August 30, 2019
Signs of cognitive impairment can be difficult to link to the early development of Alzheimer's disease and its associated symptoms of dementia, but a new study points toward the use of eye tracking tests as a way to assess future risk.
Dementia diagnoses are often preceded by a condition known as mild cognitive impairment (MCI), where subtle signs of memory loss or flawed thinking have only a minor impact on day-to-day life.
In the presence of secondary conditions such as diabetes, depression and metabolic syndrome, as many 46% of MCI patients will go on to develop dementia within a few years, according to a recent study published in Social Psychiatry and Psychiatric Epidemiology.
Researchers have classified two types of MCI — amnesiac and non-amnesiac. The first group tends to have symptoms impacting memory, while the second group suffers other cognitive issues.
Because those with amnesiac MCI are more predisposed to developing Alzheimer's, recognizing a patient's MCI subtype is an important step in managing their condition.
A new study out of Loughborough University in the United Kingdom points to the use of eye-tracking tests as a way to distinguish between MCI subtypes.
Using a series of computer-based tasks, researchers tested 42 participants with a diagnosis of amnesiac MCI, 47 people with non-amnesiac MCI, 68 participants whom doctors had diagnosed with Alzheimer's disease, and 92 healthy age-matched controls.
Participants were asked to avoid looking at a dot or other stimulus on a computer screen in a variety of tasks. An eye-tracking technology was used to calculate the rate of error for each participant.
Test results showed a clear distinction between participants with amnesiac and non-amnesiac MCI. Those with amnesiac MCI also had very similar results as those with Alzheimer's disease.
"This research is extremely important as an earlier diagnosis of Alzheimer's disease would enable effective treatments, when available, to be administered before pathological changes to the brain are widespread and permanent," study author Thom Wilcockson said.
The researchers behind the study, published in the journal Aging, plan to further develop methodologies for eye-tracking tests that can be used to screen individuals with MCI.