Otolaryngologist Allen Seiden, MD, is using this new machine to help test a patient’s senses of smell and taste. Developed by a former UC environmental health researcher, the machine is one of only a few available.
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New Machine Helps ENT Physicians Detect 'Lost' Senses
Published August 2008
Allen Seiden, MD, has an impromptu test he likes to give people who are interested in how the two senses of taste and smell are linked: He gives them a jellybean, then asks them to put it in their mouth while holding their nose.
Many are surprised to find that they can’t identify the flavor of the jellybean until they let go of their nose.
That illustrates the point of the test—that flavor perception and smell are inextricably linked— and underlines why Seiden is so pleased with a new device that makes it easier and more economical to test a patient’s sense of smell.
Called the OLFACT (Olfactory Function Assessment by Computerized Testing), the machine tests how well a patient can identify 40 different odors. Additionally, a threshold test (OLFACT-RL) uses 13 concentrations of the same odor to identify how effectively a patient can detect the presence of an odor.
“Taste is only the ability to detect salty, sour, sweet and bitter,” says Seiden, a member of the otolaryngology–head and neck surgery department and director of the UC Taste and Smell Center.
“So the flavor of food is very dependent on our smell—as we chew, we release odors that come up behind the nose and stimulate our smell. So the way you can tell chocolate from vanilla, for example, is because they smell different, not because they taste different.
“When people lose their sense of smell, they realize, ‘Hey, I can’t tell chocolate from vanilla’ or that nothing ‘tastes’ right—and that has a huge impact when you think about how important eating is to most people.”
The OLFACT was developed by Lloyd Hastings, PhD, director of research at Osmic Enterprises, Inc., in Cincinnati and a former research associate professor in the environmental health department at UC. Only a few of the machines are in use, but Hastings is showing it off at professional gatherings with hopes of gaining wider acceptance for it.
“It’s basically plumbing,” the soft-spoken inventor says modestly. “It’s just blowing air through odorized vials that contain different odorants, after which patients are asked to identify them. So it’s fairly simple.”
That’s one of the main selling points, along with economics.
“We have an operator’s manual and you open it up and it says, ‘Press the button,’” Hastings says. “So it is a big labor-saving device. And it gets good results.”
Seiden says the test remains in the validation process but “so far it seems great.” His office has been using it for about two months.
The OLFACT is designed to replace the University of Pennsylvania Smell Identification Test (UPSIT), a booklet that uses scratch-and-sniff pads. The booklets are $30 apiece, Seiden says, so while the OLFACT has a higher initial outlay (less than $5,000 including a laptop computer, Hastings says), it costs less in the long run. It is also quicker to administer and requires no significant supervision.
Patients with taste and smell problems are referred to the UC Taste and Smell Center from all over the Midwest. Very often their first complaint is “I’ve lost my sense of taste,” says Seiden.
“They come in and the first thing we do is test their sense of smell,” he continues. “Taste is a little harder to test, and taste loss is much less common than smell loss. And again, many patients confuse smell loss with taste loss.”
Seiden says that many people who lose their sense of smell find that doctors have trouble diagnosing their problem and that family and acquaintances don’t take it seriously, saying, “It’s a great way to lose weight!”
“And so it’s very important to realize how significant this problem is for the patient, how seriously this has impacted their daily life,” adds Seiden.
Common reasons for losing the sense of smell include a viral infection, head trauma, and nasal and sinus disease.
Nasal and sinus disease can be treated, Seiden says, and the sense of smell recovered. Ofactory nerve endings high in the nose that serve as receptors undergo constant turnover, so in some cases the sense of smell can recover after a viral infection. In the case of head trauma, if the nerve is damaged, recovery is unlikely.
“If you’ve never had a problem with your sense of smell, it’s easy to blow it off and not take it very seriously,” Seiden says. “We see a lot of patients who have lost their sense of smell, and believe me, it’s very traumatic. So whatever we can do to help them with that problem is important.”