Elise J. Levinoff, MSc, BSc, University of Ottawa, Faculty of Medicine, Ottawa, ON.

Dementia is a neurological disease that is associated with aging. The incidence and prevalence of dementia is increasing as the population continues to age. The two most common forms of dementia are Alzheimer’s disease (AD) and vascular dementia (VaD). Although these two forms of dementia represent different pathologies and different clinical presentations, they share similar risk factors. It is important to distinguish between the two forms of dementia because of the differing treatments, and because the risk factors for each are often preventable. This article will discuss the classification, risk factors, and diagnosis of AD and VaD, and present distinguishing characteristics between them.
Key words: dementia, Alzheimer’s disease, vascular dementia, stroke, memory.

Vadim Beletsky, MD, PhD, Senior Stroke Fellow, Department of Clinical Neurological Sciences, London Health Sciences Centre, London, ON.

Clinical presentation of cervical arterial dissection is highly variable, but headache or neck pain is frequently observed. Both invasive and noninvasive imaging are used to confirm the diagnosis but noninvasive techniques overshadow traditional digital subtraction angiography (DSA), which should be reserved for cases where invasive procedures are planned. In spite of the accumulated clinical, diagnostic, and etiological data on cervical arterial dissections in recent years, there is no evidence to support the use of a particular class of antithrombotic agents in these patients. Different pathophysiology of brain ischemia in acute and chronic states of dissection may advocate different treatment strategies, including surgical. There are also no imaging follow-up guidelines, both in terms of frequency and modality, further affecting secondary stroke prevention uncertainties.

Key words: arterial dissection, cervical, stroke, carotid, vertebral.

Ashfaq Shuaib, MD, FRCPC, FAHA, Professor of Neurology and Medicine, Director, Division of Neurology, University of Alberta, Edmonton, AB.

Stroke is a common neurological problem in older adults. Most patients have identifiable risk factors. Identification and treatment of such conditions can result in a significant reduction in recurrence. In addition, patients with an acute ischemic stroke require lifelong treatment with antithrombotic agents. For the vast majority of patients, acetylsalicylic acid (ASA) in a dose of 50-325mg per day is sufficient. In patients who are unable to tolerate ASA (75mg per day) clopidogrel may be an alternative. Both clopidogrel and ASA/ extended-release dipyridamole are useful alternative medications, especially in patients with recurrent symptoms. In 20% of patients the ischemic stroke may be secondary to cardioembolic causes (atrial fibrillation is the most frequent cardiac cause). In such subjects, treatment with warfarin with INRs in the range of two to three may provide better reduction in recurrence than ASA.

Key words: stroke, stroke prevention, antithrombotic agents, cardioembolic.

The accredited CME learning activity based on this article is offered under the auspices of the CE department of the University of Toronto. Participating physicians are entitled to one (1) MAINPRO-M1 credit by completing this program, found online at www.geriatricsandaging.ca/cme.htm

L. Creed Pettigrew, MD, MPH, Professor of Neurology, Director, Stroke Program, Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.

Stroke is the most common life-threatening neurological disease and is the fourth leading cause of death among adult Canadians. Aspirin is the most frequently prescribed antithrombotic drug to prevent stroke but may not be a suitable choice in older patients who have already had stroke symptoms despite its use, or cannot tolerate its side effects. For these patients, clopidogrel or the combination of low-dose aspirin with extended release (ER) dipyridamole should be considered for prevention of stroke. This review will compare the relative benefits of aspirin, clopidogrel, and low-dose aspirin/ER-dipyridamole in geriatric patients at risk for stroke.

Key words: stroke, myocardial infarction, aspirin, clopidogrel, dipyridamole.

Post-Stroke Depression

Ricardo E. Jorge, MD, Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
Robert G. Robinson, MD, Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA.

In most western countries, 0.2 % of the population suffer a stroke each year. One-third of them die over the next year, one- third remain permanently disabled, and the other third make a good recovery. Depression is one of the most common emotional disorders associated with cerebrovascular disease. Longitudinal studies of stroke patients have shown that about 20% of these patients will develop major depression and another 20% will develop minor depression during the first year after stroke. Depression has also been demonstrated to significantly effect clinical recovery and mortality and, more important. Post-stroke depression responds to antidepressant treatment.

