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

Patent foramen ovale and its relationship to stroke

This article discusses the relationship between patent foramen ovale and stroke, particularly in reference to paradoxical embolism as a cause of cryptogenic stroke.

Enoxaparin Versus Unfractionated Heparin in the Prevention of Venous Thromboembolism After Acute Ischemic Stroke: Rationale, Design, and Methods of an Open-Label, Randomized, Parallel-Group Multicenter Trial

BACKGROUND

Small sample size and methodologic limitations make it difficult to interpret and compare trials of low molecular-weight heparin (for example, enoxaparin) versus unfractionated heparin as prophylactic treatment for venous thromboembolism (VTE), that is, deep vein thrombosis and/or pulmonary embolism, in patients with acute ischemic stroke. This prospective, open-label, randomized, parallel-group, multicenter trial is designed to evaluate the efficacy and safety of enoxaparin versus unfractionated heparin for the prevention of VTE after acute ischemic stroke.

METHODS

Approximately 1760 patients with the diagnosis of acute ischemic stroke accompanied by leg paralysis will be randomly assigned (1:1) within 48 hours of stroke symptoms to receive enoxaparin (40 mg subcutaneously) once daily or unfractionated heparin (5000 U subcutaneously) every 12 hours for 10 +/- 4 days. Contrast venography will be used to evaluate asymptomatic patients after treatment for deep vein thrombosis. In addition, diagnostic algorithms will be used to objectively confirm or rule out VTE events for patients in whom upper- or lower-extremity deep vein thrombosis/pulmonary embolism is suggested.

RESULTS

The primary efficacy end point measure will be the cumulative occurrence of documented VTE during the initial treatment period. Secondary end points are VTE incidence; neurologic outcome at days 30, 60, and 90; safety; and health care resource use during initial hospitalization and during the 30- and 90-day follow-up periods.

CONCLUSIONS

This study will provide clinical and health economic data regarding the use of enoxaparin as primary prophylactic treatment of VTE in patients who have had an acute ischemic stroke.

Brainstem Vascular Stroke Anatomy

Brainstem infarcts comprise approximately 10% of all first ischemic brain strokes. The extrinsic vascular supply to the stem is complex. The intrinsic vascularization of the stem may be conceptualized in terms of four relatively constant and distinct vascular territories designated anteromedial, anterolateral, lateral, and dorsal (or dorsolateral). The anatomic structures found within each intrinsic territory determine the symptomatology associated with infarction of that territory. This territorial anatomy permits the knowledgeable physician to plan an MR imaging examination tailored to the patient's history and to predict the patient's neurologic deficits from the MR imaging findings.

Applying the transtheoretical model to the exercise behaviors of stroke patients

Individuals with disabilities, including stroke, are frequently deconditioned. A variety of factors, including infrequent exercise participation, may be responsible for the deconditioning observed. According to the transtheoretical model (TTM), individuals progress through cognitive processes, termed stages, that indicate their readiness to undertake a particular healthy behavior, such as exercise. Our study examined 178 community-dwelling stroke patients' readiness to initiate an exercise program and their current exercise patterns. Using the Stages of Change Questionnaire, we found over 75% of respondents to be in the exercise preadoption stages of precontemplation, contemplation, or preparation. Moreover, participants classified in the postadoption stages of maintenance and action reported exercising significantly more than those in the preadoption stages. Individuals in the postadoption stages were also participating in significantly more sessions of strenuous or moderate exercise than those in the preadoption stages. It was concluded that the TTM is a valid theoretical framework to measure stroke patients' readiness to participate in exercise. However, additional research examining the psychosocial and functional factors mitigating these attitudes, and the stability of these attitudes, needs to be performed.

Comparison of warfarin and aspirin for symptomatic intracranial arterial stenosis

BACKGROUND

Atherosclerotic intracranial arterial stenosis is an important cause of stroke. Warfarin is commonly used in preference to aspirin for this disorder, but these therapies have not been compared in a randomized trial.

METHODS

We randomly assigned patients with transient ischemic attack or stroke caused by angiographically verified 50 to 99 percent stenosis of a major intracranial artery to receive warfarin (target international normalized ratio, 2.0 to 3.0) or aspirin (1300 mg per day) in a double-blind, multicenter clinical trial. The primary end point was ischemic stroke, brain hemorrhage, or death from vascular causes other than stroke.

RESULTS

After 569 patients had undergone randomization, enrollment was stopped because of concerns about the safety of the patients who had been assigned to receive warfarin. During a mean follow-up period of 1.8 years, adverse events in the two groups included death (4.3 percent in the aspirin group vs. 9.7 percent in the warfarin group; hazard ratio for aspirin relative to warfarin, 0.46; 95 percent confidence interval, 0.23 to 0.90; P=0.02), major hemorrhage (3.2 percent vs. 8.3 percent, respectively; hazard ratio, 0.39; 95 percent confidence interval, 0.18 to 0.84; P=0.01), and myocardial infarction or sudden death (2.9 percent vs. 7.3 percent, respectively; hazard ratio, 0.40; 95 percent confidence interval, 0.18 to 0.91; P=0.02). The rate of death from vascular causes was 3.2 percent in the aspirin group and 5.9 percent in the warfarin group (P=0.16); the rate of death from nonvascular causes was 1.1 percent and 3.8 percent, respectively (P=0.05). The primary end point occurred in 22.1 percent of the patients in the aspirin group and 21.8 percent of those in the warfarin group (hazard ratio, 1.04; 95 percent confidence interval, 0.73 to 1.48; P=0.83).

CONCLUSIONS

Warfarin was associated with significantly higher rates of adverse events and provided no benefit over aspirin in this trial. Aspirin should be used in preference to warfarin for patients with intracranial arterial stenosis.

Emerging medical and surgical management strategies in the evaluation and treatment of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) accounts for approximately 10% of all strokes and causes high morbidity and mortality. Rupture of the small perforating vessels of the cerebral arteries is caused by chronic hypertension, which induces pathologic changes in the small vessels and accounts for most cases of ICH; however, amyloid angiopathy and other secondary causes are being seen more frequently with the increasing age of the population. Recent computed tomographic studies have revealed that ICH is a dynamic process with up to one third of initial hemorrhages expanding within the first several hours of ictus. Secondary injury is believed to result from the development of cerebral edema and the release of specific neurotoxins associated with the breakdown products of hemoglobin. Treatment is primarily supportive. Surgical evacuation is the treatment of choice for patients with neurologic deterioration from infratentorial hematomas. Randomized trials comparing surgical evacuation to medical management have shown no benefit of surgical removal of supratentorial hemorrhages. New strategies focusing on early hemostasis, improved critical care management, and less invasive surgical techniques for clot evacuation are promising to decrease secondary neurologic injury. We review the pathophysiology of ICH, its medical management, and new treatment strategies for improving patient outcome.

