Could Our Fingers Help Diagnose Alzheimer’s? A Finger Tapping Test Shows Promise

With devices so prevalent in our lives, the number of times we tap our fingers each day is pretty high. Could this simple and regular movement provide Alzheimer’s clues? A new study finds it might.

Research recently published in the Journal of Alzheimer’s Disease investigated how fine motor skills and Alzheimer’s are linked, testing this through a finger tapping test. The team explains that this avenue of research isn’t quite as extensive.

Neuropsychologist Marit Ruitenberg, who conducted the study along with fellow neuropsychologist Vincent Koppelmans, explains, “Many studies on Alzheimer’s primarily focus on cognitive symptoms like forgetfulness or major motor problems such as impaired balance. Vincent and I, however, found hints in the literature that there are also subtle differences in fine motor skills.”

To further investigate these differences, the researchers recruited 47 cognitively healthy people, 27 people with mild cognitive impairment, and 26 Alzheimer’s patients and had them do computerized tapping tests. This involved different directions, like tapping their right index finger on the keyboard as quickly as possible, then doing the left, and then doing them both at the same time or alternating them.

The team measured how quickly the participants began the first task, how long they took between the following tasks, and how many taps happened within certain time frames. The goal was to see if finger tapping skills could be a biomarker for Alzheimer’s and how they may link with other biomarkers, like a shrinking hippocampus.

The researchers found that compared with the control group, Alzheimer’s patients had slower reaction time and more speed variability, except during dual tapping. Those with mild cognitive impairment also had worse reaction time and speed variability on dual and non-dominant hand tapping. Additionally, tapping prowess was found to be linked with the size of the hippocampus, with those with a smaller hippocampus performing worse.

The researchers also used machine learning to see if a computer could accurately identify which group a person was in, based on their performance. It was able to do so in 70% of cases, but it didn’t perform as well with the mild cognitive impairment group.

Should their findings be replicated, the team hopes all that tapping we’re so used to doing may help with Alzheimer’s diagnosis.

Koppelmans says, “Existing diagnostic tests for Alzheimer’s work very well. Doctors use PET scans to measure the presence of specific proteins in the brain, and MRI scans measure the size of the hippocampus. These are two strong indicators of Alzheimer’s. But these methods are expensive and somewhat invasive… You could easily administer these tests in a primary care setting as part of early screening. If someone performs poorly on the test and also exhibits other symptoms indicative of Alzheimer’s, they could be referred for neuropsychological testing and possibly a PET scan.”

Something to ponder as you tap the next link after finishing this article.