Rare Cause of Facial Nerve Palsy (Petrous Apex Cholesteatoma)-Case Report and Review of Literature

Abstract

The petrous apex is a pyramid-shaped structure that is formed by the medial portions of the temporal bone. It is obliquely positioned within the skull base, with its apex pointing anteromedially and its base located posterolaterally. The petrous apex is bounded by the inner ear structures laterally, the petro-occipital fissure medially, the petrosphenoidal fissure and ICA anteriorly, and the posterior cranial fossa behind. Given its location, the petrous apex is susceptible to multiple pathologic processes which may be Inflammatory, developmental, vascular, benign and malignant lesions. We present a rare case of a 39 year old Male who presented wit unilateral facial nerve palsy and sensoneural hearing loss and was then diagnosed as petrous apex Cholesteatoma. Patient was treated surgically by Transchoclear trasnlabrynth technique.

Full text

Clinical Neurology and Neuroscience
2019; 3(1): 1-5
http://www.sciencepublishinggroup.com/j/cnn
doi: 10.11648/j.cnn.20190301.11
ISSN: 2578-8922 (Print); ISSN: 2578-8930 (Online)
Case Report
Rare Cause of Facial Nerve Palsy (Petrous Apex
Cholesteatoma)–Case Report and Review of Literature
Rauf Ahmed, Owais Makhdoomi, Omar Mohammad Shafi, Faheem Khalid*
Department of ENT and HNS, Government Medical College, Srinagar Jammu & Kashmir, India
Email address:
To cite this article:
Rauf Ahmed, Owais Makhdoomi, Omar Mohammad Shafi, Faheem Khalid. Rare Cause of Facial Nerve Palsy (Petrous Apex Cholesteatoma)–
Case Report and Review of Literature. Clinical Neurology and Neuroscience. Vol. 3, No. 1, 2019, pp. 1-5. doi: 10.11648/j.cnn.20190301.11
Received: January 9, 2019; Accepted: April 1, 2019; Published: May 11, 2019
Abstract: The petrous apex is a pyramid-shaped structure that is formed by the medial portions of the temporal bone. It is
obliquely positioned within the skull base, with its apex pointing anteromedially and its base located posterolaterally. The
petrous apex is bounded by the inner ear structures laterally, the petro-occipital fissure medially, the petrosphenoidal fissure and
ICA anteriorly, and the posterior cranial fossa behind. Given its location, the petrous apex is susceptible to multiple pathologic
processes which may be Inflammatory, developmental, vascular, benign and malignant lesions. We present a rare case of a 39
year old Male who presented wit unilateral facial nerve palsy and sensoneural hearing loss and was then diagnosed as petrous
apex Cholesteatoma. Patient was treated surgically by Transchoclear trasnlabrynth technique.
Keywords: Cholesteatoma, Facial Nerve Palsy, Petrous Apex
1. Introduction
The petrous apex is a pyramid-shaped structure that is formed
by the medial portions of the temporal bone. Petrous apex is
anatomically a complex structure due to is its medial location in
the skull base and its intimate relationship to other clinically
important structures including the cavernous sinus, Dorello canal,
and Meckel cave. The petrous apex represents a unique
intersection between the suprahyoid neck and the intracranial
compartment. Hence, the petrous apex is susceptible to a variety
of pathologic processes. Clinical presentations of these lesions,
therefore, can be quite variable and depend largely on
involvement of numerous intimately adjacent intra- and extra
cranial structures, especially the cranial nerves. Besides clinical
examination of the patient, different radiological investigations
help us in definite diagnosis of a specific lesion.
2. Case Report
A 39 year old Male presented with complaints of Decreased
hearing Left ear for 2 years, Inability to close left eye for 6
months and Tinnitus left ear for 6 months. He noticed left
sided facial asymmetry 6 months back, which progressed to
complete facial nerve palsy. At the time of presentation patient
had no systemic disease. On general examination, the patient
had grade IV facial nerve palsy (Figure 1). Taste Sensation and
lacrimation on ipsilateral side was decreased. Schirmer’s test
done showed less than 5 on schirmer’s strip. Examination of
other cranial nerves was normal. On otoendoscopic
examination, patient had Grade 1 retraction on left side and
the right ear was normal. (Figure 2) Pure tone audiogram done
showed profound Sensoneural hearing loss in Left ear. (Figure
3) Patient had no significant past history. Routine
hematological tests were within the normal limits.
Figure 1. Facial nerve Palsy.

2 Rauf Ahmed et al.: Rare Cause of Facial Nerve Palsy (Petrous Apex Cholesteatoma)–Case Report and Review of Literature
Figure 2. Right Ear Otoendoscopic view Left Ear.
Figure 3. Pure Tone Audiometry.
3. Investigations
Radiographic investigations were carried out to confirm
type and extent of the lesion.
CEMRI was done which showed evidence of 32*20*13 mm
expansile soft tissue lesion involving petrous part of Left
Temporal bone with no significant post contrast enhancement.
Lesion was causing erosion of tegmen tympani, posterior
cortex of Petrous bone, head of malleus, body of incus and
extending into internal auditory canal, vestibule, middle turn
of cochlea and facial nerve canal. No enhancement was seen
on T1 post contrast.
T1 NON CONTRAST
T1 POST CONTRAST (NO ENHANCMENT)
Figure 4. Contrast Enhanced MRI.