Antithrombotic trials in acute ischaemic stroke: a selective review

Stroke is a common cause of morbidity and mortality throughout the US and the world. Given the highly disabling nature of this disease, it is important to provide acute therapy when indicated to improve individual outcomes. Recombinant tissue plasminogen activator (rt-PA) is, at present, the only approved drug for the treatment of acute strokes due to cerebral ischaemia. It can be given intravenously within a 3-h window of the onset of neurological deficits. Intra-arterial administration of rt-PA within a 6-h window is performed at several academic centres in patients with middle cerebral and other intracranial artery occlusions based on results of a randomised clinical trial. Other thrombolytic agents are being studied in randomised trials. Although acute therapy of ischaemic stroke has received much attention since the approval of rt-PA, only a small percentage of individuals actually receive rt-PA. This article will review the main thrombolytic agents and the trials performed thus far, as well as examine some important ongoing trials. How administration of acute thrombolytic therapy may evolve in the future will also be addressed.

Epidemiology of ischemic stroke in patients with diabetes: the greater Cincinnati/Northern Kentucky Stroke Study

OBJECTIVE

Diabetes is a well known risk factor for stroke, but the impact of diabetes on stroke incidence rates is not known. This study uses a population-based study to describe the epidemiology of ischemic stroke in diabetic patients.

RESEARCH DESIGN AND METHODS

Hospitalized cases were ascertained by ICD-9 discharge codes, prospective screening of emergency department admission logs, and review of coroner's cases. A sampling scheme was used to ascertain cases in the out-of-hospital setting. All potential cases underwent detailed chart abstraction by study nurses followed by physician review. Diabetes-specific incidence rates, case fatality rates, and population-attributable risks were estimated.

RESULTS

Ischemic stroke patients with diabetes are younger, more likely to be African American, and more likely to have hypertension, myocardial infarction, and high cholesterol than nondiabetic patients. Age-specific incidence rates and rate ratios show that diabetes increases ischemic stroke incidence at all ages, but this risk is most prominent before age 55 in African Americans and before age 65 in whites. One-year case fatality rates after ischemic stroke are not different between those patients with and without diabetes.

CONCLUSIONS

Given the "epidemic" of diabetes, with substantially increasing diabetes prevalence each year across all age- and race/ethnicity groups, the significance of diabetes as a risk factor for stroke is becoming more evident. Diabetes is clearly one of the most important risk factors for ischemic stroke, especially in those patients less than 65 years of age. We estimate that 37-42% of all ischemic strokes in both African Americans and whites are attributable to the effects of diabetes alone or in combination with hypertension.

Adverse Effects and Drug Interactions of Antithrombotic Agents Used in Prevention of Ischaemic Stroke

Stroke is the third most common cause of death in the US. Primary prevention of stroke can be achieved by control of risk factors including hypertension, diabetes mellitus, elevated cholesterol levels and smoking. Approximately one-third of all ischaemic strokes occur in patients with a history of stroke or transient ischaemic attack (TIA). The mainstay of secondary prevention of ischaemic stroke is the addition of medical therapy with antithrombotic agents to control the risk factors for stroke. Antithrombotic therapy is associated with significant medical complications, particularly bleeding.Low-dose aspirin (acetylsalicylic acid) has been shown to be as effective as high-dose aspirin in the prevention of stroke, with fewer adverse bleeding events. Aspirin has been shown to be as effective as warfarin in the prevention of noncardioembolic ischaemic stroke, with significantly fewer bleeding complications. Ticlopidine may be more effective in preventing stroke than aspirin, but is associated with unacceptable haematological complications. Clopidogrel may have some benefit over aspirin in preventing myocardial infarction, but has not been shown to be superior to aspirin in the prevention of stroke. The combination of clopidogrel and aspirin may be more effective than aspirin alone in acute coronary syndromes, but the incidence of adverse bleeding is significantly higher. Furthermore, the combination of aspirin with clopidogrel has not been shown to be more effective for prevention of recurrent stroke than clopidogrel alone, while the rate of bleeding complications was significantly higher with combination therapy. The combination of aspirin and extended-release dipyridamole has been demonstrated to be more effective than aspirin alone, with the same rate of adverse bleeding complications as low-dose aspirin. When selecting the appropriate antithrombotic agent for secondary prevention of stroke, the adverse event profile of the drug must be taken into account when assessing the overall efficacy of the treatment plan.

Treatable Potential Cardiac Sources of Embolism in Patients with Cerebral Ischemic Events: A Selective Transesophageal Echocardiographic Study

OBJECTIVES

To characterize cardiac sources of emboli detected by transesophageal echocardiography (TEE) in patients without recognizable cause of transient ischemic attack (TIA) and/or ischemic stroke and TIA.

METHODS

We examined a prospective registry that included all patients with TIA and/or stroke evaluated by TEE between July 2000 and August 2001 at our medical center. Ischemic events were classified according to clinical and neuroimaging findings as cortical, lacunar, or vertebrobasilar circulation. Demographic, clinical, neuroimaging, and echocardiographic characteristics were studied.

RESULTS

TEE was performed in 237 patients without recognized cause of TIA and/or stroke, of which 105 (44%) events were cortical, 35 (15%) were lacunar, 32 (14%) were vertebrobasilar, and 65 (27%) were in multiple distributions. Mean age of patients was 59 +/- 14 years (range, 21 to 93 years); 119 (51%) were men. Potential treatable cardioembolic sources were detected in 146 (61%) patients: patent foramen ovale with right-to-left shunt (n = 59), left atrial clot (n = 6), left atrial appendage clot (n = 8), and severe thoracic aortic atherosclerotic plaque disease (plaque thickness >4 mm) (n = 79 patients [33%], 56 had an ulcerated plaque and 4 had mobile plaque). Patient age and topography of the ischemic event did not correlate with TEE-defined cardioembolic sources.

CONCLUSIONS

TEE identified high frequencies of potential treatable cardioembolic sources in patients with ischemic events. TEE should be considered in all patients who do not have identified cause of TIA and/or stroke for early treatment and prevention of recurrent events.

Buffalo Metropolitan Area and Erie County Stroke Study: Rationale, Design, and Methods

OBJECTIVES

The primary objective of this study was to define the incidence, disability, and death associated with stroke in the Buffalo metropolitan area and Erie County. This area has the highest stroke rate in New York State and therefore represents an ideal site to develop a successful model for prevention and management of stroke.

DESIGN

A cross-sectional design to study all new and recurrent strokes that occurred in the calendar year 2000 in the geographical location of Buffalo metropolitan area and Erie County. PATIENTS AND DATA COLLECTED: A retrospective review of an estimated 5,000 patients with new stroke will be performed at regional hospitals and the coroner's office to determine the stroke subtypes, cerebrovascular risk factors, diagnostic investigations, treatment provided, and outcome. The total population residing in Buffalo in the year 2000 is available through the recent census. The study will also evaluate the quality of care provided for stroke patients including effectiveness of primary and secondary stroke prevention measures within this geographical region.

