Gait as Predictor of Dementia and Falls. The Gait and Brain Cohort Study

Motor slowing and cognitive slowing are more prevalent as we age. Importantly, the presence of both in an older person increases their risk of having dementia by ten times. Currently, there are no clinically meaningful predictors of progression to dementia in people with mild cognitive impairment (MCI). The main hypothesis is that subtle variations in gait while performing a simple cognitive task is a reliable, easy to perform, and feasible methodology to detect those older adults at higher risk of progression to dementia and also, at higher risk of further mobility decline and falls.

Rationale. The Canadian population is aging. According to recent estimates, the proportion of the population aged 65 and older will increase rapidly from 13% in 2005 to 25% by 2031. This increase in proportion is accompanied by a considerable amount of disability and subsequent dependency which has major effects on both the quality of life of older adults and their caregivers, and on the Canadian health care system. An important goal of geriatric medicine is to reduce the gap between life expectancy and disability-free life expectancy by reducing disability and dependency in the later years of life. A substantial portion of this disability stems from two major geriatric syndromes: cognitive impairment and mobility limitation. The ultimate manifestations of these syndromes are dementia and falls. Interestingly, these manifestations often coexist in elderly people: falling is a common geriatric syndrome affecting about a third of older adults each year, and dementia affects about a third of Canadians aged 80 and over. Together, dementia and falls are responsible for much of the discomfort, disability, and health care utilization in older adults and each will become more prevalent as older Canadians are expected to number approximately $9 million by 2031. The combined direct cost of dementia and falls for the Canadian Health System is over $4.9 billion per year.

Establishing reliable and easy to obtain predictors to accurately identify MCI patients at highest risk of progressing to dementia is essential first, to determine who will benefit from additional and/or invasive testing and second, to implement preventative strategies, including cognitive training, physical exercises, and aggressive vascular risk factors correction to delay progression. Even a modest one-year delay in dementia incidence could save Canada $109 billion over 30 years.