title: A Life Threatening Pitfall in Ear Surgery: Extracranial Sigmoid Sinus.
abstract: OBJECTIVE
  The aim of this article is to imply the significance of temporal bone computed tomography imaging before temporal surgeries.
  
  
  METHODS
  A 74-years-old patient was admitted to emergency department with dizziness and nausea. The neurologic examination showed a spontaneous nystagmus, whereas otologic examination revealed a left tympanic membrane perforation with mild discharge. A temporal bone computed tomography imaging was scheduled to exclude cholesteatoma and perilymphatic fistula. Computed tomography detected an anterior sigmoid sinus with middle fossa defect and subcutaneous course of the sinus in posterior-superior portion of the external ear canal skin with no cholesteatoma sign. Thus, Dix-Hallpike was performed on the patient and was positive on the right side. The patient was diagnosed as benign positional vertigo.
  
  
  CONCLUSIONS
  Sigmoid sinus is an important landmark in otologic surgeries and in some patients it may be problematic because of its dehiscence. To avoid any surgical complications it is highly important to evaluate a temporal bone computed tomography imaging before any transmastoid, retroauricular and edoaural surgeries.
authors.affiliation: *Ear Nose and Throat Department, Ozel Kucukyali Delta Hospital, Istanbul †Ear Nose and Throat Department, Adiyaman University Training and Research Hospital, Adiyaman, Turkey.
authors.forename: Osman Halit
authors.initials: OH
authors.lastname: Çam
authors.forename: Mehmet
authors.initials: M
authors.lastname: Karataş
mesh_terms: D000368:Aged; D065635:Benign Paroxysmal Positional Vertigo / Q000175:diagnosis; D003392:Cranial Sinuses / Q000002:abnormalities* / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D004244:Dizziness / Q000175:diagnosis; D004424:Ear Canal / Q000000981:diagnostic imaging; D006801:Humans; D009325:Nausea / Q000175:diagnosis; D013506:Otologic Surgical Procedures; D004856:Postural Balance / Q000502:physiology; D012678:Sensation Disorders / Q000175:diagnosis; D013701:Temporal Bone / Q000002:abnormalities* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods; D018058:Tympanic Membrane Perforation / Q000175:diagnosis