The pure tone audiogram is not clear.  Is that showing air-bone gaps?   An impedance test will be far more useful than metabolic tests.  I think the parents' observations are likely to be correct.

Ttympanogram was normal and there is not any air bone gap. Aided thresholds (A symbol) with hearing aid and unaided threshold is shown on one audiogram.

These are most likely cochlear losses, in which case acoustic reflexes will be present at most frequencies.  The presence of non-acoustic (tactile) stapedial reflexes will confirm the absence of any significant ossicular problem. 

Thank you

    There are many causes of progressive cochlear losses in childhood.   In fact, I suspect that many genes cause cochlear instability rather than deafness itself, so that hearing deteriorates with each slight trauma.  Other examples of progressive loss include rubella, CMV, large aqueduct syndrome, etc.  I also suspect endolymphatic hydrops or even Meniere's disease is far commoner in children than commonly recognised.

     I remember reading many years ago of a study in Africa which found many cases of genetic deafness.  Mothers, however, said the deafness was due to measles.   I think both parties were correct.

Acoustic reflexes would likely not be present even in the event of a sensory loss due to elevated thresholds. I would suggest testing otoacoustic reflexes, auditory  brainstem response, and try to elicit an acoustic startle. I would suspect that the OAEs would be absent and the ABR to click stimuli present with prolonged wave V latencies. You may get a startle reflex if you use a broadband stimulus of high enough intensity. If OAEs are present you should perform electrocochleography looking for coclear microphonic - suspect auditory neuropathy/dysynchrony.

"Acoustic reflexes would likely not be present even in the event of a sensory loss due to elevated thresholds."

Could you please elaborate what you mean based on the PTAs shown in the figure?

There is clear relationship between audiometric thresholds (ATs) and acoustic reflex thresholds (ARTs) in normal hearing ears and those and with sensory (cochlear) loss. Above approximately 50 dB HL, one expects an approximately 1:1 linear increase in ARTs with increasing ATs. Considering the thresholds in the child’s audiogram are generally > 70 dB HL (and some severe-to-profound), one would not expect to observe ARTs at the ouput limits of any commercial middle ear analyzer. See the old work of Silman, Gelfand, and colleagues (e.g., Silman S & Gelfand SA. (1981). The relationship between magnitude of hearing loss and acoustic reflex threshold levels.  Journal of Speech & Hearing Disorders, 46(3), 312-6; Gelfand SA, Schwander T & Silman S. (1990). Acoustic reflex thresholds in normal and cochlear-impaired ears: effects of no-response rates on 90th percentiles in a large sample.  Journal of Speech & Hearing Disorders, 55(2), 198-205).

"one would not expect to observe ARTs at the ouput limits of any commercial middle ear analyzer."

Reading off Fig 2 from Gelfand (1990), one would expect ARTs to be below 110db at 500 and 1000Hz.  There is all the difference in the world between the presence of stapedial reflexes, albeit at somewhat elevated levels, and having none at all.  There is no way I would consider the PTAs shown above to be consistent with cochlear deafness if I could not elicit some acoustic reflexes.  (I would routinely check tactile stapedial reflexes to exclude any conductive component and use an aural puff for maximal stimulation).

I agree with Andrew Stuart,

Investigate for auditory neuropathy with OAEs and ABR. Have you performed any imaging? Might help exclude EVA

Yes, one would expect ARTs at 500 and 1000 Hz if it was a sensory deficit. However, the absence of ARTs is in no way confirmatory of a retrocochlear pathology. Absent ARTS in the case of a sensory deficit is propable and would not be unexpected in some cases: "An absent acoustic reflex is minimal until the degree of hearing level exceeds about 45 dB and begins to exceed 10% when the hearing level exceeds about 70 dB HL" Gelfand et al. (1990). Margolis (1993, Detection of Hearing Impairment with the Acoustic Stapedius Reflex. Ear & Hearing, 14(1), 3-10. ) also noted, "the data for patients with severe losses are confounded by the fact that most patients with losses of 70 dB or more do not have measurable reflexes." In addition, it is not uncommon for a small percentage of normal hearing and otologically normal children (see Haapaniemi JJ. (1996). Immittance findings in school-aged children. Ear & Hearing, 17, 19-27) and hearing impaired children (see Kankkunen A & Liden G. (1984). Ipsilateral acoustic reflex thresholds in neonates and in normal-hearing and hearing-impaired pre-school children. Scandinavian Audiology, 13, 139-44) to have absent ARTs. Bottomline - a complete workup is necessary... 

Might be interesting to document the status of middle ear in this child. The absent ART may in some circumstances be seen in severe middle ear pathology also, and VEMP may be required in such cases (Zhou, Poe & Gopen, 2012). We reported some years back the coexistence of serous otits media with severe sensorineural hearing loss in 3 children, highlighting the management dilemma such finding poses (Olusesi AD, 2006 ). So I agree with Andrew that a complete workup is necessary. 

http://dx.doi.org/10.1016/j.pedex.2005.12.007

"However, the absence of ARTs is in no way confirmatory of a retrocochlear pathology."

I agree, but, for 70db losses, absence is not consistent with a cochlear loss.  The most likely cause for absent reflexes is a conductive loss, the next most common is an undetected conductive component.   To exclude this, tactile stapedial reflexes must be present, reversed stapedial reflexes checked out, normal (non-reversed) tensor tympani reflex present, and a positive Bing test (T fork louder with occlusion).

I think the Margolis quotation is contradicted by Gelfand 1990, but cannot check this at present.

Have she done any imaging? We have seen flactuations in cases of enlarged vestibular aquaduct. 

Hi thanks to all of you. Tympanometry was normal and acoustic reflexes are absent. Inner ear and mastoid imaging was normal.

Now that I am writing to you her hearing again is getting better ( like last year). I do not know if this attack would happen again! Parents are worried. 

Imaging here is mandatory to document the possibility of an EVA and thus the probability of further hearing deterioration. Such kids do respond dramatically to intratympanic steroids. However if one of the ears gets an irreversible profound lossb early CI should be considred and benefit from the residual contralateral aided ear in rehabilitation as the possibility of further deterioration is high in both ears.

What is her family history and were there any genetic studies performed?

This child did not have any significant history (no infection, no trauma, no medication, no hyperbilirubinemia, no genetic history of hearing loss...)

They did not have genetic study.

The parents are right to be concerned, so continued testing is warranted until at least a site-of-lesion diagnosis is made.  Is it possible to have a recent improved PTA together with concomitant impedance results and acoustic reflex thresholds or maximum stimuli used? Absent stapes reflexes are the key, and further expensive or complex tests may not be needed.

        In a research program on sudden or progressive nerve deafness it is found that such a loss of hearing is an accompany or sequel of one or multiple NTM (non-tubercular mycobacterium) infection.

        In nerve deafness the status of other nerves in the body is required to be assessed.

Please find out –

1.      Speech development of the child.

2.      Ascertain the sign of nerve thickening or tenderness. For example radial nerve in radial groove in arm, lateral popleteal N. at the neck of fibula etc.

3.      Cutaneous sense - light anesthesia at hand (fingers) and foot or hyper-asthenia at different parts of body.

4.      Skin patches – depigmented, black purple or white may be found. Hyper keratotic patches at malleolus or back of elbow may be found. Also there may be such circumscribed patches with changed color and painful or with numbness may be found in different parts of body.

Since the patient is a child the finding will be ambiguous frequently. if some such findings are there consider NTM.