Dear Anthony,

Frankly, this is not the field of my expertise. However, I have been toght that air is there. That is there are barotraumaus etc. Please, our ENT-colleagues will comment this.

The best, KL

I too have been taught in my studies there can be small amounts of air in the labyrinth, but have never actually read the research around it. My (admittedly basic) understanding is that air movements within the balance organ can be a culprit for many balance issues, or being sick when flying for example.

Interestingly - as a scuba diver - i was taught about air compression inside the ear's balance part (they never said labyrinth, since i guess saying the ear will suffice in diving theory) being possible to disorientate the diver, past certain depths. I dont know much about the medical and audiological reasoning behind that. Basically diving teaches if you get disorientated, close your eyes and if the disorientation (knowing which is up and down) doesnt go away - time for backup plan, buddy needs to know and abort the dive with the appropriate plan for surfacing. Im guessing that if its not a visual disorientation, its an ear problem and its not going to solve itself while in the water.

This must have been air from the middle ear, where the ossicles are located. The bony labyrinth contains the membranous labyrinth, separated by perilympathic fluid. The vestibular and the cochlear system, including the vestibule, are filled with perilymph or endolymph, respectively. There is no physiological air space in the inner ear.

"I too have been taught in my studies there can be small amounts of air in the labyrinth"

I haven't come across any mention or discussion of this in the ENT literature from the last century, except for rare(?) cases of pneumolabyrinth where air from the middle ear is sucked in after minor head injury via fistulae, or in decompression sickness where bubbles (nitrogen?) might form in the cochlear fluids.

"This must have been air from the middle ear, where the ossicles are located. The bony labyrinth contains the membranous labyrinth, separated by perilympathic fluid. The vestibular and the cochlear system, including the vestibule, are filled with perilymph or endolymph, respectively. There is no physiological air space in the inner ear."

Fine, so you are saying these old anatomists were incompetents, they did not know their air space from their cochlea?

the Onanser paper sounds like it was mentioned in passing in my undergraduate course...i guess the lecturer had read it and wanted to give some historical spin to his start of a lecture? I didnt know the name of the authors, but your description matches what my lecturer said, with opening labyrinths underwater. I recall because I was like "oh that kinda helps explain some diving stuff that ive been taught"

So my answers probably more of interest, than of use to your quest to verify this claim?

Dear Anthony,

you are ear specialist - so where do you think is air in the system? We are talking about physiological not pathological situations, right?

btw, describing something that is later falsified does not mean someone is "incompetent", I think that is common in science, happened to me several times in my papers ...

Stefan

 In a healthy ear, there should be no more likelihood of air in the labyrinth than in the cochlea since the fluid are essentially the same and since there is communication between the two "organs" which are in fact one complex integrated system. In an ear that has sustained damage, however, the presence of air bubbles - possibly microscopic in size - may be present and may account for various balance disorders. It is also possible that they may  be temporary and reabsorbed over time. I know of no research structured to first cause and then analyze air in either the labyrinth or the cochlea. 

"where do you think is air in the system? We are talking about physiological not pathological situations, right?"

I think that temporary perilymph leaks are very common, and as fluid leaks into the middle ear, so air is sucked back in.  This gives a much simpler and more rational explanation for Benign Paroxysmal Positional Vertigo than the convention explanation that heavy particles are wandering around inside the semi-circular canals.  PFs occur after minor trauma, but there may be a more physiological scenario as well, as for example after one gets out of bed in the morning and stands up. 

"describing something that is later falsified does not mean someone is "incompetent""

I do not think anyone has repeated and hence falsified their observation of air bubbles exiting the labyrinth.  The most likely reason for this is that nowadays we regard these old investigators as incompetents who can be safely ignored.

dear Anthony,

Although not an expert in this field i am inclined to answer.

During cholesteatoma surgery i've removed this disease out of the labyrinth on many occassions. It is regular practice in our department to perform this with the mastoid being irrigated and the defect being completely under water. we evaluated 45 of such cases recently and in 4 cases we made a defect in the  membranous labyrinth. In none of these cases we have seen air escape. 

Could it be possible the air bubbles that were seen was air trapped in the round window nice? We do commonly see air remaining in that region when the ear is fully irrigated.

I hope you find this comment usefull.

Kind regards

Erik van Spronsen

Thanks for your experience Erik, though it leads to another question.   Why did you not see air bubbling up, given the known fluid/air pathways (labyrinthine fistulas) in your cases?  What would the effect of anaesthesia have been?

Dear Anthony,

Perhaps due to the fact that the fistulas were only bony and not membranous? Or the cholesteatoma 'plugged' the defect?

Or there is no air in the labyrinthine system at all?

We do not see any air in the inner ear structures when using CT or MRI imaging as well.

I asked a anesthesist if he would expect that anesthesea would influence this in any way and he did not see any reason why. But then again no reason why not.

Sorry i can not be more helpfull 

Kind regards,

Erik van Spronsen

We seem to be reaching an impasse.  It is probably time for contributors to this question (including myself!!) to make the time and effort to read the original papers from 2 centuries ago, and see exactly what did happen.

As ear surgeon I have seen CT and MRI's showing quite commonly air in the labyrinth following stapes surgery, cholesteatoma surgery with labyrinth fistulas, following temporal bone fracture or even in congenital inner ear fistulas. (Lovblad K.-O, Ozdoba C, Negri S, Häusler R. CT-Cisternography in Congential Perilymphatic Fistula. J Comp Ass Tomography 19 (5):797-799 (1995)Lovblad K.-O, Ozdoba C, Negri S, Häusler R. CT-Cisternography in Congential Perilymphatic Fistula. J Comp Ass Tomography 19 (5):797-799 (1995)). I have not seen documents showing ear in the labyrinth without a pathological explanation

No pathology, no air. The system is designed to work in the absence of air within it. Any observations of air bubbles arising from a labyrinth opened under water would most likely be due to experimental artifact or the generation of "air" bubbles due a chemical reaction of labyrinthine fluids with the "water" in which the  labyrinth was opened. 

"No pathology, no air."

Fine, but absence of evidence is not evidence of absence.  I think perilymph fistulas are very common, but since they usually heal quickly are very hard to spot.  As well as unknown knowns, there are unknown unknowns.  PFs have only been recognized for  half a century.

air should b present, though in negligible amount ,