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100			_aSreeraj Konadath
245		0	_aAuditory brainstem response and late latency response in individuals with tinnitus having normal hearing
260			_c2016
270			_aDepartment of Audiology, All India Institute of Speech and Hearing, Mysuru, Karnataka State, India.
300			_a262-268
490			_vVolume 5 Issue 4
520			_aTinnitus is a commonly encountered complaint in routine audiology practice. The pathophysiology and exact generation site of tinnitus is not precisely established. Auditory brainstem response (ABR) and late latency response (LLR) findings in individuals with tinnitus show mixed results in the literature. Majority of studies have focused on individuals having tinnitus with peripheral hearing loss. The present study explores ABR and LLR characteristics among tinnitus patients with normal audiometric presentation; with no direct indication of any cochlear lesion. This study aims at characterizing the ABR and LLR findings in individuals with tinnitus having normal audiometric presentation. ABR and LLR waveform characteristics were recorded and compared between participants with tinnitus (Group 1) and those without tinnitus (Group 2). The ABR analysis indicated no significant differences in latency and amplitude between Groups 1 and 2. However, patients with tinnitus showed abnormally reduced absolute amplitudes of peaks I and V. LLR analysis indicated no significant differences in latency and amplitude between Groups 1 and 2 except enhanced amplitude of P1. The reduced amplitude of peaks I and V along with normal absolute latencies of peaks I, III and V indicate that the origin of tinnitus is possibly due to reduced excitation of auditory nerve fibres arising from a peripheral hearing loss beyond 8 kHz. The P1 amplitude enhancement could be attributed to mechanism explaining central gain model; which suggests that central auditory structures recalibrates the mean firing rate, considering the reduced output from sensory structures, generating neural noise perceived as tinnitus
653			_aAuditory brainstem responses, late latency response, tinnitus, central gain mechanism
700			_aPuttabasappa Manjula
773			_aIntractable & rare diseases research
856			_uhttps://doi.org/10.5582/irdr.2016.01053
942			_cFJAS _yFJAS
999			_c17928 _d17928