Clinical Neurology and Neuroscience 2019; 3(1): 1-5 3
T2
DWI IMAGE
Figure 5. T2 and DWI imaging.
HRCT Temporal bone was done which showed lesion
Involving petrous part of temporal bone on left side extending
through epitympanum causing erosion tegmen tympani, head
of malleus and body of incus.
CORONAL VIEW
AXIAL VIEW
Figure 6. HRCT Temporal bone.
Table 1. Imaging features of petrous apex lesions.
Petrous apex lesion
MRI T1 W MRI T2W Other MRI Features CT
Schwannoma Isointense to brain Hypo or Hyperintense Homogenous enhancment Expansile, minimally erosive,
isodense
Mucocele Isointense or hyperintense
(depends on ptotein conc) Hyperintense Periphral enhancment Destroyed septa
Chondrosarcoma Isointense Hyperintense Avid enhancment Detroys bone, Ring and arc
appearance
Cholesteatoma Hypointense Hyperintense No enhancement, DWI shows
restricted diffusion Smooth erosion of bone
4. Treatment
Surgical removal of the petrous apex Cholestetoma was
done. Transchochlear translabrynthine approach was followed.
Cul de sac closure was done. Bills Island was created. (Figure
6, 7) Cholestetoma was seen eroding Tegmen plate, and going
deep to sigmoid sinus plate. It was also seen reaching deep to
anterior wall close to carotid artery, Eustachian tube, root of
zygoma, and was seen reaching to trautmans triangle and
petrous apex over posterior fossa dura. Facial nerve was seen
to be non viable in labyrinthine segment. All the efforts were
taken towards complete surgical removal of Cholestetoma.
Obliteration of the cavity was done using abdominal fat. Post

4 Rauf Ahmed et al.: Rare Cause of Facial Nerve Palsy (Petrous Apex Cholesteatoma)–Case Report and Review of Literature
operatively patient was relieved of tinnitus. Facial paralysis
and hearing didn’t improve and was same as pre operative.
Histopathology was suggestive of Cholestetoma.
Figure 7. Shows site of Incision.
Figure 8. (Bills island).
Figure 9. Intra op findings.
5. Discussion
Congenital Cholestetoma of petrous apex is rare.
Cholesteatoma of petrous apex has two different origins,
congenital, and acquired. Congenital Cholestetoma is believed
to arise from squamous cell rest. [1] In fetal life there is a close
relation of tympanic ring with internal auditory canal that
makes migration of external canal ectoderm possible. 83-94%
presents with sensorineural hearing loss and 20-25% presents
with lower motor neuron facial paralysis. Imaging techniques
have critical roles on management and surgical outcome of
petrous apex Cholestetoma. Computed Tomography and MRI
are the best modalities for definition of petrous apex lesions,
differential diagnosis or making a decision for surgical
approach and to see the recurrences. On temporal bone CT,
there is a smooth expansile lesion of the petrous apex . The
central portions of the lesion shows no calcification or bony
matrix. On MRI, Cholestetoma typically is hypo intense on T1,
hyper intense on T2, And intermediate in signal on FLAIR
images (12). Diffusion restriction is reported to be characteristic
of this lesion. After contrast administration, there may be subtle
peripheral rim enhancement. [2, 3] Diffusion-weighted imaging
is useful in diagnosis of Cholestetoma, as the lesions often show
restricted diffusion, a feature that can be particularly beneficial
in detection of recurrent Cholestetoma after surgical resection.
Pandya etal [4] described some points that must be taken into
considerations when treating patient with petrous apex
Cholestetoma. These are
i Complete eradication of the disease
ii Preservation of facial nerve function
iii Prevention of CSF leakage and meningitides; and
iv Cavity obliteration.
(10) Hearing preservation is not the primary aim of
treatment after radical removal of Cholestetoma. Tran mastoid
Tran labyrinthine approach with or without Tran cochlear
approach is the basic surgery for removal. However these
approaches are insufficient to remove Cholestetoma situated
deep in petrous apex and adherent to middle cranial fosse dura
so middle cranial fossa approach is advised for such cases. [5]
Despite use of different surgical techniques, recurrence is still
a big problem. The most important reasons for this problem
are incomplete removal of Cholestetoma because of critical
structures like dura, facial nerve, carotid artery etc. Therefore,
an endoscopic examination with 30 degree and/or 45 degree
endoscopes should be done after removing the Cholestetoma
in terms of residual Cholestetoma. [6, 8, 9] Generally, it is
hard to preserve hearing level in transotic approach, Trans
labyrinthine or Tran’s cochlear approaches. The aim of
complete eradication of disease nessacites scarifying the
labyrinth. When facial nerve is damaged in extensive
Cholestetoma of petrous apex, literature suggests even
sacrificing official nerve which has residual function for
complete eradication. [7, 10, 11]
6. Conclusion
It is hard to manage the Cholestetoma located in petrous

Clinical Neurology and Neuroscience 2019; 3(1): 1-5 5
part of temporal bone because of vital structures. So that,
advanced imaging techniques are required for describing the
pathology and planning the surgical approach. In addition, a
proper classification depending on extent of pathology should
be done before the surgery and patient should be informed
about surgical outcomes.
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