Sunnybrook and Women's College Health Sciences Centre

Sunnybrook and Women's College Health Sciences Centre

June 14, 2005 09:31 ET

Alzheimer's accurately predicted up to 10 years before symptom onset

Attention: Assignment Editor, Health/Medical Editor, Media Editor, News Editor, Science Editor TORONTO, ONTARIO--(CCNMatthews - June 14, 2005) - Using neuropsychological testing, researchers at Sunnybrook & Women's have accurately predicted which study participants would be most likely to develop Alzheimer's disease within five and ten years.

"The identification of individuals at risk for Alzheimer's disease will be a critical first step in the selection of candidates for therapy if new treatments emerge that will delay the onset of symptoms," says Dr. Mary Tierney, principal investigator of the study and director of the Geriatric Research Unit at Sunnybrook and Women's College Health Sciences Centre. "Early prediction is also important in order that those requiring more careful monitoring are recognized early and receive the care they require."

Large numbers of study participants were drawn from the Canadian Study of Health and Aging (CSHA), a national study initiated in 1990 to investigate the incidence, prevalence and progression of dementia. The second wave of the study was undertaken in 1995 and a third in 2000.

"The CSHA provided an opportunity to examine the utility of neuropsychological tests in the prediction of AD for a longer term period and from a large sample," says Dr. Tierney, also a Professor in the Department of Family and Community Medicine at University of Toronto. "For this study, we focused on the ten-year period between the first and third waves of the national study, and the five-year period between the second and third waves."

Initially over one thousand study participants, who did not have dementia or any condition likely to affect the brain, completed several neuropsychological tests. After five and ten years, participants underwent a diagnostic assessment for dementia. The study found that three of the neuropsychological tests, which measured verbal memory, general information, and the ability to name items from a category, accurately identified those likely to develop AD after five years and a test of verbal memory accurately identified those likely to develop AD after ten years. The lower the score on the tests, the higher the probability of developing AD.

Because the study provided a way of quantifying an individual's risk of AD for as long as five or ten years before diagnosis, the methods could also be used to identify participants for clinical trials that examine conversion to Alzheimer's disease and the effectiveness of treatments for those at risk.

Previous studies were able to accurately predict AD in shorter periods of time, and some studies showed predictions for ten and even 15 years, but these studies did not provide an indication of the predictive accuracy of the tests. The findings found in this study provide validity, demonstrating the ability to identify individuals at risk over the long-term.

Co-investigators of the study are: Christie Yao, research assistant in the Geriatric Research Unit at Sunnybrook & Women's, Dr. Alex Kiss, scientist in Research Design and Biostatistics at Sunnybrook & Women's, and Dr. Ian McDowell, professor in the Department of Epidemiology & Community Medicine at University of Ottawa.

Sunnybrook and Women's College Health Sciences Centre is transforming health care through the dedication of its more than 10,000 staff members who provide compassionate and innovative patient focused care. An internationally recognized leader in women's health, academic research and education and an affiliation with the University of Toronto distinguishes Sunnybrook & Women's as one of Canada's premier health sciences centres. Sunnybrook & Women's specializes in caring for newborns, adults and the elderly, treating and preventing cancer, heart problems, orthopaedic and arthritic conditions, neurological and psychiatric disorders, and traumatic injuries. /For further information: Nadia Norcia
Communications Advisor
Sunnybrook & Women's

Contact Information

  • Nadia Norcia
    Primary Phone: 416-480-4040