title: Spontaneous intraparenchymal otogenic pneumocephalus: A case report and review of literature.
abstract: BACKGROUND
  Pneumocephalus is commonly associated with head and facial trauma, ear infection, or surgical interventions. Spontaneous pneumocephalus caused by a primary defect at the temporal bone level without association with pathological conditions is very rare. Few cases have been published with purely intraparenchymal involvement. We describe a rare case of spontaneous pneumocephalus arising from the mastoid cells with intraparenchymal location and present an extensive review of the existing literature.
  
  
  METHODS
  A 57-year-old woman presented a brief episode of sudden otalgia in her left ear that was followed by a motor aphasia. Imaging revealed a left temporal intraparenchymal pneumocephalus in a close relationship with a highly pneumatized temporal bone. Left temporal craniotomy and decompression were performed. Further subtemporal exploration confirmed a dural defect and other osseous defects in the tegmen tympani, which were both consequently closed watertight.
  
  
  CONCLUSIONS
  Although extremely rare, a spontaneous intraparenchymal pneumocephalus with mastoidal origin should be considered as a possible diagnosis in patients with suggestive otological symptoms and other non-specific neurological manifestations. Surgery is indicated to repair bone and dural defects.
authors.affiliation: Department of Neurosurgery, Hospital de Clínicas de Buenos Aires, Argentina.
authors.forename: Santiago G
authors.initials: SG
authors.lastname: Abbati
authors.forename: Rafael R
authors.initials: RR
authors.lastname: Torino