke among blacks

Racial disparities in the filling of warfarin prescriptions for nonvalvular atrial fibrillation

BACKGROUND

Warfarin has been shown to decrease the rate of thromboembolic events in patients with nonvalvular atrial fibrillation, but it is frequently underprescribed. Our goal was to establish whether there have been racial disparities in the filling of warfarin prescriptions for patients with newly incident nonvalvular atrial fibrillation.

METHODS

We conducted a retrospective analysis of Ohio Medicaid claims between January 1, 1997 and May 31, 2002, for recipients with newly incident nonvalvular atrial fibrillation. Race was identified from the demographic information in the database, and the analysis was limited to white and African-American patients. The main outcome measure was the filling of a prescription for warfarin at any time between 7 days prior to the initial diagnosis of atrial fibrillation and 30 days after the initial diagnosis. To evaluate the independent role of race in the filling of warfarin prescriptions, we created a multivariable logistic regression model incorporating predictors significant at P < 0.10 in the univariate model.

RESULTS

A total of 6283 patients were identified as having newly incident nonvalvular atrial fibrillation, 18.5% of whom were African-American. In general, African-American patients had a higher rate of comorbid illness. Warfarin prescriptions were filled for 9.4% of white patients and 7.6% of African-American patients. When controlling for significant confounders in the multivariable logistic regression model, African-American patients had an adjusted odds ratio for receiving warfarin of 0.76 (95% CI, 0.60-0.98) when compared with white patients.

CONCLUSION

African-American patients in the Ohio Medicaid population between 1998 and 2002 were significantly less likely than white patients to fill a warfarin prescription for newly incident nonvalvular atrial fibrillation.

Does statin therapy decrease the risk for bleeding in patients who are receiving warfarin?

PURPOSE

Recent observations in patients with atrial fibrillation who are receiving warfarin suggest that concomitant treatment with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) decreases the risk for bleeding.

METHODS

We conducted a population-based, nested case-control study using the linked administrative databases of Ontario, Canada, to assess whether statin use decreases the risk of bleeding in warfarin users. Eligible patients were Ontario residents, age 66 years or more, with atrial fibrillation who were prescribed warfarin between April 1, 1994, and December 31, 2001. Patients were followed until hospitalization for upper gastrointestinal or intracranial bleeding, study end (March 31, 2002), discontinuation of warfarin, or death. Cases were matched to controls by age and sex. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between bleeding and statin use.

RESULTS

We identified 79,207 warfarin users with atrial fibrillation. There were 1518 cases with an upper gastrointestinal or intracranial bleed and 15,100 matched controls without bleeding. Long-term (>/=1 year) statin use was associated with a lower risk for any bleeding (OR=0.80; 95% CI, 0.66-0.97). However, there was no association between bleeding and recent (<6 months) statin use (OR=1.04; 95% CI, 0.74-1.48) or statin use of any duration (OR: 0.91; 95% CI, 0.77-1.07), suggesting potential confounding of the association between statin use and bleeding by a health-user effect.

CONCLUSION

Long-term statin use may be associated with a decreased risk for bleeding in warfarin users with atrial fibrillation. Additional research is needed to further explore this putative association.

Ethnic difference in the relationship between acute inflammation and serum ferritin in US adult males

This study examined the ethnic difference in the association between increased serum ferritin (SF) (>300 microg/l) and acute inflammation (AI) (C-reactive protein > or = 1.0 mg/dl) between black and white males aged > or = 20 years. Using data from the third National Health and Nutrition Examination Survey (NHANES III), we determined the risk for having elevated SF in black males (n=164) and white males (n=325) with AI present as well as black males (n=1731) and white males (n=2877) with AI absent. Black subjects with AI present were 1.71 times (95% CI 1.18-2.49), and 1.87 times (95% CI 1.46-2.40) more likely to have increased SF than AI absent blacks and AI present whites, respectively. Furthermore, with AI present, every increment of C-reactive protein, white blood cell count, serum albumin, lymphocyte count and platelet count was associated with higher odds of having elevations in SF in blacks than whites. Regardless of AI status, blacks were more likely to have elevations in SF than whites, and the prevalence of elevated SF was significantly higher in blacks than whites. This finding suggested that black males may respond to inflammation with a more aggressive rise in SF compared to white males. Future research is needed to investigate the underlying mechanisms.

Evaluating Cardiac Sources of Embolic Stroke with MRI

The evaluation of patients with stroke includes identifying its etiology in order to appropriately tailor therapy. Currently, the diagnostic work-up includes imaging of the brain, the arteries of the head and neck, the aorta, and the heart. Traditional methods of imaging include magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA), duplex ultrasound, and transthoracic echocardiography (TTE) and/or transesophageal echocardiography (TEE). While echocardiography remains a cornerstone in the field of cardiac imaging, MRI is increasingly able to assess for the most common causes of cardioembolic stroke such as left atrial/left atrial appendage thrombus, left ventricular thrombus, aortic atheroma, cardiac masses and patent foramen ovale. This review will focus on the advantages and limitations of echocardiography and cardiac magnetic resonance (CMR) imaging in diagnosing patients suspected of having an embolic stroke and the role these modalities play in clinical practice today.

Prevalence of elevated blood pressure in 563,704 adult patients with stroke presenting to the ED in the United States

PURPOSE

The aim of this study was to estimate the prevalence of elevated blood pressure in adult patients with acute stroke in the United States (US).

METHODS

Patients with stroke were classified by initial systolic blood pressure (SBP) into 4 categories using demographic, clinical, and treatment data from the National Hospital Ambulatory Medical Care Survey, the largest study of use and provision of emergency department (ED) services in the United States. We also compared the age-, sex-, and ethnicity-adjusted rates of elevated blood pressure strata, comparable with stages 1 and 2 hypertension in the US population.

RESULTS

Of the 563704 patients with stroke evaluated, initial SBP was below 140 mm Hg in 173120 patients (31%), 140 to 184 mm Hg in 315207 (56%), 185 to 219 mm Hg in 74586 (13%), and 220 mm Hg or higher in 791 (0.1%). The mean time interval between presentation and evaluation was 40 +/- 55, 33 +/- 39, 25 +/- 27, and 5 +/- 1 minutes for increasing SBP strata (P = .009). A 3- and 8-fold higher rate of elevated blood pressure strata was observed in acute stroke than the existing rates of stages 1 and 2 hypertension in the US population. Labetalol and hydralazine were used in 6126 (1%) and 2262 (0.4%) patients, respectively. Thrombolytics were used in 1283 patients (0.4%), but only in those with SBP of 140 to 184 mm Hg.

CONCLUSIONS

In a nationally representative large data set, elevated blood pressure was observed in over 60% of the patients presenting with stroke to the ED. Elevated blood pressure was associated with an earlier evaluation; however, the use of thrombolytics was restricted to patients with ischemic stroke with SBP below 185 mm Hg.

The Paul Coverdell National Acute Stroke Registry: initial results from four prototypes

BACKGROUND

This paper summarizes the experiences of the Paul Coverdell National Acute Stroke Registry first four prototype registries in Georgia (GA), Massachusetts (MA), Michigan (MI), and Ohio (OH), and includes information on their sampling design, case ascertainment, and data collection methods, as well as some key findings.

