Sigmoid sinus dehiscence
Sigmoid sinus dehiscence, also known as sigmoid plate dehiscence, refers to a defect in the sigmoid plate such that the sigmoid sinus is not separated by bone from the air in the mastoid air cells.
Clinical presentation
Although patients may be asymptomatic, sigmoid sinus diverticulum and dehiscence, which many studies group together, is the most frequent venous cause of pulsatile tinnitus .
Radiographic features
CT
CT with or without contrast identifies the "air-on-sinus" sign, in which there is no bony separation between a lateral portion of the sigmoid sinus and the air within mastoid air cells .
Treatment and prognosis
Surgical treatment consists of sigmoid sinus wall reconstruction/resurfacing, using soft tissue graft, hydroxylapatite cement, and/or autologous bone pâté.
See also
