JAN 18, 2016

Eye Movement and Alzheimer's Disease

WRITTEN BY: Brenda Kelley Kim
Alzheimer’s disease (AD) and other forms of dementia are on the rise. There is no known cause of AD and there isn’t even a definitive way to diagnose the disease until after a person has died. A key area in neuroscience research is the search for an early test for AD so that patients and their families can have time to arrange care and look for ways to deal with the memory loss and other factors.

The most recent figures show that approximately 5.1 million Americans might be suffering from the effects of Alzheimer’s disease. And those figures are going up. Current research from the National Institute on Aging indicates that the prevalence of Alzheimer's disease doubles every five years beyond age 65.  By the year 2050 the costs of treating AD could rise to $1.1 trillion, up from the $226 billion estimated through the year 2015. Finding a way to test for the disease has become a crucial part of the research surrounding Alzheimer’s disease. 
 
Chilean neurologists however may have found a process for diagnosing Alzheimer's disease early, even before memory loss and other symptoms develop. Researchers at Chile's Biomedical Neuroscience Institute (BNI) believe they can identify early stages of dementia and even some other psychiatric and neurological diseases by observing eye movement patterns and the brain's electrical activity. Using a computer simulation game with virtual reality technology the neurologists in Chile studied patients playing along in a game where they  had to navigate through a virtual landscape and find "keys" to complete a task. Lead neurologist Enzo Brunetti said the tests were able to detect very early signs of cognitive impairment, even in patients who showed no symptoms. 
 
Brunetti told Reuters, "In this study, what we did was that we applied spatial navigation tasks using a computer, and with the help of a software we examined in detail which were the early functions that became altered in Alzheimer's disease (patients) and focused on a very specific function, linked to the codification and development of cognitive memory, that helps people move through the physical environment. This is one of the cognitive functions that were altered in patients with Alzheimer's and we observed that they were altered from very early stages. Therefore we believe this is a biomarker for the disease, which would give us an opportunity to shed light on an early diagnosis for this disease." 

The team in Chile also fitted study participants with caps containing electrodes and conducted EEG testing while the patients were navigating through the game. This monitoring, along with recording the eye movements of patients convinced Brunetti that diagnosing AD before significant memory loss and cognitive impairment is vital to helping patients and that a larger clinical trial is necessary to fine tune the process. Take a look at the video below to learn more about the study and how it could impact dementia patients and their families.