METHODS

Using a combination of different sampling methods, each prototype obtained a representative statewide sample of hospitals. Acute stroke admissions were identified through prospective (MA, MI) or retrospective (GA, OH) methods. A common set of case definitions and data elements were used by each registry. Weighted site-specific frequencies and 95% confidence intervals were generated for each outcome. A summary estimate, representing a weighted average of the four site-specific estimates, was also calculated.

RESULTS

Of the total 6867 admissions, 1487 (21.6%) were from the GA registry, 1206 (17.6%) from MA, 2566 (37.4%) from MI, and 1608 (23.4%) from the OH prototype. Just less than 60% of admissions were ischemic strokes (site-specific estimates ranged from 52% to 70%), with transient ischemic attack (18.5%) and intracerebral hemorrhage (8.8%) making up most of the remainder. Twenty-one percent of patients admitted were younger than 60 years of age, and 55.3% were women. The proportion of black subjects varied from 7.1% (MI) to 30.6% (GA). Twenty-three percent of admissions arrived at the emergency department within 3 hours of onset. Overall 4.5% of ischemic stroke admissions were treated with recombinant tissue plasminogen activator; site-specific treatment rates were 3.0% (GA), 3.2% (OH), 3.4% (MI), and 8.5% (MA). Only a small minority of treated patients (range, 10.8% [OH] to 19.6% [MI]) received recombinant tissue plasminogen activator within the recommended 1 hour door-to-needle time. A minority of eligible subjects were screened for dysphagia (45.4%), underwent lipid testing (33.6%), or received smoking-cessation counseling (21.4%). In contrast, compliance with antithrombotic treatments at discharge was high (91.5%).

CONCLUSIONS

A minority of acute stroke patients are treated according to established guidelines. Quality improvement interventions, targeted primarily at the healthcare systems level, are needed to improve acute stroke care in the United States.

Prevention of Venous Thromboembolism, Recurrent Stroke, and Other Vascular Events After Acute Ischemic Stroke: The Role of Low-Molecular-Weight Heparin and Antiplatelet Therapy

Patients with stroke or transient ischemic attacks (TIAs) are at increased risk of vascular events, such as recurrent stroke or venous thromboembolism (VTE), and thus the secondary prevention of such events is an important element of managing these patients. Current guidelines recommend that patients with acute stroke, restricted mobility, and no contraindications to anticoagulants receive thromboprophylactic therapy with low-dose unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), or heparinoids to prevent VTE. This recommendation is based on clinical trial evidence that UFH is effective in reducing the incidence of deep vein thrombosis (DVT) after stroke. LMWHs have been shown to be at least as effective as UFH in preventing VTE, and offer advantages in terms of a more predictable anticoagulant effect, lower risk of bleeding, and ease of administration. However, adequately powered trials are needed to confirm their relative benefits and risks; the Prevention of VTE after Acute Ischemic Stroke with LMWH (PREVAIL) study with enoxaparin, currently in progress, should provide valuable information in this context. Antiplatelet therapy has been shown to be effective in preventing recurrent vascular events, as evidenced by the results of studies such as the Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events (CAPRIE) trial. In contrast, evidence for the efficacy of LMWH in this situation is contradictory. Given the potential benefits of LMWH in preventing VTE in stroke patients, a potential rationale exists for combination therapy with antiplatelet agents and LMWHs. Clinical trials with such combinations are warranted.

Primary intracerebral hemorrhage

This article reviews the epidemiology, pathophysiology and management of primary intracerebral hemorrhage. In North American and European populations, 15% of strokes are due to intracerebral hemorrhage. Pathologically in hypertension, early arteriolar proliferation of smooth muscle is followed later by smooth muscle cell death and collagen deposition. This eventually leads to occlusion or ectasia of arterioles. The latter leads to Charcôt-Bouchard aneurysm formation and possible intracerebral hemorrhage. Amyloid deposition in the tunica media causes similar brittle arterioles. Fibrin globes in concentric spheres attempt to seal off the site of bleeding. But vasculopathy (either amyloid or hypertensive) inhibits the contractile capability of arterioles. The size of the final sphere of blood at cessation of bleeding determines the clinical spectrum, from asymptomatic to fatal. Since arteriolar bleeding is slower than arterial bleeding, several hours exist where intervention may be useful. While medical intervention is controversial, guidelines for blood pressure, intracranial pressure, glucose and seizure management exist. Surgical trials have tended to show no benefit. Recombinant factor VIIa is undergoing investigation as hemostatic therapy for intracerebral hemorrhage, to limit clot expansion and possibly also as a hemostatic adjunct to surgery.

High prevalence of previous antiplatelet drug use in patients with new or recurrent ischemic stroke: Buffalo metropolitan area and Erie County stroke study

STUDY OBJECTIVE

To determine the proportion of patients in a large metropolitan population who developed ischemic stroke despite having received antiplatelet drug therapy, and their associated characteristics and in-hospital outcomes.

DESIGN

Retrospective, cross-sectional study.

SETTING

Eleven hospitals in western New York State.

PATIENTS

One thousand five hundred eighty-two patients with new or recurrent ischemic stroke who were admitted to one of the 11 study hospitals between January 1 and December 31, 2000, and for whom data were available regarding previous drug therapy.

MEASUREMENTS AND MAIN RESULTS

The proportion of patients taking antiplatelet drugs before the onset of stroke was determined. Demographic and clinical characteristics, stroke subtypes, in-hospital bleeding complications, mortality, and discharge drugs were compared between patients with and those without previous antiplatelet drug use. Previous use of antiplatelet drugs was observed in 642 (41%) of the 1582 patients admitted with ischemic stroke. The antiplatelet drugs were aspirin alone (494 patients), clopidogrel alone (70), aspirin and clopidogrel (36), aspirin in combination with other antiplatelet drugs (20), and others (22). Patients with previous use of antiplatelet drugs were older and more likely to have hypertension, diabetes mellitus, hyperlipidemia, and a history of cardiovascular disease. The proportion of patients with large-vessel disease was greater among patients with previous use of antiplatelet drugs. Patients with previous use of antiplatelet drugs were more likely to be discharged with aspirin, clopidogrel, and an aspirin-dipyridamole combination.

CONCLUSION

The relatively high proportion of patients who developed ischemic stroke despite taking antiplatelet drugs observed in this regional hospital-based study mandates clinical trials specifically addressing therapeutic intervention for this group of patients.

Diffusion-weighted magnetic resonance imaging versus computed tomography in the diagnosis of acute ischemic stroke

Current treatment protocols using reperfusion therapy for acute ischemic stroke rely on non-contrast computed tomography (NCCT), with most indications including the absence of acute hemorrhage or large volume of infarction in the presence of clinical signs and symptoms. This predictably results in a significant incidence of the administration of reperfusion therapy to patients with "stroke mimics," such as migraine headache or Todd's paralysis after a seizure. Diffusion-weighted imaging (DWI) is a technique based on magnetic resonance imaging (MRI) that may be more sensitive and specific for acute cerebral ischemia than NCCT. In addition, data for techniques such as perfusion-weighted imaging can be acquired with minimal additional time required. This may allow better risk assessment of a clinical response to reperfusion therapy vs. the possibility of hemorrhagic complications. This article describes a methodical review of studies comparing the sensitivity, specificity, positive predictive value, and negative predictive value of DWI vs. NCCT in the evaluation of acute ischemic stroke. Data from studies meeting our screening criteria are combined to produce overall values for each.