CONCLUSIONS

We believe that this information will assist in allocation of resources and implementation of steps to improve stroke prevention and treatment.

Racial Disparities in Subarachnoid Hemorrhage Mortality: Los Angeles County, California, 1985–1998

We examined the racial distribution of subarachnoid hemorrhage (SAH) mortality in a unique multiracial community. Mortality rates for SAH among the residents of Los Angeles County were calculated from death certificate data (1985-1998). Residential postal zones were classified into three strata as a measure of socioeconomic status. The number of SAH deaths was 2,897. The age-adjusted SAH mortality rate was 1.9 in whites, 2.7 in Hispanics, 3.0 in Asians and 3.7 in blacks. In those younger than 70 years of age, the SAH mortality rate among blacks was 2.2 times that of whites and 1.8 times that of Hispanics and Asians. The SAH mortality rate declines after age 70 in blacks. The SAH mortality rate was higher in women than in men in all races and it was highest in elderly Asian women (23.5 per 100,000). An inverse relationship was observed between income and SAH mortality rates in all racial groups except whites.

Stroke Outcome Measures

Stroke is the third leading cause of death and the foremost cause of adult neurological disability in the United States. Comprehensive assessment of persons with stroke is necessary for appropriate management of care and evaluation of interventions and outcomes. With the emergence of new effective treatments for stroke, the opportunity to document stroke impairments and disabilities to monitor recovery and to plan for reentry back to the community is a high nursing priority. The utilization of well-validated standardized instruments makes this goal attainable.

Apolipoprotein E isoprotein-specific interactions with tissue plasminogen activator

Apolipoprotein E (Apo E) is an important genetic risk factor for multiple neurological, vascular and cardiovascular diseases. Previously, we reported Apo E isoprotein-specific modulation of tissue plasminogen activator (tPA) using an in vitro blood-clotting assay. Here, we studied the conformational changes of Apo E2, E3 and E4 in the presence of tPA and vice versa using circular dichroism (CD) and dual polarization interferometry (DPI). We report isoprotein and state-specific intermolecular interactions between the Apo E isoforms and tPA. Apo E2 interaction with immobilized tPA leads to significant conformational changes which are not observed with Apo E3 or E4. Additionally, tPA induces changes in helicity of lipidated Apo E2 whereas no detectable changes were observed in Apo E3 or E4. The Tukey's test for interaction indicated a significant (P < 0.001) interaction between tPA and Apo E2 in the lipidated environment. These results may be important regarding the mechanism by which Apo E has isoprotein-specific effects on many biological processes and diseases involving blood clotting, proteolysis and perfusion.

Synergism between smoking and vital exhaustion in the risk of Ischemic stroke: evidence from the ARIC study

PURPOSE

To examine the synergism between vital exhaustion and cigarette smoking in producing ischemic stroke. Vital exhaustion (VE), a state characterized by unusual fatigue, irritability, and feelings of demoralization, is measured by the Maastricht questionnaire (MQ), a 21-item inventory of symptoms.

METHODS

The Atherosclerosis Risk in Communities (ARIC) Study is an ongoing cohort study, initiated in 1987. The MQ was administered at the second follow-up visit (1990-1992), and participants were subsequently followed for an average of 6.27 years. Four US communities (Minneapolis, Minnesota; Washington County, Maryland; Forsyth County, North Carolina; and Jackson, Mississippi). 13,066 participants aged 48 to 67 years at baseline (Visit 2) with no history of stroke. Validated hospitalized ischemic stroke.

RESULTS

During the follow-up period, there were 202 incident ischemic strokes. After multivariate adjustment, current smoking, and high VE were independent risk factors for incident stroke: (smoking vs. non-smoking HR=1.76, p < 0.01; high VE vs. low VE HR=1.94, p < 0.01). For persons with both VE and smoking vs. persons with neither, HR=2.71 (p < 0.001). The proportion of stroke disease burden due to VE and smoking that could be attributed to their interaction was 81 to 93 percent.

CONCLUSIONS

The combination of cigarette smoking and VE is synergistic in the production of stroke.

Involuntary job loss as a risk factor for subsequent myocardial infarction and stroke: findings from the Health and Retirement Survey

BACKGROUND

The role of stress in the development of cardiovascular disease is well established. Previous research has demonstrated that involuntary job loss in the years immediately preceding retirement can be a stressful life event shown to produce adverse changes in physical and affective health. The objective of this study was to estimate the risk of myocardial infarction (MI) and stroke associated with involuntary job loss among workers nearing retirement in the United States.

METHODS

We used multivariable survival analysis to analyze data from the first four waves of the Health and Retirement Survey (HRS), a nationally representative sample of older individuals in the US. The analytic sample includes 457 workers who experienced job loss and a comparison group of 3,763 employed individuals.

RESULTS

The results indicate that involuntary job loss is not associated with subsequent risk of MI (adjusted HR = 1.89; 95% CI = 0.91, 3.93); the risk of subsequent stroke associated with involuntary job loss is more than double (adjusted HR = 2.64; 95% CI = 1.01, 6.94).

CONCLUSIONS

Our findings present new data to suggest that involuntary job loss should be considered as a plausible risk factor for subsequent cardiovascular and cerebrovascular illness among older workers.

Therapeutic yield and outcomes of a community teaching hospital code stroke protocol

OBJECTIVES

To describe the experience of a community teaching hospital emergency department (ED) Code Stroke Protocol (CSP) for identifying acute ischemic stroke (AIS) patients and treating them with tissue plasminogen activator (tPA) and to compare outcome measures with those achieved in the National Institute of Neurological Disorders and Stroke (NINDS) trial.

METHODS

This study was a retrospective review from a hospital CSP registry.

RESULTS

Over a 56-month period, CSP activation occurred 255 times, with 24% (n = 60) of patients treated with intravenous (IV) tPA. The most common reasons for thrombolytic therapy exclusion were mild or rapidly improving symptoms in 37% (n = 64), intracerebral hemorrhage (ICH) in 23% (n = 39), and unconfirmed symptom onset time for 14% (n = 24) of patients. Within 36 hours of IV tPA treatment, 10% (NINDS = 6%) of patients (n = 6) sustained a symptomatic ICH (SICH). Three months after IV tPA treatment, 60% of patients had achieved an excellent neurologic outcome, based on a Barthel Index of > or =95 (NINDS = 52%), while mortality measured 12% (NINDS = 17%). Among IV tPA-treated patients, those developing SICH were significantly older and had a significantly higher mean initial glucose value. Treatment protocol violations occurred in 32% of IV tPA-treated patients but were not significantly associated with SICH (Fisher's exact test).

