Shari Al, BSc, MSc

Alzheimer's Disease (AD) is defined as a disorder characterized by the progressive deterioration of mental function. Specific research into the genetics of this disease has recently uncovered several important details as to the pathology and progression of the disorder. These discoveries, in turn, may lead to improved diagnosis and/or treatment of AD, with obvious repercussions for clinicians. In the case of AD genetic heterogeneity and the discovery that variations at any one of several loci cause the same disease, initially made it difficult for researchers to progress. The table below summarizes the results of current genetic research showing which genes are linked to each specific type of AD, and the percentage of patients affected by each type.

Andrea Sotirakopoulos, BSc

Gonadal steroids have wide and complex roles that reach beyond the regulation of gonadotrophin and prolactin secretion and the modulation of sexual behavior.¹ These hormones have several clinical effects on brain function throughout the life span, beginning during gestation and continuing into senescence. Estrogen is a female steroid hormone that is produced in the ovary and circulates in the blood stream. The specific proteins that bind to estrogen are distributed throughout the limbic brain, forebrain, hypothalamus, midbrain and anterior pituitary, and in organs such as the ovary and uterus. The widespread hormonal influence of estrogen on brain function could prove to be an important tool in the fight against Alzheimer's Disease (AD).

AD is characterized by neuropathologic features such as the accumulation of neurofibrillary tangles, neuritic plaques and amyloid deposits within regions of the cerebrum and brainstem² and by the progressive decline of mental function affecting long-term memory and other cognitive domains.³ A close relationship between neurofibrillary tangles and cell death exists within the brains of patients with AD. In the cholinergic basal forebrain and the hippocampus, these tangles are found inside neurons of cell groups that are progressively depopulated.

Lilia Malkin, BSc

According to a study conducted by Dr. Elaine Hyle and associates at the Massachusetts General Hospital and Harvard Medical School in Boston and reported in the March 4, 1998 issue of the Journal of the American Medical Association (JAMA), acetaminophen significantly increases the level of anticoagulation, measured and commonly reported as the international normalized ratio (INR). Other important risk factors for increased anticoagulation identified in the study included decreased food intake, diarrhea, and increased warfarin dosage, as well as a recently initiated course of antibiotics or other medications previously known to augment the response to warfarin. Hylek and associates also identified factors that inversely affected the INR, such as alcohol and increased dietary intake of Vitamin K.

Kim Wilson, BSc, MSc

Regular exercise is associated with cardiovascular, respiratory, neuromuscular and metabolic benefits. It is also an important factor in improving the immune system and preventing diseases, such as osteoporosis and coronary artery disease, while reducing disability. Physical activity also gives an energy boost, lowers cholesterol, enhances mood, and increases general feelings of well being.^1,2,3

Research has shown that regular exercise decreases the mortality rate in middle-aged men and probably in middle-aged women, but whether this occurs in the elderly has not been studied extensively.⁴ Very little research has been done to determine how much exercise an elderly person needs to do to obtain health benefits.

The intensity of exercise required to promote cardiovascular health among older persons has remained controversial.⁵ Some studies suggest strenuous activity reduces coronary disease risk while other studies found that less intense activity reduces the risk of coronary disease.^4,5 Not surprisingly, physicians are confused about how to prescribe an exercise regimen to their older patients.

Research in the area of exercise and health has traditionally focused on younger individuals.

Sandra MacMillan, RN, BScN,
Irene Swinson, RN, BScN,
Angela Pisan, RN, BScN,
Jennifer Fuller, RN, BScN, MEd
The North York Public Health Department

Introduction

Falls are a leading cause of morbidity and mortality in seniors. In Ontario, falls cause 600 deaths annually for those over the age of 65.¹ In North York, falls are the second leading cause of hospitalization in females over the age of 65, and the fifth leading cause for males of the same age.² Hill et al. reported that one third of seniors experience one or more falls each year.³ The City of North York Public Health Department has developed and implemented a Falls Prevention Program in conjunction with community partners, designed to reduce the incidence of falls in seniors. The newest component of this program is the Fall Prevention Clinics which have been modelled after the Fall Prevention Project conducted at the Ottawa-Carleton Health Department and the Community Health Research Unit, University of Ottawa. Preliminary results from the Ottawa study suggest that it was successful in reducing the number of falls, however, a final report is pending. North York Public Health Nurses have worked closely with The Bernard Betel Centre for Creative Living, North York Seniors Centre and Taylor Place.