Delay in initiation and termination of tibialis anterior contraction in lower-limb hemiparesis: relationship to lower-limb motor impairment and mobility

OBJECTIVE

To assess the relationship between delays in initiation and termination of tibialis anterior contraction in the hemiplegic lower limb and clinical measures of lower-limb motor impairment and mobility.

DESIGN

Cross-sectional correlational study.

SETTING

Outpatient rehabilitation clinic of an academic medical center.

PARTICIPANTS

Convenience sample of 22 chronic stroke survivors with lower-limb hemiparesis.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Delays in initiation and termination of tibialis anterior electromyographic activity during isometric contraction, lower-limb Fugl-Meyer Assessment (FMA), and Modified Emory Functional Ambulation Profile (mEFAP).

RESULTS

The affected lower limb exhibited significantly longer delays in initiation and termination of tibialis anterior contraction relative to the unaffected limb. Delay in termination of 3-second tibialis anterior contraction of the affected limb correlated significantly with the FMA and mEFAP. However, delay in initiation of tibialis anterior contraction did not correlate with clinical measures.

CONCLUSIONS

Delay in termination of muscle activity in the hemiparetic lower limb may have important clinical implications, but delay in initiation did not correlate with clinical measures. Controlled, interventional trials are needed to demonstrate a cause and effect relationship.

Stroke: epidemiology, classification, risk factors, complications, diagnosis, prevention, and medical and dental management

Cerebrovascular accident, or stroke, refers to an acute onset of neurologic deficits lasting more than 24 hours or culminating in death caused by a sudden impairment of cerebral circulation. Stroke is the third leading cause of death and a major cause of long-term disability in the United States. This article provides the dental community with an up-to-date understanding of the epidemiology, classification, risk factors, complications, diagnosis, prevention, and medical and dental management issues pertaining to stroke.

Efficacy of thrombolytic (rt-PA) therapy in old stroke patients: the Perugia Stroke Unit experience

The use of intravenous recombinant tissue plasminogen activator (rt-PA) administered within 3 hrs from symptom onset is beneficial in selected patients independent of age; although oldest patients (> or = 80 years) are excluded a priori. We report an experience relative to rt-PA treatment in the oldest patients including outcome at 3 months. Data were from the hospital-based Perugia Stroke Registry. Seventy-two consecutive acute stroke patients, fulfilling NINDS and EUSI-criteria were treated with rt-PA of these 23 patients (30.5%) were > or = 80 years. The median and mean age were, respectively, 72.5 and 71.1 +/- 12.7 years (range 35-94). The proportion of favorable outcome at 3-months did not differ between groups (55% elderly versus 51.1% of younger patients). Proportions of unfavorable outcome and death from baseline were similar in both groups of patients. Age did not influence prognosis in patients treated with rt-PA. The oldest stroke patients should not be excluded from rt-PA treatment on the basis of age per se.

Detection of carotid stenosis in African Americans with ischemic heart disease

OBJECTIVES

This study was conducted to define the frequency of internal carotid stenosis in African American patients with ischemic heart disease (IHD).

METHODS

We recruited 101 African American patients with IHD from a university medical center for carotid duplex examination.

RESULTS

The frequency of >30%, >50%, and >70% stenosis was 21%, 11%, and 5%, respectively. Age >60 years (21% vs 3%, P < .01) and diabetes mellitus (22% vs 5%, P < .01) were predictors of unilateral stenosis of >50% and remained significant on multivariate testing.

CONCLUSION

African American patients with established IHD have higher rates of extracranial carotid stenosis than community dwelling African American subjects and comparable rates with other populations.

Data mining for improved cardiac care

Cardiovascular Disease (CVD) is the single largest killer in the world. Although, several CVD treatment guidelines have been developed to improve quality of care and reduce healthcare costs, for a number of reasons, adherence to these guidelines remains poor. Further, due to the extremely poor quality of data in medical patient records, most of today's healthcare IT systems cannot provide significant support to improve the quality of CVD care (particularly in chronic CVD situations which contribute to the majority of costs).We present REMIND, a Probabilistic framework for Reliable Extraction and Meaningful Inference from Nonstructured Data. REMIND integrates the structured and unstructured clinical data in patient records to automatically create high-quality structured clinical data. There are two principal factors that enable REMIND to overcome the barriers associated with inference from medical records. First, patient data is highly redundant -- exploiting this redundancy allows us to deal with the inherent errors in the data. Second, REMIND performs inference based on external medical domain knowledge to combine data from multiple sources and to enforce consistency between different medical conclusions drawn from the data -- via a probabilistic reasoning framework that overcomes the incomplete, inconsistent, and incorrect nature of data in medical patient records.This high-quality structuring allows existing patient records to be mined to support guideline compliance and to improve patient care. However, once REMIND is configured for an institution's data repository, many other important clinical applications are also enabled, including: quality assurance; therapy selection for individual patients; automated patient identification for clinical trials; data extraction for research studies; and to relate financial and clinical factors. REMIND provides value across the continuum of healthcare, ranging from small physician practice databases to the most complex hospital IT systems, from acute cardiac care to chronic CVD management, and to experimental research studies. REMIND is currently deployed across multiple disease areas over a total of 5,000,000 patients across the US.

Temporal trends in the incidence and case fatality of stroke in children and adolescents

A recent study reported that mortality from stroke in children and adolescents decreased by 58% from 1979 to 1998, although it wasn't clear if the case fatality or the incidence of stroke in this age group is decreasing. We report trends of stroke incidence and case fatality in children and adolescents within a large biracial population. The study involved collection of all strokes in the study population between January 1, 1988 and December 31, 1989, July 1, 1993 and June 30, 1994, and January 1, 1999 and December 31, 1999, at all of the regional hospitals serving the Greater Cincinnati/Northern Kentucky population (only the children's hospital in 1988). Study nurses reviewed the medical records of all inpatients with stroke-related discharge diagnoses and abstracted relevant data. A study physician reviewed each abstract to determine whether a stroke or transient ischemic attack had occurred. A total of 54 strokes occurred in children or adolescents younger than 20 years during the three study periods (30% African American, 70% Caucasian, and 56% female). The overall incidence rate of all strokes in children younger than 15 years was 6.4/100,000 in 1999, a nonsignificant increase when compared to 1988. The 30-day case-fatality rates were 18% in 1988-1989, 9% in 1993-1994, and 9% in 1999. We found that the incidence of strokes in children has been stable over the past 10 years. The previously reported nationwide decrease in overall stroke mortality in children might be due to decreasing case fatality after stroke and not decreasing stroke incidence. Based on our data, we conservatively estimated that approximately 3000 children less than 20 years old would have a stroke in the United States in 2004.

