dehiscent jugular bulb
The estimated incidence is ~5% (range 3.5-7%) of the symptomatic population (e.g. those with tinnitus) .
It is one of the causes of pulsatile tinnitus and is a common cause of a retrotympanic vascular mass.
Patients can present with conductive hearing loss. This may occur when the jugular bulb contacts the tympanic membrane, interferes with the ossicular chain, or obstructs the round window .
- given the often turbulent flow within the jugular bulb, the signal on MRI can be confusing
- the presence of the sigmoid plate can only be ascertained on CT
- high riding jugular bulb: intact sigmoid plate
- glomus jugulare / tympanicojugulare paragangliomas: adjacent destructive bone changes
Clearly, if it is mistaken for a middle ear tumor and biopsied, then the consequences can be disastrous (as is biopsying an aberrant internal carotid artery).
- Cavum tympani
- aberrante Arteria carotis interna
- sigmoid plate
- pulssynchrones Ohrgeräusch
- jugular foramen schwannoma
- jugular diverticulum
- jugular foramen meningioma
- Protrusion des Bulbus jugularis in das Tympanon