The cochlear promontory is the rounded bony prominence on the medial wall of the middle ear cavity, produced by the basal turn of the cochlea immediately beneath. It forms the most prominent feature of the medial middle ear wall. Jacobson nerve (tympanic branch of CN IX) forms the tympanic plexus on its surface. The round window niche lies just inferior and posterior to the promontory, and the oval window superior to it.
The cochlear promontory is the surgical landmark for cochlear implantation: cochleostomy for electrode array insertion is performed anterior to the round window on the basal turn, precisely at the promontory level. Glomus tympanicum tumours arise from paraganglionic tissue on the tympanic plexus over the promontory, producing a red pulsatile middle ear mass visible through the tympanic membrane. Promontory stimulation testing (electrical stimulation of the cochlear nerve through the promontory) assesses auditory nerve viability before cochlear implant candidacy decisions.
Paraganglioma arising from the tympanic plexus on the cochlear promontory produces a vascular red pulsatile mass behind the tympanic membrane causing pulsatile tinnitus and conductive hearing loss, confirmed by CT showing a soft tissue mass on the promontory and managed by surgical excision through a transcanal or postauricular approach.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