Trends in hospitalization and mortality for subarachnoid hemorrhage and unruptured aneurysms in the United States

OBJECTIVE

During the past decade, endovascular obliteration of intracranial aneurysms and new treatments for vasospasm and cerebral ischemia have been introduced. To analyze the effectiveness of these new strategies, we evaluated changes in morbidity and mortality rates in patients at least 18 years of age who were hospitalized for ruptured and unruptured intracranial aneurysms during the past 16 years.

METHODS

National estimates of hospitalization for subarachnoid hemorrhage (SAH) and unruptured intracranial aneurysms and associated in-hospital outcomes and mortality were obtained from National Hospital Discharge Survey data. All the variables pertaining to hospitalization were compared for three distinct time periods: 1986-1990, 1991-1995, and 1996-2001.

RESULTS

There were 94,692, 104,746, and 133,269 admissions for SAH during the periods 1986-1990, 1991-1995, and 1996-2001, respectively. Mortality rates for hospitalizations related to SAH demonstrated no significant change in mortality during the periods 1986-1990, 1991-1995, and 1996-2001 (27.6%, 24.6%, and 26.3%, respectively. Procedures performed for SAH from 1996 to 2001 included surgical clipping (28%), endovascular/wrapping (2%), and no procedure (70%). The number of admissions for unruptured intracranial aneurysms was 23,481 from 1986 to 1990, 28,017 from 1991 to 1995, and 51,904 from 1996 to 2001. There was an overall trend (P = 0.07) toward reduced in-hospital mortality during the three periods: 5.9%, 6.3%, and 1.4% for 1986-1990, 1991-1995, and 1996-2001, respectively.

CONCLUSION

The mortality rate for unruptured intracranial aneurysms demonstrates a significant trend of reduction during the past 16 years. The mortality rate for SAH demonstrates limited change during the same period; it is presumed that this is attributable to the multitude of factors that influence outcome.

Pharmacologic management of ischemic stroke: relevance to stem cell therapy

Pharmacologic management of the acute phase of the ischemic stroke includes treating the physical and medical conditions that can worsen cerebral injury; administering intravenous thrombolytic therapy (recombinant tissue plasminogen activator) in those who meet current guidelines; instituting prophylactic measures to prevent medical complications; and initiating passive rehabilitation measures. New approaches under investigation include intra-arterial thrombolytic therapy; endovascular embolectomy and clot disruption; and neuroprotective treatments to preserve surviving ischemic tissue. One neuroprotective agent given within 6 h after stroke onset, NXY059, recently met the primary outcome measure in a phase III clinical trial. Pharmacologic management of the subacute and chronic phases involves treatment of risk factors for recurrent stroke and other forms of cardiovascular disease, including hypercholesterolemia, hypertension, and diabetes mellitus. In this phase, antiplatelet therapy can be initiated or continued; smoking, obesity and alcohol intake can be managed; and active rehabilitation can begin through physical, occupational, and speech therapy. A few medications to augment rehabilitation have shown promising results in small clinical trials, but none have been tested in large phase III trials or approved by the US or European regulatory agencies. Thus, there are no pharmacologic measures available to enhance central nervous system restorative processes after acute stroke, and implantation of stem cells provides one promising approach, not only for cell replacement but also for the provision of therapeutic molecules.

Hyperacute therapy of acute ischemic stroke: intraarterial thrombolysis and mechanical revascularization strategies

Ischemic stroke is a major cause of morbidity and mortality. Despite the fact that it is the third most common cause of death in the United States, there is only one FDA approved treatment for patients. This is Intravenous recombinant tissue plasminogen activator given within 3 hours of symptom onset. Furthermore, despite the approval of this drug, it has been underutilized in the community. The limited time window of 3 hours disqualifies many patients from receiving the drug. In addition, fears of intracranial hemorrhage have resulted in underutilization of the drug in the community setting. Efforts to increase the time window to treatment include utilization of the intraarterial route for delivery of thrombolytic drug and interventional mechanical strategies to revascularize intracranial vessels. In this report we review the major intraarterial thrombolysis trials and review the mechanical strategies being developed to treat patients with acute ischemic stroke.

Opening the black box of post-stroke rehabilitation: stroke rehabilitation patients, processes, and outcomes

DeJong G, Horn SD, Conroy B, Nichols D, Healton EB. Opening the black box of post-stroke rehabilitation: stroke rehabilitation patients, processes, and outcomes. This article introduces the journal's supplement devoted to the methods and findings of the 7-site Post-Stroke Rehabilitation Outcomes Project (PSROP), a study designed to provide a very granular in-depth understanding of stroke rehabilitation practice and how practice is related to outcomes. The article summarizes current knowledge about the effectiveness of post-stroke rehabilitation, outlines where the PSROP fits into the broader traditions of stroke rehabilitation outcomes research, underscores the study's methodologic innovations, and summarizes the scope of the articles that follow.

Antithrombotic and Thrombolytic Therapy for Ischemic Stroke

Thrombolytic and antithrombotic agents form the cornerstone of stroke treatment and prevention. Recombinant tissue plasminogen activator improves outcome in patients treated within 3 hours of stroke onset. Emerging trials are directed to extend the therapeutic window and identify agents that could provide better safety profiles. Large, randomized trials have also highlighted the effectiveness and safety of early and continuous antiplatelet therapy in reducing atherothrombotic stroke recurrence. Aspirin has become the antiplatelet treatment standard against which several other antiplatelet agents have been shown to be more effective. The prevention of cardioembolic stroke is best accomplished with oral anticoagulation, barring any contraindications.

Fibrinolytic treatment for acute ischaemic stroke

Ischaemic stroke is a leading cause of death and disability in the US. At present, intravenous administration of tissue plasminogen activator within 3 h of symptom onset is the only proven effective treatment for patients with acute ischaemic stroke. Unfortunately, most treated patients do not make a functional recovery and very few patients presenting with acute stroke qualify for intravenous tissue plasminogen activator therapy. The focus of current research is to extend the therapeutic window for intervention beyond 3 h, and to improve the outcome of treated patients. The purpose of the present paper is to describe the current state of affairs for intravenous plasminogen activators, and to review recently published research. Agents and strategies under investigation include the intra-arterial delivery of plasminogen activators or antiplatelet agents, as well as combined intravenous/intra-arterial protocols.

Time to hospital arrival, use of thrombolytics, and in-hospital outcomes in ischemic stroke

OBJECTIVE

To determine the interval between symptom onset and hospital arrival and its relationship to baseline clinical characteristics, use of thrombolysis, and in-hospital outcomes in patients with acute ischemic stroke admitted to the 11 hospitals in the Buffalo metropolitan area and Erie County.

METHODS

The medical records of 1,590 patients were reviewed to determine the severity of the neurologic deficits (NIH Stroke Scale [NIHSS]), in-hospital mortality, favorable outcome (modified Rankin Scale score of < or = 2 at discharge), and strata of time interval between symptom onset and hospital arrival.

