Call for routine cognitive screening for over-50s

Annual cognitive screening for all older people should be the new normal to rule out preclinical Alzheimer’s disease, according to a leading neuropsychologist

Dr Duke Han, an associate professor of family medicine at the University of Southern California, says standard cognitive tests can detect early Alzheimer’s disease before symptoms arise, negating the need for PET scans or cerebrospinal fluid analysis up front.

He points to the results of his latest research, a meta-analysis of 61 studies, which found that people who had amyloid plaques performed worse on neuropsychological tests of global cognitive function, memory, language, visuospatial ability, processing speed and attention/working memory/executive functions than people who did not have amyloid plaques.

The study, published in Neuropsychology Review, also found that people with tau pathology or neurodegeneration performed worse on memory tests than people with amyloid plaques.

Amyloid plaques and tau pathology were confirmed by PET scan or cerebrospinal fluid analysis.

"The presumption has been that there would be no perceivable difference in how people with preclinical Alzheimer's disease perform on cognitive tests,” he says.

“This study contradicts that presumption.”

Dr Han believes the results provide a solid argument for incorporating cognitive testing into routine, annual checkups for older people.

“Having a baseline measure of cognition before noticing any kind of cognitive change or decline could be incredibly helpful because it's hard to diagnose early Alzheimer's disease if you don't have a frame of reference to compare to," he says.

"If people would consider getting a baseline evaluation at age 50 or 60, then it could be used as a way to track whether someone is experiencing a true decline in cognition in the future."