Presentation
Vertigo and headache for years.
Patient Data
A prominent vein is identified in the posterior right temporal bone (red arrow). This represents a collateral vessel from the right sigmoid sinus and there appears to be congenital hypoplasia of the upper portion of the right internal jugular vein and distal sigmoid sinus. The right jugular foramen is rudimentary with the left foramen being dominant. There is mild mucoperiosteal thickening identified in the right middle ear with hypoplasia of the right mastoid air cells.
Case Discussion
Enlarged emissary veins that normally involute during development can be a dominant draining source to the internal jugular vein when associated with a hypoplastic sigmoid venous sinus or jugular foramen1.
This non-contrasted CT suggests the presence of a trans-mastoid emissary vein collateral. Further imaging is required to confirm this diagnosis.
The patient's complaint of tinnitus may be secondary to the prominent trans-mastoid emissary vein, or the vein may be of no consequence.