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September 26, 2021
Live 24 years without being able to smell the smell of a Christmas fir or the scent of a rose or the aroma of freshly baked bread and then, suddenly, be hit by some of these smells, with a devastating psychological impact that in some cases led to a fainting: this is the case of a 24-year-old German born with anosmia due to a lack of olfactory bulbs, the tissues that are used to send the nervous message produced by the smells that arrive in our nose to the brain.
To describe it in the journal Neurocase were experts from the University of Dresden in Germany who subjected the young woman to a battery of olfactory tests and then to electroencephalogram and magnetic resonance, without however understanding the reasons for the mysterious case.
The young woman, diagnosed with congenital anosmia due to lack of olfactory bulbs at the age of 13, suddenly began to smell some odors for no clear reason. once they acquired a sense for her nose she did not like, even if it was about perfumes. The new smells came to her from week to week, in one case the woman even fainted due to the strong emotional impact of this new and sudden perception.
The German team coordinated by Thomas Hummel subjected the young woman to a series of olfactory tests: the girl was able to recognize about half of the odors proposed, for example that of orange, ginger, smoke, mint. Instead, he continued not to recognize smells such as that of leather, banana, coconut, licorice, cocoa. The patient was subjected to an electroencephalogram during the olfactory tests: the trace shows that when the woman recognizes smells, her brain responds normally to them. But the MRI shows that the woman still does not have olfactory bulbs, which has left the scientists baffled.
According to experts, for unknown reasons the woman has acquired the ability to perceive odors by activating alternative brain areas that are free from the normal neural pathways of smell.
The fact that the woman is disgusted by smells may instead depend on not having learned from an early age to associate certain smells with certain events or emotions or situations.
The woman is currently undergoing olfactory training which helps her to get used to her new world full of smells;
he has already learned to appreciate some aromas by associating them with pleasant experiences.
His case suggests that the brain's plasticity is such that other patients with congenital anosmia could also discover smells with proper training, explains Hummel.
"Our brain is something miraculous - he concludes - it is always full of surprises".