Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-25T15:56:40.881Z Has data issue: false hasContentIssue false

Distance between the middle turn of the cochlea and labyrinthine portion of the facial nerve: a surgical-radiological comparison and assessment of clinical importance

Published online by Cambridge University Press:  25 November 2021

R Lakhawat
Affiliation:
Department of Otorhinolaryngology and Head Neck Surgery, Sawai Man Singh (SMS) Medical College and Hospital, Jaipur, India
M Grover
Affiliation:
Department of Otorhinolaryngology and Head Neck Surgery, Sawai Man Singh (SMS) Medical College and Hospital, Jaipur, India
S Sharma*
Affiliation:
Department of Otorhinolaryngology and Head Neck Surgery, Sawai Man Singh (SMS) Medical College and Hospital, Jaipur, India
M Charan
Affiliation:
Department of Microbiology, Jawaharlal Nehru (JLN) Medical College, Ajmer, India
N Lohar
Affiliation:
Department of Otorhinolaryngology and Head Neck Surgery, Sawai Man Singh (SMS) Medical College and Hospital, Jaipur, India
S Samdani
Affiliation:
Department of Otorhinolaryngology and Head Neck Surgery, Sawai Man Singh (SMS) Medical College and Hospital, Jaipur, India
*
Author for correspondence: Dr Shivam Sharma, C-17, Deepak Marg, Adarsh Nagar, Sharma Hospital, Jaipur302004, Rajasthan, India E-mail: [email protected]

Abstract

Objective

To highlight the close anatomical relationship between the middle turn of the cochlea and the labyrinthine segment of the facial nerve, which will be helpful to predict the probability of occurrence of facial nerve stimulation following cochlear implant surgery.

Methods

High-resolution computed tomography of 40 cadaveric temporal bones was performed, followed by microscopic dissection. Cochleo-facial distance was measured with the help of a Digital Imaging and Communications in Medicine (‘DICOM’) viewer on high-resolution computed tomography and by a millimetre scale in the dissected specimen.

Results

The cochleo-facial distance on high-resolution computed tomography was 0.62 ± 0.09 mm, ranging from 0.41 to 0.81 mm, and on dissection it was 0.57 ± 0.10 mm, ranging from 0.35 to 0.74 mm.

Conclusion

The labyrinthine segment is the most likely area of stimulation in patients suffering from facial nerve stimulation following cochlear implantation. Pre-operative high-resolution computed tomography of the temporal bone can be used to examine the bone separating the labyrinthine segment of the facial nerve from the middle turn of the cochlea. This has clinical significance regarding implant side selection and pre-operative patient counselling.

Type
Main Article
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press on behalf of J.L.O. (1984) LIMITED

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Dr S Sharma takes responsibility for the integrity of the content of the paper

References

Wysocki, J, Skarzyñski, H. Distances between the cochlea and adjacent structures related to cochlear implant surgery. Surg Radiol Anat 1998;20:267–71CrossRefGoogle ScholarPubMed
Kelsall, DC, Shallop, JK, Brammeier, TG, Prenger, EC. Facial nerve stimulation after Nucleus 22-channel cochlear implantation. Am J Otol 1997;18:336–41Google ScholarPubMed
Cohen, NL. Medical or surgical complications related to the Nucleus Multichannel Cochlear Implant. Ann Otol Rhinol Laryngol 1989;98:754Google ScholarPubMed
Cohen, NL, Hoffman, RA. Complications of cochlear implant surgery in adults and children. Ann Otol Rhinol Laryngol 1991;100:708–11CrossRefGoogle ScholarPubMed
Kruschinski, C, Weber, BP, Pabst, R. Clinical relevance of the distance between the cochlea and the facial nerve in cochlear implantation. Otol Neurotol 2003;24:823–7CrossRefGoogle ScholarPubMed
Bigelow, DC, Kay, DJ, Rafter, KO, Montes, M, Knox, GW, Yousem, DM. Facial nerve stimulation from cochlear implants. Am J Otol 1998;19:163–9Google ScholarPubMed
Sainz, M, Garcia-Valdecasas, J, Ballesteros, JM. Complications and pitfalls of cochlear implantation in otosclerosis: a 6-year follow-up cohort study. Otol Neurotol 2009;30:1044–8CrossRefGoogle ScholarPubMed
ImageJ: Image Processing and Analysis in Java. In: https://imagej.nih.gov/ij/ [3 March 2022]Google Scholar
Redleaf, MI, Blough, RR. Distance from the labyrinthine portion of the facial nerve to the basal turn of the cochlea. Temporal bone histopathologic study. Ann Otol Rhinol Laryngol 1996;105:323–6CrossRefGoogle Scholar
Gold, SR, Miller, V, Kamerer, DB, Koconis, CA. Fluoride treatment for facial nerve stimulation caused by cochlear implants in otosclerosis. Otolaryngol Head Neck Surg 1998;119:521–3CrossRefGoogle ScholarPubMed
Niparko, JK, Oviatt, DL, Coker, NJ, Sutton, L, Waltzman, SB, Cohen, NL. Facial nerve stimulation with cochlear implantation. VA Cooperative Study Group on Cochlear Implantation. Otolaryngol Head Neck Surg 1991;104:826–30CrossRefGoogle Scholar