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A new study published in Neurology, explores the potential to predict how quickly cognitive decline will occur in individuals with early Alzheimer’s disease. The research also examines how newly approved drugs for the disease may slow this decline.
“The rate of cognitive decline varies greatly from person to person, and people are very interested in what to expect from the disease in themselves or their loved ones, so better prediction models are urgently needed,” said study author Pieter J. van der Veere, MD, of Amsterdam University Medical Center, Netherlands.
The study involved developing predictive models to estimate the progression of thinking and memory skills over time. Researchers tested these models against actual data from 961 participants, with an average age of 65. Of these, 310 had mild cognitive impairment and 651 had mild dementia, all displaying amyloid-beta plaques in their brains—an early sign of Alzheimer’s disease.
Participants were assessed using a cognitive test where scores range from zero to 30. Scores above 25 indicate no dementia, 21 to 24 indicate mild dementia, 10 to 20 indicate moderate dementia, and scores below 10 signify severe dementia. Over five years, those with mild cognitive impairment saw their scores drop from 26.4 to 21.0, while those with mild dementia experienced a decline from 22.4 to 7.8.
The predictive models proved useful but highlighted the uncertainty inherent in forecasting cognitive decline. For half of those with mild cognitive impairment, the difference between predicted and actual scores was less than two points. For those with mild dementia, the difference was less than three points.
In hypothetical scenarios, a person with mild cognitive impairment, a baseline score of 28, and a certain level of amyloid plaques would be predicted to progress to moderate dementia (a score of 20) in six years. If drug treatments reduced the decline rate by 30%, this progression would be delayed to 8.6 years. For someone with mild dementia and a baseline score of 21, the progression to a score of 15 would take 2.3 years, or 3.3 years with a 30% reduction in decline rate due to treatment.
Van der Veere emphasized the importance of these models in addressing practical concerns from patients and caregivers. “We understand that people with cognitive problems and their care partners are most interested in answers to questions like ‘How long can I drive a car?’ or ‘How long can I keep doing my hobby?’ In the future, we hope that models will help make predictions about these questions about quality of life and daily functioning. But until then, we hope these models will help physicians translate these predicted scores into answers for people’s questions.”
This research marks a significant step towards personalized care for Alzheimer’s patients, providing a foundation for future models that could more accurately predict the impact of the disease on daily life and help tailor treatments to individual needs.