CONCLUSIONS

Over the study period, the CSP yielded approximately one IV tPA-treated patient for every four screened and, despite prevalent protocol violations, attained three-month functional outcomes equal to those achieved in the NINDS trial. For community teaching hospitals, ED-directed CSPs are a feasible and effective means to screen AIS patients for treatment with thrombolysis.

Declining stroke rates in Californian children with sickle cell disease

Although the Stroke Prevention Trial in Sickle Cell Anemia (STOP) demonstrated the efficacy of blood transfusions for primary stroke prevention in high-risk children with sickle cell disease (SCD) in 1998, the impact of this trial on public health has not been studied. Our objective was to determine whether stroke rates in Californian children with SCD have declined since 1998. Using a California-wide hospital discharge database, we identified all first admissions for stroke in children with SCD from 1991 through 2000. Annual stroke incidence rates were calculated as the number of admissions divided by the estimated population of Californian children with SCD in that year. For 1991-2000, 93 children with SCD were admitted to Californian hospitals with a first stroke during 12 030 person-years of follow-up; 92.5% were ischemic and 7.5% hemorrhagic. Overall, the rate of first stroke was 0.77/100 person-years. For the study years 1991-1998, the rate for first stroke was 0.88/100 person-years compared to 0.50 in 1999 and 0.17 in 2000 (P <.005 for trend). Since the publication of the STOP study in 1998, annual rates of admissions for first stroke for Californian children with SCD have declined.

Seasonal variation in hospitalisation for hypertension-related morbidities in Sokoto, north-western Nigeria

OBJECTIVE

To determine the relationship between hospital admissions of hypertension-related morbidities, seasons and meteorological factors in a tropical climate.

STUDY DESIGN

Retrospective analysis of hospitalised patients (440) with hypertension-related morbidities including heart failure (36.4 %), stroke (34.8%), chronic renal failure (7.1%) and others (21.7%) from 1995 to 2000. The relationship between hospital admission, seasons and meteorological factors was determined using simple proportions, univariate, multivariate and regression analysis.

RESULTS

The subjects were aged 21-85 years and represented 9.3 % of all hypertensives and 7.0% of medical admissions. Mean blood pressure was 187.3 +/- 34.0/120 +/- 23 mmHg. Mild, moderate and severe hypertension occurred in 30 (6.8%), 59 (13.4%) and 351 (79.8%) patients, respectively. The monthly admission rate ranged from 3-11; (mean 6.1 +/- 1.9) patients. Admission rates peaked in January/February and August/September, corresponding with the peaks of harmattan and the wet seasons, respectively. Mean monthly admission rates were significantly higher during harmattan than during the hot season (6.7 +/- 2 versus 5.2 +/- 1.4 patients; p < 0.05), and during wet season than during the hot season (6.4 +/- 1.9 versus 5.2 +/- 1.4 patients; p < 0.05). Considering the hypertensives as a whole, a significantly higher proportion of patients was hospitalised during the cold season than during the hot season (11% versus 8.2%; odds ratio = 1.34). Linear regression analysis showed that hospital admission was significantly associated with the monthly minimum temperature (p = 0.02) and solar radiation (p = 0.01). Multiple regression analysis revealed that hospital admission was also significantly associated with combined meterological factors (temperature, radiation, dust haze days and relative humidity) (p = 0.04).

CONCLUSIONS

Hospital admissions of patients with hypertension-related morbidities showed seasonal variation. Appropriate clothing and health planning during cold seasons are recommended.

New Perspectives on the Pharmacotherapy of Ischemic Stroke

OBJECTIVE

To provide an overview of the impact of ischemic stroke and the steps that can be taken to reduce its burden through greater awareness of the disease, improved diagnosis and better treatment, with emphasis on the use of antiplatelet agents.

DATA SOURCES

Recent (1995-2003) published scientific literature, as identified by the authors through Medline searches, using the terms stroke, transient ischemic attack, cerebrovascular disease, atherothrombosis, risk factors, pharmacotherapy, prevention, and reviews on treatment.

STUDY SELECTION

Recent systematic English-language review articles and reports of controlled randomized clinical trials were screened for inclusion.

DATA SYNTHESIS

Ischemic stroke is generally the result of an atherothrombotic process leading to vessel obstruction or narrowing. Of the two types of ischemic stroke, thrombotic stroke is caused by a thrombus that develops within the cerebral vasculature, while embolic stroke arises from a distant embolus that lodges in a cerebral artery. The neurologic manifestations of stroke depend on the location of injury in the brain and the degree of ischemia or infarction. Symptoms may be reversible or irreversible and range from sensory deficits to hemiplegia. Risk factors for development of ischemic stroke include hypertension, diabetes, dyslipidemia, smoking, atrial fibrillation, prior stroke, and transient ischemic attack. Tissue plasminogen activator is currently the only available drug treatment for acute ischemic stroke. Stroke recurrence rates are high (about 40% over 5 years), and all ischemic stroke patients should receive antithrombotic therapy (unless contraindicated) for secondary prevention. Of the oral antiplatelet therapies, aspirin, clopidogrel (Plavix--Bristol-Myers Squibb/Sanofi Pharmaceuticals Partnership), and the extended-release dipyridamole plus aspirin combination are acceptable first-line agents, while anticoagulants (warfarin) are preferred in patients with atrial fibrillation.

CONCLUSION

Lifestyle changes and drug therapy are important components of primary and secondary prevention strategies in ischemic stroke. Risk factors such as elevated blood pressure and high cholesterol should be aggressively treated. Antiplatelet agents, antihypertensive agents, and cholesterol-lowering agents are therapeutic cornerstones for secondary prevention.

Anticoagulants for acute ischaemic stroke

BACKGROUND

Most ischaemic strokes are caused by blood clots blocking an artery in the brain. Clot prevention with anticoagulant therapy could have a significant impact on patient survival, disability and stroke recurrence.

OBJECTIVES

The objective of this review was to assess the effect of anticoagulant therapy versus control in the early treatment of patients with acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched 30 October 2003). For previous updates of this review, we searched the register of the Antithrombotic Trialists' (ATT) Collaboration, consulted MedStrategy (1995), and contacted relevant drug companies.

