Do you ever catch a whiff of something you know isn’t there: sulfur, bad perfume, a gas leak, or another mysterious odor that isn’t present in reality? That’s just what happened to the Mad Men character Gene, who suffered from dementia after having a stroke: in a Season Three episode, he smelled oranges while eating chocolate ice cream. Shortly thereafter, this same man died while standing in line at A&P; the story line suggests that the orange scent foreshadowed his imminent demise. Our brains naturally retain scent memories, but sometimes these phantom smells, or phantosmia, can be signs of serious health problems.
In Search of Lost Time
Our brains do create scent memories, according to Stephen Shea, PhD, the lead author of a study published in the Journal of Neuroscience, who teamed with researchers at Duke University Medical Center to show that the part of the brain that processes scents, the olfactory bulb, is active in producing long-term memories. “We can all relate to the experience of walking into a room and smelling something that sparks a vivid, emotional memory about a family member from years or even decades ago,” Shea is quoted as saying in a 2008 ScienceDaily article.
I Smell a Rat
When we smell something that isn’t there, though, this may be a sign of a serious health issue, according to Dr. Alan Hirsch, a psychiatrist and nationally recognized smell and taste expert at the Smell and Taste Treatment and Research Foundation in Chicago, Illinois.
“By all means, a phantom smell could mean something serious,” he told Diane Mapes, contributing writer for The Body Odd blog on MSNBC.com. “It absolutely needs to be evaluated. It could be a tumor—that’s on the top of your list of things to rule out—but it could also be a cyst or some infectious agent housed in the area of the brain where the smell is processed.”
Hirsch also lists temporal lobe seizures, epilepsy, head trauma, and Alzheimer’s as serious conditions associated with phantosmia. A more benign affliction, he says, is the onset of a migraine. Anyone experiencing phantom smells should call her doctor immediately and undergo tests such as MRIs, CT scans, and EEGs to confirm a diagnosis.
Something’s Fishy …
However, it’s possible to have isolated phantosmia, a smell disorder without any underlying condition; in fact, the phenomenon isn’t that rare. According to a 1994 survey, 2.7 million Americans have some kind of olfactory problem, including anosmia (an inability to smell); hyposmia (a decreased ability to smell); and parosmia (a distorted sense of smell—for example, instead of perfume, a person with parosmia smells rotting garbage).
This wouldn’t be so bad, except that the brain seems to prefer sour smells to sweet ones. “It’s usually more unpleasant stuff or odors that are hard to describe [that patients will report],” says Hirsch. “People will say it’s chemical-like or talk about a burning smell.”
Hirsch’s patients list hydrogen sulfide (rotten eggs), bad perfume, raw sewage, leaking gas, wet dog, body odor, and spoiled fish, among other pungent odors, as their common phantom scents. He hypothesizes that the brain may trigger such unpleasant smells, rather than nice ones, because humans learned very early to avoid noxious fumes for survival.
Psychiatric Fallout
As you might imagine, life with such a disorder is no fun. “Frequently, [patients will] lose a substantial amount of weight because they can’t stand the way everything tastes,” says Hirsch, explaining that taste and smell are linked in the brain. He adds that doctors often treat phantosmia like a psychiatric problem, and that patients visit an average of seven physicians before getting help.
Ironically, some people with phantosmia do develop psychiatric disorders, like depression or suicidal behavior, because of their condition. “Approximately half of my patients who have sought surgery for their distortions have at one time considered suicide because of the hopelessness of living a life where all food smelled like spoiled meat or worse,” Dr. Donald Leopold, of the University of Nebraska Medical Center’s otolaryngology department, wrote in the 2002 edition of Chemical Senses.
