The visual and auditory hallucinations are the best known. However, virtually any sense can be affected by stimuli that do not really exist. There are those who can feel the touch of a hand on theirs, or notice that the mobile vibrates in their pocket when it is actually on the table. There we would be talking about touch. And there are even some more rare, and closely related, like the gustatory and olfactory. The latter, technically known as phantosmiaare quite rare, but are very well documented, being related to a wide range of conditions.
They can be given in different ways. Sometimes it is a smell that comes and goes, but always the same and with nothing nearby that smells that way. Other times the aroma remains to live in the nose of who suffers from hallucinations. In one nostril, or both. It can be a pleasant or unpleasant smell. In fact, when it is unpleasant, the hallucination has a second name: cacosmia. In this case, a stench similar to that of rotting meat, dirt or smoke can be perceived. Some describe it as a burning smell.
For example in Gizmodo described the case of a woman who lived for a year with a permanent smell of dirt in the nose. She continued like this until one night her husband burned a chilli cooking. The dirt was gone, but it was replaced by this powerful and unpleasant smell, which stayed with her until one day, without her intending to, it gave way to a lavender scent that no matter how far he stayed from any stimulation of this floral effluvium.
But what exactly is this due to? Today several causes are known. From brain tumors until migrainespassing by respiratory infections, nasal polyps, epilepsy, or neurodegenerative diseases. Cases have also been reported in patients with mental illnesses, such as depression or schizophrenia. A case has even been documented as a side effect of coronavirus vaccines. A case. It is important to take this into account, especially since they have been detected many more cases associated with coronavirus infection to which these vaccines reduce its severity. And, eye, some were not pleasant either. In a study that analyzed nine different cases, one described a permanent smell of soap, three of food, one of mold and the remaining four of dirt.
The origin of olfactory hallucinations
There appear to be several possible origins for phantosmia. On the one hand, it could be that the hallucinations occur because some sensory neurons they do an incorrect sending of signals to the brain. It is also believed that they can occur as a consequence of experiencing seizures for any of the reasons mentioned above. Or for any other. Many of these cases may be associated with respiratory or nasal infections.
The other option is that the cause is merely cerebral, when for some reason there are lesions in the brain. temporal lobe, which is involved precisely in sensory processing. Although it can also be associated with orbitofrontal regions, the amygdala, or the olfactory bulb.
Ultimately, the fault may be in the signal reception or in its processing. It is important to know what other pathology it may be associated with, since it often subsides when treated. For example, it has been seen that with treatments for migraine or depression, hallucinations disappear. Same for respiratory infections.
In other cases, if nothing serious is affected, it may go away on its own after a while. Cases have even been documented in which it seems that olfactory hallucinations are going to start, but do not occur. It happens, for example, after a surgical intervention. And it is not suggestion, since it has been seen by means of positron emission tomography (PET) that these patients have a great brain activity in areas associated with olfactory processing.
The composer whose phantosmia was the harbinger of something worse
In its neurology blogthe scientist José Ramón Alonso told the story of the pianist and composer George Gershwinknown for works as important as Rhapsody in Blue.
His case is a clear example of the importance of review the causes of phantosmia; since, although they may be due to something mild and reversible, it is common to be related to more serious brain injuries.
Specifically, Gershwin began to smell a pungent and frequent smell of burning rubber. The doctors did some tests, but they didn’t give it too much importance. Especially since the tests they did initially did not show any other illnesses. However, along with olfactory hallucinations Other symptoms began to appear. Dizziness, migraines, balance problems, mood swings… Even her sister-in-law came to refer to behavior as strange as, when someone gave her a box of chocolate, crushing everything and rubbing it all over her body.
In the absence of a diagnosis, he continued with his normal life, although piano concerts were increasingly complicated, given his situation. It took the disease to get much worse for it to finally be seen what was happening to him. One night in July 1937 she passed out at a friend’s house to which he had temporarily moved. The doctors who came to treat him verified that he had a brain tumor in a very advanced state. He underwent emergency surgery, but they failed to save his life. He died at only 38 years old.
If they had paid more attention to her phantosmia case, she might have had a chance at survival. Unfortunately it was not. That is why these hallucinations, like the rest, must also be shown the attention they deserve.