SELECTION CRITERIA

Randomised trials comparing early anticoagulant therapy (started within two weeks of stroke onset) with control in patients with acute presumed or confirmed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

Twenty-two trials involving 23,547 patients were included. The quality of the trials varied considerably. The anticoagulants tested were standard unfractionated heparin, low-molecular-weight heparins, heparinoids, oral anticoagulants, and thrombin inhibitors. Based on nine trials (22,570 patients) there was no evidence that anticoagulant therapy reduced the odds of death from all causes (odds ratio (OR) = 1.05, 95% confidence interval (CI) 0.98 to 1.12) at the end of follow-up. Similarly, based on six trials (21,966 patients), there was no evidence that anticoagulants reduced the odds of being dead or dependent at the end of follow-up (OR = 0.99; 95% CI 0.93 to 1.04). Although anticoagulant therapy was associated with about 9 fewer recurrent ischaemic strokes per 1000 patients treated (OR = 0.76; 95% CI 0.65 to 0.88), it was also associated with a similar sized 9 per 1000 increase in symptomatic intracranial haemorrhages (OR = 2.52; 95% CI 1.92 to 3.30). Similarly, anticoagulants avoided about 4 pulmonary emboli per 1000 (OR = 0.60, 95% CI 0.44 to 0.81), but this benefit was offset by an extra 9 major extracranial haemorrhages per 1000 (OR = 2.99; 95% CI 2.24 to 3.99). Sensitivity analyses did not identify a particular type of anticoagulant regimen or patient characteristic associated with net benefit.

REVIEWERS' CONCLUSIONS

Immediate anticoagulant therapy in patients with acute ischaemic stroke is not associated with net short- or long-term benefit. The data from this review do not support the routine use of any type of anticoagulant in acute ischaemic stroke. People treated with anticoagulants had less chance of developing deep vein thrombosis (DVT) and pulmonary embolism (PE) following their stroke, but these sorts of blood clots are not very common, and may be prevented in other ways.

Stroke

The search for evidence-based treatments has resulted in an exciting new era for neurorehabilitation intervention strategies for stroke. Although stroke rehabilitation research poses many methodologic challenges, evaluation of stroke rehabilitation interventions is clearly moving beyond descriptive and observational studies toward well designed randomized clinical trials. The goals of this article are to summarize issues of trial design for stroke rehabilitation, to discuss promising stroke rehabilitation treatments currently undergoing rigorous evaluation, and to present treatments that may be candidates for randomized clinical trials in the future on the basis of promising preliminary data. Several examples of new developments in neuroscience research that are leading to possible rehabilitation interventions will be discussed. New modalities to evaluate the response of neural networks to rehabilitation interventions are also reviewed.

Risk Factors for Incident Stroke among Patients with End-Stage Renal Disease

ABSTRACT. Although patients with ESRD experience markedly higher rates of stroke, no studies in the US have identified risk factors associated with stroke in this population. It was hypothesized that black race, malnutrition, and elevated BP would be associated with the risk of stroke among patients with ESRD. Data from the United States Renal Data Systems were used. Adult Medicare-insured hemodialysis and peritoneal dialysis patients without a history of stroke or transient ischemic attack (TIA) were considered for analysis. The primary outcome was hospitalized or fatal stroke. Cox proportional hazards models were used to determine the associations between the primary predictor variables and stroke. The rate of incident stroke was 33/1,000 person-years in the study sample. After adjustment for age and other patient characteristics, three markers of malnutrition were associated with the risk of stroke—serum albumin (per 1 g/dl decrease, hazard ratio [HR] = 1.43), height-adjusted body weight (per 25% decrease, HR = 1.09), and a subjective assessment of undernourishment (HR = 1.27)—as was higher mean BP (per 10 mmHg, HR = 1.11). The association between black race varied by cardiac disease status, with blacks estimated to be at lower risk than whites among individuals with cardiac disease (HR = 0.74), but at higher risk among individuals without cardiac disease (HR = 1.24). This study confirms the extraordinarily high rates of stroke in ESRD patients on dialysis and identifies high mean BP and malnutrition as potentially modifiable risk factors. The association between black race and stroke differs by cardiac disease status; the reasons for this differing effect of race deserve further investigation. E-mail: seliger@u.washington.edu

Behavioural recovery correlated with MRI in a rat experimental stroke model

PRIMARY OBJECTIVE

To characterize a necrotic lesion using MRI and motor recovery using behavioural methods.

RESEARCH DESIGN

Stroke model based on two steps: (1) development of a lesion using MR-imaging parameters and (2) behavioural recovery.

METHODS AND PROCEDURES

Seventy male Sprague-Dawley rats were used. A focal lesion of the right sensorimotor cortex was induced photochemically.

MAIN OUTCOMES AND RESULTS

The maximum volume of oedema and the lesion damage was reached by approximately 6 hours. In the lesion area, the apparent diffusion coefficient (ADC) increased from 6 hours, then decreased from 24 hours. All animals spontaneously recovered motor function by day 10, despite the continued presence of the cortical lesion.

CONCLUSIONS

The results show that this model mimics a core lesion, as well as the late phase in a human stroke episode. This model might be used for longitudinal study of the basic mechanisms of motor recovery.

The effect of race and gender on patterns of rt-PA use within a population

To date, there have been no population-based data published regarding the influence of the patient's demographic factors on rt-PA use. We present preliminary data regarding the effect of race and gender on patterns of rt-PA use in the pre-FDA approval era, in a population with demographic and socioeconomic characteristics similar to the United States. All ischemic strokes within a biracial population of 1.3 million were identified by review of all primary and secondary hospital ICD-9-CM codes 430-438 from July 1993 to June 1994 at all hospitals in the region. The number of patients treated with rt-PA or placebo as part of the blinded NINDS rt-PA trial, as well as demographic characteristics, were recorded and analyzed. There were a total of 1973 hospitalized ischemic strokes that occurred at a hospital participating in the NINDS rt-PA trial. Patients that received rt-PA were significantly younger than those that did not (mean age 67 v 72, respectively, P = .01). Of the 413 strokes that occurred in African Americans, 2.2% were treated with rt-PA vs. 2.6% of the 1560 non-African Americans. Women (2.0%) and men (3.0%) were equally likely to receive rt-PA. The single academic center was as likely to give rt-PA as the community medical centers. In the Greater Cincinnati/Northern Kentucky population, patterns of rt-PA use in 1993-94 did not appear to vary according to race or gender, or type of medical center. These findings may be in part because of the regionally-based method of stroke care delivery in the area.

Successful endovascular therapy for acute basilar thrombosis in an adolescent

Pediatric stroke is an underrecognized, potentially treatable cause of childhood neurologic disease. Acute basilar artery thrombosis is a devastating disease rarely encountered in children. Acute interventions with both chemical and mechanical thrombolysis techniques can improve outcomes in adults with arterial thrombosis of the posterior cerebral circulation. We report a case of intervention with both intra-arterial alteplase (tissue plasminogen activator) and cerebral balloon angioplasty to treat a prolonged basilar artery occlusion secondary to idiopathic thrombosis in an adolescent. Despite the patient being clinically locked-in and intervention being delayed at least 20 hours from symptom onset, he obtained complete neurologic recovery. Issues of pediatric stroke, late therapeutic intervention, chemical thrombolysis, and cerebral angioplasty are discussed. This case highlights the underrecognition and subsequent delay in diagnosis of pediatric stroke and how acute intervention may cure otherwise catastrophic strokes in children.

