The radiographic prevalence of geniculate ganglion dehiscence in normal and congenitally thin temporal bones.
OBJECTIVE
To determine the prevalence of a dehiscent geniculate ganglion on routine temporal bone computed tomography (CT).


METHODS
Retrospective case review.


METHODS
Tertiary referral center.


METHODS
Two hundred seventy-eight consecutive temporal bone CT examinations for a total of 556 sides were reviewed. One hundred ninety-one sides were excluded. Reasons for exclusion included reconstructed coronal views, no coronal views, or a pathologic process, which involved the geniculate ganglion. Six examinations were from patients with clinical superior canal dehiscence confirmed by surgical repair or positive vestibular evoked myogenic potentials. Twenty-four scans were from patients with radiographic superior canal dehiscence confirmed by two independent readings.


METHODS
The incidence of geniculate ganglion dehiscence in patients with and without radiographic or clinical superior canal dehiscence. Dehiscent geniculate ganglion was defined as at least two consecutive cuts on a coronal CT showing no bone overlying the geniculate ganglion.


RESULTS
The overall incidence of a dehiscent geniculate ganglion was 14.5% in the 365 sides reviewed. The incidence of a dehiscent geniculate ganglion is increased in patients with radiographic and clinical superior canal dehiscence as compared with normal patients and was significantly different by chi analysis (38.1 versus 11.4%).


CONCLUSIONS
The presence of radiographic geniculate ganglion dehiscence is common. This finding has particular importance when the middle cranial fossa or subtemporal approach is used, as the facial nerve is more at risk especially when used to address superior canal dehiscence.
Isaacson
Brandon
B
Department of Otolaryngology-Head and Neck Surgery, University of Texas-Southwestern Medical Center, Dallas, Texas 75390-9035, USA. Brandon.Isaacson@UTSouthwestern.edu
Vrabec
Jeffrey T
JT
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D005260:Female; D005830:Geniculate Ganglion / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D011183:Postoperative Complications; D015995:Prevalence; D013529:Surgical Wound Dehiscence / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology*; D013701:Temporal Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed