A CT Radiologic Assessment of the Incidence of Cochlear–Facial Dehiscence and the Thickness of Bone between the Cochlea and Facial Nerve among Normal Temporal Bones

Abstract

Cochlear–facial dehiscence (CFD) is a relatively new diagnosis which occurs when the bony partition between the labyrinthine segment of the facial nerve and the cochlea is dehiscent. This is considered one of several third window lesions which produce varying degrees of auditory and vestibular symptoms. Imaging studies have identified a consistently higher incidence of CFD when compared with the only histopathologic study present in the literature. This research effort adds to the literature using uniform computed tomography scan images across over 226 ears (114 patients) to identify the radiographic incidence of CFD in normal patients without ear pathology or symptoms. This study identified an incidence of 18.1% of the ears analyzed having dehiscence without any correlation to age or gender. When dehiscence was not identified, the mean thickness of bone between the cochlea and the facial nerve was 0.60 ± 0.24 mm.

Keywords

cochlear–facial dehiscence - CFD - third window lesions - cochlea - facial nerve - temporal bone

Publikationsverlauf

Eingereicht: 19. Oktober 2023

Angenommen: 23. Januar 2024

Accepted Manuscript online:
25. Januar 2024

Artikel online veröffentlicht:
19. Februar 2024

• References

• 1 Blake DM, Tomovic S, Vazquez A, Lee HJ, Jyung RW. Cochlear-facial dehiscence–a newly described entity. Laryngoscope 2014; 124 (01) 283-289
• 2 Arsenault JJ, Romiyo P, Miao T. et al. Thinning or dehiscence of bone in structures of the middle cranial fossa floor in superior semicircular canal dehiscence. J Clin Neurosci 2020; 74: 104-108
• 3 Miao T, Johanis M, Kaur T. et al. Analysis of temporal bone thickness outside of the petrous temporal bone between superior semicircular canal dehiscence and normal patients. J Clin Neurosci 2021; 84 (23–28): 23-28
• 4 Wackym PA, Balaban CD, Zhang P, Siker DA, Hundal JS. Third window syndrome: surgical management of cochlea-facial nerve dehiscence. Front Neurol 2019; 10 (10) 1281
• 5 Koroulakis DJ, Reilly BK, Whitehead MT. Cochlear-facial dehiscence in a pediatric patient. Pediatr Radiol 2020; 50 (05) 750-752
• 6 Garaycochea O, Domínguez PD, Manrique M, Manrique-Huarte R. Cochlear-internal canal and cochlear-facial dehiscence: a novel entity. J Int Adv Otol 2018; 14 (02) 334-336
• 7 Camerin GR, Passos UL, da Costa SS, Gebrim EMMS, Cruz OLM. Cochlear facial dehiscence detected after cochlear implant. Otol Neurotol 2020; 41 (02) e293-e294
• 8 Chen J, Chen B, Zhang L, Li Y. Severe and persistent facial nerve stimulation after cochlear implantation in a patient with cochlear-facial dehiscence: a case report. J Int Med Res 2021; 49 (11) 3000605211057823
• 9 Schart-Morén N, Larsson S, Rask-Andersen H, Li H. Anatomical characteristics of facial nerve and cochlea interaction. Audiol Neurotol 2017; 22 (01) 41-49
• 10 Song Y, Alyono JC, Bartholomew RA, Vaisbuch Y, Corrales CE, Blevins NH. Prevalence of radiographic cochlear-facial nerve dehiscence. Otol Neurotol 2018; 39 (10) 1319-1325
• 11 Motasaddi Zarandy M, Kouhi A, Emami H, Amirzargar B, Kazemi MA. Prevalence of otic capsule dehiscence in temporal bone computed tomography scan. Eur Arch Otorhinolaryngol 2023; 280 (01) 125-130
• 12 Fang CH, Chung SY, Blake DM. et al. Prevalence of cochlear-facial dehiscence in a study of 1,020 temporal bone specimens. Otol Neurotol 2016; 37 (07) 967-972
• 13 Hong M, Mozaffari K, Uy B. et al. Postoperative outcomes of patients with thin bone overlying the superior semicircular canal: a single institution's experience. World Neurosurg 2022; 166: e93-e98