meningiomas: CT and MR appearances.
The horizontal segment lies inferior to the geniculate ganglion
and posteromedial to the eustachian tube and the greater superficial petrosal nerve.
In the vast majority of facial nerves (88%), the geniculate ganglion
is the major component of facial nerve sensory input; in 4% of facial nerves, the number of cells in the geniculate and meatal ganglia are approximately equal, and in 8%, the meatal ganglion is larger than the geniculate ganglion
Brain MRI has often demonstrated segmental enhancement of the VIIth and VIIIth cranial nerves, geniculate ganglion
, and membranous labyrinth, (3) but petrosal inflammation has only been reported once in Ramsay Hunt syndrome.
T1-weighted magnetic resonance imaging (MRI) with gadolinium contrast can demonstrate enhancement of the cochleovestibular complex, the facial nerve, and the geniculate ganglion
A facial nerve schwannoma was seen extending from the geniculate ganglion
to the parotid gland and terminating just proximal to the pesanserinus; the schwannoma was completely removed.
Between June 1, 1984, and June 30, 1993, we surgically treated 220 cases of traumatic facial paralysis with good cochlear reserve by decompressing the tympanic and mastoid segments via a transmastoid approach followed by decompression of the geniculate ganglion
and the distal half of the labyrinthine segment via a middle fossa approach.
5) In the middle ear or mastoid portion of the temporal bone, an intracranial meningioma can extend along the path of least resistance through a tegmen tympani to dehiscence, the sulci of the greater and lesser superficial petrosal nerves, the sigmoid sinus plate, the geniculate ganglion
area, the internal auditory canal, the lateral semicircular canal, and the perilabyrinthine cell tracts or jugular foramen.
1-3) Facial nerve hemangiomas arise from vascular plexuses distributed along the facial nerve paths in the geniculate ganglion
region, in the mastoid segment of the facial nerve near the origin of the chorda tympani, and in the internal auditory canal around Scarpa's ganglion.
The sensory root (nervus intermedius) consists of central processes of neurons located in the geniculate ganglion
and axons of parasympathetic neurons from the superior salivatory nucleus.
It entails facial nerve procedures medial to the geniculate ganglion
Although Bell palsy has been defined as idiopathic, there is now good evidence to implicate the activation of herpes simplex virus near the geniculate ganglion
as the cause of this disorder.
Facial nerve schwannomas have a predilection for the area of the geniculate ganglion
, although they can occur at any point along the nerve between its origin in the pons and its exit in the stylomastoid foramen and parotid segment.
The middle fossa approach provides neurotologic surgical access to lesions of the geniculate ganglion
and the labyrinthine portion of the facial nerve as well as to the internal acoustic canal, and therefore helps preserve cochlear function.
When the pain becomes intractable, an operation to surgically excise the nervus intermedius and geniculate ganglion
via the middle cranial fossa approach is indicated.