Case of bilateral pneumolabyrinth presenting as sudden, bilateral deafness, without temporal bone fracture, after a fall

Abstract

Pneumolabyrinth is an uncommon condition in which air is present in the vestibule or cochlea. It is rarely found, even with fractures violating the otic capsule or with transverse fractures of the temporal bone. In addition, its bilateral occurrence is extremely rare. In this article, we describe a case of bilateral pneumolabyrinth presenting as sudden, bilateral deafness, without temporal bone fracture, an occurrence which has not previously been reported.

Computed tomographic characteristics of pneumolabyrinth in a French bulldog with otitis media and externa

“…Although, in this case, the cochlear and vestibular membranes were not clearly identified during surgery, it has been established in humans that the abnormal communication may be confirmed at surgery by exploring the vestibular and cochlear windows . Evaluation of the cochlear and vestibular membranes has historically been used to diagnose perilymphatic fistulas.…”

“…This abnormal communication is also referred to as ‘perilymphatic fistula’ in the human literature . Potential gas entry sites include vestibular or cochlear windows, the fissula ante fenestram, and microfissures between the posterior semicircular canal and the cochlear window . In most cases, pneumolabyrinth is of traumatic origin, secondary to a head trauma with temporal bone fracture .…”

“…In most cases, pneumolabyrinth is of traumatic origin, secondary to a head trauma with temporal bone fracture . Nontraumatic pneumolabyrinth is much less common . The first cause of nontraumatic pneumolabyrinth is external force applied to these thin membranes from barometric pressure change, compression trauma to the ear, and Valsalva's maneuver .…”

“…In this case, hearing evaluation was not performed, therefore hearing loss was not evaluated. Brainstem auditory evoked responses can be recorded to evaluate auditory function and could have been performed in this case …”

“…Evaluation of the cochlear and vestibular membranes has historically been used to diagnose perilymphatic fistulas. However, it is often assumed in human medicine that the presence of pneumolabyrinth confirms a perilymphatic fistula and exploratory tympanotomy (or other means to visualize the communication) is reserved for patient with persistent neurological deficits or hearing loss …”