Conclusions: IAC stenosis and vestibulocochlear nerve hypoplasia/aplasia must be excluded as an etiology of sensorineural hearing loss. Results: Hypoplasia/aplasia of the vestibulocochlear nerve in association with IAC stenosis is an important consideration in the differential diagnosis of sensorineural hearing loss, as it is a relative contraindication for cochlear implant placement. The MR findings include left IAC stenosis and IAC neural structures absence secondary to aplasia of the vestibulocochlear nerve on each IAC. These findings are pathognomonic for left IAC stenosis. The temporal bone CT shows diminished left IAC diameter (less than 2 mm), right IAC absence and normal inner ear structures. Methods: A 4 year old girl presents with sensorineural hearing loss and bilateral recurrent otitis media. To describe the embryological development of the IAC structures and the natural history of IAC stenosis. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.Objectives: To describe the computed tomography (CT) and magnetic resonance (MR) findings in a patient with a diagnosis of internal auditory canal (IAC) stenosis. The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). This is particularly important when the recommended agent is a new and/or infrequently employed drug. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. Usage and distribution for commercial purposes as well as any distribution of modified material requires written permission.
#Internal auditory canal ct license
This article is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND). Our patient had a radiologically normal middle ear with intact ossicles and had no rhinorrhea upon presentation. Terminology Vestibular schwannomas are commonly known as acoustic neuromas, which is a misnomer.
Congenital perilymphatic fistulas, however, are predominantly associated with middle-ear anomalies or CSF otorrhea. The finding of profound sensorineural hearing loss with erosion of the otic capsule in a 14-month-old patient raised concerns for a congenital perilymphatic fistula. Genicular and tympanic segments of the facial nerve were also poorly delineated. Marked dilation of the IAC with thinning of the otic capsule and erosion, and a lack of bone covering between the cochlea and the IAC was visualized on CT. In our case, MRI demonstrated an ill-defined cystic lesion centered in the left IAC and petrous apex isointense on T1 and T2 sequences without any significant enhancement. MRI is the imaging modality of choice for defining lesions in the cerebellopontine angle and IAC. Imaging is therefore critical for distinguishing between the type of lesions in the IAC prior to any intervention.
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