jueves, 30 de diciembre de 2010

ACUFENOS-Seccíon Tecnicas de diagnostico

DPOAE in estimation of the function of the cochlea 
in tinnitusnext term patients with normal hearing

Aleksandra Sztukaa, Lucyna Pospiecha, Wojciech GawronCorresponding Author Contact Information, a, E-mail The Corresponding Author and Krzysztof Dudeka
a Wroclaw Medical University, ENT Department, Borowska 213, Wroclaw, Poland

Available online 26 June 2009.



The most probable place generating previous termtinnitusnext term in the auditory pathway is the outer hair cells (OHCs) inside the cochlea.
Otoacoustic emissions are used to assess their activity.
The objective of the investigation was to measure the features of distortion product otoacoustic emissions (DPOAE) in a group of previous termtinnitusnext term patients without hearing loss, estimate the diagnostic value of the parameters for the analysis of cochlear function in the patients, emphasizing those most useful in localizing previous termtinnitusnext term generators, and determine the hypothetical influence of hyperacusis and misophony on DPOAE parameters in previous termtinnitusnext term patients.

Patients and methods

The material consisted of 44 patients with previous termtinnitusnext term and without hearing loss.
In the control group were 33 patients without previous termtinnitusnext term with the same state of hearing.
The previous termtinnitusnext term patients were divided into three subgroups: those with hyperacusis, those with misophonia, and those with neither.
After collecting medical history and performing clinical examination of all the patients, tonal and impedance audiometry, ABR, and discomfort level were evaluated.
Then DPOAE were measured using three procedures.
First the amplitudes of two points per octave were assessed, second the “fine structure” method with 16–20 points per octave (f2/f1 = 1.22, L1 = L2 = 70 dB), and the third procedure included recording the growth function in three series for input tones of f2 = 2002, 4004, and 6006 Hz (f2/f1 = 1.22) and L1 = L2 levels increasing by increments of 5 dB in each series.

Results and conclusions

Hyperacusis was found in 63% and misophonia in 10% of the previous termtinnitusnext term patients with no hearing loss.
DPOAE amplitudes in recordings with two points per octave and the fine structure method are very valuable parameters for estimating cochlear function in previous termtinnitusnext term patients with normal hearing.

Function growth rate cannot be the only parameter in measuring DPOAE in previous termtinnitusnext term patients, including subjects with hyperacusis and misophonia.

The markedly higher DPOAE amplitudes in the group of previous termtinnitusnext term patients without hearing loss suggest that previous termtinnitusnext term may be caused by increased motility of the OHCs induced by decreasing efferent fiber activity, and not by OHC failure.

Hyperacusis significantly increases the amplitude of DPOAE in previous termtinnitusnext term patients with no hearing loss.
Keywords: previous termTinnitusnext term; Hyperacusis; Misophonia; DPOAE

Corresponding Author Contact InformationCorresponding author at: ul. Krzycka 32, 53-020 Wroclaw, Poland. Tel.: +48 603672132.

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