|Intraoperative round window recordings to acoustic stimuli from cochlear implant patients.|
|PMID: 23047261 Owner: NLM Status: MEDLINE|
|HYPOTHESIS: Acoustically evoked neural and hair cell potentials can be measured from the round window (RW) intraoperatively in the general population of cochlear implant recipients.
BACKGROUND: Cochlear implant performance varies greatly among patients. Improved methods to assess and monitor functional hair cell and neural substrate before and during implantation could potentially aid in enhanced nontraumatic intracochlear electrode placement and subsequent improved outcomes.
METHODS: Subjects (1-80 yr) undergoing cochlear implantation were included. A monopolar probe was placed at the RW after surgical access was obtained. The cochlear microphonic (CM), summating potential (SP), compound action potential (CAP), and auditory nerve neurophonic (ANN) were recorded in response to tone bursts at frequencies of 0.25 to 4 kHz at various levels.
RESULTS: Measurable hair cell/neural potentials were detected to 1 or more frequencies in 23 of 25 subjects. The greatest proportion and magnitude of cochlear responses were to low frequencies (<1,000 Hz). At these low frequencies, the ANN, when present, contributed to the ongoing response at the stimulus frequency. In many subjects, the ANN was small or absent, whereas hair cell responses remained.
CONCLUSION: In cochlear implant recipients, acoustically evoked cochlear potentials are detectable even if hearing is extremely limited. Sensitive measures of cochlear and neural status can characterize the state of hair cell and neural function before implantation. Whether this information correlates with speech performance outcomes or can help in tailoring electrode type, placement or audiometric fitting, can be determined in future studies.
|Baishakhi Choudhury; Douglas C Fitzpatrick; Craig A Buchman; Benjamin P Wei; Margaret T Dillon; Shuman He; Oliver F Adunka|
|Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't|
|Title: Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology Volume: 33 ISSN: 1537-4505 ISO Abbreviation: Otol. Neurotol. Publication Date: 2012 Dec|
|Created Date: 2012-11-15 Completed Date: 2013-04-29 Revised Date: 2013-12-04|
Medline Journal Info:
|Nlm Unique ID: 100961504 Medline TA: Otol Neurotol Country: United States|
|Languages: eng Pagination: 1507-15 Citation Subset: IM|
|APA/MLA Format Download EndNote Download BibTex|
Action Potentials / physiology
Aged, 80 and over
Audiometry, Evoked Response / methods*
Auditory Threshold / physiology
Cochlear Microphonic Potentials
Cochlear Nerve / physiology
Data Interpretation, Statistical
Evoked Potentials, Auditory / physiology
Hair Cells, Auditory / physiology
Hearing Loss / etiology, surgery, therapy
Monitoring, Intraoperative / methods*
Neurons / physiology
Round Window, Ear / physiology*
|5T32DC005360-08/DC/NIDCD NIH HHS; T32 DC005360/DC/NIDCD NIH HHS|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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