Fine motor skills of hands and fingers may reveal dementia at early stages
Dementia is typically considered to be a cognitive disorder, but physical function is often also impaired in older adults with dementia. For example, people with dementia tend to perform worse in tests of physical function, such as grip strength and gait speed, than people without dementia. It is, however, not clear to what extent deterioration in physical function precedes dementia, and how much dementia progression causes deteriorated physical function. In this study, the researchers investigated whether specific aspects of physical performance change more rapidly in older adults who later develop dementia. These results were compared with changes in physical function in a matched group who did not develop dementia.
Photo by Quân Phan on Unsplash
Data from three NEAR studies were used: Swedish Adoption/Twin Study of Aging (SATSA), Origins of Variance in the Oldest Old (OCTO-Twin), and Aging in Women and Men: A Longitudinal Study of Gender Differences in Health Behavior and Health among the Elderly (GENDER). The study sample consisted of 259 older adults who developed dementia and 259 who did not over the course of the study, but were of the same age. Physical function was measured with three objective tests: time to complete a three-meter out-and-back walk (gait speed), grip dynamometry (grip strength), and time to complete a functional fine motor test (functional fine motor), including everyday tasks such as inserting a key into a lock and turning it, or plugging in an electrical cord. Cognitive performance was measured with the Mini-Mental Status Exam.
The results showed that gait speed and grip strength declined with age in both groups, but the rate of decline did not differ between those who developed dementia and those who did not. In contrast, functional fine motor performance showed a significantly steeper decline among participants who later developed dementia. Their performance deteriorated at around twice the rate observed among those who did not develop dementia. Notably, the decline in fine motor skills also outpaced that observed in MMSE scores, suggesting that the functional fine motor test may be more sensitive to eventual dementia than a global cognitive screen like the MMSE, which has been shown to be insensitive to early cognitive changes.
In conclusion, objectively measured functional fine-motor tasks, such as inserting a key into a lock, may identify an elevated risk for developing dementia earlier than other gross-motor tasks. This is particularly important in cases where memory tests may not be reliable. Simple functional fine-motor tasks can be easily added to assessments of functioning in both clinical and research settings and may improve dementia diagnosis and prognostic estimates.
Sydney Y Schaefer, Associate Professor and first author of the study. Photo: West Eal Photography.
Congratulations, Sydney, on you results! What was the most unexpected research finding?
I think the two most unexpected findings were how early the functional fine motor test showed deficits prior to the diagnosis of dementia, and how different the time course was relative to the other physical function assessments.
What are the advantages and disadvantages of using NEAR data?
The biggest advantage for me was simply how much data there were to answer our research question, and how easy and straightforward accessing the datasets were. Other researchers who are considering using NEAR data in the future are encouraged to set aside sufficient time to look through all the available variables, as there are lots!
Best tips for working with NEAR data:
Do not hesitate to reach out for assistance, and ideally, collaborate with researchers who are familiar with the original studies.
Best tips to regain focus:
I stayed focused by thinking about how novel and interesting our findings would be, and how excited I was to be working with such robust data. I encourage others to focus on the big picture and the novelty of their work to help them stay on track!
Publication
Schaefer SY, Peterson DS, Ernsth-Bravell M, Finkel D. Predicting the onset of dementia with longitudinal performance-based measures of physical function. The journals of gerontology Series B, Psychological sciences and social sciences. 2025;80(12).
