Patulous Internal Auditory Canal

Abstract

Patulous canal is a rare anatomical variant of the internal auditory canal (0.3%), and its association with inflammatory ear disease accompanied by conductive hearing impairment appears to have been incidental in both cases in the present study.

Deep phenotyping of the neuroimaging and skeletal features in KBG syndrome: a study of 53 patients and review of the literature

“…Its significance in the pathogenesis of congenital hearing impairment is controversial. 33 34 In our cohort, hearing loss was reported in only two of the eight participants with patulous IAC, but in all four with confirmed normal IAC, suggesting that an association seems unlikely. Nevertheless, IAC evaluation may be considered during the follow-up of individuals with KBG syndrome and hearing defects, since patulous IAC was proposed as a risk of complications during ear surgery.…”

“…This rare anatomical variant, found in less than 0.5% of the general population, is characterised by a bilateral and usually symmetrical height increase at the midportion of the IAC. 33 It differs from dilatation due to acoustic neuromas because the cortical margins and falciform crest of the canal are preserved. Its significance in the pathogenesis of congenital hearing impairment is controversial.…”

Enlarged internal auditory canal and sudden deafness

“…However, enlarged internal auditory canal is commonly associated with normal hearing. In all reported cases of this condition, patulous internal auditory canal was not combined with any anomaly of the labyrinth 3 , 4 …”

“…In all reported cases of this condition, patulous internal auditory canal was not combined with any anomaly of the labyrinth. 3,4 The pathogenetic mechanism of the hearing impairment caused by enlarged internal auditory canal is not well defined and is a subject of debate. However, the present case seems to suggest a new potential pathogenetic mechanism.…”

Anatomical variations of the temporal bone on high-resolution computed tomography imaging: how common are they?

“…None of our six patients demonstrated any abnormalities of the cortex or transverse crest. Some authors have reported a correlation between an enlarged IAM and sensorineural hearing loss, but the significance of this is questionable 17 , 18 …”