close
close

New Algorithms Predict How Fast Alzheimer’s Will Progress

New Algorithms Predict How Fast Alzheimer’s Will Progress

A study investigating predictive models for cognitive decline in patients with early Alzheimer’s disease examined the effects of new drugs that target amyloid-beta plaques. The researchers developed models that compared predicted declines in cognitive test scores with actual outcomes, and monitored both the accuracy of these predictions and the potential delay in decline due to drug treatments. Source: SciTechDaily.com

A study conducted in 2024 evaluates predictive models Alzheimer’s disease-addresses associated cognitive decline and evaluates the effectiveness of new medications in slowing this decline.

A new study attempts to predict how quickly people with early Alzheimer’s disease will experience cognitive decline. The study was published in the July 10, 2024 online issue of neurologyIt’s the medical journal of the American Academy of Neurology. It also looked at how new drugs recently approved for the disease might reduce relapse.

“The rate of cognitive decline varies greatly from person to person, and people are very concerned about what to expect from the disease in themselves or their loved ones, so better prediction models are urgently needed,” said study author Dr. Pieter J. van der Veere of the University Medical Center Amsterdam in the Netherlands.

Study Details and Cognitive Assessment

The researchers developed models to predict how quickly people’s scores would decline on a test of thinking and memory skills. They then compared the models with people’s actual results over time. They studied 961 people, with an average age of 65; 310 had mild cognitive impairment and 651 had mild dementia. All had amyloid-beta plaques in their brains, an early sign of Alzheimer’s disease and targeted by new drugs.

For the cognitive test, scores range from zero to 30; scores of 25 and above indicate no dementia, scores of 21 to 24 indicate mild dementia, scores of 10 to 20 indicate moderate dementia, and scores of less than 10 indicate severe dementia. Test scores for people with mild cognitive impairment dropped from 26.4 at the beginning of the study to 21.0 after five years. Scores for people with mild dementia dropped from 22.4 to 7.8 after five years.

Insights from Models of Cognitive Decline

The models helped predict the rate of cognitive decline, but they also showed the uncertainty of these estimates, van der Veere noted. For half of the people with mild cognitive impairment, the actual test score differed from the predicted score by less than two points. For people with mild dementia, the scores differed by less than three points for half of the people.

Estimated Outcomes and Drug Effect

The researchers determined that a hypothetical person with mild cognitive impairment, a baseline test score of 28, and some level of amyloid plaques would be predicted to reach the moderate dementia stage (test score of 20) after six years. If treatment with medications reduced the rate of decline by 30%, that person would not reach the moderate dementia stage until 8.6 years later. For a hypothetical person with mild dementia, a baseline score of 21, and some level of amyloid, the predicted time to reach a score of 15 was 2.3 years, or 3.3 years if the decline was reduced by 30%.

Future Applications and Study Limitations

“We understand that people with cognitive issues and their care partners are most interested in answers to questions like, ‘How long can I drive?’ or ‘How long can I continue to do 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 that these models will help doctors translate these predicted scores into answers to people’s questions,” Van der Veere said.

One limitation of the study was that the cognitive tests were not always given at the same time of day, and people with cognitive decline may have lower scores later in the day when they were more tired.

Reference: “Prediction of Cognitive Decline in Amyloid-Positive Patients with Mild Cognitive Impairment or Mild Dementia” July 10, 2024, neurology.
DOI: 10.1212/WNL.0000000000209605

The study was supported by Eisai, ZonMW and Health~Holland, Top Sector Life Sciences and Healthcare.