Health

Rapid loss of smell predicts dementia and smaller brain areas linked to Alzheimer’s

Credit: Unsplash/CC0 Public Domain

Although we often underestimate our sense of smell compared to our sense of sight and hearing, our sense of smell provides our brain with valuable information, from detecting hazards like smoke to recognizing the smell of baking cookies.

Researchers at the University of Chicago Medicine have discovered another reason to thank our hackers. Not only can it decrease in a person sense of smell Over time the loss of their cognitive function is predicted, it can tell the structural changes in my regions brain important in Alzheimer’s disease and dementia.

The results of the study, based on a a long study from 515 big big published July 2 a Alzheimer’s & Dementia: Journal of the Alzheimer’s Associationit can lead to the development of a smell test for detection misunderstanding previously in patients.

“This study provides some insight into how a rapid decline in the sense of smell is the real sense of what will end the process that happens in other areas of the brain, “said the lead author Jayant M. Pinto, MD, professor of surgery at the University of Chicago and ENT who examines olfactory and sinus disease.

It is estimated that more than 6 million Americans have Alzheimer’s disease, which is related memory loss and other symptoms, such as mood swings and difficulty completing daily tasks. There is no cure for Alzheimer’s disease, but some medications can temporarily reduce its symptoms.

The brain plays an important role in the ability to perceive smell, and researchers have long known the link between smell and dementia. The tangles and tangles that characterize the type of tissue affected by Alzheimer’s disease often appear in areas related to smell and memory before development in other parts of the brain. It is not yet known whether this damage actually causes a person’s sense of smell to decline.

Pinto and his team wanted to see if changes in the brain associated with the loss of smell and cognitive function could be identified over time.

“Our view is that people who have a rapid decline in their sense of smell over time will be in worse shape – and may have brain problems and even Alzheimer’s itself – than people who decline more slowly or maintain and the smell of culture,” said Rachel. Pacyna, a fourth-year medical student at the University of Chicago Pritzker School of Medicine and lead author of the study.

The team published anonymized patient data from Rush University’s Neuroimaging Center (MAP), at study group It was started in 1997 to investigate the nature of aging and neurodegenerative diseases such as Alzheimer’s disease. MAP participants are seniors who live in retirement or senior housing in Northern Illinois and are tested annually for their ability to detect certain odors, for cognitive function and for symptoms of dementia, among other health parameters. Some participants also received an MRI scan.

UChicago medical scientists have found that rapid decline in a person’s sense of smell during normal cognitive periods predicts several features of Alzheimer’s disease, including smaller gray matter in areas of the brain associated with smell and memory, the worse understand the greater risk. of madness among these great adults. In fact, the risk of smell loss is similar to carrying the APOE-e4 gene, a known genetic risk for developing Alzheimer’s disease.

The changes are more prominent in the primary olfactory regions, including the amygdala and the entorhinal cortex, which is the main input to the hippocampus, a key area in Alzheimer’s disease.

“We were able to show that the size and shape of the gray matter in the areas related to the brain and memory of people with a rapid decline in the sense of smell were smaller compared to people who did not have a severe decline,” he said. said Pinto.

Autopsies are the gold standard for determining whether someone has Alzheimer’s disease, and Pinto hopes to eventually extend these findings by analyzing brain tissue for signs of Alzheimer’s. The team also hopes to study the effectiveness of using smell tests in clinics – in ways similar to the use of visual and auditory tests – as a way to screen and monitor older people for early signs of dementia. and the development of new treatments.

The smell test is a cheap, easy-to-use tool that consists of a series of sticks that look like felt-tip pens. Each stick is infused with a unique scent that individuals must identify from a list of four choices.

“If we can identify people in their 40s, 50s and 60s who are at higher risk early on, we can get enough information to enroll them in clinical trials and develop better treatments,” Pacyna said. .

The study was limited in that the participants had only one MRI, which means the team did not have data to show when the structural changes in the brain started or how the brain regions collapsed.

“We have to take our studies in the context of all the risk factors we know about Alzheimer’s disease, including the effects of diet and exercise,” Pinto said. “The sense of smell and changes in the sense of smell should be an important part of the context of what we believe affects the brain in health and aging.

Also, because the majority of MAP participants are white, more research is needed to determine whether underrepresented populations have similar effects. The team before work showed significant racial differences, with African Americans experiencing the most severe impairments in olfactory function.

Previous studies by Pinto have examined the sense of smell as an important indicator for declining health in the elderly. His 2014 paper the appearance of adults without meaning smell they were three times more likely to die within five years—a better predictor of death than a diagnosis of lung disease, heart failure or cancer.

Other scientists who contributed to “Rapid olfactory decline in aging predicts degeneration and loss of GMV in AD brain regions” include Kristen Wroblewski, MS, in Public Health Sciences and Martha McClintock, Ph.D. , David Lee Shillinglaw Distinguished Service Professor Emerita, Departments. of Psychology and Comparative Human Development at the University of Chicago, and Duke Han, Ph.D., Professor of Family Medicine, Neurology, Psychology and Gerontology at the University of Southern California.


This stinks: New research has identified the meaning of smell and the link to lung cancer


Additional information:
Rapid olfactory loss during aging predicts degeneration and loss of GMV in AD brain regions, Alzheimer’s & Dementia (2022). DOI: 10.1002/alz.12717

hintRapid loss of smell predicts dementia and smaller brain areas associated with Alzheimer’s (2022, July 28) Retrieved 28 July 2022 from https://medicalxpress.com/news/2022-07-rapid-loss-dementia-smaller- brain.html

This document is subject to copyright. Except for any bona fide transaction for research or investigation purposes, no part may be reproduced without written permission. Content is provided for informational purposes only.

Rapid loss of smell predicts dementia and smaller brain areas linked to Alzheimer’s Source link Rapid loss of smell predicts dementia and smaller brain areas linked to Alzheimer’s

Related Articles

Back to top button