March 15, 2004
RICHMOND, Va. – Patients who have total or partial loss of their olfactory sense – the ability to smell – are more likely to experience hazardous events than people with normal olfactory function, according to a new study by researchers in the Smell and Taste Clinic at the Virginia Commonwealth University Medical Center.
The study, published in the March issue of Archives of Otolaryngology Head and Neck Surgery, found 37 percent of patients with olfactory impairment experienced at least one olfactory-related hazardous event, compared with 19 percent of patients with normal olfactory function.
Researchers reviewed 767 medical records from the Smell and Taste Clinic and identified 445 patients that had undergone olfactory function testing between 1983 and 2001. Of those, 340 had a confirmed olfactory impairment. Based on a hazard review questionnaire given during their evaluation, 124 patients indicated they had experienced a cooking-related accident, been exposed to an undetected fire or gas leak, or ingested spoiled food or a toxic substance.
“Olfactory impairment has long been overlooked as a debilitating condition or public health problem,“ said Evan Reiter, M.D., an otolaryngologist and head and neck surgeon in the Smell and Taste Clinic at VCU. “These findings indicate serious and potentially life threatening circumstances that collectively pose a significant public health risk.”
Cooking-related accidents were the most frequently experienced hazardous events, accounting for 45 percent of the incidents, followed by spoiled food and toxic substance ingestion – 25 percent, and gas leaks or fires that went undetected – 23 and 7 percent respectively.
“Many people don’t even recognize they have an olfactory problem, until something happens that draws attention to it,“ said Richard Costanzo, Ph.D., a VCU neurophysiologist, who has done extensive research on the regeneration of olfactory nerves. “One person with olfactory loss ingested a glass of jewelry cleaner thinking it was water.”
Olfactory impairment occurs when the delicate olfactory nerves at the base of the brain, or other smell receptor sites become damaged, as a result of head trauma, chronic sinusitis, viral infections, nasal obstructions, some medications, or even aging. In many cases, olfactory function never returns. And while function may return for some, the signals going to the brain may be altered, distorting and making unpleasant once familiar smells and tastes.
“One of the first things patients notice when they lose their sense of smell, is they can no longer taste their food – even though their taste nerves may be working just fine – they are no longer able to appreciate the aromas of the foods they are eating,” said Costanzo.
As a result, poor nutrition often is another consequence of olfactory dysfunction. Costanzo adds, patients report they eat less, or they eat less healthy food because the foods they once enjoyed no longer taste the same or have no taste at all. “It’s not unusual to see patients with olfactory impairment who have lost significant amounts of weight.”
Despite medical advances in better understanding the olfactory system and disorders associated with it, treatment options remain limited. Costanzo is hopeful his research aimed at understanding how the olfactory nerves regenerate, or recover from injury, may someday lead to new treatments for olfactory disorders.
“Unfortunately, there isn’t a magic cure. Some causes of olfactory loss are treatable, many are not – regardless, patients need to be properly evaluated and counseled because there are things they can do to cope with their condition,” Reiter said. “The most important thing physicians can do is make patients aware of their limitations and the consequences that can occur as a result of their condition.”
Contributing study authors also include Daniel Santos, M.D., and Laurence DiNardo, M.D. with VCU’s Smell and Taste Clinic.
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