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.

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.

Naushad Hirani BSc, MD

With the falling incidence of rheumatic fever in developed countries, the incidence of mitral stenosis has been steadily declining, although it remains one of the most common valvular lesions in developing nations. This lesion can present for the first time in elderly patients, as it often exists for many years before becoming clinically apparent. Knowledge of the etiology, pathogenesis, diagnosis, and treatment of this once common disease would be useful to any physician dealing with geriatric patients.

Etiology & Pathophysiology
The predominant cause of mitral stenosis (MS), as already alluded to above, is rheumatic fever, although there are several rare causes. Acute rheumatic fever itself is diagnosed using the Jones criteria, but often goes undiagnosed in young people. It is not therefore surprising that a reliable history is usually difficult to obtain and that the history is not the best guide as to the likelihood of the disease being present. The mechanisms by which the disease process is initiated remain controversial. It may be a slowly progressive autoimmune inflammatory reaction which begins with the illness and takes many years to become clinically significant, or it may be that the initial insult causes a deformity that with subsequent constant trauma due to turbulence leads to fibrosis, thickening, and calcification of the valve.

Elana Lavine, BSc

As the elderly population becomes an increasingly larger proportion of society, a key focus of scientific research will be the process of normal brain aging. Exactly what processes are considered to be a part of normal aging? Much of the literature examines the pathological changes observed in the brain of patients with such diseases as Alzheimer's and Parkinson's. However, the changes in brain morphology during senescence, as evidenced by studies of the healthy elderly, help shed light on what is truly attributable to aging and what is attributable to disease. The distinction between the two may be blurred by influences of lifestyle, such as diet and exercise. Individual variation in outcome measures, such as short-term memory, may create a wide range of what may be categorized as "normal" function. In addition, there exists a relative absence of neuropathological data from well-characterized healthy aged adults studied over extended periods of time.¹

Brain Size & Morphological Change
By 80 years of age, the average brain has decreased 15% in weight, and is noted as having smaller gyri, separated by wider sulci.² Specific research has focused on finding out exactly which parts of the human brain contribute to the decrease in weight. Supratentorial brain atrophy has been shown to progress with aging, and specifically with a reduction in the volume of gray matter.

Anna Liachenko, BSc, MSc

People with diabetes mellitus can have both acute and chronic complications from their disease. This article focuses on Hyperglycemic Hyperosmolar Non-Ketotic Syndrome (HHNS) and hypoglycemia, which are two important acute complications that occur in elderly diabetics.

Hyperglycemia
The key problem with diabetes is abnormal metabolism of carbohydrates leading to hyperglycemia. Blood glucose levels between 8 mmol/L and 10 mmol/L are sufficient to cause tissue damage but can be present in some patients without clinical symptoms for many years. This increases the risk of developing multiple long-term complications such as retinopathy, nephropathy and neuropathy.

During the life of a diabetic person, various factors may acutely raise hyperglycemia to symptomatic levels. These include high carbohydrate foods, stress, illness (usually infection), and medications (e.g. glucocorticoids, nicotinic acid, diuretics and phenytoin). If blood sugar rises above 10 mmol/L, it exceeds the renal reabsorption threshold and causes osmotic diuresis, resulting in loss of water and electrolytes (mainly sodium, potassium, phosphorus and magnesium). This creates a cycle of progressive hyperglycemia potentially having acute life-threatening consequences: diabetic ketoacidosis (DKA) or hyperglycemic hyperosmolar non-ketotic syndrome (HHNS). DKA occurs primarily in patients with Type 1 diabetes which tends to occur in younger patients.

Olya Lechky

Two Toronto hospitals--The Princess Margaret and Mount Sinai--have the distinction of being on the cutting edge in the early detection of breast cancer.

These two pre-eminent institutions in the study, diagnosis and treatment of breast cancer are the first centres in North America to have installed full field digital mammography systems. At a recent press conference, experts hailed General Electric's Senographe 2000D as the single biggest breakthrough in mammography during the past 30 years. This claim is based on over 8,000 clinical studies performed on five prototype machines during the past decade. "Digital mammography represents a milestone in the diagnosis of breast disease and it will soon replace conventional mammography all over the world," said Dr. Patrice Brett, professor of radiology at the University of Toronto.