RESULTS

The time interval between symptom onset and hospital arrival was 0 to 3 hours in 337 (21%) patients, 3 to 6 hours in 177 (11%) patients, 6 to 24 hours in 301 (19%) patients, > 24 hours in 420 (26%) patients, and undetermined in 355 (22%) patients. IV (n = 23) and intra-arterial (n = 4) thrombolysis was used in 27 (8%) of the 337 patients that presented within 3 hours of symptom onset. In 1,235 patients with known time interval between symptom onset and hospital arrival, an association (p = 0.008) was observed between strata of increasing time interval and higher proportion of favorable outcomes at discharge. The initial NIHSS score was higher with decreasing interval between symptom onset and hospital arrival (p < 0.0001).

CONCLUSIONS

A small proportion of patients who present within 3 hours of symptom onset receive thrombolytic therapy. The observation that patients with more severe neurologic deficits and subsequently worse in-hospital outcomes appear to present early after symptom onset to the hospital may have implications for clinical studies.

Time course and outcome of recovery from stroke: relevance to stem cell treatment

Stroke is the third leading cause of death in the United States after heart disease and cancer; it has an incidence of approximately 750,000 cases per year, and it is a leading cause of disability in adults. The factors predicting a poor outcome from stroke include severe initial neurological dysfunction, hypertension, cardiac arrhythmias, myocardial infarction, hypercholesterolemia, and diabetes mellitus. The armamentarium available for improvement of neurological function after stroke is currently limited to placement in specialized stroke units, optimal therapy for medical complications, and intense physical, occupational and speech rehabilitation. Despite many trials, no pharmacological intervention has been shown convincingly to improve neurological outcome. This review was undertaken to determine the appropriate time for new approaches to the therapy of stroke such as the infusion of stem cells into the central nervous system. The literature shows in large case series that functional recovery from stroke reaches a maximum level by 3-6 months after onset, and no further recovery occurs beyond this time. Nevertheless, about 80% of these patients reach their maximum function for activities of daily living within 6 weeks from onset. Initiation of a clinical trial of stem cell therapy would require demonstration of optimal clinical improvement by neurological evaluations, with no change over at least 4 weeks of observation. Accordingly, in subjects with first-ever ischemic stroke who remained neurologically unchanged from the second until the third month after the acute event, implementation of stem cell therapy would be appropriate at approximately 3 months after the stroke.

Intracardiac Devices for Stroke Prevention

Stroke is a significant cause of serious disability and death worldwide. A substantial proportion of strokes are related to an underlying cardiac embolic source, most commonly in association with atrial arrhythmias (fibrillation/flutter). Atrial fibrillation is considered a major risk factor for stroke. Although long-term prophylactic oral anticoagulation has been shown to be very effective in reducing stroke in patients with atrial fibrillation, it has a number of major limitations and is not feasible in all patients. In such cases, the use of percutaneously (transvenous) implanted left atrial appendage occlusive devices or surgical appendage obliteration is being explored. Similarly, the presence of a patent foramen ovale, especially in the presence of an atrial septal aneurysm, is now recognized as an important potential mediator of paradoxical cardiogenic embolism. Percutaneous patent foramen ovale closure is becoming increasingly established as a safe and effective means of preventing recurrent strokes in the presence of a patent foramen ovale. In this account, the authors discuss the intracardiac devices and techniques available and the relative merits of their use for stroke prevention.

Modern Emergent Stroke Imaging: Pearls, Protocols, and Pitfalls

Stroke remains one of the most important clinical diagnoses for which patients are referred to the radiologist for emergent imaging. Timely and accurate imaging guides admission from the emergency department or transfer to a hospital with a dedicated stroke service, triage to the intensive care unit, anticoagulation, thrombolysis, and many other forms of treatment and management. It is important to approach each patient's imaging needs logically and tailor each work-up, and constantly to review the entire process for potential improvements. Time saved in getting an accurate diagnosis of stroke may indeed decrease morbidity and mortality. This article discusses the current management of stroke imaging and reviews the relevant literature.

Risperidone treatment in elderly patients with dementia: relative risk of cerebrovascular events versus other antipsychotics

BACKGROUND

The possibility that low-dose antipsychotic treatment is associated with increased risk of cerebrovascular events (CVEs) in elderly patients with dementia has been raised. The objective was to determine whether risperidone is associated with an increased risk of CVEs relative to other commonly considered alternative treatments.

METHODS

An analysis of Medicaid data from 1999 to 2002, representing approximately 8 million enrollees from multiple states, was conducted. The primary outcome was the incidence of acute inpatient admission for a CVE within 3 months following initiation of treatment with atypical antipsychotics (risperidone, olanzapine, quetiapine, or ziprasidone), haloperidol, or benzo-diazepines.

RESULTS

Descriptive analyses found similar rates of incident CVEs across evaluated agents. Multivariate analyses found no differences in comparisons of risperidone with olanzapine or quetiapine. Risperidone and other antipsychotics as a group were also not associated with a higher odds ratio (OR) of incident CVE than either haloperidol or benzodiazepines. With risperidone as the reference group: olanzapine, OR = 1.05, 95% CI 0.63-1.73; quetiapine, OR = 0.66, 95% CI 0.23-1.87; haloperidol, OR = 1.91, 95% CI 1.02-3.60; benzodiazepines, OR = 1.97, 95% CI 1.30-2.98. With benzodiazepines as the reference group, the OR of incident CVE for all antipsychotics as a class was 0.49, 95%CI 0.35-0.69.

CONCLUSIONS

This study found no significant difference in the incidence of CVEs between patients taking risperidone and those taking other atypical antipsychotics. Risperidone and all atypical antipsychotics were not associated with higher risk than two common treatment alternatives (haloperidol and benzodiazepines). These findings do not support the conclusion that risperidone is associated with a higher risk of CVE than other available treatment alternatives. The data also suggest that patient characteristics other than antipsychotic use are more significant predictors of CVEs. Given the relatively low rates of incident CVEs, a larger sample of patients with groups closely balanced on a wide spectrum of potential risk factors could provide a more precise assessment of risk.

Stroke subtypes among young patients with systemic lupus erythematosus

PURPOSE

Systemic lupus erythematosus (lupus) is a systemic inflammatory disease associated with premature atherosclerosis, vasculitis, coagulopathy, and excessive incidence of stroke, especially among young patients. Little is known about subtypes of stroke in lupus.

METHODS

A 20% sample of all the hospitalizations in the United States in the years 2001 and 2002 (N approximately 15 million) were analyzed to identify hospitalizations of young patients (age < or =50 years) with systemic lupus erythematosus (n=25704). Proportions of hospitalization for stroke subtypes were compared between the lupus group and the general population group. Age- and sex-adjusted odds ratios for stroke were calculated with logistic regression models.

RESULTS

In the lupus group, there were 313 hospitalizations for stroke of which 206 hospitalizations had stroke as the primary diagnosis. Age- and sex-adjusted stroke risk was higher among the lupus group (odds ratio 1.5, 95% confidence interval 1.3-1.8). Patients with lupus had higher risk for all stroke subtypes except in subarachnoid hemorrhage in which a trend toward a lower risk was observed (odds ratio 0.57, 95% confidence interval 0.34-0.96). Although 12.3% (n=38) of stroke admissions in the lupus group resulted in in-hospital death, this case fatality rate was not statistically different from that for stroke in the general population group.

