Is it Phantosmia, Anosmia or Parosmia?

My little chickadee lent me a couple of books last week that she picked up at the library.

One of them is, "Remembering Smell:  A Memoir of Losing -- and Discovering -- the Primal Sense"  by Bonnie Blodgett.

It's basically the author's depiction of her personal journey as a result of her losing, and then regaining, her sense of smell.  A most interesting read indeed, and an extremely well documented reference tool.

I'm not half way through the book yet but I'm learning a whole new vocabulary very quickly.

She discusses phantosmia, which means phantom scent -- the phenomenon of smelling odours that are not present.  Apparently, this phase precedes the complete loss of smell which is known as anosmia, the absence of scent -- that's when a person truly doesn't smell any odours.

Now, I'm a researcher by nature so when something new comes to my attention, I usually go digging.

Both these terms are new to me, someone who lost her sense of smell some twelve years ago (I really don't know how long ago it was -- I've lost count).  Apparently, I would have been in a phase of anosmia at that point, because I could smell nothing -- nada.

However, ever since I had that seizure episode in Halifax in October of 2009, I've been experiencing a return, if you will, of my sense of smell.  But only of unpleasant odours, it seems.  Apparently, that's typical of phantosmia -- olfactory hallucinations.  (I discussed the phenomenon with my neurologist at the time, and he never mentioned the term phantosmia to me.)

Bonnie Blodgett explains that phantosmia precedes anosmia (mine appears to have happened in the opposite order).  So I went to the internet to dig up more information.

Now, nothing I state here is definitive of course because I'm no expert on this topic.  I can only relate my personal experience with the disorder.  (I've now learned that dysosmia is the collective term for olfactory disorders.)

When I first became aware that I couldn't smell anything, the ENT specialist I saw at the time explained that my olfactory bulbs had been destroyed as a result of the repeated severe respiratory infections I had suffered in the recent past.  And once killed, they never regenerate.  At least he had never heard of their coming back.  (Blodgett's sense of smell apparently came back.  I haven't read the how yet -- gotta read faster!)

In the intervening years, I dealt with my loss of smell and all that comes with it (smell is often the first indication of danger, ie smoke; rotten food etc).  I mourned the loss of taste that results from not being able to smell (Thanksgiving and Christmas dinners don't have nearly the enjoyment that they used to bring).

Then when I started to be able to smell again, I thought, "Wow, won't my ENT specialist be surprised to hear this?"

Except the only things I could smell were unpleasant odours.  And it turned out that what I was smelling wasn't really there.  I was the only one who could smell that rotten garbage.  And everything I could smell, smelled the same -- like rotten garbage.  Obviously, my sense of smell had not returned.  My brain was playing tricks on me.

Now, as a result of reading this book and researching the new vocabulary, I learn that phantosmia -- the phenomenon that I've been experiencing since my seizure -- can be caused by an injury to the head. (I suffered a concussion at the time.)  So did the concussion actually induce phantosmia, when anosmia had been present prior to that incident?

But wait!

There's also parosmia which is the distortion of smell that is present.  Parosmia can occur after a severe respiratory infection and is usually accompanied by a loss of sense of smell.

Subtle differences, but differences nonetheless.

I think I'll just leave it that I have dysosmia -- one or more of the olfactory disorders.  And when next I see my ENT specialist and/or my neurologist, I'll throw out these terms and watch their reactions.  Should be fun.