Would you share your experience regarding Inner ear conductive hearing loss.
I met one adult case with history of left decrease hearing since early of childhood. Otoscopy showed bilateral intact thin TM, PTA revealed left mild CHL & right normal hearing and tympanometry revealed bilateral type Ad. Even CT-temporal was unremarkable.
I would probably start with an middle ear inspection. We know that even with a normal CT scan you can find anomalies with middle ear inspection.
The discussion whether you should perform surgery is mainly based on the magnitude of the air bone gap. If it is small, just wait.
Is there any history of otitis media? Is there vertigo (check the scan for superieur canal dehisc) ? Good luck with your patient
Thanks Digna for your comment. CT scan findings are normal. No history of vertigo. There is history of one episode of left ear otorrhea at early of infancy & stopped but now the TM is intact with no retrotympanic effusion. PTA revealed mild CHL and about 30 dB ABG.
Thanks Anu for your comment. Acoustic reflexes are not included. Regarding my answer on your question '' if the conductive component is seen only in higher frequencies or not?" not. The differential diagnosis is:
1) Inner ear CHL.
2) Ossicular dislocation as the tymp. was type A(d) but which is against that are bilaterality of tymp. type A(d) even in normal ear ( this may be due to bilateral thin tympanic membranes), mild CHL & normal CT findings.
3) Otosclerosis but which against are tymp. type A(d) & not A(s), no familial history & his hearing loss is stable since its occurrence.
I can not add OME as otoscopic ex showed intact TM with no retrotympanic effusion, tymp. type A(d) (not type B), ME cavity is aerated in CT & also my endoscopic ex pf patient's nasopharynx is normal.
So, the most potent diagnosis goes with inner ear CHL.
In this situation, is there need to do exploratory tympanotomy? what can it add? what is the management of this case?
Hazem, this is a great question, and one that may pass over or under the radar of many who may not realize that conductive loss in the inner ear is a far different beast than the conductive loss of the outer and middle ear, and usually involves nerve suppression or electrolyte distortions. I will come back to this question when I have a break from a pressing publication schedule. But wanted to let you know you've picked a great topic that needs a lot of exploration by anyone involved in handling vertigo, tinnitus, and hearing loss patients.
Quick answer to the high or low frequency involvement: It can be any frequency whose ganglion or acoustic nerves are suppressed, damaged, or otherwise abnormal. The highs tend to manifest most often in cases where electrical potential of the cochlear is deficient. But in cases of Meniere's we see far more loss in the low frequencies, which over time, usually subsides as endolymph/perilymph chemistry is restored. Hence, one would only see the low frequency aspect during an episodic attack in progress.
Can you in some way reveal the thresholds (air and bone conduction) for each ear and the frequencies tested. Better yet, can you somehow show the audiogram?
Michael, air/bone thresholds combined with tone decay, impedence audiometry, ABR, OAE, case history, video otoscopy, and test/retest history, as well as physical examination are involved. Accompanying patient reports and other considerations, including considering etilogy and causation (medication side/interaction/withdrawal effects is a big sleeper in the US). Except in a "burned out Meniere's" I've never seen a stable audiometric pattern in cochear-based conductive loss.
Thanks for Sharing. The following article showed the experience of my institute "KAUH, ENT department" regarding CHL of inner ear origin:
Al Muhaimeed H1, El Sayed Y, Rabah A, Al-Essa A. Conductive hearing loss: investigation of possible inner ear origin in three cases studies. J Laryngol Otol. 2002 Nov;116(11):942-5.
Why do you consider that this is mild CHL originated from inner ear pathology such as third window etc (see the paper entitled as Conductive Hearing Loss Caused by Third-Window Lesions of the Inner Ear by Saumil N. Merchant and John J. Rosowski).
If the case has autophony or Tulio-like symptoms or an evident tinnitus in history, you may; or
if the case presents normal acoustic reflexes + mild CHL with supranormal bone thresholds, you may.
If the case has a normal VEMP respones, you may. (ECHOG and VNG are also helpful.)
If you do recognize any inner abnormality in CT such as large VA or 3rd window, you may.
Otherwise, it is better for a clinician to consider that this is a middle ear problem. Statistically acquired (and + congenital) causes of CHL due to "some" pathology in the middle ear are more common.
Decision to operation depends on patients' demands. A case with 30 dB HL CHL probably will have good satisfaction after a successful surgery.
But, if you do not have any evident reason that this is an inner ear problem, it is better to prefer middle ear surgery as the first. Information provided by CT -even in high definition- about middle ear ossicular problems such as tympanosclerosis etc, or loss of some portions of the ossicles are not convenient.
Good points, Yusuf, differentiation between middle and inner ear pathologies is the first task, also considering patient complaint/expectations. Without vertigo and/or tinnitus and/or complaints of pressure (ie, tone decay results) attendant with the complaint, it would be rare to consider inner ear pathology. In fact, these additional issues would almost be needed to confirm anything. But again, low frequency suppression of thresholds also would be a key marker.
Thanks Yusuf for your sharing. Please, you would return to my previous comments & attached article.
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