Elevated risk of stroke among patients with end-stage renal disease

BACKGROUND

Although end-stage renal disease (ESRD) has been associated with accelerated vascular disease of the cerebral circulation, there are no prior studies that have estimated the risk of hemorrhagic and ischemic stroke among the United States dialysis population relative to the general population.

METHODS

We performed a population-based cohort study to compare rates of hospitalized ischemic and hemorrhagic stroke among incident dialysis patients in the United States Renal System database and non-ESRD subjects from the general population identified in the National Hospital Discharge Survey.

RESULTS

After adjustment for age, gender, and race, estimated rates of hospitalized stroke were markedly higher for dialysis patients compared to the general population. The age-adjusted relative risk (RR) of stroke among dialysis patients compared to the general population was 6.1 [95% Confidence Interval (95% CI) 5.1, 7.1] for Caucasian males, 4.4 (95% CI 3.3, 5.5) for African American males, 9.7 (95%CI 8.2, 11.2) for Caucasians females and 6.2 (95%CI 4.8, 7.6) for African American females. When considered as separate outcomes, hospitalization rates for hemorrhagic and ischemic stroke were both markedly elevated for subjects treated with dialysis (ischemic, RR = 4.3 to 10.1; hemorrhagic, RR = 4.1 to 6.7).

CONCLUSION

Incident dialysis patients are at markedly higher risk for hospitalized stroke when compared to the general population. Although prior public health initiatives have focused primarily on cardiac disease among patients treated with dialysis, our data suggest that new initiatives are needed to control the high risk of stroke in this population.

Improvement in walking speed in poststroke spastic hemiplegia after intrathecal baclofen therapy: a preliminary study

OBJECTIVE

To explore whether intrathecal baclofen (ITB) therapy improves ambulation in stroke survivors.

DESIGN

Case series.

SETTING

Tertiary care center.

PARTICIPANTS

Ten adults with poststroke hemiparesis who were ambulatory at the time of pump implantation.

INTERVENTIONS

Implantation of ITB pump after inadequate control of spasticity with other interventions. Time from stroke onset to implantation averaged 28.6 months (range, 9-55mo).

MAIN OUTCOME MEASURES

Customary walking speed was measured from the time required to walk 50ft (15m) at a self-selected pace. Evaluators rated spastic hypertonia and functional mobility.

RESULTS

Statistically significant improvements occurred in walking speed, functional mobility ratings, and spasticity (P<.05) at a follow-up interval that averaged 8.9 months. Mean walking speed over 50ft improved from 36.6 to 52cm/s. Mean Modified Ashworth Scale scores in the muscles of the affected lower limb improved from 2.0 to 0.4. Normal muscle strength (5/5) was preserved in the unaffected limbs.

CONCLUSIONS

This preliminary study suggests that ITB therapy, in combination with physical therapy, may improve walking speed and functional mobility in ambulatory individuals with poststroke spastic hemiplegia.

Risk of stroke in children: ethnic and gender disparities

METHODS

Using a California-wide hospital discharge database, the authors analyzed all first admissions for stroke in children 1 month through 19 years of age from 1991 through 2000. Incidence rates were estimated as the number of first hospitalizations divided by the person-years at risk; case fatality rates were based on in-hospital deaths.

RESULTS

The authors identified 2,278 first admissions for childhood stroke, yielding an annual incidence rate of 2.3 per 100,000 children (1.2 for ischemic stroke, 1.1 for hemorrhagic stroke). Compared with whites, black children were at higher risk of stroke (for ischemic stroke, relative risk [RR] 2.59, 95% CI 2.17 to 3.09, p < 0.0001; subarachnoid hemorrhage [SAH], RR 1.59, CI 1.06 to 2.33, p = 0.02; intracerebral hemorrhage [ICH], RR 1.66, CI 1.23 to 2.13, p = 0.0001). Hispanics, however, had a lower risk of ischemic stroke (RR 0.70, CI 0.60 to 0.82, p < 0.0001) and ICH (RR 0.77, CI 0.64 to 0.93, p = 0.0004), whereas Asians had similar risks as whites. Boys were at higher risk for all stroke types than girls (ischemic stroke, RR 1.25, CI 1.11 to 1.40, p = 0.0002; SAH, RR 1.24, CI 1.00 to 1.53, p = 0.047; ICH, RR 1.34, CI 1.16 to 1.56, p = 0.0001). After eliminating cases with coexisting sickle cell disease, excess stroke risk persisted in blacks; after elimination of trauma, excess stroke risk persisted in boys. Case fatality rates were similar among different ethnic groups. Compared with girls, boys had a higher case fatality rate for ischemic stroke (17 vs 12%; p = 0.002) but not for ICH or SAH.

CONCLUSIONS

Rates of hospitalization for stroke are higher among black children and boys; sickle cell disease and trauma do not fully account for these findings.

Risks of acute hospital transfer and mortality during stroke rehabilitation

OBJECTIVE

To identify demographic, medical, and functional factors associated with transfer of stroke patients to acute hospital services and/or mortality during stroke rehabilitation.

DESIGN

Two case-control studies in which logistic regression was used to control for clinical traits associated with differences in likelihood.

SETTING

A total of 542 US inpatient and rehabilitation units.

PARTICIPANTS

A total of 64,471 patients discharged during 1995.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Transfer to an acute hospital service and death.

RESULTS

There were 5847 (9.1%) acute hospital transfers and 320 (0.5%) deaths. Greater disability at admission was associated with higher odds of both acute hospitalization and mortality. Cardiopulmonary arrest, chest pain, gastrointestinal problems, bleeding disorders, hypercoagulable states, and acute renal difficulties increased the relative odds of acute hospitalization from 3.1 (95% confidence interval [CI], 2.3-4.2) to 12.7 (95% CI, 9.2-17.6). The likelihood of mortality for patients 85 years of age or older was more than 2-fold (2.5; 95% CI, 1.7-3.6) that of patients 65 years of age or younger for blacks, it was nearly 2-fold (1.7; 95% CI, 1.3-2.3) compared with whites, after adjusting for clinical differences.

CONCLUSION

Higher likelihoods of mortality among older patients versus younger, black patients versus white, and patients with more rather than less disability at admission suggest the need for greater vigilance in monitoring medical status.