Key words: stroke, mood disorders, antidepressants, cognitive disorders, disability.

Colin P. Derdeyn, MD, Associate Professor, Mallinckrodt Institute of Radiology and the Departments of Neurology and Neurological Surgery, Washington University School of Medicine, St. Louis, MO, USA.

The brain requires the continuous delivery of oxygen and glucose for normal function. Even brief interruption or impairment of this supply can cause permanent injury, most dramatically and catastrophically in the form of stroke. There is emerging data that in addition to stroke, microvascular arterial obstructive disease may be a common cause of dementia. With normal aging, and as an effect of a number of diseases common in older adults such as hypertension, several pathological conditions of the brain vasculature may develop. This brief review will discuss a few common cerebrovascular diseases of older adults and recent data regarding their treatment. These conditions include intracranial aneurysms, atherosclerosis and atherosclerotic stenosis, and vascular dementia.

Key words: intracranial aneurysms, atherosclerosis, stroke, brain vasculature, vascular dementia.

Claudio S. Cinà, MSc, FRCSC, Associate Clinical Professor, Department of Surgery, Division of Vascular Surgery, McMaster University, Hamilton, ON.
Catherine M. Clase, MSc, FRCPC, Associate Professor, Department of Medicine, Division of Nephrology, McMaster University, Hamilton, ON.

Carotid endarterectomy is effective in preventing strokes in patients with symptomatic carotid stenosis greater than 50%. The magnitude of the benefit is greater with increasing degree of stenosis, male sex, greater number of risk factors for strokes, strokes or hemispheric transient ischemic attacks rather than amaurosis fugax, recurrent events, plaque ulceration, contralateral carotid occlusion and tandem (intracranial and extracranial) stenosis. The effectiveness of carotid endarterectomy, however, is very sensitive to the rate of perioperative events, and centres providing care for these patients need to prospectively monitor their complication rates.
Key words: carotid stenosis, carotid endarterectomy, stroke, transient ischemic attacks.

Is it possible that virtual reality--the stuff of Matrix movies and futuristic fantasy--helps elderly stroke survivors along the road to recovery? Researchers from the University of Toronto think it's a question worth investigating, and have already begun a pilot study of stroke survivors 60 years and older to explore the possible benefits of this immersive, interactive, 3-D computer experience.

Theoretically, the researchers explain, virtual reality can encourage competence, expression and pleasure in leisure activities in older stroke survivors. They believe that virtual reality has the potential to offer people with disabilities greater control over events in their environment, thereby contributing to a sense of competence and satisfaction with life.

How might this be possible? The Mandala® Gesture Xtreme virtual reality system uses a video camera as a capturing and tracking device to give the user the sense of being immersed in the virtual environment. The user sees herself on a television screen while the virtual reality system responds to her movements. The user does not have to wear, touch or hold anything, making this system especially ideal for the disabled elderly. By means of the system's video gesture capability, the user's movements (reaching, bending) trigger visible or invisible icons to score points and manipulate animations, such as playing a virtual drum kit.

One concept the investigators use to illustrate how disabled elderly interact with and may benefit from virtual environments is entexturing--the awareness of the body with respect to a variety of sensory stimuli (space, light, colour, sound) and the regulation of activity surrounding the body in order to produce a finely articulated and satisfying whole. In the virtual environment shown here, the user was required to reach out to the sides and across her body to hit the various drums placed around her. By hitting the drums, the user is executing an activity by responding to auditory and visual stimuli, creating a rhythm and expressing creativity.

The use of virtual reality, according to the investigators, can be a positive addition to the lives of people recovering from stroke. Although they will be focusing on the social and psychological benefits of virtual reality, the potential physical gains, such as improved balance and range of motion, merit exploration as well.

While investigating the benefits of statin therapy in the seldom studied elderly, the PROSPER study found that pravastatin reduced the risk of coronary disease as it has in studies of middle-aged people, yet unlike previous studies, did not have a clear effect on risk of stroke.

