With the fitness wearable market exploding in popularity, especially among senior citizens keen to track heart health, a team of researchers from the Johns Hopkins Bloomberg School of Public Health wondered whether these devices could be used to detect the earliest signs of dementia. A new study suggests that could be possible after finding distinct differences in daily movement patterns when comparing cognitively healthy older adults and Alzheimer’s patients.
The association between neurodegeneration and motor movement is well-known. In fact, over the last few years researchers have found they can accurately diagnose Alzheimer’s disease by simply tracking a patient’s walking patterns.
A limitation of these kinds of gait studies is the need for complex computer systems to detect movement characteristics that correlate with dementia. So far, it’s not a system that could be easily deployed at home. But this new research looked to leverage more common accessible data gathered by popular fitness tracking wearables, such as the Fitbit.
The study analyzed data from 585 subjects enrolled in an ongoing aging research project. The goal was to find out whether there was any correlation between daily activity patterns and cognitive health.
Although the study found no differences in overall all-day activity measures when comparing cognitively healthy seniors to those with Alzheimer’s, some stark differences appeared when the researchers homed in on the more granular time-of-day data.
Across an afternoon block, from midday to 6pm, the researchers found those subjects with cognitive impairments moved significantly less than the healthy cohort. This afternoon movement in the impaired group was also markedly fragmented, meaning the activity was broken up into noticeably short bursts.
Lead author on the study Amal Wanigatunga said this reduction in afternoon movement interestingly recalls a known phenomenon in Alzheimer’s called “sundowning”.
"Seeing this difference in the afternoons was interesting – one of the main symptoms of Alzheimer's dementia is the 'sundowning' phenomenon involving increased confusion and mood changes that start in the afternoon, and it might be that these activity markers are capturing some movement related to these symptoms,” Wanigatunga explained.
It’s early days for the researchers, and plenty more work is needed before this translates into some kind of dementia-monitoring app for your Fitbit. The next step will be to look at data from these activity monitors over a longer period of time to find out whether measurable changes in movement can signal shifts from healthy cognition to mild impairment.
Wanigatunga is optimistic these findings could one day lead to a movement-monitoring system that catches brain changes at their earliest stages. Any way to flag these kinds of declines early offer doctors the best opportunity to deliver interventions that can slow the progression of disease.
"We tend to think of physical activity as a potential therapy to slow cognitive decline, but this study reminds us that cognitive decline may in turn slow physical activity – and we might someday be able to monitor and detect such changes for earlier and more efficient testing to delay and maybe prevent cognitive impairment that leads to Alzheimer's," said Wanigatunga.
The new study was published in the Journal of Alzheimer's Disease.
