Title:
Auditory efferent dysfunction in normal-hearing chronic idiopathic tinnitus
Authors:
S.-Y. Hsu , P.-C. Wang 1,2, T.-H. Yang , T.-F. Lin , S.-H. Hsu and C.-J. Hsu 4,5
Institutions:
Department of Otolaryngology, Cathay General Hospital, Taipei, Taiwan; Fu-Jen Catholic University, School of Medicine, New Taipei City, Taiwan; Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan; Department of Otolaryngology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Lin Otolaryngology Clinic, New Taipei City, Taiwan; Department of Family Medicine, National Taiwan University Hospital Jinshan Branch, New Taipei City, Taiwan
Keywords:
Otoacoustic emissions; contralateral suppression; auditory brainstem responses; medial olivocochlear bundle
Pages:
101 - 109
Abstract:
Auditory efferent dysfunction in normal-hearing chronic idiopathic tinnitus. Objective: To investigate the function of the auditory efferent system in patients with chronic idiopathic tinnitus, but normal pure-tone audiograms. Methods: We studied 15 subjects with normal hearing that had experienced either unilateral or bilateral persistent tinnitus for at least 3 months. The ears of the 15 subjects were classified into tinnitus-positive-ear (TPE) and tinnitus-negative-ear (TNE) groups. The control-ear group (CE) comprised the ears of 15 subjects with normal hearing and no tinnitus. We measured different types of otoacoustic emissions (OAEs), including spontaneous (SOAEs), transient evoked (TEOAEs), and distortion product (DPOAEs). We also analyzed contralateral suppression of OAEs and auditory brain- stem responses (ABRs). Data were compared among TPE, TNE, and CE groups. Results: The data associated with cochlear mechanics, including the prevalence of SOAEs, the number of SOAE peaks, and the overall TEOAE responses in the absence of a contralateral stimulus, were not significantly different among the TPE, TNE, and CE groups. In the TPE group, contralateral stimuli failed to significantly suppress overall TEOAEs, and contralateral suppression of DPOAEs was significantly reduced over a limited frequency range. Furthermore, the TPE group showed prolonged latencies in waves III and V of ABRs. Conclusion: This study demonstrated that abnormal contralateral suppression of OAEs and ABRs indicated a dysfunction in the ipsilateral efferent medial olivocochlear system; this might play a role in normal-hearing tinnitus.
Issue:
Vol. 9, 2013, 2nd trimester


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Auditory efferent dysfunction in normal-hearing chronic idiopathic tinnitus