Predicts Alzheimer’s

Smell Test Predicts Alzheimer’s Disease Early, Studies Find

 

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According to the Alzheimer’s Association, every 66 seconds someone in the United States develops Alzheimer’s. This severe disease kills more people than breast and prostate cancer combined. It’s estimated that a total of 5.4 million Americans of all ages will have Alzheimer’s disease in 2016. Due to the fact the exact cause of the disease is unknown, detecting cognitive decline and early stages of Alzheimer’s can be difficult. However, findings from two latest studies can change that.

Who Conducted the Studies?

Both studies were conducted by D. P. Devanand and team of scientists at the Columbia University Medical Center as well as the New York State Psychiatric Institute, and Ne-wYork-Presbyterian. Also, findings from both studies were presented at the Alzheimer’s Association’s International Conference in Toronto, Canada. The conference was held from July 22 to July 28, 2016.

Study #1

The first study included 397 adults with the mean age of 80; none of them were diag-nosed with dementia. The participants were administered with USPIT (University of Pennsylvania Smell Identification Test). USPIT is a commercially-available test for smell identification to test the functionality of the person’s olfactory system. It inspects indi-vidual’s ability to detect odors at a suprathreshold level. The test usually takes only a few minutes and includes four 10-page booklets with a total of 40 questions; each page contains different scratch and sniff strip. These tests can also be ordered online.

Also, every participant had an MRI scan that measured the thickness of the first brain area affected by Alzheimer’s disease, the entorhinal cortex. In 2013, the journal Nature Neuroscience published results of the study conducted by researchers at the Columbia University wherein they discovered the exact location in the brain where Alzheimer’s disease starts and from there it spreads to other areas such as the parietal cortex.
This time, researchers discovered that 12.6% of participants i.e. 50 of them developed dementia four years after the study began. Also, 20% of participants experienced cognitive decline. Unlike the entorhinal cortex thickness, the USPIT scores had a strong relationship with Alzheimer’s disease and dementia. On the other hand, the thickness of entorhinal cortex was strongly linked with UPSIT score in individuals who transitioned to dementia.

Low UPSIT scores show reduced ability to identify odors correctly. Moreover, they suc-cessfully predicted cognitive decline. These findings revealed that odor identification impairment has a tremendous potential to predict the transition to dementia. In fact, odor impairment might precede the thickness of the entorhinal cortex in the early stage of the Alzheimer’s disease.

Study #2

This research focused on the usefulness of the UPSIT and tests which measure the amount of amyloid in the brain to predict memory decline. Amyloids are protein pieces that are “sticky” and gradually build up into plaques in individuals with the Alzheimer’s disease.
For the purpose of this study, scientists included 84 participants with the mean age of 71, administered UPSIT and performed either analysis of cerebrospinal fluid or beta amyloid PET scanning. Scans and UPSIT showed that 58 participants had mild cognitive impairment which is why scientists followed them for 6 months and at the follow-up about 67% of participants showed signs of cognitive decline.
Scientists found that testing positive for amyloid successfully predicted cognitive decline, but USPIT score didn’t. Why? Researchers believe it’s due to younger age of participants, shorter follow-up, and higher education.
However, UPSIT is less expensive and easier to administer than PET scanning. Odor identification testing can help doctors counsel patients who are concerned about their memory loss and cognitive decline.

Conclusion

Alzheimer’s disease and dementia affect millions of people in the United States. Both severe diseases are characterized by memory loss and overall cognitive decline. Thanks to two studies presented at theAlzheimer’s Association’s International Conference, healthcare providers will be able to predict cognitive decline successfully with smell test.