While conventional film mammography has been of great benefit in the screening and diagnosis of breast disease, the technique has always had inherent limitations, said Dr. Karina Bukhanov, head of the division of breast imaging, joint department of breast imaging, University Health Network and Mount Sinai Hospital. "Digital mammography will bring breast cancer diagnosis into the digital age, enabling all the benefits of modern computer technology and software to be applied to the fight against cancer," she said.

In digital mammography an electronic detector replaces the traditional film screen.

Nariman Malik, BSc

Hyperthyroidism is defined as an excess of circulating thyroid hormones, either thyroxine (T4) or triiodothyronine (T3).¹ In Canada, its prevalence is approximately 1.9% and it is ten times more common in women than in men.² The disease can present at any age but is less common before the age of 15.3

Hyperthyroidism is an important cause of morbidity in the elderly. The clinical manifestations of hyperthyroidism vary from one patient to another and no single clinical manifestation is a specific indicator of the condition. Hyperthyroidism classically presents with symptoms that affect almost every organ system.³ The typical features include: weight loss with preserved appetite, heat intolerance, nervousness, anxiety, insomnia, proximal muscle weakness, fatigue, tremor, heart palpitations, and increased frequency of bowel movements. Other general signs include hyperactivity, tachycardia, atrial fibrillation, systolic hypertension, hyperreflexia, lid lag, and eyelid retraction.

Elderly persons may present with these classic symptoms or more usually, their presentation is atypical (please refer to table 1).

Neil Fam, BSc, MSc

Diabetes is a common chronic disease characterized by metabolic abnormalities that have both acute and long term complications. In Canada, at least 1.5 million individuals (5% of the population) are afflicted by the disease, and this number is predicted to increase to 2.2 million by the year 2000. Diabetes has considerable associated morbidity and mortality. It is a major cause of coronary artery disease and stroke and is a leading cause of blindness and kidney disease in adults. Furthermore, individuals with diabetes have a shortened life expectancy when compared to those without the disease. Long-term complications occur in both type 1 and type 2 diabetes and result from the chronic hyperglycemia and hypertension associated with the disease. This article summarizes the chronic complications of diabetes, including effects on the vascular system, kidneys, eyes and nervous system.

The diabetic patient may develop one or all of a myriad of complications, including vascular disease, hypertension, retinopathy, nephropathy, neuropathy and foot disease.

Vascular Complications and Hypertension
The vascular complications of diabetes can be divided into microvascular and macrovascular disease.

A. Mark Clarfield, MD

In 1989 the first Canadian Consensus Conference on the Assessment of Dementia (CCCAD) met in Montreal to try to come to grips with the vexed question of dementia assessment. In those days, there was still a lively debate going about the extent to which dementia should be worked up in an attempt to find the "reversible" cases.

Nearly ten years later in 1998, the group reconvened to look at assessment again but extended its mandate as well. What follows is a brief "compare and contrast" essay which examines what the two meetings had in common as well as how they differed.

To start off, they were both held in the beautiful city of Montreal, in 1989 under the joint chairmanship of myself and Dr. Serge Gauthier. In 1998, Dr. Gauthier was still in charge but this time Dr. Chris Patterson of McMaster University joined as the co-chair. (In 1992, I had moved to Israel, but was honoured to be invited back.)

In 1989 before (or perhaps at the beginning of) the extensive government cutbacks, we were able to fund the meeting with 50% government money, both federal and Quebec provincial. The rest of the support came from private sources, mainly drug companies. By 1998 it seems that government wanted no part of consensus meetings at least in the field of the dementias, and they did not participate in the funding this time.

A decade ago the 38 participants were mainly Canadian with four American visitors.

D'Arcy Little, MD, CCFP
York Community Services, Toronto and
Department of Family Medicine, Sunnybrook Campus of Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario

Epidemiology
Diabetes mellitus, a metabolic disease characterized by hyperglycemia secondary to defective insulin secretion and/or action, is an extremely common, chronic illness with a high burden of potentially preventable complications. It is a leading cause of coronary artery disease, peripheral vascular disease, kidney failure, peripheral neuropathy and new-onset blindness. A full five percent of Canadians have been diagnosed with the disease, and this percentage is predicted to translate into 2.2 million cases by the year 2000. However, statistics from the United States suggest that for every person diagnosed with diabetes, another has the disease and remains undiagnosed. Appropriate screening for diabetes provides the means to identify those undiagnosed individuals who may benefit from earlier intervention.

The terms insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetes were eliminated in favour of the terms "Type 1" and "Type 2" diabetes in an effort to emphasize pathogenesis over treatment in disease diagnosis.