About 500,000 Canadians are living with Alzheimer’s disease or a related dementia. This number is expected to soar to 1.1 million within 25 years. To date, there is no definitive way for health care professionals to forecast the onset of dementia in a patient with memory complaints. However, new research provides a glimmer of hope.
As a geriatrician, I have been looking at walking speed and variability as a predictor of dementia’s progression and whether it is associated with physical changes in the brain.
The “Gait and Brain Study” is a longitudinal cohort study funded by the Canadian Institutes of Health Research (CIHR). It assessed up to 150 seniors with mild cognitive impairment (MCI) — a pre-dementia syndrome — in order to detect an early predictor of cognitive and mobility decline, and progression to dementia.
While walking has long been considered an automatic motor task, emerging evidence suggests cognitive function plays a key role in the control of walking, avoidance of obstacles, and maintenance of navigation.
In our recent research, my team asked people with mild cognitive impairment to walk on a specially-designed mat linked to a computer. The computer recorded the individual’s walking gait variability and speed. This information was then compared to their walking gait while simultaneously performing a demanding cognitive task, such as counting backwards or doing calculations while walking (“walking-while-talking”).
It was subsequently determined that some specific gait characteristics are associated with high variability, particularly during walking-while-talking. These gait abnormalities were more marked in MCI individuals with the worst episodic memory and with executive dysfunction revealing a motor signature of cognitive impairment.
If confirmed in subsequent studies, these gait changes can be an effective predictor of cognitive decline and may eventually help with earlier diagnoses of dementia.
Finding early dementia detection methods is vital. In the future, it is conceivable that we will be able to make diagnoses of Alzheimer’s disease and other dementias before people even have significant memory loss. We believe that gait, as a complex brain-motor task, provides a golden window of opportunity for researchers to see brain function. The high variability observed in people with mild cognitive impairment can be seen as a “gait arrhythmia,” predicting mobility decline, falls, and now, cognitive impairment. Our hope is to combine these methods with promising new medications to slow or halt the progression of mild cognitive impairment to dementia.
Image Credit: Elderly person walking CC0 via Pixabay