Case 1.  An 81-year-old gentleman complained of intermittent ear drainage from the left ear for about 25 years.  He has had myringotomy tubes for most of that time, reinserted periodically.  Without the tube, he had ear pressure and hearing loss.  With the tube, he had drainage that was occasionally purulent. Cultures showed E.coli, Klebsiella, and corynebacteria.  Various courses of oral and topical antibiotics did not relieve the drainage. On physical exam, the left eardrum was dull, and there was a patent myringotomy tube with scanty purulent drainage.  CT scan showed fluid in the mastoid cells and soft tissue in the attic without scutal erosion (Figure 1). 

Figure 1

A mastoidectomy was recommended. At surgery, there was a small encephalocele protruding through a 4 mm tegmen defect (arrow, Fig. 2), with intermittent CSF leakage.  The encephalocele stalk was fulgurated and the dura repaired with perichondrium and the tegmen with conchal cartilage.(Fig. 3).  An abdominal fat graft was placed in the mastoid cavity.  An indwelling myringotomy tube was left in place as a sentinel for continued CSF leakage.  

Figure 2                                                                              Figure 2

Postoperatively, his drainage immediately resolved and his hearing improved to normal (preoperatively he had a 35 dB conductive loss).  He has not re-leaked after 9 months of follow-up and he is very happy.  

This case illustrates that CSF leak should be suspected in all cases of chronic refractory otorrhea, even when the drainage is not clear or profuse.  The CT was not definitive, and although it did demonstrate a tegmen defect, this is not an unusual finding in chronic ear disease. The surgery proved the diagnosis and allowed a direct route for repair.  Temporal bone encephalocele with CSF leak can be treated through a transmastoid approach, with a success rate of about 90%.  In an older patient, the transmastoid approach avoids the potential morbidity of a craniotomy.  Failures have only occurred in patients with very large defects, chronically elevated ICP, and prior radiation, and these few were successfully treated via transcranial approach.

Case 2.   A 55 year old woman complained of pressure and hearing loss in the left ear for >10 years. An otolaryngologist originally diagnosed serous otitis media and performed a myringotomy tube. This led to continuous clear drainage. The tube was removed and the hearing loss recurred.  There was no history of headaches, neck stiffness, fever, otalgia, or visual changes.  Physical examination revealed clear fluid effusion in the left ear.  CT scan revealed diffuse opacification of the mastoid and middle ear, and a small tegmen tympani defect in the anterior part of the epitympanum, near the petrous apex.  MRI indicated a small encephalocele at the same location as the tegmen defect, and fluid in the middle ear and mastoid with the same imaging density as CSF.  CT-MRI fusion imaging indicated that the leak was coming from this location. 
     A myringotomy tube was performed and profuse clear drainage resulted. The fluid was positive for beta-2-transferrin.  A neurosurgical consult was obtained.  A transcranial repair was planned because of the anteromedial location of the leak. 
     The area was approached through a temporal craniotomy.  A lumbar drain was placed and immediately clamped. The tegmen defect and encephalocele were isolated through an extradural approach.  The tegmen was repaired with a split calvarial bone graft.  An epidural repair or the dura was attempted but the leak could not be controlled because of the medial location of the dural defect. An intradural approach was then performed, with secure placement of a graft of acellular dermis across the dural defect.  The repair was reinforced with a layer of abdominal fat and fibrin glue in the epidural space. The dural incision was closed in a watertight fashion, and the craniotomy with titanium mesh. The drain was left open for 3 days and the CSF leak resolved.  She was discharged from hospital and did well, with a dry ear and improvement in hearing. The myringotomy tube was left in place as a sentinel.  

After 3 months, she complained of intermittent clear drainage from the tube.  A fluid sample was positive for beta-2-transferrin.  CT-MRI fusion imaging revealed a fluid tract medial to the original repair, at the petrous apex at Meckel’s cave (Fig. 4). A ventriculoperitoneal shunt was performed and the leak resolved. 

Figure 4

This case illustrates that certain cases of CSF otorrhea can become chronic if they are not diagnosed.  A transcranial approach is necessary if the site of leakage cannot be accessed through the mastoid.  Increased intracranial pressure may be a cause of failure of direct repain, and may require the placement of a ventriiculoperitoneal shunt.