CONCLUSIONS

Stroke is an important poor outcome in young patients with lupus. Compared with the general population, patients with lupus are more likely to be hospitalized for the risk of ischemic stroke and intracerebral hemorrhage. The risk of subarachnoid hemorrhage, however, seems to be lower in patients with lupus.

Obstructive sleep apnea as a risk factor for stroke and death

BACKGROUND

Previous studies have suggested that the obstructive sleep apnea syndrome may be an important risk factor for stroke. It has not been determined, however, whether the syndrome is independently related to the risk of stroke or death from any cause after adjustment for other risk factors, including hypertension.

METHODS

In this observational cohort study, consecutive patients underwent polysomnography, and subsequent events (strokes and deaths) were verified. The diagnosis of the obstructive sleep apnea syndrome was based on an apnea-hypopnea index of 5 or higher (five or more events per hour); patients with an apnea-hypopnea index of less than 5 served as the comparison group. Proportional-hazards analysis was used to determine the independent effect of the obstructive sleep apnea syndrome on the composite outcome of stroke or death from any cause.

RESULTS

Among 1022 enrolled patients, 697 (68 percent) had the obstructive sleep apnea syndrome. At baseline, the mean apnea-hypopnea index in the patients with the syndrome was 35, as compared with a mean apnea-hypopnea index of 2 in the comparison group. In an unadjusted analysis, the obstructive sleep apnea syndrome was associated with stroke or death from any cause (hazard ratio, 2.24; 95 percent confidence interval, 1.30 to 3.86; P=0.004). After adjustment for age, sex, race, smoking status, alcohol-consumption status, body-mass index, and the presence or absence of diabetes mellitus, hyperlipidemia, atrial fibrillation, and hypertension, the obstructive sleep apnea syndrome retained a statistically significant association with stroke or death (hazard ratio, 1.97; 95 percent confidence interval, 1.12 to 3.48; P=0.01). In a trend analysis, increased severity of sleep apnea at baseline was associated with an increased risk of the development of the composite end point (P=0.005).

CONCLUSIONS

The obstructive sleep apnea syndrome significantly increases the risk of stroke or death from any cause, and the increase is independent of other risk factors, including hypertension.

Tissue plasminogen activator for acute ischemic stroke: A New York city emergency medicine perspective

Nationally, only 2-3% of patients with acute ischemic stroke (AIS) currently receive tissue plasminogen activator (TPA). To better understand the reasons, we investigated the practice patterns, level of familiarity and acceptance of TPA for AIS among emergency physicians in New York City (NYC). Fifty-seven 911-receiving hospital emergency department directors were surveyed regarding TPA use. Of those responding, 37% had never used TPA to treat AIS. Lack of neurological support was reported by 33%. Departments with formal protocols were more likely to use TPA for AIS. In conclusion, there is considerable variation in the practice, knowledge, and attitudes regarding the use of TPA for AIS in NYC emergency departments. Improved educational efforts and institutional support may be necessary to ensure the appropriate use of TPA by emergency physicians.

Cerebrovascular diseases as primary hospital discharge diagnoses: national trend (1970-2000) among older adults

BACKGROUND

Cerebrovascular diseases are a common cause of mortality, morbidity, and hospitalization among older adults. However, the long-term national trends in cerebrovascular disease-related hospitalizations in this age group are not well known.

METHODS

We used the National Center for Health Statistics trend data from the National Hospital Discharge Surveys (1970-2000) to determine incidence of cerebrovascular disease-related hospitalizations among persons 65 years and older in the United States. Only patients discharged with a primary discharge diagnosis of cerebrovascular disease were included. We estimated rates of hospitalization per 1000 civilian residents 65 years and older, for all patients and stratified by age, sex, and race.

RESULTS

Among persons 65 years of age and older, the total number of cerebrovascular disease-related hospitalizations increased from 372,000 in 1970 to 711,000 in 2000. However, the rates of hospitalization due to cerebrovascular disease remained unchanged at 20.7/1000 in 1970 and 20.4/1000 in 2000. The rates for persons 75-84 years and >85 years were, respectively, 2 and 3 times higher than that for persons 65-74 years throughout the study period. Rates for men and women were comparable and stable during the study period. Rates for African Americans, in contrast, increased from 14/1000 in 1970 to 20.6/1000 in 2000, peaking in 1985 (27.4/1000).

CONCLUSIONS

The overall rates of hospitalization due to cerebrovascular disease remained high yet stable. However, the absolute number of hospitalizations due to cerebrovascular disease increased considerably, with potential for serious social, financial, and public health implications for the coming decades.

Patent Foramen Ovale and Stroke: Prognosis and Treatment in Young Adults

A patent foramen ovale (PFO) is found with increased frequency in patients with stroke of undetermined origin but the significance and therapeutic implications of this observation remain unclear. Several lines of evidence suggest a role for the PFO in stroke pathophysiology for some cryptogenic stroke patients, such as those whose PFO is accompanied by a prothrombotic state, atrial septal aneurysm, or lower extremity/pelvic DVT. Diagnostic evaluation of the patient with cryptogenic stroke and PFO is directed at identifying these subgroups. Appropriate therapy for primary and secondary stroke prevention in a subject with a PFO remains unclear given current uncertainties as to the pathophysiological significance of PFO. Additional studies are needed, such as those focused on lower extremity veins or the cardiac interatrial septum, to guide therapy in specific stroke subpopulations.

The timed up & go test: its reliability and association with lower-limb impairments and locomotor capacities in people with chronic stroke

OBJECTIVES

To examine test-retest reliability of the Timed Up & Go (TUG) test, its ability to differentiate subjects with chronic stroke from healthy elderly subjects, and its associations with ankle plantarflexor spasticity, ankle muscle strength, gait performance, and distance walked in 6 minutes in subjects with chronic stroke.

DESIGN

Cross-sectional study.

SETTING

University-based rehabilitation center in Hong Kong, China.

PARTICIPANTS

Ten healthy elderly subjects and 11 subjects with chronic stroke.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Time taken to complete the TUG test was recorded. Plantarflexor spasticity and ankle muscle strength were assessed, respectively, by the Composite Spasticity Scale and a load-cell together with electromyography. Gait parameters and walking endurance were measured respectively by walkway system (GAITRite II) and 6-minute walk test. Intraclass correlation coefficients (ICCs) were calculated as measures of reliability, and all correlation analyses were conducted using Spearman correlation coefficients.

RESULTS

The TUG test showed excellent reliability (ICC>.95). Subjects with chronic stroke had significantly more spastic and weaker plantarflexors, slower walking speeds, and poorer walking endurance when compared with healthy elderly subjects (all P<.003). The strength of the affected ankle plantarflexors (rho=-.860, P<.01), gait parameters (rho range, .620-.900; P<.05), and walking endurance (rho=-.960, P<.01) correlated with TUG scores.

