Symptoms of Alzheimer and dementia are mostly diagnosed during the late stages. Due to lack of available medical procedures and devices to determine the onset of the disease, treatment can be too late for some people. However, a recent study suggests that using the sense of smell, physicians may now identify early signs of Alzheimer and dementia.
A study conducted
by experts from the Perelman School of Medicine at the University of Pennsylvania confirmed that by performing a simple "sniff test", diagnosis of Alzheimer and dementia can become more accurate.
"There's the exciting possibility here that a decline in the sense of smell can be used to identify people at risk years before they develop dementia," said principal investigator David R. Roalf, PhD, an assistant professor in the department of Psychiatry at Penn.
The process may also be useful to determine a pre-dementia condition called mild cognitive impairment (MCI), which normally advances to Alzheimer's dementia after a couple of years.
Experts have used a Sniffin’ Sticks Odor Identification Test, which is currently commercially available. The goal of the test is to identify 16 distinct scents. Together with a standard cognitive test (the Montreal Cognitive Assessment), they performed the trials to 728 elderly individuals.
The participants were already diagnosed before the 'sniff test' using neurological methods. They have been classified into three groups: “healthy older adult,” “mild cognitive impairment,” or “Alzheimer’s dementia.”
The experts conducted random tests where they used the cognitive test alone, or combined with the sniff test. This is to determine how well the new method performs in diagnosing.
Results showed that cognitive tests are more accurate when combined with the sniff tests.
"These results suggest that a simple odor identification test can be a useful supplementary tool for clinically categorizing MCI and Alzheimer's, and even for identifying people who are at the highest risk of worsening," Roalf said.
Some neurologists have begun including the sniff test in diagnosing such illnesses. However, the method isn't common to many physicians, as it takes more time than the usual process in determining the disease. Roalf and his team are now trying to develop a briefer test that works as accurate as the longer ones.
“We’re hoping to shorten the Sniffin’ Sticks test, which normally takes 5 to 8 minutes, down to 3 minutes or so, and validate that shorter test’s usefulness in diagnosing MCI and dementia—we think that will encourage more neurology clinics to do this type of screening,” Roalf said.