Optimizing Stroke Recovery: New Frontiers

David J. Gladstone, BSc, MD
Stroke Fellow, Sunnybrook and
Women's College Health Sciences Centre,
University of Toronto,
Toronto, ON.

Cynthia Danells, BScPT
Physiotherapist and Research
Associate,
Sunnybrook and Women's College Health Sciences Centre,
University of Toronto,
Toronto, ON.

Sandra E. Black, MD, FRCPC
Head, Division of Neurology,
Sunnybrook and Women's College Health Sciences Centre, and
Professor of Medicine (Neurology),
University of Toronto,
Toronto, ON.

Delaina Walker-Batson, PhD
The Stroke Center-Dallas,
Professor,
Texas Woman's University, and
Associate Clinical Professor,
Departments of Neurology and Radiology,
The University of Texas Southwestern Medical Center,
Dallas, Texas, USA.

Stroke is a Treatable Condition
Together with advances in the prevention and acute treatment of stroke, the field of stroke rehabilitation is becoming an increasingly exciting frontier for basic science and clinical development (see Table 1). The scientific basis of stroke recovery is becoming better understood, and the post-stroke period is being viewed as an important target for improved therapeutic intervention.

Treatment of Hyperlipidemia to Prevent Stroke in the Elderly

Wilbert S. Aronow, MD, CMD
Department of Medicine,
New York, Medical College
Department of Geriatrics and Adult Development,
Mount Sinai School of Medicine,
New York, NY, USA.

There are conflicting data regarding the association of abnormal serum lipids with stroke in older men and women.^1-4 Despite these conflicting data, simvastatin and pravastatin have been demonstrated to cause a significant reduction in the incidence of stroke in older men and women with coronary artery disease (CAD) in the Scandinavian Simvastatin Survival Study,⁵ in the Cholesterol and Recurrent Events Trial,^6-10 and in the Long-Term Intervention With Pravastatin in Ischaemic Disease Study (Table 1).^11,12

Scandinavian Simvastatin Survival Study
The Scandinavian Simvastatin Survival Study was a prospective double-blind, placebo-controlled trial which randomized 4,444 men and women (2,282 of whom were 60 to 70 years of age) with CAD and hypercholesterolemia to treatment with either 20 mg to 40 mg of simvastatin daily or placebo.⁵ Simvastatin significantly reduced serum total cholesterol by 25% from 261 mg/dL to 196 mg/dL, serum low-density lipoprotein (LDL) cholesterol by 35% from 188 mg/dL to 122 mg/dL, and serum triglycerides by 10% from 133 mg/dL to 120 mg/dL. It significantly increased serum high-density lipoprotein (HDL) cholesterol by 8% from 48 mg/dL to 52 mg/dL.⁵ At 5.

Improving the Outcome from Stroke: A Work in Progress

James Kennedy, MB, MRCP(UK)
Clinical Stroke Fellow,
University of Calgary, Calgary, AB.

Alastair M Buchan, MB, FRCP
Professor of Stroke Neurology,
University of Calgary, Calgary, AB.

"It is in the nature of stroke to partly take away the use of a man's limbs and to throw him on the parish if he had no children to look to."¹

While treatments have changed since George Eliot's time, attitudes to the consequences of stroke have not. Stroke, when mild, is viewed by the elderly as a devastating event; when severe it is viewed as being worse than death itself.²

Stroke is the third most common cause of death and the leading cause of disability in most of the developed world.³ It is one of the most common causes for the elderly to be admitted to a chronic care facility, such as a nursing home. Ischemic stroke increases in incidence as people age, rising from 2.1 per 1000 for men aged 55 to 64 to 9.4 per 1000 for men aged 75 to 84.⁴ Age is also one of the major determinants of outcome from stroke. Older patients are less likely to recover than are younger patients with similar sized infarcts and, following a stroke, are more likely to decline physically than to recover.

Constraint-induced Therapy in Stroke Patients

Despite new diagnosing and treatment modalities, stroke continues to be the third largest cause of mortality in Canada and the leading cause of disability. A recent study shows that a novel therapy may be able to alleviate some of the disability that accompanies stroke. A group of scientists have reported that Constraint-Induced Therapy (CIT), increases the use and function of upper extremities in patients who have suffered a stroke. CIT is intensive in that it is administered 5-7 hours a day for two weeks and emphasizes forced use of the paretic limb while constraining the other, functional limb. The researchers used focal transcranial magnetic stimulation to map the cortical motor output area of a hand muscle, on both sides of the body, in 13 stroke patients in the chronic stage of their illness both before and after a 12-day-period of CIT. After treatment, the size of the muscle output area in the affected hemisphere was significantly enlarged, corresponding to a greatly improved motor performance of the paretic limb. The researchers hypo-thesize that the shift in the centre of the output map in the affected hemisphere spurrs the recruitment of adjacent brain areas. This improvement was still evident in follow-up examinations up to 6 months after treatment, demonstrating the possibility of a long-term alteration in brain function.

Sources

1. Liepert J, Bauder H, Miltner WHR, TaubE, Weiller C. Stroke 2000 31: 1210-1216.
2. Brickner, Elizabeth M.. American Journal of Medicine. April 1996; 100(4): 465-474.
3. Statistics Canada, Health Canada, Heart and Stroke Foundation of Canada. Heart disease and stroke in Canada. Toronto: Heart and Stroke Foundation of Canada; 1997.

