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Detecting Non-Organic Hearing Loss at CI Assessment

Cullington, Helen PhD

doi: 10.1097/01.HJ.0000513792.67299.0f
Journal Club

Dr. Cullington is an associate professor, a research coordinator, and the principal clinical scientist at the University of Southampton Auditory Implant Service.

Non-organic hearing loss can be defined as “a decrease in hearing that is unexplained by anatomic or physiologic abnormalities, or both” (Semin Neurol. 2006;26[3]:321 It has also been called functional hearing loss, psychogenic hearing loss, pseudohypacusis, and “hysterical hearing loss,” which is hopefully no longer used today. A patient with normal hearing can present with non-organic loss; equally, this condition could be an exaggeration of organic hearing loss.

Non-organic hearing loss is often discussed in medicolegal cases. It is not difficult to understand why someone may exaggerate a hearing complaint when decibels mean dollars. But one area in audiology where non-organic hearing loss is not usually mentioned is cochlear implantation. Prior to the study of Mistry, et. al, only nine cases were reported on non-organic hearing loss among patients with cochlear implants (Cochlear Implants Int. 2016;17[6]:276; Acta Otolaryngol. 2015;135[4]:376; Am J Otol. 1994;15[5]:652

In the United Kingdom, cochlear implant centers follow the guidelines provided by the National Institute for Health and Care Excellence (NICE) in determining cochlear implant candidacy (NICE, 2009 Without satisfying these criteria, the procedure will not be funded by the National Health Service (NHS). Many clinicians and patients feel that the guidelines are too strict, and some people who may benefit from an implant are being rejected. Considering the strict criteria, which forged a public perception that it is difficult to get an implant through the NHS, it may not be surprising that some people with severe hearing loss exaggerate their condition in hopes of receiving extra help.

Mistry and colleagues presented an interesting and clinically relevant discussion on non-organic hearing loss (Cochlear Implants Int. 2016 Their study was a retrospective review of patients referred to the Yorkshire Auditory Implant Service between 2003 and 2015. During this period, 1,541 people were assessed for a cochlear implant; 760 of them underwent implant surgery. Thirty-two people were found to have non-organic hearing loss, five of which have normal hearing thresholds.

Presenting for cochlear implantation despite having normal hearing seems like a big cry for help. Having a cochlear implant in a normal ear poses unnecessary economic, surgical, and health risks. For example, inserting a cochlear implant electrode damages the cochlea and causes permanent hearing loss.

The same issues are of concern in those patients with non-organic hearing loss in the presence of some organic impairment. The 32 people with non-organic hearing loss were between 14 and 82 years old, with a mean age of 43. There were slightly more women than men. The authors noted that none of the patients with normal hearing thresholds had any psychiatric history, although a small number of those with exaggerated organic loss did. In addressing cases of non-organic hearing loss, clinicians need to employ a sensitive and thorough approach to understand the complex underlying factors. This treatment approach is notably important for patients requesting a cochlear implant and may merit psychiatric assessment.

The authors also documented how non-organic hearing loss was diagnosed—mismatches between observed behavior and testing, stapedial reflex thresholds lower than audiometric thresholds, and a history of sudden hearing loss. They recommended the use of cortical evoked response audiometry (CERA) to assess patients with any of the following factors:

* Measured stapedial reflexes at levels below the reported hearing threshold (PTA)

* Any reported or documented sudden decrease in hearing thresholds in one or both ears

* A mismatch between hearing thresholds and functional hearing test results at clinicians’ discretion

* A mismatch between hearing thresholds and observed behavior at clinicians’ discretion

* A mismatch between functional hearing test results and observed behavior at clinicians’ discretion

* Indications of suspected non-organic hearing loss from local audiology documentation

* Use of English as a second language and little experience of performing PTA

This paper estimated the incidence of non-organic hearing loss during cochlear implant assessment to be around two percent. This suggests that one or two cases per year may present at various cochlear implant centers. However, these cases seem underreported, and there is currently no clinical guidelines on how to manage them.

Audiology professionals have committed to helping people with hearing impairments; people with non-organic hearing problems are no exception. They may not benefit from a cochlear implant, but they would benefit from different forms of assistance. It is the job of audiologists and clinicians to evaluate all patients sensitively and effectively, and make the best decisions to help them.

Journal Club Highlight

Inside implant criteria or not? – Detection of non-organic hearing loss during cochlear implant assessment

Mistry SG, Carr SD, Tapper L, et. al. Cochlear Implants Int. 2016;17(6):276

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