A New Angle on Diagnosis

 

In Alzheimer disease, brain cells stop functioning, lose their connections with other neurons and eventually die.

Occasional lapses in memory are a normal and expected part of the aging process. However noticeable and consistent memory loss that disrupts daily living can be an early sign of Alzheimer disease (AD).
 
A definitive diagnosis for AD can be difficult to obtain as it requires a battery of tests that rely heavily on verbal communication and mental tasks. As such, there is a need for more reliable methods for diagnosing and monitoring AD, particularly at early stages of the disease when treatments might be more effective.
 
TRI Affiliate Scientist Dr. Krista Lanctôt and her team are trying to improve early diagnosis for AD by developing and evaluating new methods for measuring mental function.
 
They recently completed a two-year study in which individuals with AD were tested for their ability to pay attention to computer images that were either new or repeated. This test is considered a good indicator of one’s ability to hold information in short term memory in order to learn new things—a skill that is considerably impaired in patients with AD.
 
The research team discovered that study participants with AD had lower attention spans and a reduced preference for looking at new images compared with elderly participants without AD. Moreover, participants who had the greatest decline in mental function (measured using a well-established cognitive test) were the least likely to pay attention to new images.
 
“Our findings show a reduced preference for novel images might be a useful predictor of the earliest stages of cognitive decline that occur in Alzheimer disease” explains PhD student Sarah Chau, lead author of the study.
 
Adds Dr. Lanctôt, “The study demonstrates the potential for using novelty preference as a non-verbal and non-invasive method for monitoring disease progression. The method could easily be adopted by clinicians to identify those most at risk of decline in order to adapt treatment and management plans.”

This work was supported by a Sunnybrook/Glaxo Drug Safety Graduate Fellowship, the Consortium of Canadian Centres for Clinical Cognitive Research, the Natural Sciences and Engineering Research Council of Canada and the Toronto Western Hospital Vision Science Research Program.
 
Chau SA, Herrmann N, Sherman C, Chung J, Eizenman M, Kiss A, Lanctôt KL. Visual selective attention toward novel stimuli predicts cognitive decline in Alzheimer's disease patients. J Alzheimers Dis. 2017. doi: 10.3233/JAD-160641.