BAEP testing also shows widely variable audiological results, from severely altered wave morphology to no wave formation, thus reflecting the multifaceted and heterogeneous nature of the pathophysiology of this auditory disorder 5. Individuals with auditory neuropathy spectrum disorder (ANSD) may present mild to severe, unilateral or bilateral hearing loss associated with disproportional impairment of speech discrimination in relation to hearing loss 4. It was then realized that the term auditory neuropathy describes an array of disorders that may range from auditory dyssynchrony to auditory nerve neuropathy 3. The change in nomenclature was due to a study carried out in 2002 in which it was revealed that approximately half the children with auditory neuropathy had the same speech detection skills as children with sensorineural hearing loss, in addition to auditory brainstem responses, while the other half had unsatisfactory results in speech detection tests and no auditory brainstem responses. The term auditory neuropathy spectrum was produced through international consensus during the Guidelines Development Conference on the Identification and Management of Infants with Auditory Neuropathy, held in June of 2008 2. The term auditory neuropathy was used for the first time in a study carried out in 1996 to categorize a group of subjects with hearing symptoms and normal cochlear function associated with cochlear nerve dysfunction 1. The term auditory neuropathy has been used to describe diseases affecting children and adults characterized by normal outer hair cell function and anomalous or absent auditory nerve function it has been described as a set of auditory disorders that combine otoacoustic emissions (OAEs) and/or cochlear microphonics (CM) with absent or desynchronous waves generated in brainstem auditory evoked potentials (BAEPs). ConclusionĪNSD was seen in 1.2% of the individuals with SNHL included in this study. In terms of age, 14.8% were aged between zero and 20 years, 44.1% were 41 to 60 years old, and 7.4% were above the age of 60. Mild SNHL was seen in 29.6% of the individuals with ANSD 55.5% had moderate SNHL 7.4% had severe SNHL and 7.5% had profound SNHL. Twenty-seven (1.2%) of the 2,292 subjects with SNHL had ANSD (37% males 63% females). Inclusion criteria: presence of OAEs and/or cochlear microphonic (CM) absent or altered BAEPs, and normal MRI scans of the brain. Data from otolaryngological and audiological examinations based on pure-tone and speech audiometry, impedance tests, otoacoustic emissions (OAEs), and brainstem auditory evoked potentials (BAEPs) were collected. This retrospective study was carried out between 20 and included the charts of 2,292 individuals with SNHL. To establish the prevalence of ANSD in subjects with sensorineural hearing loss (SNHL). Auditory neuropathy spectrum disorder (ANSD) is characterized by impairment of the auditory nerve associated with preservation of outer hair cell function.
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