Abstract
This case report describes a patient who was found to have a cerebrospinal fluid (CSF) leak originating from the petrous apex. The patient initially presented with multiple bouts of meningitis. The patient was treated surgically via a middle cranial fossa approach but presented five years later with recurrent meningitis and was found to have an osseous defect of the petrous apex which was not recognized prior to the initial surgery.
1
Introduction
Cerebrospinal fluid (CSF) otorrhea develops when there is an abnormal communication between the subarachnoid space and the aerated confines of the temporal bone. Common causes of temporal bone CSF leaks include aberrant arachnoid granulations, idiopathic intracranial hypertension (IIH), trauma, iatrogenic injury, and congenital malformations. CSF leaks caused by arachnoid granulations or IIH are classified as “spontaneous” . Spontaneous leaks are challenging to diagnose, as they are commonly misdiagnosed as chronic serous otitis media. Generally, the diagnosis is made by the presence of B2-transferrin in the middle ear fluid. The most significant complication of persistent CSF otorrhea is meningitis, which may be the initial presentation in some patients .
The present case describes a unique posterior fossa defect with an associated meningocele arising in the petrous apex just superior to the internal auditory canal.
2
Case report
A 61-year-old female presented with a history of recurrent meningitis and a persistent middle ear effusion. She was initially evaluated in 2006 after her first two episodes of meningitis and underwent a left middle fossa approach. Her initial computed tomography (CT) and magnetic resonance imaging (MRI) scans revealed a small defect along the floor of the middle fossa. A small osseous defect on the superior surface of the petrous apex was sealed with bone wax and covered with fascia at her initial surgery. She had an uncomplicated hospital course and was discharged on post-operative day two. Her middle ear effusion resolved and she maintained her normal state of health until she developed a left ear infection that progressed to meningitis in 2013. She was admitted to the hospital for eight days and was treated with intravenous antibiotics followed by fifteen days of rehabilitation.
At presentation she reported daily rhinorrhea from both nostrils when she leaned forward or bent over. She also reported bilateral hearing loss and bilateral aural fullness, left worse than right. Examination revealed an amber-appearing middle ear effusion on the left side. Left tympanocentesis was performed and the middle ear fluid was analyzed for β 2 -transferrin, which was negative. CT of the temporal bones revealed partial bilateral mastoid opacification and a defect in the left medial aspect of the petrous apex just superior to the porus acusticus. The air cells adjacent to the petrous apex defect were opacified, consistent with a possible osseous and dural dehiscence involving the left petrous apex ( Fig. 1 A and B ).
The patient underwent a revision surgery via a preauricular middle fossa approach. The superior aspect of the petrous apex was opened with an otologic drill exposing the superior surface of the internal auditory canal. A meningocele with CSF leakage emanating through an osseous defect in the medial petrous apex superior to the internal auditory canal was identified ( Fig. 2 ). The meningocele was reduced and the defect was plugged with an abdominal fat graft and fibrin glue. Post-operative imaging revealed fat filling the petrous apex up to the osseous defect and mild pneumonocephalus ( Fig. 1 C). The patient had an uneventful hospital course and was discharged three days after surgery.
The patient experienced transient dizziness and headaches after surgery with eventual resolution of her middle ear effusion. A lumbar puncture performed approximately six weeks after surgery demonstrated a normal opening pressure of 11 cm H 2 O.
2
Case report
A 61-year-old female presented with a history of recurrent meningitis and a persistent middle ear effusion. She was initially evaluated in 2006 after her first two episodes of meningitis and underwent a left middle fossa approach. Her initial computed tomography (CT) and magnetic resonance imaging (MRI) scans revealed a small defect along the floor of the middle fossa. A small osseous defect on the superior surface of the petrous apex was sealed with bone wax and covered with fascia at her initial surgery. She had an uncomplicated hospital course and was discharged on post-operative day two. Her middle ear effusion resolved and she maintained her normal state of health until she developed a left ear infection that progressed to meningitis in 2013. She was admitted to the hospital for eight days and was treated with intravenous antibiotics followed by fifteen days of rehabilitation.
At presentation she reported daily rhinorrhea from both nostrils when she leaned forward or bent over. She also reported bilateral hearing loss and bilateral aural fullness, left worse than right. Examination revealed an amber-appearing middle ear effusion on the left side. Left tympanocentesis was performed and the middle ear fluid was analyzed for β 2 -transferrin, which was negative. CT of the temporal bones revealed partial bilateral mastoid opacification and a defect in the left medial aspect of the petrous apex just superior to the porus acusticus. The air cells adjacent to the petrous apex defect were opacified, consistent with a possible osseous and dural dehiscence involving the left petrous apex ( Fig. 1 A and B ).
