*Corresponding author:Sabharisan Paramasivam, Junior resident, Department of ENT, Jawaharlal Institute of Postgraduate Medical Education and Research, India
How to cite this article: Sabharisan P, Karthikeyan R, Arun A, Sunil K S. A Rare Cause of Vertigo- Case Report and Review of Literature. Glob J Oto,
2020; 23 (5): 556121 DOI: 10.19080/GJO.2020.23.556121
Presence of air within the labyrinth constitutes the term Pneumo-labyrinth. Pneumo-labyrinth may be associated with perilymph fistula. Most commonly trauma involving the otic capsule is associated with pneumolabyrinth. Depending on the location of the air bubble within the inner ear pneumolabyrinth can be subdivided into pneumocochlea and pneumovestibule, in which air is present in the cochlea and vestibule respectively . In this case report we discuss
50 years old male patient presented to Outpatient Department with history of giddiness and ringing sensation in the ear for two months. He also complained of reduced hearing in the right year. On further probing of history, he gave history of trauma to the right ear two and a half months ago while doing field work, where while loading goods a stick had accidentally injured his right ear (stick entered into his external auditory canal). Following the trauma, he had one episode of ear bleed immediately.
In examination, on otoscopy examination of the right ear - tympanic membrane was intact and mobile with signs of healed perforation. In the left ear he had a small central perforation involving the inferior quadrant. Bilateral facial nerve was intact and had no cerebellar signs. Rest of the otorhinolaryngology examination was normal. Pure tone audiogram showed >90dB hearing loss and 48dB hearing loss (moderately mixed hearing loss) in right and left ear respectively (Table 1). High Resolution Computed Tomography (HRCT) of the temporal bones showed presence of air pocket within the membranous labyrinth.
Anesthetic clearance was obtained and exploratory tympanotomy was planned. Intra operatively stapes dislocation
with fracture of stapes supra-structure were present. Dislocated stapes was removed, defect in the oval window was identified and was sealed with temporalis fascia graft and tissue seal. The stapes was repositioned back into the middle ear over the graft and was packed around with gel foam. Post-operative period was uneventful. Labyrinthine sedatives were given in the post-operative period. Wound sutures were removed on post-operative day 10. Symptomatic relief of giddiness was present post operatively on follow up. Post-operatively he did not give history of improvement in hearing (Figures 1-3).
Temporal bone trauma could be otic capsule involving or
otic capsule sparing. Pneumolabyrinth could be seen in both
these conditions, but more common among otic capsule violating
temporal bone fracture patients. The incidence of occurrence of
pneumolabyrinth is seldom in comparison to other sequelae of
temporal bone trauma. In a series by Choi et al the incidence of
pneumolabyrinth was 8% among the trauma cases with temporal
bone fracture while in another series by Choi et al it was 1.5%
[2,3]. The various causes other than temporal bone fracture
causing pneumolabyrinth are rupture of round window due to
an impulsive force, perilymphatic fistula, displacement of stapes
prosthesis into vestibule, congenital malformations, fracture
or dislocation or subluxation of stapes and cochleostomy with
cochlear implant within [4-10]. Stapes footplate luxation out of
the oval window or into the vestibule is rare [6-9]. The two main
i. stapes is firmly attached to the oval window due to
annular ligament and
ii. the anatomical location of stapes deep within the middle
The most probable mechanism of injury in the present case
might be that the foreign object entered the middle ear after
perforating the tympanic membrane and got hinged near to the
stapes. Upon withdrawal of the foreign body it might have caused
dislocation of the stapes footplate leading to patient’s current
symptoms. Patients with pneumolabyrinth can also present with
delayed onset of symptoms [11,12].
Diagnosing a patient of pneumolabyrinth is important for
appropriate management. Mafee et al. were the first to describe
pneumolabyrinth in computed tomography and suggested the
presence of pneumolabyrinth as a feature of stapes footplate
fracture . Thereafter High-Resolution Computed Tomography
(HRCT) became an essential entity in diagnosing pneumolabyrinth.
Presence of air within the labyrinth appears as black areas in
HRCT. These air pockets might move with movement of head
while attaining HRCT and chance of dislocation of the air bubble is
also possible in cases with disrupted membranous labyrinth .
The probability of positive HRCT finding increases when imaging
study is acquired immediately following trauma. Though over
time on serial imaging these air bubbles might dissipate [3,14].
Choi et al. advocates obtaining early HRCT imaging to predict the
audio-vestibular outcome .
The exact cause for sensorineural hearing loss among these
subsets of patients might be due to the direct injury of membranous
labyrinth and might be due to the presence of air bubble within
the labyrinth. One hypothesis is that these air bubbles cause
disruption of the travelling wave along the basilar membrane
. Kobayashi et al in their study concluded that hearing loss is
due to interference in the generation of cochlear microphonics
and compound action potential rather than dysfunction of the
stria vascularis. Further on comparison between the findings of
presence of air in scala vetibuli and scala tympani, even with a
very small volume of air (3μL) there was hearing loss in scala
vestibule. Hearing did not return to the baseline on removal of air
from scala vestibule in some cases .
The treatment options available for management are either
observation or surgical exploration. Surgical exploration can be
considered in cases with progressive sensorineural or fluctuating
hearing loss and in patients having persistent vertigo .
Exploratory tympanotomy serves useful for diagnosing as well
as for surgical management. The major lacuna in managing these
cases are the lack of sructured protocol due to very few numbers of
cases. The vestibular symptoms usually alleviate post operatively
as per Tsubota et al. The hearing improvement as per their study
is dependent on three predictive factors:
a. existence of stapes lesion
b. bone conduction hearing level at the onset of the disease
c. time interval until surgery 
Yet another predictive factor as per Hidaka et al. is the
location of air bubble. Better hearing outcome can be expected
in pneumocochlea whereas outcomes are poorer in cases of
pneumovestibule or in combination of both . Various surgical
methods have been described example using fascia to repair the
involved window along-with muscle obliteration or using tragal
perichondrium . When taken up for surgery, the patient should
be made aware that even after surgery there may/may not be any
Even-though pneumo-labyrinth is a rare entity that we
encounter clinically, a general prospective on its clinical features
and findings are must to diagnose these less frequent cases
for adequate management. We should also keep in mind that
treatment of dizziness among these patients is often successful
while the same cannot be for treatment of hearing loss.