New Alzheimers Test Checks for the Ability to Identify Odors
Are we one step closer to the early detection of memory decline and dementia? Two new important studies have been released this week at the Alzheimer’s Association International Conference (AAIC) 2016 that may provide the answer.
The two new studies ”evaluated changes in odor identification as an early predictor of cognitive decline, or of the transition to dementia”, and could lead to new relatively cheap screening tests revealing the possibility of a patient developing Alzheimer’s disease. Testing of patients may include the ability to identify familiar odors such as smoke, coffee, raspberry and turpentine.
Currently, any tests that are able to spot people in the earliest stages of Alzheimer's are costly and difficult. They include PET scans of the brain, and spinal taps that measure the levels of certain proteins in spinal fluid.
In both new studies, people who were in their 60s and older took a standard odor detection test. And in both cases, those who did poorly on the test were more likely to already have, or go on to develop, problems with memory and thinking.
"The whole idea is to create tests that a general clinician can use in an office setting," says Dr. William Kreisl, a neurologist at Columbia University, where both studies were done. The research was presented at the Alzheimer's Association International Conference in Toronto.
Questions Remain - Are the Results of the New Alzheimer’s Studies Valid?
Finding simple tests for brain disorders has always been elusive and difficult. Existing biomarkers, for Alzheimer's disease for instance, have serious limitations.
And the question remains: Do the tests identify a patient’s inability to sense an odor, or rather remember what the odor is? For example, did one patient forget what turpentine smelled like or instead did they never know what turpentine smelled like? This is important as the area of the brain responsible may differ.
Also the size of the studies leading to the announcement brings into question the validity of the findings. In one, researchers studied 84 people in their 60s and 70s, including 58 with the sort of memory problems that suggest early Alzheimer's. And another study by another team from Columbia followed, for more than four years, 397 people whose average age was 80 at the start. Some may question such optimism concerning results from under 500 patients over the course of many years with some participants already of advanced age. The fact is that millions currently suffer form Alzheimer's disease and related dementia.
Nevertheless, the idea of an odor detection test arose, in part, from something doctors have observed for many years in patients with Alzheimer's disease.
"Patients (with Alzheimers) will tell us that food does not taste as good," says Dr. Kreisl. The reason is often that these patients have lost the ability to smell what they eat. “That's not surprising, given that odor signals from the nose have to be processed in areas of the brain that are among the first to be affected by Alzheimer's disease.”
The point remains however, that odor tests aren't perfect. For one thing, other degenerative brain diseases, including Parkinson's, can also affect odor detection. Also, the ability to smell can be diminished by smoking, certain head injuries and even normal aging.
Continued Funding for Alzheimer’s Research Encouraged
While the results of these newly released studies are encouraging and raise hope, the need for continuing and increased funding for new Alzheimers research is imperative. To this day there is still no drug that can slow or halt the disease.
Currently more than 5 million Americans are living with Alzheimers disease. Also, nearly 1 in 3 seniors will die from Alzheimers or another form of dementia. And in 2015 more than 15 million caregivers provided an estimated 18.1 billion house of unpaid care.
For more startling facts about the cost of Alzheimers in America, visit the Alzheimers Association web page - 2016 ALZHEIMER’S DISEASE FACTS AND FIGURES
About the Alzheimer’s Association International Conference (AAIC)
The Alzheimer’s Association International Conference (AAIC) is the world’s largest gathering of researchers from around the world focused on Alzheimer’s and other dementias. As a part of the Alzheimer’s Association’s research program, AAIC serves as a catalyst for generating new knowledge about dementia and fostering a vital, collegial research community.