title: Persistence of multiple emissary veins of posterior fossa with unusual origin of left petrosquamosal sinus from mastoid emissary.
abstract: Emissary veins are valveless veins which pass through the cranial apertures and connect the dural venous sinuses and the extracranial veins. The clinical importance of emissary veins is increasingly being appreciated. Some emissary veins like the petrosquamosal sinus and mastoid emissary vein may cause significant bleeding during middle ear and skull base surgeries. A dilated mastoid emissary vein or condylar emissary vein can sometimes be a rare cause of tinnitus. Radiological identification of these venous channels has been described in recent years and assumes significance in light of their clinical importance. We describe the CT and MRI findings of a rare case that had persistence of multiple emissary veins and presented clinically with tinnitus. The radiological findings included a dilated left mastoid emissary vein, bilateral petrosquamosal sinuses, posterior condylar veins, occipital emissary veins and an intrapetrous venule. The left petrosquamosal sinus had an unusual origin from the dilated mastoid emissary vein. The patient also had major anomalies of posterior fossa venous sinuses which are discussed. A relevant review of literature is included.
authors: Department of Radiodiagnosis, Dr Rajendra Prasad Government Medical College-Tanda, Set No A3, Type IV Quarters, Kangra, Himachal Pradesh, India. narvirschauhan@yahoo.com
authors: Narvir Singh
authors: NS
authors: Chauhan
authors: Yash Paul
authors: YP
authors: Sharma
authors: Tilak
authors: T
authors: Bhagra
authors: Bindu
authors: B
authors: Sud
references: J Anat. 2006 Dec;209(6):711-20
references: 17118059
references: Am J Otol. 1986 May;7(3):204-7
references: 3717312
references: J Anat Physiol. 1914 Jan;48(Pt 2):107-73
references: 17232988
references: Eur J Radiol. 2005 Jun;54(3):335-43
references: 15899333
references: J Anat. 1930 Oct;65(Pt 1):108-21
references: 17104299
references: J Anat Physiol. 1881 Oct;16(Pt 1):27-42
references: 17231415
references: AJNR Am J Neuroradiol. 2001 Jun-Jul;22(6):1186-93
references: 11415917
references: AJNR Am J Neuroradiol. 2007 Jan;28(1):22-4
references: 17213417
references: Folia Morphol (Warsz). 2002;61(4):199-208
references: 12725485
references: J Otolaryngol. 1989 Aug;18(5):232-5
references: 2769838