CONCLUSIONS

The TUG scores were reliable, were able to differentiate the patients from the healthy elderly subjects, and correlated well with plantarflexor strength, gait performance, and walking endurance in subjects with chronic stroke.

Place of drug therapy in the treatment of carotid stenosis

Carotid stenosis is an important cause of transient ischaemic attacks and stroke. The cause of carotid stenosis is most often atherosclerosis; contributing to the pathogenesis of the lesion are endothelial injury, inflammation, lipid deposition, plaque formation, fibrin, platelets and thrombin. Carotid stenosis accounts for 10-20% of cases of brain infarction, depending on the population studied. Despite successful treatment of selected patients who have had an acute ischaemic stroke with tissue plasminogen activator and the promise of other experimental therapies, prevention remains the best approach to reducing the impact of ischaemic stroke. High-risk or stroke-prone patients can be identified and targeted for specific interventions. At this juncture, treatment of carotid stenosis is a well established therapeutic target and a pillar of stroke prevention. There are two main strategies for the treatment of carotid stenosis. The first approach is to stabilise or halt the progression of the carotid plaque through risk factor modification and medication. Hypertension, diabetes mellitus, smoking, obesity and high cholesterol levels are closely associated with carotid stenosis and stroke; control of these factors may decrease the risk of plaque formation and progression. The second approach is to eliminate or reduce carotid stenosis through carotid endarterectomy or carotid angioplasty and stenting. Carotid endarterectomy, which is the mainstay of therapy for severe carotid stenosis, is beyond the scope of this review. Anticoagulants seem to play little role (if any) in the medical (i.e. non-surgical) treatment of carotid stenosis. Adoption of a healthy lifestyle combined with the reduction of risk factors has been shown to lead to a reduction in the extent of carotid stenosis. The medical treatment of carotid stenosis should be based on the triad of the reduction of risk factors, patient education, and use of antiplatelet agents.

A comparison of morning blood pressure surge in African Americans and whites

African Americans have twice the risk of suffering a stroke compared to whites, but the reasons for this disparity have yet to be elucidated. Recent data suggest that the morning blood pressure (BP) surge is an independent predictor of strokes. Whether African Americans and whites differ with respect to morning BP surge is unknown. African-American (n=183) and white (n=139) participants, age 18-65, were studied with 24-hour ambulatory BP monitoring. Morning surge was defined as morning BP minus the trough BP during sleep. The morning surge was significantly lower in African Americans than in whites (23 mm Hg vs. 27 mm Hg; both SEM=1.0; p=0.009). This relationship was no longer evident after adjusting for gender, age, and body mass index (23 mm Hg vs. 26 mm Hg; SE=1.0 and 1.1; p=nonsignificant). Morning BP surge is unlikely to account for differences in stroke incidence between African Americans and whites.

Intravenous thrombolysis in acute ischaemic stroke: optimising its use in routine clinical practice

Stroke is a common and important medical problem. Intravenous thrombolysis with alteplase (recombinant tissue plasminogen activator; rtPA) is the only available direct treatment that reduces neurological injury following ischaemic stroke. Strong efficacy data from randomised, controlled trials support the use of intravenous thrombolysis to improve outcomes for patients with acute ischaemic stroke. Numerous studies have provided effectiveness data that demonstrate that intravenous thrombolytic therapy can be given safely outside clinical trial settings. However, effectiveness studies have demonstrated that intravenous thrombolytic therapy is often given despite protocol violations when it is prescribed in routine clinical practice. Protocol violations must be avoided because they are associated with adverse events including higher mortality and increased haemorrhagic complications. Although thrombolytic therapy with alteplase is currently being used in only <10% of patients with acute ischaemic stroke, recent studies demonstrate that quality management efforts can improve both the absolute rate of use as well as the proficiency with which alteplase is administered. Given the complexities inherent in prescribing thrombolysis for patients with acute ischaemic stroke, alteplase should be used by clinicians who are experienced in the diagnosis and management of stroke, working in medical centres that have systems in place to ensure that alteplase is given without protocol violations.

Physical activity and stroke risk

Stroke represents a leading cause of morbidity and mortality especially among the elderly people, and therefore the need for effective preventive strategies is imperative. The value of physical activity for stroke prevention is not as well established as for other cardiovascular diseases. Despite some conflicting results, the majority of published studies have demonstrated a negative association between physical activity and stroke risk. In this article, we provide a concise overview of the epidemiological studies that investigate this association as well as a comprehensive analysis of the most relevant underlying pathophysiological mechanisms.

Outcomes among valvular heart disease patients experiencing ischemic stroke or transient ischemic attack in Olmsted County, Minnesota

OBJECTIVE

To estimate the rates and predictors of survival and recurrence among residents of Olmsted County, Minnesota, who received an Initial diagnosis based on 2-dimensional color Doppler echocardiography of moderate or severe mitral or aortic stenosis or regurgitation and who experienced a first ischemic stroke, transient ischemic attack (TIA), or amaurosis fugax.

PATIENTS AND METHODS

At the Mayo Clinic in Rochester, Minn, we used the resources of the Rochester Epidemiology Project to identify Individuals who met the criteria for inclusion in the study and to verify exclusion criteria. The study included all residents of Olmsted County, Minnesota, who experienced a first Ischemic stroke, TIA, or amaurosis fugax within 30 days of or subsequent to receiving a first-time 2-dimensional color Doppler echocardlography-based diagnosis of moderate or severe mitral or aortic stenosis or regurgitation between January 1, 1985, and December 31, 1992. The Kaplan-Meier product-limit method was used to estimate the rates of subsequent stroke and death after the ischemic stroke, TIA, or amaurosis fugax. The Cox proportional hazards model was used to assess the effect of several potential risk factors on subsequent stroke occurrence and death.

RESULTS

For the 125 patients in the study, the Kaplan-Meier estimates of the risk of death and the risk of stroke at 2-year follow-up were 38.6% (95% confidence interval [CI], 29.9%-47.5%) and 18.5% (95% CI, 10.0%-27.0%), respectively. Compared with the general population, death rates were significantly Increased (standardized mortality ratio = 1.75; 95% CI, 1.38-2.19; P < .001) but rates of subsequent stroke occurrence were not (standardized morbidity ratio = 1.20; 95% CI, 0.75-1.84; P = .40). After adjustment for age, sex, and cardiac comorbidity, neither the type nor severity of valvular heart disease was an independent determinant of survival or subsequent stroke occurrence.

CONCLUSIONS

Patients with mitral or aortic valvular heart disease who experience Ischemic stroke, TIA, or amaurosis fugax have Increased rates of death, but not recurrent stroke, compared with expected rates. Other cardiovascular risk factors are more important determinants of survival In these patients than the type or echocardiographic severity of the valvular heart disease.