Lawrence J. Papoff

As Canadians age, they are becoming concerned with the infirmities that aging can bring. And one of those infirmities is Alzheimer's Disease (AD). It is the specter of the Alzheimer patient, unable to fend for herself or himself, suffering a prolonged period of dying, incapable of communicating a decision to end life-sustaining treatment, that has popularized the use of the living will.

Geriatrician Dr. Barbara Clive says she sees an increasing number of living wills in use among her patients, one-third of whom suffer from some form of dementia, most often AD. More and more patients are filling out the paperwork and having discussions with their families about end of life decisions.

A living will, or advance directive, is a written document that contains the will maker's wishes regarding medical treatment and personal care. Taking effect only when the maker is incapable of understanding and appreciating what medical treatment or care is required, it instructs a representative, called an attorney, to decide what treatment should be used, and when it should be terminated. The document may also give decision-making ability to a number of attorneys and provide for resolution of disagreements among them.

Olya Lechky

A new multi-national clinical trial of donepezil (Aricept) confirms and augments the encouraging findings from previous multi-centre studies that the drug significantly improves cognition and global functioning in patients with mild to moderate Alzheimer's Disease (AD).

Presented by Dr. Serge Gauthier and colleagues at the McGill Centre for Studies in Aging in Montreal, the new trial provided the international (including Canadian) data showing efficacy and safety. Following HPB approval of donepezil last August, Canadian physicians for the first time have a highly specific, effective, non-toxic and well-tolerated drug with which to treat the rapidly growing number of older people affected by this progressive and ultimately fatal disease.

According to Dr. Gauthier, the large multi-centre trial published in Neurology (January 1998) showed that donepezil improved memory, orientation and the use of language in addition to the performance of daily functions such as bathing, dressing and eating. The new trial, reported at the 5th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy in April in Geneva, Switzerland, confirmed these findings.

Michele Kohli, BSc

Cardiopulmonary bypass (CPB) machines, which oxygenate and pump blood, allow surgeons to stop the heart during cardiac surgery. Complicated surgeries are technically easier to perform on a non-beating heart. However, CPB can damage blood cells and increase the risk of complications including damage to the lung, excessive bleeding, low output syndrome, renal failure and perioperative myocardial infarction.¹ Also, bringing the patient on and off the CPB pump increases the overall operating time, which in turn increases the risk of complications. The other major causes of morbidity and mortality in cardiac surgery include the sternotomy and manipulation of the aorta.^2,3,4 In a recent survey of cardiac surgeons at a forum in Montreal, 81% identified CPB as the most common cause of complication, while 19% cited sternotomy.⁵

Recently, work in minimally invasive abdominal and general thoracic techniques has provoked interest in utilizing these techniques for cardiac surgery.⁴ Also, surgeons in South America such as Benetti and Buffolo reported that coronary artery bypasses performed on a beating heart, had mortality rates similar to conventional procedures with CPB. ^3,4

In the past few years, interest in a variety of techniques that eliminate use of CPB, sternotomy and aortic manipulation has grown.

Thomas Tsirakis, BA

Alzheimer Disease (AD) is the leading cause of dementia in Canada, affecting 8% of the general population over 60 years of age, and more than 35% of those over 80 years of age. The current number of Canadians affected with the disease is estimated to be 160,000 with approximately 10,000 dying of AD and related dementias every year.

The normal progression of AD typically follows a gradual 7- to 10-year decline in cognitive abilities. All brain functions are eventually affected, but disturbances in judgment, memory, and language appear early on in the disease, with motor function, and bowel and bladder control being maintained during this time period. The progressive and slow decline of an individual's cognitive abilities in AD has been compared to observing the process of normal human development in a reverse order.

Since there is currently no definitive clinical test available for establishing the presence of AD, it is imperative that the clinician utilize standardized diagnostic criteria and formal testing in order to rule out the possibility of any reversible forms of dementia. Individuals presenting with cognitive deficits of a rapid onset should be suspected of having some underlying etiology other than AD.