New Study Associates Behavior From Digital Cognitive Assessments With Key Biological Markers for Alzheimer’s Disease

New research recently published in Frontiers in Aging Neuroscience provides further validation of the ability of digital clock drawing assessments to help uncover deficits in mental planning tied to certain biological markers. Mental planning is a cognitive ability essential to the completion of complex tasks of daily living and frequently disrupted in individuals with mild cognitive impairment (MCI) and dementia, which often occur as a result of Alzheimer's disease. The study, conducted primarily by researchers at the University of Florida, specifically showed a link between the accuracy of the placement of numbers within the clock face and underlying biological factors tied to Alzheimer’s disease—opening up new potential opportunities for early detection and treatment around emergent illness.

The study combined neuropsychological testing—including a digital clock drawing test to assess mental planning—with functional brain imaging using MRI to explore a potential link specifically between digit misplacement and functional brain connectivity with the basal nucleus of Meynert (BNM) and the anterior cingulate cortex (ACC). The BNM and ACC are both areas of the brain involved with executive abilities like mental planning and the BNM is a major source of acetylcholine (ACH), a key neurotransmitter related to executive abilities that is often disrupted in patients with Alzheimer’s disease. Measuring connectivity between the BNM and ACC gives new insight into the functional integrity of the ACH system and how digital clock drawing behavior can support early detection of cognitive deficits in individuals with suspected MCI or dementia.

The 201 participants were older adults without dementia, 24 of whom met research criteria for MCI. Researchers compared people with and without MCI, finding that those with MCI had greater clock drawing digit misplacement and lower BNM-ACC connectivity. “Previous research has shown that digital clock drawing tests can help screen for MCI, which is considered a prodromal phase for dementia,” says Catherine Price, PhD, an associate professor of clinical and health psychology and department of anesthesiology, Perioperative Cognitive Anesthesia Network at the University of Florida. “This study builds on this by showing an association between the accuracy of a digit placement within the clock face and functional connectivity between key brain structures involved in attention.”

“These results are exciting not only because they indicate that digit misplacement measures could be a neurocognitive biomarker for Alzheimer’s disease, but also because digital innovation has paved the way for expanded use of clock drawing tests in clinical settings,” adds David J. Libon, PhD, a professor of geriatrics and gerontology at Rowan University. “The precision and automation of digital assessments reduces reliance on neuropsychology experts to analyze results, while objective scoring lessens subjectivity and inter-rater reliability issues.”

The specific digital clock drawing test used in the study is proprietary Linus Health technology. It was designed to combine sensitive assessments with practical administration for both researchers and clinicians.

“Efficient, actionable assessments are key to determining if a patient has early signs of cognitive issues and, if so, what the best intervention options are for them,” says Alvaro Pascual-Leone, chief medical officer at Linus Health, medical director of the Wolk Center at Hebrew SeniorLife, and a professor of neurology at Harvard Medical School. “Tying the easy-to-capture measure of digit placement accuracy to known biological factors offers the potential to better identify patients who would benefit from reducing anticholinergic drug burden and/or using treatments targeted at enhancing ACH.”

Source: Linus Health