Dementia and sense of smell

Caregivers, and healthcare professionals,here is some great information

Here is a great dementia resource for caregivers and healthcare professionals,

Your residents will love the Amazon Kindle Fire

Here is information on being the best caregiver you can be

Here is a way for nurses administrators, social workers and other health care  professionals to get an easyceu or two

Follow alzheimersideas on twitter
The Dementia Caregiver's Little Book of Hope [Kindle Edition]

DIAGNOSTIC TESTS that measure the sense of smell may soon become common in neurologists' offices. Find out why. 

---

University of Pennsylvania-School of Medicine

PHILADELPHIA--Tests that measure the sense of smell may soon become common in neurologists' offices. Scientists have been finding increasing evidence that the sense of smell declines sharply in the early stages of Alzheimer's, and an innovative study from the Perelman School of Medicine at the University of Pennsylvania published in the Journal of Alzheimer's Disease confirms that administering a simple "sniff test" can enhance the accuracy of diagnosing this dreaded disease. 

The sniff test also appears to be useful for diagnosing a pre-dementia condition called mild cognitive impairment (MCI), which often progresses to Alzheimer's dementia within a few years. 

Neurologists have been eager to find new ways to identify people who are at high risk of Alzheimer's dementia but do not yet show any symptoms. There is a widespread consensus that Alzheimer's medications now under development may not work after dementia has set in. 

"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. 

Roalf and his colleagues used a simple, commercially available test known as the Sniffin' Sticks Odor Identification Test, in which subjects must try to identify 16 different odors. They administered the sniff test, and a standard cognitive test (the Montreal Cognitive Assessment), to 728 elderly people. 

The subjects had already been evaluated by doctors at Penn with an array of neurological methods, and according to expert consensus had been placed in one of three categories: "healthy older adult," "mild cognitive impairment," or "Alzheimer's dementia." Roalf and his team used the results from the cognitive test alone, or combined with the sniff test, to see how well they identified subjects in each category. 

As researchers report, the sniff test added significantly to diagnostic accuracy when combined with the cognitive test. 

For example, the cognitive test alone correctly classified only 75 percent of people with MCI, but that figure rose to 87 percent when the sniff test results were added. Combining the two tests also enabled more accurate identification of healthy older adults and those with Alzheimer's dementia. The combination even boosted accuracy in assigning people to milder or more advanced categories of MCI. 

"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. 

Prompted by prior studies that have linked a weakening sense of smell to Alzheimer's, doctors in a few larger dementia clinics already have begun to use smell tests in their assessments of elderly patients. Part of the reason the practice has not yet become common is that the tests that seem most useful take too long to administer. Roalf and colleagues are now trying to develop a briefer test that works as well 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. 

Roalf and his laboratory also plan to investigate whether protein markers of Alzheimer's, which are present in the olfactory region of the brain before dementia occurs, can be detected in nasal fluid to provide an even earlier warning of the disease process. 

Studies suggest that a high proportion of older adults who have cognitive impairment are not identified as such, in part due to lack of adequate screening. 

MORE INFORMATION:

• The study's first author was Penn's Megan Quarmley; the other co-authors were Paul J. Moberg, Dawn Mechanic-Hamilton, Sushila Kabadi, and David A. Wolk, all of Penn, and Steven E. Arnold of Harvard University and Massachusetts General Hospital. Data for this study was collected through the Penn Memory Center.
• Funding was provided by the National Institute of Mental Health (K01 497 MH102609), National Institute on Aging (P30 AG10124), and the Penn Center of Excellence for Research on Neurodegenerative Diseases.

Success: Smell Test for Cognitive Decline

Here is a great dementia resource for caregivers and healthcare professinals,

Here is information on being the best caregiver you can be

Here is a way for nurses administrators, social workers and other health care professionals to get an easyceu or two

WebMD

Researchers Report Early Success With Smell Test for Cognitive Decline

Australian researchers say they’re a step closer to developing a simple smell test that may help predict which older adults will develop cognitive impairment and Alzheimer's disease.

The work is still very preliminary. But it appears that people who have memory loss and other signs of mental decline that can lead to Alzheimer's may have trouble discriminating between smells, says study leader Hamid R. Sohrabi, PhD, a neuropsychologist at Edith Cowan University in Perth, Australia.

William Thies, PhD, chief medical and scientific officer at the Alzheimer’s Association, tells WebMD that animal and lab research suggests there is an association between cognitive decline and smell, but that efforts to develop a commercial test have failed to date.

"It's not too surprising that the sense of smell changes, as the amyloid plaques and tangles that are thought to cause Alzheimer's develop in the same area of the brain that houses our olfactory pathway," he says.

The Sniffin' Stick Test
To determine whether cognitive impairment is associated with trouble smelling, Sohrabi and colleagues studied 308 people aged 46 to 86 with no memory problems.

All were given the "Sniffin' Stick" test, in which a person is presented three sticks, two of which have the same odor. Then he or she needs to pick out the one with the different odor. If the wrong stick is identified, the test is repeated with a slightly higher concentration of the odor, for a total of up to 16 times.

Over the next three years, 58 participants showed signs of cognitive decline, as determined by worsening scores on a simple questionnaire called CAMCOG that is used to assess memory and assist in the diagnosis of Alzheimer's.

Results showed that participants who had more trouble distinguishing between smells at the start of the study were more likely to shows signs of mental decline.

The analysis took into account other factors that can affect memory loss, such as age, sex, and education.

The findings were presented here at the Alzheimer's Association International Conference 2011.

Sohrabi says he hopes that test can be refined and someday be used to detect Alzheimer's disease early, before symptoms develop.

Other tests are further along in development, but none yet ready for clinical use.

"There is a long way to go,” Thies says. “You have to figure out which odor is best, test it in hundreds of people and validate it and then standardize the test so results are the same from one place to the next.”

Other tests are further along in development. These include tests that look for changes in the blood and cerebrospinal fluid that have been linked to the amount of Alzheimer's-associated plaque in the brain and an experimental test that looks for changes in the eye that can precede the development of Alzheimer's.

These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.