Surgical Management of Spontaneous Acute Hydrocephalus and Intraventricular Pneumocephalus Secondary to Right Anterior Mastoid Tegmen Defect and Cystic Temporal Encephalomalacia

Introduction: Development of Spontaneous intraventricular otogenic pneumocephalus and acute hydrocephalus is extremely rare. The authors add to literature right middle fossa approach to repair of anterior mastoid tegmen defect that led to development of right temporal cystic encephalomalacia communicating with the temporal horn of right ventricle.

Methods: A 67-years old female presented to emergency room (ER) with one day history of acute onset of confusion and disorientation and severe headache after a bowel movement the night before. Patient was on airplane 2 weeks prior to presentation with severe headache. Patient had MRI study of brain that showed no acute abnormality 3 months prior to presentation for evaluation of right hearing loss.
CT and MRI study of brain with and without contrast in the ER showed large intraventricular pneumocephlaus, acute hydrocephalus, and right temporal cystic encephamalomalacia in close proximity to the right temporal horn of the ventricle. CT of temporal bones showed small amount of air adjacent to right anterior mastoid sinus suspicious for tegmen defect.

Results: Patient underwent placement of right frontal ventriculostomy. Cerebrospinal fluid cultures from the ventriculostomy showed no evidence of infection. Six days later, right middle fossa approach to exploration of right temporal cystic encephalomalacia and anterior mastoid sinus showed 5 mm anterior tegmen defect and encephalocoele. Right temporalis muscle and fascia were placed over the mastoid tegmen defect and covered with a thin plate of bone from the right craniotomy bone flap followed by application of Duraseal (Integra, Princeton, New Jersey).
Culture of right temporal cyst fluid was negative. Ventriculostomy was removed 4 days later and patient was discharged home. At 1 month follow-up, Head CT showed compete resolution of hydrocephalus and pneumocephalus and patient has returned to normal neurological condition.

Conclusion : Spontaneous intraventricular otogenic pneumocephalus and acute hydrocephalus can develop from mastoid sinus tegmen defect. Risk factors may include air plane travel as well as Valsava maneuver. Surgical management with urgent ventriculostomy and repair of mastoid tegmen defect can lead to excellent clincal outcome.