Predicting Alzheimer’s disease has proven to be almost as elusive and difficult as curing it — but new research has provided promising avenues for identifying it early.
Now two independent research projects have found clues to early-stage Alzheimer’s in the eyes of test subjects.
The first, conducted by a team of researchers led by Thom Wilcockson of the School of Sports, Exercise, and Health Sciences at Loughborough University, involves measuring eye movements when subjects tried to ignore onscreen distractions.
The second, from scientists from the University of California San Diego School of Medicine, suggests that the speed at which a subject’s pupils dilate when focusing on a cognitive test offers an early clue to Alzheimer’s.
A matter of focus
The Loughborough researchers propose that the ability to maintain focus may predict which patients with mild cognitive impairments will develop Alzheimer’s disease. The findings were published in Aging journal.
Mild cognitive impairment (MCI) is itself a strong predictor of Alzheimer’s. Some studies have found that 46% of people over 65 who have MCI will develop full-blown dementia within three years, compared with just 3% of other people in the same age group.
Test subjects were instructed to avoid looking at distracting objects on a computer. Scientists then calculated the amount of times people failed to ignore these randomly appearing spots and assigned a score that strongly correlated with the occurrence of Alzheimer’s.
The team’s conclusion: The mind’s ability, not just to focus or recall facts, but to ignore stimuli, seems a powerful predictor of Alzheimer’s.
Peering at pupils
Meanwhile, the UCSD team led by William Kremen on the observation that tau proteins, published its latest findings about pupil dilation in Neurobiology of Aging.
Tau proteins that comprise the plaques and tangles in brains affected by Alzheimer’s first damage a region of the brain called the locus coeruleus, which controls pupil dilation. The researchers focused on whether tau buildup that affects the eyes can identify Alzheimer’s long before it affects memory.
The UCSD team tested the pupil response of 1,119 men age 56 to 66, then compared their performance on the test with family histories of Alzheimer’s.
The result: Men whose relatives had developed Alzheimer’s had slower pupil responses, suggesting another way eye tests can diagnose Alzheimer’s early.
A growing set of diagnostic tools
These new reports are the latest in a string of recent developments that may power early-warning systems for Alzheimer’s.
Sea Hero Quest, a video game designed to spot telltale memory gaps, has been used by more than 4 million people. According to its creators, the game generates the same amount of data in two minutes of play as it would take scientists five hours to collect in a lab.
A recent study by Eli Lilly & Co., Apple, and Evidation Health found that the way someone uses their mobile device — whether it be an iPhone, tablet or wearable — could be used to predict signs of dementia.
Meanwhile, a new blood test may be able to identify markers of Alzheimer’s disease up to two decades before those symptoms arise, an initial study from Washington University School of Medicine shows. The blood test measures levels of amyloid beta, a protein fragment that builds up in the brain to create the plaques and tangles characteristic of Alzheimer’s.