Title: Conductive Hearing Loss Due to a Dehiscent Facial Nerve
Authors: Dr Hamjol Singh Chakkal, Dr Sandip M Parmar, Dr Meenu Chaudhary
DOI: https://dx.doi.org/10.18535/jmscr/v5i1.111
Abstract
Objective- The relative position of the developing tympanic segment of facial nerve (fallopian canal) to that of the stapes and oval window niche may lead to Ossicular anomalies responsible for a conductive hearing loss. We hereby present five cases of unilateral conductive hearing loss due to a dehiscent tympanic segment of the facial nerve causing impingement and/or anomalous development of the stapes crura.
Result-The stapes was found to be mobile in each of five patients suspected of having a conductive or mixed hearing loss due to otosclerosis. A dehiscent, inferiorly malpositioned, tympanic segment of facial nerve was found to be impinging on the stapes crura in all the cases and to be associated with malformed stapes crura in one of the case. No further middle ear surgery was performed in any of the cases.
Keywords: - hearing loss, dehiscent, facial nerve.
References
1. Conductive Hearing Loss Due to an Anomalous Facial Nerve, Angel J. Perez, MD, LT MC USN and Jeffery J. Kuhn, MD, FACS Department of Otolaryngology ‐ Head and Neck Surgery, Naval Medical Center, Portsmouth VA
2. Baxter A. Dehiscence of the fallopian canal. J Laryngology Otology 85. 1971; 587-94.
3. Li D ET. Al Facial canal dehiscence: a report of 1,465 stapes operations. Ann Otology Laryngology 105(6). 1996; 467-71.
4. Tange RA ET. Al. Dehiscence of the horizontal segment of the facial canal in otosclerosis. ORL J Otorhinolaryngology Relat Spec 59(5). 1997; 277-9
5. Nager, GT and Proctor B. Anatomic Variations and Anomalies involving the Facial Canal. Otology Clinics N A, 24 (3) 1991; 531-53.
6. Welling, DB, ET. Al. Avulsion of the anomalous facial nerve at stapedectomy. Laryngoscope 102, 1992; 729-33.
7. Casparosa RJ and Klassen D. Congenital Anomalies of the stapes and Facial nerve. Arch Otolaryngology, 83, 1966; 420-1.
8. Ebert CS, Zanation AM, Buchman CA. Another Cause for Conductive Hearing Loss With Present Acoustic Reflexes. Laryngoscope: 118, 2008; 2059-61.
9. Huang, TS. Anomalously coursing facial nerves above and below the oval window: three case reports. Otolaryngology Head Neck Surgery, 116(4), 1997.