Guidelines for Echocardiography Use in New Stroke Patients: TTE vs TEE

Alejandro Floh, BSc

Echocardiography has long been recognized as one of the most valuable non-invasive methods of investigating the heart. With recently-acquired understanding of the importance of cardiac disease in the pathogenesis of stroke, the role of echocardiography, whether transthoracic or transesophageal, in the management of stroke patients has become an area of extensive study. The Canadian Task Force on Preventive Health Care has therefore released their recommendations for the use of this imaging technique in newly diagnosed stroke patients.

Cerebral ischemia, a form of cerebral vascular disease, is caused by the reduction of blood supply to the nervous tissue of the brain. The result is often a rapid onset of focal neurological deficit or global impairment; this is commonly referred to as a stroke or cerebral vascular accident (CVA).¹ Despite similar presentations, the etiology of ischemic strokes vary considerably, and must be differentiated rapidly in order to provide appropriate care.

Despite new diagnostic and treatment modalities, stroke continues to be the third largest cause of mortality in Canada and the leading cause of disability.^2,3 Currently, approximately 50,000 new cases of strokes emerge annually, leading to an overall prevalence of 200,000 cases.³ Furthermore, strokes continue to be a leading cause of hospital admissions, even higher than acute myocardial infarctions, costing the Canadian health care system $2.

Is There a Role for Thrombolytic Therapy in the Management of Acute Ischemic Stroke?

Joyce So, BSc

While thrombolytic therapy has become an established part of treatment for acute ischemic heart disease, the controversy continues regarding its potential and practical use in acute ischemic stroke. In a situation where time is of the essence, is thrombolysis the best available solution?

Acute ischemic stroke (AIS), or "brain infarction", is most commonly a result of intracerebral artery occlusion due to embolism from proximal sites such as the internal carotid arteries, heart or aorta. Unlike cardiac arrest, where brain viability is measured in minutes, AIS presents with a mixture of salvageable tissue, allowing for a therapeutic window that can last several hours. While the definitive time frame has yet to be pinned down, the generally accepted mantra "Time is Brain" reflects the notion that prognosis is improved by early intervention. The question now is whether there is a role for thrombolytic therapy in the management of AIS.

The two most prominent candidates for use in thrombolytic AIS therapy are streptokinase and recombinant tissue plasminogen activator (rtPA), both serine proteases that catalyze the conversion of plasminogen to plasmin, which digests fibrin clots.

Secondary Prevention of Stroke: The Role of Antiplatelet and Anticoagulant Agents

D'Arcy L. Little, MD, CCFP
York Community Services, Toronto, ON

Introduction
Every year there are approximately 50,000 strokes in Canada. Currently, close to 300,000 Canadians are stroke survivors. As stroke is an age-related condition, the number of strokes is predicted to increase as the Canadian population ages. The resultant national cost, which is estimated at 2.7 billion annually, will also increase unless improvements are made to prevention and treatment.¹ Approximately 1 in 6 survivors of a first stroke experiences a recurrent stroke over the next 5 years, of which 25% are fatal within 28 days.² The above statistics suggest that attention to secondary stroke prevention would be important in reducing the morbidity, mortality and cost to society of stroke. The purpose of this article is to review the role of anti-platelet and anticoagulant agents in the secondary prevention of stroke.

Goals of Therapy
Therapeutic measures in secondary stroke prevention aim to prevent recurrent stroke or transient ischemic attacks, with the aim of preventing morbidity and mortality from incremental neurological deficits, as well as preventing associated cardiac ischemic events.

Primary Prevention Credited for Decreasing Incidence and Severity of Stroke

Lilia Malkin, BSc

A global decline in stroke-related mortality occurred over the last two decades. Canada boasts one of the lowest rates in the developed world: "only" seven percent of its citizens' deaths are attributed to cerebrovascular disease (CVD). Advances in the medical management of stroke combined with health promotion and risk factor modification are being credited with dropping CVD death rates by decreasing stroke severity and incidence.¹ However, CVD-related morbidity remains an important issue for Canadian seniors, with CVD-related hospital admissions creeping upwards as this country's population ages.¹

Preventing the occurrence of the first stroke would not only contribute to decreasing CVD-related deaths, but would alleviate a tremendous burden of suffering by diminishing the stroke-associated morbidity. This article will focus on risk factors associated with CVD and strategies for primary stroke prevention.

Internet Resources on Stroke

An Aspirin A Day Keeps A Stroke Away--Really?

SMH Alibhai, MD, FRCPC

As any physician knows, stroke is a common cause of morbidity and mortality in older patients. Strokes can be divided into three major aetiological groups--haemorrhagic, thromboembolic, and lacunar. Practically speaking, if neuroimaging does not show evidence of haemorrhage, physicians will generally treat patients who present with an acute stroke (or a transient ischaemic attack (TIA), for that matter) with either antiplatelet or anticoagulant therapy. For patients with a well-documented embolic source (e.g. atrial fibrillation), warfarin is the treatment of choice. For all other patients with non-haemorrhagic stroke, the treatment is traditionally antiplatelet therapy.

However, there are several options within antiplatelet therapy. The standard drug has been acetylsalicylic acid (ASA), or aspirin. At least four large randomized controlled trials revealed Ticlopidine to be slightly more effective in reducing the incidence of strokes and TIAs than aspirin, although it was more costly and more toxic.¹ However, a later meta-analysis of 145 studies suggested ticlopidine was probably as equally effective as aspirin.² Although newer antiplatelet agents are on the horizon (e.g.