Image-based predictor of dementia in patients with Down syndrome

Neural biomarkers could be used to predict the risk for dementia in individuals with Down syndrome, according to a University of Kentucky study.

One of the most common chromosomal abnormalities, present in about 1 in 1000 births each year, Down syndrome includes symptoms such as intellectual impairment and distinctive facial features. But a lesser-known aspect of the syndrome is the increased risk of early-onset Alzheimer’s disease. By 40 years of age, almost every individual with Down syndrome will have protein deposits in the brain that are considered hallmarks of Alzheimer’s—but not everyone with Down syndrome will develop Alzheimer’s symptoms. The mechanisms behind this are unknown, but a strategy for early detection of dementia is critical for treatment and intervention.

Researchers from the University of Kentucky’s Sanders-Brown Center on Aging set out to determine if proton magnetic resonance spectroscopy (H-MRS) could be used to detect dementia in adults with Down syndrome. A group of 22 individuals with down syndrome and 15 age- and gender-matched controls were enrolled in the study. Led by first author Elizabeth Head, PhD, associate professor at the University of Kentucky, the team used H-MRS to measure the levels of neuronal markers such as N-acetylaspartate (NAA) and myo-iositol (MI) in the subjects’ brains.

The results indicated that individuals with Down syndrome had a shifted neural metabolism (lower NAA, higher MI) and the shift was even more pronounced in subjects with dementia. Furthermore, the higher amounts of MI were already present in Down syndrome individuals at the age of 35, suggesting that the increase may be an “early aging event.” These findings may have predictive power for individuals with down syndrome in the future.

While the study possessed a small sample size, the differentiation between Alzheimer’s, non Alzheimer’s and control subjects is encouraging, according to Head.

"This is a great first study of its kind in Down syndrome," said Head. "We hope to extend the study as we follow people over time. Ultimately, the technique may be useful in future clinical trials of dementia treatments in people with Down syndrome."

The entire study, published in the journal NeuroImage: Clinical, can be read here.