Sniff test can help identify precursor to Alzheimer’s

People in the early stages of Alzheimer’s disease typically lose their sense of smell. Now scientists at the University of Pennsylvania have found that a sniff test can help detect a condition called mild cognitive impairment earlier than a memory assessment alone.

Dr. David Roalf, an assistant professor of psychiatry, studies the relationship between smell and neurodegenerative diseases such as Alzheimer’s.

“The sense of smell gives us kind of a window into the brain,” he said.

In particular, his research has opened a window on identifying mild cognitive impairment, which the Mayo Clinic calls “an intermediate stage between expected cognitive decline of normal aging and the more-serious decline of dementia.”

“The most traditional way of screening for mild cognitive impairment or Alzheimer’s is to give a memory test. And that works pretty well when somebody has full blown Alzheimer’s disease,” Roalf said. “But in the pre-clinical stage, mild memory screens aren’t as sensitive or as specific as we would like them to be.”

But by asking patients to identify different scents infused in magic markers, researchers were able to diagnose them more accurately than by testing memory alone.

Patients are given magic markers infused with different scents.

“And then they’re given a four choice option — four choice test — to say which one of these items do you think that this marker smells like?” Roalf said.

Alzheimer’s disease gets worse as time goes on, but Roalf said catching someone’s illness earlier helps families create a safer environment for the patient and a better care plan.

Roalf’s next goal is to shorten the smell assessment so that primary care doctors could be able to administer it during a normal 15 minute checkup.