The benefits of statins have been demonstrated for the primary and secondary prevention of both coronary and cerebrovascular events, but most of this evidence has involved middle-aged people. The rationale for such treatment in those older than 70 years is less clear, since the association between cholesterol levels and risk of coronary artery disease diminishes with increasing age, and the frequency of stroke is associated with hypertension rather than with cholesterol. However, there has been enough conflicting evidence to challenge these concepts such that investigators launched the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) to look more closely at the efficacy of statin therapy in older people. The researchers set out to determine whether pravastatin reduces the risk of cardiac events, stroke, cognitive decline and disability in those with existing (secondary prevention) and those at high risk of developing (primary prevention) vascular disease.

A total of 5,804 men and women 70-82 years old were recruited if they had pre-existing vascular disease or a high risk of developing vascular disease due to smoking, hypertension or diabetes. Of these, 2,891 were randomized to treatment with pravastatin 40mg per day and 2,913 to placebo. Plasma total cholesterol levels had to be 4.0-9.0mmol/L and their triglyceride concentration less than 6.0mmol/L. Every three months, lipoprotein profiles were measured, and every year an electrocardiogram was recorded and cognitive function tests and disability assessments were performed. Follow-up was 3.2 years on average and the primary outcome was the combined endpoint of definite or suspect death from coronary heart disease, non-fatal myocardial infarction and fatal or non-fatal stroke. Secondary outcome was a separate examination of coronary and cerebrovascular components, while tertiary outcomes included disability and cognitive function.

Pravastatin was found to reduce the risk of the primary endpoint by 15% (relative reduction; p=0.014), yet this risk reduction was largely attributable to a reduction in risk of coronary events only. Upon separation, investigators noted a 19% reduction in coronary events (p=0.006) but no discernable effect on cerebrovascular events (p=0.81). Reductions, although non-significant, were found in transient ischemic attacks and the frequency of revascularization procedures among participants taking pravastatin. There were no observed differences between treatment and placebo groups in all-cause mortality or rates of hospital admissions for heart failure. Furthermore, serious adverse events were reported with similar frequency in both groups, and cognitive function declined at the same rate.

The overall reduction in the primary endpoint in pravastatin-treated subjects was less than predicted because of the lack of effect on rates of stroke. This finding was not, however, due to pravastatin's inability to lower low-density lipoprotein (LDL) cholesterol; at three months LDL cholesterol was 34% lower in treated subjects and after two years remained 33% lower than levels measured in placebo subjects. Researchers propose that the lack of effect on stroke might be due to a lack of statistical power, or may be a consequence of the short duration of the trial since other research suggests that stroke benefit from statin therapy does not begin to appear until after three years (whereas coronary risk reduction is an early event).

Extrapolating results from the PROSPER study to clinical practice is difficult. Although it provides clear evidence that statin therapy in elderly individuals reduces the risk of coronary disease, as it does in middle-aged people, a clear result on stroke would require a longer period of treatment if indeed statins are even beneficial for this indication in the elderly.

Source

1. Shepherd J, Blavw GJ, Murphy MB, et al. Pravastatin in elderly individuals at risk of vascular disease (PROSPER): a randomised controlled trial. Lancet 2002;360:1623-30.

Robert W Teasell, MD, FRCPC, Professor and Chair-Chief, Department of Physical Medicine & Rehabilitation, St Joseph's Health Care, London, University of Western Ontario, London, ON.

Timothy J Doherty, MD, PhD, FRCPC, Assistant Professor, Department of Physical Medicine and Rehabilitation, The University of Western Ontario, London, ON.

Defining Stroke Rehabilitation
Rehabilitation has been defined as an active process by which those disabled by injury or disease can realize their optimal physical, mental and social potential with integration into the most appropriate discharge environment. Comprehensive stroke rehabilitation programs are staffed by a full range of rehabilitation professionals--nurses, physical and occupational therapists, speech-language pathologists, psychologists, social workers, recreational therapists and physicians. An interdisciplinary team skilled in the care of stroke patients provides a comprehensive rehabilitation program for each patient. Brandstater and Basmajian,¹ and Roth et al.