Researchers say that measuring how quickly a person’s pupil dilates while they are taking cognitive tests may be a low-cost, low-invasive method to aid in screening individuals at increased genetic risk for AD before cognitive decline begins.
In a new study published online in the September 9, 2019 issue of the Neurobiology of Aging, scientists at University of California San Diego School of Medicine say that, with further developments, associated with cognition than amyloid-beta.
The study was led by first author William S. Kremen, PhD, and senior author Carol E. Franz, PhD, both professors of psychiatry and co-directors of the Center for Behavior Genetics of Aging at UC San Diego School of Medicine.
The LC drives pupillary response the changing diameter of the eyes’ pupils during cognitive tasks. (Pupils get bigger the more difficult the brain task.)
In previously published work, the researchers had reported that adults with mild cognitive impairment, often a precursor to AD, displayed greater pupil dilation and cognitive effort than cognitively normal individuals, even if both groups produced equivalent results.
Critically, in the latest paper, the scientists link pupillary dilation responses with identified AD risk genes.
“Given the evidence linking pupillary responses, LC and tau and the association between pupillary response and AD polygenic risk scores (an aggregate accounting of factors to determine an individual’s inherited AD risk), these results are proof-of-concept that measuring pupillary response during cognitive tasks could be another screening tool to detect Alzheimer’s before symptom appear,”
Co-authors include: Matthew S. Panizzon, Jeremy A. Elman, Anders M. Dale, Daniel E. Gustavson and Nathan Whitsel, UC San Diego; Eric L. Granholm, UC San Diego and Veterans Affairs San
Diego Healthcare System; Ole A. Andreassen, Oslo University Hospital; Nathan A. Gillespie and Michael C. Neale, Virginia Commonwealth University; Mark W. Logue, VA Boston Healthcare System and Boston University; Michael J. Lyons, Boston University; and Chandra A. Reynolds, UC Riverside.
This research was published at