Is there any condition where the B type tympanogram is present , with the normal ear canal volume (0.48) and thye acoustic relexes are present across the frequencies at 95- 100 dB? ( while the other ear yielded a B type tympanogram -ear canal volume 0.42 with reflexes absent due to middle ear fluid.)
https://www.ihsinfo.org/ihsv2/Ceus/pdf/jun2012/CE%20Article_Tympanometry.pdf
check this out Anu :)
This may help
https://www.ihsinfo.org/ihsv2/Ceus/pdf/jun2012/CE%20Article_Tympanometry.pdf
How low does your ME pressure measure go? A Type C curve with a peak at -600mm could look like a Type B up to -400.
To distinguish a Type C from a Type B curve, you need to measure down to -600. Type C curves with a ME pressure of -600 will indicate a very retracted eardrum, and if the hearing at 4 and 8 kHz is better than 15 db, there will be no fluid. The stapedius muscle may then be connected with a moveable part of a small retraction pocket.
With a small tympanic membrane perforation, ARs may be present and the tympanogram could be flat. If the middle ear volume is quite small because of lifelong chronic ear disease and the bony ear canal is relatively small, the volume might be normal.
"With a small tympanic membrane perforation, ARs may be present and the tympanogram could be flat"
I agree reflexes could be present with some perforations, but you still have an enclosed cavity with a definite middle ear pressure and sufficient motility to record a reflex. So, although compliance may be low, there should still be a definite sharp peak corresponding to ME pressure, providing pressure is recorded down to -600. In the case in question, there was no perforation as EAM volumes were equal.
Anthony, was an ear microscope exam done on this patient with pneumatic otoscopy to be sure no TM perforation was present? Insufficient information seems to exist to state assuredly that a perforation was not present. The case said fluid existed in the other ear. It might be possible for a retracted TM with a very thin middle ear effusion to produce this picture, as well. It would be pretty unlikely for isolated myringosclerosis to produce a pretty flat tympanogram that is really a stiff tympanogram without causing conductive hearing loss and loss of ARs. I think the most likely scenario is an anterior TM perforation that is quite small. I have actually seen this scenario with a very thin TM anteriorly with a perforation hard to see. On one occasion, I had to use a 30 degree otoendoscope to see the perforation. The clue was that on placing antibiotic ear drops in the ear and then using negative pressure with the Bruening-Segal pneumatic otoscope, I got air bubbles back. That finding means a perforation is present even if not seen. Fortunately, the hospital next door was willing to lend us a 30 degree otoendoscope and light-tower to visualize the perforation in the office. The boy went on to tympanoplasty.
Since the AR response means a change in reflectance of the probe tone, it does not mean a pressure change. An intact tympanic membrane is not essential to see an AR but most perforations occur in middle ear systems that have more than minimal conductive hearing loss and are often accompanied by increased ossicular change stiffness, which makes ARs too hard to see in the test environment. .
"Anthony, was an ear microscope exam done on this patient with pneumatic otoscopy to be sure no TM perforation was present"
The case in question was that of Anu -- see top. I have very occasionally detected perforations that had been missed by expert otoscopists under the operating microscope much to my and their embarassment . I once caught an ENT surgeon sneaking in to use the impedance machine to repeat my measurement on a patient as he felt sure, wrongly as it turned out, that he could not have missed the perforation.
Speaking of a type of TM perforation that is rarely noted in the literature and yet observable in women is what we dubbed "gestation perforatons" or stress cracks (very small perfs on the TM that could only be seen under high resolution otoscopy when air pressure was applied in women who had difficult pregnancies. We began to look for these in cases of toxemia and found them almost uniformly thereafter. Evidence that they existed even years later in the same women were the small calcified plaques that outlined them in the epithelium long after the fibrous layer had healed. These might be some of the tiny perforations to which Athony refers. Acoustic trauma cracks look similar in both sexes--such as we see in the military or in some musicians. We also found these to heal spontaneouly over time, but many times were still visible by virtue of the plaques formed in the scar tissue. These would appear as Type B while perforated, only to return to Type A after healing.
I must clarify my comment on "rarely evidenced in the literature" that I have not checked it on this topic in about a decade, so I might be wrong. But I recall in the early 1990s that gestation perforations were virtually unkown in the otolaryngology field. We made quite a splash about it in the education community, hoping doctoral level students would pick up on it and help us document it in their dissertations.
I have never seen such nor can I find it at Pubmed under "gestational tympanic membrane perforation" nor "tympanic membrane perforation pregnancy." All I have done now for 35 years is ears and I have done over 8000 ear surgeries, about 40% of that for chronic ear diisease. If you are seeing such, I encourage you to photo-document it and publish it with the audiologic findings.
We did photograph it a number of times but that was before the Internet. I agree it is probably being missed in the literature, just as most of the gestational hearing losses we see are not acknowledged by their medical professionals until we point it out to them. There is much that is not yet in the literature, such as the rising prevalence of keratosis obturans that is most often misdianosed as impacted cerumen and treated as such, when in truth is coming off another site of lesion (most off the jaw/teeth, some in upper respiratory, some intestinal, or as far removed as something like a festering end grown toenail). With the dramatic and unabated rise of diabetes mellitus in the US population we are seeing them more and more, including the peeled keratin (corneum status) layer from the external meatus. Perhaps you have seen some of my work in that area. But the inordinate and continuous rise of chronic disease and egregious polypharmacy is taking a toll on hearing health, in general.
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