In asymptomatic IAC stenosis, palliative IAC decompression of cochlear nerve can be considered if sudden onset of deafness occurs. In most cases of congenital sensorineural hearing loss caused by IAC stenosis, hearing devices or cochlear implantation may not be helpful. Background:Exostoses of the internal auditory canal is a rare finding that may present with disabling symptoms of dizziness, hearing loss, and vestibular. Li Y, Yang J, Liu J, Wu H (2014) Restudy of malformations of the internal auditory meatus, cochlear nerve canal and cochlear nerve. There is residual fluid signal in the fundus of the internal auditory canal with a normal signal in the membranous labyrinth. Hyperpneumatization of the petrous apex can also result in abnormal narrowed conditions. Haberkamp TJ, Meyer GA, Fox M (1998) Surgical exposure of the fundus of the internal auditory canal: anatomic limits of the middle fossa versus the retrosigmoid transcanal approach. Many clinical and experimental studies have been done to analyze the anatomical and functional aspects of the internal auditory canal (IAC) in human beings. The internal auditory meatus(also meatus acusticus internus, internal acoustic meatus, internal auditory canal, or internal acoustic canal) is a canal within the petrous part of the temporal boneof the skullbetween the posterior cranial fossaand the inner ear. Also, underlying skeletal disease causing hypertrophy of the surrounding bone (Paget’s disease or otosclerosis) can contribute to IAC stenosis. In addition to primary causes of IAC narrowing, osseous lesions such as an exostosis or an osteoma can cause secondary narrowing of the IAC. IAC hypoplasia/atresia has been associated with other inner ear abnormalities 4, such as incomplete partition variants, cochlear and semicircular canal. Patients with IAC stenosis may present with congenital sensorineural hearing loss caused by aplasia of the vestibulocochlear nerve during development, but in very rare cases it can be asymptomatic. IAC stenosis without other abnormalities is extremely rare. ![]() Approximately 12% of patients with congenital sensorineural hearing loss have radiographic evidence of inner ear abnormalities including IAC stenosis. ![]() CHAPTER 36 Internal Auditory Canal Stenosis/AtresiaĪn internal auditory canal (IAC) measuring less than 2 mm in vertical dimension by high-resolution temporal bone computed tomography (CT) is considered stenotic.
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