D'Arcy L. Little, MD*
Anu Kumar, MD**
*Chief Resident, Family Medicine. Sunnybrook Health Science Centre, North York, Ontario
**Radiology Resident, Mount Sinai Hospital, Toronto, Ontario

As our society ages, dementia increases in prevalence. Although uncommon before age fifty, it is estimated that 10% of those over age 65 years, and up to 40% of those over age 85 years suffer from a type of dementia. Although there are over 70 different causes of dementia, Alzheimer's Disease (AD) is the most common type (See Table 1) . Some conditions that cause dementia can be treated and this can alleviate or occasionally resolve the dementia. As a result, patients with cognitive impairment should undergo appropriate investigation to assess any potential for reversibility.

Alzheimer's Disease is a progressive neurodegenerative disease with characteristic clinical and pathological features. A definitive diagnosis of AD requires the analysis of brain tissue, usually at autopsy, looking for the classic features of cortical atrophy, synaptic and neuronal loss, amyloid angiopathy, neuritic plaques with an amyloid core, neurofibrillary tangles with paired helical filaments, and localized inflammatory reaction. However, the combination of clinical features, and appropriate laboratory and/or radiologic techniques results in a diagnostic accuracy of approximately 80 percent.

Michelle Durkin, BSc

How to determine when people suffering from Alzheimer's disease and other dementias should stop operating a motor vehicle is a complex and controversial issue. The decision can affect the patient (by impairing independence and mobility), his or her family, and the safety of the general public. As a greater percentage of the population ages, the number of functionally impaired drivers only increases, further complicating the issue.

The Canadian Medical Association's Guide for Physicians in Determining Fitness to Drive (5th edition) states that physicians should monitor the driving competence of a patient with dementia. Until now this has been difficult because an appropriate and accurate evaluation tool has not been available. Physicians relied solely on their own judgement. Now, however, the research of Dr. Allen Dobbs of the University of Alberta may provide this needed, effective evaluation tool with the development of a computer-based test called the Competence Screen.

In an interview, Dr.

Agustinus S. Suhardja, MD

Introduction

Dementia is reported to affect 3-11% of the population over 65 years of age, with a greater propensity among institutionalized residents.¹

Due to the increasing number of dementing illnesses in the elderly population, the prevalence of dementia can be expected to continue to rise. The evaluation and care of patients with dementia could ultimately become a major component of the health care delivery system.

Dementia by definition, is the loss of intellectual abilities previously attained. Even though memory loss is the cardinal feature, the diagnosis of dementia according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), requires at least one more intellectual deficit (language, perception, visuospatial function, calculation, judgment, abstraction, and problem solving skills) which leads to impairment in day to day functioning.

Within the last two decades, some authors have proposed that as many as 10% of dementias are potentially treatable.² It is more likely that treatable dementias occur in less than 5% of cases.

Robin Dwarka, BSc, BAA

The incidence of depression among the elderly has been widely documented in recent studies. Approximately 2% of the population over 65 years of age who remain in the community have major depression, while up to 15% show significant depressive symptoms. In institutional settings, the figures jump to over 10% having major depression, and symptoms.

With the proportion of Canadians over 65 growing rapidly, recognition and treatment of depression in senior citizens is of growing concern.

Recognizing depression in the elderly poses a unique problem because of its symptomatic links to Alzheimer's Disease (AD), according to geriatric psychiatrist Dr. Richard Shulman of Sunnybrook Health Science Centre in Toronto.