Medical prevention of stroke, 2003

Stroke is a preventable tragedy for nearly 750,000 people each year. Primary stroke prevention measures applicable to the general public include a healthy diet containing fruits, vegetables, fish, and low fat; exercise; smoking cessation; limiting alcohol to moderate use; and perhaps avoidance of stress. Screening for hypertension, cholesterol, heart disease, and carotid artery stenosiscan lead to even more effective stroke prevention in high-risk patients. Specific antihypertensive drugs such as angiotensin-converting enzyme inhibitors and angiotensin-converting enzyme receptor blockers may be especially protective against stroke. Secondary stroke prevention in patients who have already had a stroke or transient ischemic attack is even more effective in preventing more serious strokes. Measures include antihypertensive and cholesterol-lowering agents, carotid endarterectomy, anticoagulation for atrial fibrillation and other cardiac sources of embolic stroke, and antiplatelet therapy. Stroke prevention depends on the application of these well-known and widely available treatments to a large number of patients.

Management of acute stroke

Stroke ranks as the third leading cause of death and the most common cause of permanent disability in adults. Timely recognition and treatment is imperative to reduce stroke-related morbidity and mortality. Patients with acute ischemic stroke should be evaluated for administration of intravenous tissue plasminogen activator (t-PA); those who do not qualify for t-PA should receive aspirin therapy in the absence of a contraindication. In all stroke patients, intravenous hydration with normal saline should be administered, hypoxia should be corrected with supplemental oxygen, and hyperglycemia and fever should be treated aggressively. Blood pressure management should be individualized on the basis of stroke pathophysiology and specific treatment plan (e.g., planned thrombolysis) following published guidelines. Evaluation of stroke etiology should be undertaken, and the results should be used to guide secondary stroke prevention efforts.

Treatment of chronic hypertension for the prevention of stroke

Because current therapies for acute stroke are limited, attention must be paid to primary and secondary prevention of stroke. This article focuses on the treatment of chronic hypertension in particular. There is no "one-size-fits-all" treatment, although recent randomized trials have shown that certain agents may be more helpful. Although an exhaustive review would require a textbook, this article reviews some major recent trials and provides evidence-based guidelines for treatment of hypertension for both primary and secondary prevention of stroke.

Neuromuscular electrical stimulation for motor relearning in hemiparesis

Neuromuscular electrical stimulation may have an important role in improving the motor function of stroke survivors. Active, repetitive movement training mediated by transcutaneous cyclic and EMG-triggered NMES may facilitate the motor recovery of stroke survivors. Multicenter, double-blinded, randomized clinical trials should be pursued to confirm the motor-relearning effects of transcutaneous NMES and to define appropriate prescriptive specifications. Intramuscular EMG-controlled NMES may be superior to transcutaneous systems and is presently undergoing preliminary randomized clinical trials. Neuroprostheses systems may provided the highest level of goal-oriented activity and cognitive investments, which may lead to significant motor relearning. Implementation of clinically viable neuroprosthesis systems, however, will probably require additional technical developments including more reliable control paradigms and methods for blocking undesirable muscle contractions. In view of the dynamic nature of the present health care environment, the future of NMES technology is difficult to predict. By necessity, scientists and clinicians must continue to explore new ideas and to improve on the present systems. Components will be smaller, more durable, and more reliable. Control issues will remain critical for both motor relearning and neuroprosthetic applications, and the implementation of cortical control is likely to dictate the nature of future generations of NMES systems. Finally, consumers will direct future developments. In the present health care environment, where cost has become an overwhelming factor in the development and implementation of new technology, the consumer will become one of technology's greatest advocates. The usual drive toward greater complexity will be tempered by the practical issues of clinical implementation, where patient acceptance is often a function of a tenuous balance between the burden or cost associated with using a system and the system's impact on the user's life.

Trends in community knowledge of the warning signs and risk factors for stroke

CONTEXT

Poor public knowledge of stroke warning signs and risk factors limits effective stroke intervention and prevention.

OBJECTIVE

To examine temporal trends in public knowledge of stroke warning signs and risk factors.

DESIGN AND SETTING

Population-based random-digit telephone survey conducted in July-November 2000 among individuals in the greater Cincinnati, Ohio, region.

PARTICIPANTS

A total of 2173 survey respondents (69% response rate) were randomly identified based on their demographic similarities to the ischemic stroke population with regard to age, race, and sex.

MAIN OUTCOME MEASURES

Spontaneous recall of at least 1 important stroke warning sign and 1 established stroke risk factor in comparison with findings from the same survey in 1995.

RESULTS

In 2000, 70% of respondents correctly named at least 1 established stroke warning sign vs 57% in 1995 (P<.001), and 72% correctly named at least 1 established stroke risk factor vs 68% in 1995. Groups of individuals with the highest risk and incidence of stroke, such as persons at least 75 years old, blacks, and men, were the least knowledgeable about warning signs and risk factors. Television was the most frequently cited source of knowledge, 32% in 2000 vs 24% in 1995 (P<.001).

CONCLUSIONS

Public knowledge of stroke warning signs within the greater Cincinnati region has significantly improved from 1995 to 2000, although knowledge of stroke risk factors did not improve significantly during the same time period. Public education efforts must continue and should focus on groups at the highest risk of stroke.

Short-term, intermediate-term, and long-term mortality in patients hospitalized for stroke

Cerebrovascular disease is the third leading cause of death and the primary cause of long-term disability in the United States. Although the risk factors for stroke have been well defined, less is known about stroke mortality over varying time periods within the same cohort of patients. The purpose of this study is to define rates of short-term, intermediate-term, and long-term stroke mortality among patients experiencing a first-ever hemorrhagic or ischemic stroke between 1994 and 1998. Patients were identified from the Patient Treatment Files of the Department of Veterans Affairs (VA). We included all patients who were discharged from a VA inpatient facility with a diagnosis of acute stroke. Patients were excluded from the study if they had an admission within the previous 5 years for stroke or hemiplegia. We obtained information on the patient's age, gender, and coexisting illnesses. Unadjusted and adjusted 30-day mortality rates were computed using Kaplan-Meier analyses and Cox proportional hazards regression models. The survival-dependent Cox proportional hazards regression models were run for 31-90 days and 91-365 days from the index admission date, for patients who had survived to the start of each of these time periods. Separate models were run for ischemic (n = 34,866 patients) and hemorrhagic (n = 5,442 patients) strokes. Unadjusted 30-day mortality was 8.2 and 20.5% for ischemic and hemorrhagic strokes, respectively. The adjusted 30-day mortality rate was 7.4 and 18.8% for ischemic and hemorrhagic strokes, respectively. For ischemic stroke, age 65 years and older was associated with an increased risk for short-term, intermediate-term, and long-term mortality, while chronic heart failure was associated with an increased risk for short-term and long-term mortality. For hemorrhagic stroke, age 75 years and older, malignancy, and chronic heart failure were associated with increased mortality during all three time periods. Thirty-day mortality is over two times greater following hemorrhagic stroke vs. ischemic stroke. For patients who survive 30 days after an ischemic stroke, the risk factor that remains significantly associated with long-term mortality, which may be improved with appropriate process of care, is chronic heart failure. For patients with a hemorrhagic stroke, variables that remain significantly associated with increased short-term and long-term mortality include malignant neoplasm and chronic heart failure. Information on stroke mortality is important for patients, physicians, and researchers. In addition to stroke treatment, clinicians must be able to provide families of stroke victims with appropriate prognostic information. Further work is needed to assess the impact of actual care patterns, for the above identified risk factors, on stroke prognosis over varying time periods.

