Auditory Neuropathy/Dyssynchrony in Biotinidase Deficiency

Biotinidase deficiency is a disorder inherited autosomal recessively showing evidence of hearing loss and optic atrophy in addition to seizures, hypotonia, and ataxia. In the present study, a 2-year-old boy with Biotinidase deficiency is presented in which clinical symptoms have been reported with auditory neuropathy/auditory dyssynchrony (AN/AD). In this case, transient-evoked otoacoustic emissions showed bilaterally normal responses representing normal function of outer hair cells. In contrast, acoustic reflex test showed absent reflexes bilaterally, and visual reinforcement audiometry and auditory brainstem responses indicated severe to profound hearing loss in both ears. These results suggest AN/AD in patients with Biotinidase deficiency.

The Effects of Middle Ear Negative Pressure on the Transiently Evoked (TEOAEs)and Distortion Product (DPOAEs) Otoacoustic Emissions / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The clinical utility of otoacoustic emissions (OAEs) has been well established in childhood hearing screenings. As middle ear negative pressure prevails in normal children, and since all OAEs must be transmitted through the middle ear before they can be measured in the ear canal, OAEs can be affected by middle ear negative pressure. The purpose of this study is to elucidate the effect of middle ear negative pressure on the detectability of OAEs. MATERIAL AND METHODS: TEOAEs were recorded for 36 ears using click before & after tonsillectomy and, or adenoidectomy (T and, or A) operations. Before & after T and or A operations, DPOAEs were generated at six geometric mean frequencies between 1-6 kHz for two different groups, Group I (40 ears) and Group II (36 ears). Group I: 3(f2/f1) ratios (1.21, 1.22 and 1.23) were used at the fixed stimulus level (70-70 dB SPL). Group II:3 stimulus levels were used (70-70 dB SPL, 60-70 dB SPL and 30-40 dB SPL). RESULTS: The negative middle ear pressure attenuated low frequency emission more than high frequency emission. CONCLUSION: Negative middle ear pressure may increase false alarm. So pneumatic otoscopy and aural immittance testing should be utilized to predict the feasibility of applying OAEs in childhood hearing screening test.

Test / Retest Reliability of DPOAE and TEOAE / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Otoacoustic emissions (OAEs) are the objective and noninvasive methods to assess cochlear function. The purpose of the present study is to determine the short-term and long-term test/retest reliability of the distortion-product otoacoustic emissions (DPOAEs) and transient-evoked otoacoustic emissions (TEOAEs). MATHODS: The short-and long-term reliability of DPOAE and TEOAE were examined in 11 normally hearing adults. DPOAE were collected in two basic forms consisting of audiograms and input/output (I/O) functions and reliabilities for TEOAE level, reproducibility index and peak stimulus level were calculated. RESULTS: The result of this study showed that the reliability of DPOAE and TEOAE was generally excellent. CONCLUSIONS: The DPOAE and TEOAE are highly reliable and useful tests to monitor the cochlear function for the purpose of study or clinical use in combination with other standard tests of audiometric function.