Possible pathophysiologic mechanisms supporting the superior stroke protection of angiotensin receptor blockers compared to angiotensin-converting enzyme inhibitors: clinical and experimental evidence

Stroke is a major cause of death and disability and its incidence increases linearly with age and the level of systolic and diastolic blood pressure. Stroke, besides being a cause of long-term disability for the affected person, also imposes a significant burden on society and healthcare costs. Although good blood pressure control is very critical for stroke prevention, angiotensin receptor blockers (ARBs) may be superior to angiotensin-converting enzyme inhibitors (ACEIs) for the same degree of blood pressure control. This hypothesis has clinical and experimental support. ARBs prevent stroke incidence by blocking the angiotensin II (AII), AT1 receptors preventing brain ischaemia and allowing AII to stimulate the unoccupied AT2 receptors, which improve brain ischaemia. ACEIs, by reducing AII generation, are less effective in preventing stroke. This hypothesis provides evidence that AII plays an important role in the prevention of stroke. Certain ARBs like losartan, and telmisartan, irbesartan and candesartan possess additional properties which may play a role in stroke prevention, which is independent of AII. These include antiplatelet aggregating, hypouricemic, antidiabetic and atrial antifibrillatory effects. However, the most critical factor in stroke prevention is good blood pressure control irrespective of drug used.

Thrombolytic treatment of acute cerebral infarction

Stroke is a common cause of death and disability throughout the world. Acute neurologic deficits due to ischemic injury deserve rapid recognition and diagnosis in order to provide effective therapy. Intravenous tissue plasminogen activator (t-PA) provided to carefully selected patients that can be treated within 3 hours of stroke onset results in improved outcome in these patients. Intra-arterial administration of t-PA within a 6-hour window is performed at several academic centers in patients with middle cerebral and other intracranial artery occlusions based on results of one randomized clinical trial and numerous case reports. Although acute therapy of ischemic stroke has received much attention since the approval of intravenous t-PA, only a small percentage of individuals suffering a stroke actually receive t-PA. This article will review the optimal management of the acute stroke patient and discuss thrombolytic clinical trials that have been completed as well as those that are in progress.

Epidemiology of stroke in African Americans and Hispanic Americans

Many minorities continue to experience disparities in the level of their personal health and overall health care in the United States. This article explores disparities in stroke as they relate to two minority populations: African Americans and Hispanic Americans. These two groups have been chosen for review and discussion because the available epidemiologic databases are relatively broad, and the authors have personal experience in the conduct of research studies in these populations.

Racial differences in demographics, acute complications, and outcomes in patients with subarachnoid hemorrhage: a large patient series

OBJECT

Few studies have focused on the impact of racial differences in demographics, clinical characteristics, acute complications, and outcomes of patients with aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to examine this issue.

METHODS

The authors evaluated prospectively collected data on 1711 adult patients with aneurysmal SAH who were entered into two randomized, double-blind, placebo-controlled trials conducted at neurosurgical centers in North America between 1991 and 1997. Admission characteristics, treatment modalities, in-hospital complications, and 3-month outcomes assessed by application of the Glasgow Outcome Scale were compared using the chi-square test, a t-test, the Wilcoxon rank-sum test, and multiple logistic regressions based on a significance level of 0.05 in 241 African-American, 1342 Caucasian, and 128 other racial minority patients. Caucasian patients were significantly older than patients of other races (p < 0.0001). African-American patients more frequently had a history of hypertension (p < 0.0001) and an elevated blood pressure at the time of admission (p < 0.0001). African-Americans and other racial minorities were more likely to have internal carotid artery aneurysms and Caucasians were more likely to have posterior circulation aneurysms (p = 0.0002). Rates of in-hospital complications were not significantly different except that pulmonary edema occurred more commonly in Caucasians (p = 0.036). After an adjustment was made for significant admission characteristics, the 3-month outcome was not significantly different among the races.

CONCLUSIONS

Race was not found to be a prognostic factor for outcome after aneurysmal SAH. The higher SAH mortality rate previously observed in African-American patients is likely a result of a higher incidence of SAH in this group. These findings highlight the importance of primary prevention programs aimed at modifying risk factors for SAH.

The reasons for geographic and racial differences in stroke study: objectives and design

The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study is a national, population-based, longitudinal study of 30,000 African-American and white adults aged > or =45 years. The objective is to determine the causes for the excess stroke mortality in the Southeastern US and among African-Americans. Participants are randomly sampled with recruitment by mail then telephone, where data on stroke risk factors, sociodemographic, lifestyle, and psychosocial characteristics are collected. Written informed consent, physical and physiological measures, and fasting samples are collected during a subsequent in-home visit. Participants are followed via telephone at 6-month intervals for identification of stroke events. The novel aspects of the REGARDS study allow for the creation of a national cohort to address geographic and ethnic differences in stroke.

Hyperacute Therapy of Ischemic Stroke: Intravenous Thrombolysis

Stroke is the third most common cause of death in the United States following heart disease and cancer. Following the success of thrombolysis for myocardial infarction in the early 1990s, major trials for evaluation of this new therapeutic approach for ischemic stroke were initiated. The majority of ischemic strokes are due to occlusion of a cerebral vessel by a blood clot. Occlusion of a cerebral blood vessel leads to a core of infracted tissue surrounded by a relatively hypoperfused but viable brain tissue (the ischemic penumbra), which can be potentially salvaged by rapid recanalization of the target vessel. The underlying rationale for introduction of thrombolytic drugs is the lysis of an obliterating thrombus and reestablishment of blood flow. In this article we review the major intravenous thrombolysis trials leading to approval of intravenous recombinant tissue plasminogen activator, the only FDA approved treatment available today for acute ischemic stroke.

The number of injections does not influence absorption of bupivacaine after cervical plexus block for carotid endarterectomy

STUDY OBJECTIVE

To investigate the efficacy and kinetics of bupivacaine when used for deep cervical plexus block (CPB), using either a single-injection or multiple-injections technique.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Operating room of a university hospital.

PATIENTS

Twenty-four adult patients (16 men, 8 women) scheduled for carotid endarterectomy.

INTERVENTIONS

Patients were randomly assigned to receive CPB either by a single injection or after 3 injections. Patients in the multiple-injections group received a total dose of 15 mL of 0.5% bupivacaine (5 mL each deposited at C2, C3, and C4 over 2 minutes). Patients in the single-injection group received a single 15-mL injection of 0.5% bupivacaine. After the deep CPB, a superficial CPB was performed with 20 mL of 0.5% bupivacaine in all patients.

MEASUREMENTS

An anesthesiologist and a surgeon graded the success of the block. Arterial plasma concentrations of bupivacaine were measured using liquid chromatography-mass spectroscopy.

MAIN RESULTS

No significant differences were seen between the 2 groups with respect to the mean peak concentration of bupivacaine (single injection 2314 +/- 1385 ng/mL vs multiple injections 2255 +/- 1105 ng/mL) or time to reach the maximal concentration (time to maximum concentration [single injection 12.1 +/- 7.2 minutes vs multiple injections 12.5 +/- 3.9 minutes]). Furthermore, there were no significant differences in mean block scores between the single-injection and the multiple-injections groups, evaluated either by the anesthesiologists or the surgeon.

CONCLUSIONS

The results of this study showed that the absorption of bupivacaine is independent of the number of injections after CPB, and that anesthesia for carotid endarterectomy may be accomplished successfully using either technique.