Treatment of high-risk African American patients: left ventricular dysfunction, heart failure, renal disease, and postmyocardial infarction

African Americans experience more mortality and morbidity from hypertension-related complications than other racial groups. Although angiotensin-converting enzyme (ACE) inhibitors have clearly been shown to reduce mortality and morbidity in hypertensive white patients with heart failure, renal dysfunction, stroke, and acute myocardial infarction, African American patients have been underrepresented in these trials. The lack of direct evidence of the benefit of ACE inhibitors in these individuals and the suggestion that ACE inhibitors are less efficacious in this group has resulted in a reluctance to use ACE inhibitors in African Americans. However, retrospective analyses in black patients with heart failure and a recent randomized clinical trial in African Americans with renal dysfunction suggest that a regimen based on ACE inhibitors is efficacious in this racial group. Although diuretics remain first-line therapy, data now suggest that ACE inhibitors provide additional benefit and should be considered for use in patients with high-risk complications regardless of race.

Time-resolved contrast-enhanced magnetic resonance angiography of the carotid arteries: diagnostic accuracy and inter-observer variability compared with selective catheter angiography

RATIONALE AND OBJECTIVES

To assess the diagnostic accuracy and interobserver variability of contrast-enhanced magnetic resonance angiography (CE-MRA) in a time-resolved technique compared with digital subtraction angiography (x-ray DSA) in patients with suspected stenoses of the internal carotid artery.

MATERIALS AND METHODS

A total of 43 patients were enrolled in this prospective study. All patients underwent selective x-ray DSA involving a total of 84 carotid arteries. CE-MRA was performed in a time-resolved technique with a fast gradient-echo sequence on a 1.5 T MR scanner: TR 3.8 milliseconds, TE 1.49 milliseconds. Four consecutive measurements, each a duration of 10 seconds, were performed with omission of measuring bolus transit time. Four independent radiologists scored the degree of stenosis. The interobserver variability was calculated for CE-MRA and x-ray DSA.

RESULTS

In the 43 cases, at least one MRA measurement showed arterial contrast without venous degradation. Compared with x-ray DSA the mean sensitivity and specificity for grading stenosis > or = 70% were 98% and 86%, respectively. The interobserver agreement was substantial with no significant difference between CE-MRA (kappa value 0.794) and x-ray DSA (kappa value 0.786).

CONCLUSIONS

The short acquisition time of a fast CE-MRA sequence allows a selective visualization of the internal carotid arteries without degradation from venous enhancement. It is a reliable method with a good interobserver agreement.

Comparison of the responsiveness of the Barthel Index and the motor component of the Functional Independence Measure in stroke: the impact of using different methods for measuring responsiveness

Two disability measures frequently used to assess the effects of interventions on stroke recovery are the Barthel Index (BI) and the motor component of the Functional Independence Measure (FIM Instrument). This study compared multiple measures of responsiveness of these instruments to stroke recovery between 1 and 3 months. Data on a 1- to 3-month change in the Instruments were obtained for 372 subjects who improved or maintained function on the modified Rankin Scale (MRS), using a subset of 459 eligible patients with confirmed stroke as defined by WHO criteria recruited from 12 participating hospitals in the Greater Kansas City area. Subjects were excluded because of death, early withdrawal from the study, missing MRS, or outcome data (57) decline on MRS (26), or inability to improve on MRS (4). Techniques used to assess responsiveness were: area under the ROC curve, Guyatt's effect size, paired t-statistics, standardized response mean, Kazis effect size, and mixed model adjusted t-statistic. The FIM Instrument and BI show little difference in responsiveness to change. The different responsiveness measures are generally consistent with this conclusion, with no measure clearly superior to the others. Large differences in the responsiveness measures were obtained within an instrument depending on the populations used (changers only or both changers and those who maintained function). Results also suggest responsiveness assessments are likely to be affected by time frame and phase of rehabilitation over which the responsiveness of a measure is determined.

Prehospital care of the stroke patient

Acute stroke care is a multidisciplinary effort. It crosses the boundaries of traditional hospital-based medicine, relying heavily on prehospital providers to obtain a significant amount of clinical information. Currently, modifications of existing EMS systems are underway to support the idea that "time is brain." Dispatchers and EMS providers are vital players in the Chain of Recovery, and are challenged to perform within this new paradigm for acute stroke care. In the near future, optimal management of the acute stroke patient may include the administration of neuroprotective medications in the prehospital setting. Educational efforts targeting high risk and elderly populations also continue to be a priority for healthcare providers and public interest groups such as the NSA. Stroke victims, family members, and caregivers must all be aware of the warning signs and symptoms of stroke. The importance of using EMS during the initial phase of acute stroke cannot be overstated. Emergency physicians must lead in coordinating the resources, placing greater emphasis on educating and assessing the performance of prehospital providers [50]. These leaders must ensure that prehospital providers understand they are integral members of the stroke team, vital to improving stroke care in the community.

Intracerebral hemorrhage

There is a significant variation in the management of ICH by neurologists, neurosurgeons, and emergency physicians. Most of the randomized clinical therapeutic trials have focused on subarachnoid hemorrhage (SAH) and acute ischemic stroke (AIS). Well-organized practice guidelines are now available for the management of ICH. Exciting research areas are being aggressively explored. Medical and surgical interventions for SAH, AIS, and ICH are always time-dependent, which places additional responsibility on the EP to correctly and promptly recognize these conditions to prevent further injury. The time-dependent care of these patients places the EP on the front lines of future stroke care. Special thanks to Dr. Daniel Woo and Dr. Stewart Wright for their assistance in reviewing the manuscript and Amy Hess for preparation of the manuscript.

Transient ischemic attacks: an emergency medicine approach

Recent advances in TIA research provide emergency physicians a new understanding of the disease process. Untreated or under-treated patients with TIA are at significant risk. Prompt and thorough evaluation must be undertaken to prevent devastating harm to this group of patients. This is truly a paradigm shift for many physicians, and one area in which emergency physicians lead in education and patient advocacy. The authors wish to acknowledge Dr. Stewart Wright, Dr. Alex Schneider, and Dr. Dawn Kleindorfer for their expert review, and Amy Hess for her assistance in the preparation of this manuscript.