'Peanut Butter' Test
Can Help Diagnose Alzheimer's Disease, Researchers Find
 |
| University of Florida researcher Jennifer Stamps demonstrates the peanut butter test. Researchers have found that patients in the early stages of Alzheimer’s disease have an asymmetry in their ability to detect smells, with the left nostril becoming weaker than the right. (Credit: UF Health file photo) |
A
dollop of peanut butter and a ruler can be used to confirm a diagnosis of early
stage Alzheimer's disease, University of Florida Health researchers have found.
Jennifer
Stamps, a graduate student in the UF McKnight Brain Institute Center for Smell
and Taste, and her colleagues reported the findings of a small pilot study in
the Journal of the Neurological Sciences.
Stamps
came up with the idea of using peanut butter to test for smell sensitivity
while she was working with Dr. Kenneth Heilman, the James E. Rooks
distinguished professor of neurology and health psychology in the UF College of
Medicine's department of neurology.
She
noticed while shadowing in Heilman's clinic that patients were not tested for
their sense of smell.
"Dr.
Heilman said, 'If you can come up with something quick and inexpensive, we can
do it,'" Stamps said.
She
thought of peanut butter because, she said, it is a "pure odorant"
that is only detected by the olfactory nerve and is easy to access.
In
the study, patients who were coming to the clinic for testing also sat down
with a clinician, 14 grams of peanut butter -- which equals about one
tablespoon -- and a metric ruler. The patient closed his or her eyes and mouth
and blocked one nostril. The clinician opened the peanut butter container and
held the ruler next to the open nostril while the patient breathed normally.
The clinician then moved the peanut butter up the ruler one centimeter at a
time during the patient's exhale until the person could detect an odor. The
distance was recorded and the procedure repeated on the other nostril after a
90-second delay.
The
clinicians running the test did not know the patients' diagnoses, which were
not usually confirmed until weeks after the initial clinical testing.
The
scientists found that patients in the early stages of Alzheimer's disease had a
dramatic difference in detecting odor between the left and right nostril -- the
left nostril was impaired and did not detect the smell until it was an average
of 10 centimeters closer to the nose than the right nostril had made the
detection in patients with Alzheimer's disease.
This was not the case in
patients with other kinds of dementia; instead, these patients had either no
differences in odor detection between nostrils or the right nostril was worse
at detecting odor than the left one.
Of
the 24 patients tested who had mild cognitive impairment, which sometimes
signals Alzheimer's disease and sometimes turns out to be something else, about
10 patients showed a left nostril impairment and 14 patients did not. The
researchers said more studies must be conducted to fully understand the
implications.
"At
the moment, we can use this test to confirm diagnosis," Stamps said.
"But we plan to study patients with mild cognitive impairment to see if
this test might be used to predict which patients are going to get Alzheimer's
disease."
Stamps
and Heilman point out that this test could be used by clinics that don't have
access to the personnel or equipment to run other, more elaborate tests
required for a specific diagnosis, which can lead to targeted treatment. At UF
Health, the peanut butter test will be one more tool to add to a full suite of
clinical tests for neurological function in patients with memory disorders.
One
of the first places in the brain to degenerate in people with Alzheimer's
disease is the front part of the temporal lobe that evolved from the smell
system, and this portion of the brain is involved in forming new memories.
"We
see people with all kinds of memory disorders," Heilman said. Many tests
to confirm a diagnosis of Alzheimer's disease or other dementias can be
time-consuming, costly or invasive. "This can become an important part of
the evaluation process."
Story Source:
The
above story is based on materials provided by University of Florida.
Note: Materials may be edited for content and length. For further
information, please contact the source cited above.
Journal Reference:
1.
Jennifer J. Stamps,
Linda M. Bartoshuk, Kenneth M. Heilman.A brief olfactory test for
Alzheimer's disease. Journal of the Neurological Sciences,
2013; 333 (1-2): 19 DOI:10.1016/j.jns.2013.06.033
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University of Florida (2013, October 10). 'Peanut butter' test can
help diagnose Alzheimer's disease, researchers find. ScienceDaily.
Retrieved October 10, 2013, from http://www.sciencedaily.com/releases/2013/10/131010092427.htm
