Purpose: First aim of the study was to define normal shape and diameter of the internal auditory canal (IAC). In the second part the clinical relevance of IAC-enlargement was analyzed, considering also lesions of the subtle structures at the fundus of the internal auditory canal.
Materials And Methods: 440 high resolution CT-scans of the temporal bone were used for retrospective analysis of the internal auditory canal and its fundus region.
Results: The mean value of the IAC diameter in axial and coronal plane was determined. In 20 of 440 patients IAC enlargement was found. In the group with pronounced enlargement (3fold SD) nearly all patients suffered from hearing impairment. In some of them we found structural abnormalities near the IAC fundus in the CSF/perilymph border zone.
Conclusion: A new CT-based definition of normal shape and diameter of the internal auditory canal is presented. There is some evidence that a pathologic transmission of CSF-pressure in case of IAC-enlargement and/or abnormal fistulous communications could play an important role in the pathophysilogy of hearing loss.
Key Points: • New CT-based definition of normal internal auditory canal.• Nearly all patients showing pronounced IAC-enlargement suffer from hearing impairment.• Possible pathomechanism: Transmission of CSF-pressure on the inner ear.
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http://dx.doi.org/10.1055/s-0034-1399009 | DOI Listing |
PLoS One
January 2025
Institute of Endocrinology, Prague, Czech Republic.
Objectives: Hearing impairment can have major impacts on behavior, educational attainment, social status, and quality of life. In congenital hypothyroidism, the incidence of hearing impairment reaches 35-50%, while in acquired hypothyroidism there is a reported incidence of 25%. Despite this, knowledge of the pathogenesis, incidence and severity of hearing impairment remains greatly lacking.
View Article and Find Full Text PDFFront Psychol
January 2025
Program in Neuroscience, Department of Zoology and Physiology, University of Wyoming, Laramie, WY, United States.
The process of decision making is a complex procedure influenced by both external and internal conditions. Songbirds provide an excellent model to investigate the neural mechanisms of decision making, because females rely on acoustic signals called songs as important stimuli in directing their mate choice. Previous experiments by our group and others have implicated secondary auditory brain sites in female evaluation of song quality, including the caudal portions of the nidopallium (NC) and mesopallium (CM).
View Article and Find Full Text PDFSci Rep
January 2025
Université Laval, Quebec, Canada.
The preferred period hypothesis posits a slowing down of motor and perceptual rhythmic preferences with age, both reflecting an increase in the common internal oscillation period. This study further investigates the preferred period hypothesis by improving the measurement of perceptual rhythmic preferences through two tasks, tempo adjustment and tempo judgment, conducted in auditory and visual modalities. The study was conducted with three groups of children (5-6, 8-9, and 11-12 years old), and a group of young adults (21 to 30 years old) during the same time of the day.
View Article and Find Full Text PDFBMJ Case Rep
January 2025
Department of Neurology, UT Southwestern Medical Center, Dallas, Texas, USA
Indian J Nephrol
June 2024
Mansoura Nephrology and Dialysis Unit, Department of Internal Medicine, Mansoura, Egypt.
Background: It has been claimed that tacrolimus may have harmful effects on the auditory system, where it has been linked to ototoxicity and sensorineural hearing loss (SNHL). We evaluated silent SNHL in kidney transplant recipients (KTRs) receiving tacrolimus and the different factors affecting it compared to healthy controls.
Materials And Methods: In this case control study, hearing functions were studied in 42 KTRs receiving tacrolimus as maintenance immunosuppressive therapy for more than 3 months in comparison to 27 age- and gender-matched healthy subjects using tympanometry, pure-tone audiometry (PTA), extended high frequency audiometry (EHFA), and transient evoked oto-acoustic emissions (TEOAEs).
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