Facial Nerve Flashcards
Facial Nerve is mixed/motor /sensory?
Mixed but mainly motor
Sensory part of facial nerve is aka
Nerve of wrisberg/Nerve of intermedius
Bony canal that covers facial nerve
Fallopian canal
Where is Fallopian canal shortest and narrowest?
Labyrinthine segment
Most common Site where viral infection lead to compression and ischemia of facial nerve
Labyrinthine segment
Landmarks for facial nerve on medial wall of middle ear
Processus cochleriformis
Oval window
Lateral SCC
Most common site of dehiscence of fallopian canal
Horizontal segment
Vertical segment is located on which wall
Posterior wall of middle ear
Landmarks to define vertical segment of facial nerve location
Pyramid
Fossa incudis
Chorda tympani
Aditus
1st branch of facial nerve is given off from
1st genu -GSPN
Second branch is given at
At the pyramid -nerve to stapedius
Branch given just above stylomastoid foramen
Chorda tympani
What happens if 1st branch of facial nerve is damaged
Dry eye
Schirmers test
What happens if second branch is injured
Loss of stapedial reflex
Hyperacusis
Function of chorda tympani
Taste and salivation
What are the topodiagnostic test done to know the site of lesions of facial nerve
Schirmers
Stapedial
Taste
Salivation
Electrodiagnostic test will assess prognosis
What are the test done
ENG
EMG - fibrillation potential and action potential
why should we wait 3 days before performing ENG
Wallerian Degeneration
MC idiopathic facial nerve palsy
Bells palsy
Viral cause of Bell’s palsy
HSV1
Most common site for bells palsy
Labyrinthine segment
Symptoms of pt with bells palsy
Dry eye
Hyperacusis
Lack of taste and salivation in ant 2/3
Lmn palsy of one side of face
How to manage pt of bells palsy
Dose of steroid
And antiviral can be useful upto __ days
No hospitalization 1 mg/ kg steroid 3 days antiviral Physiotherapy nerve stimulation Eye care lubrication and padding
Idiopathic facial nerve palsy
Swelling of lips
Fissures of tongue
Melkerson Rosenthal syndrome
Infection of EAC leading to facial nerve palsy
Malignant otitis externa
Csom
Aom
Ramsay hunt syndrome due to herpes zoster
Mcc traumatic cause of facial nerve palsy
Surgical
Parotid > Mastoid
Which fracture of temporal bone is most common cause of f n palsy
Transverse fracture
Best investigation for trauma to temporal bone
Hrct
Important sign seen in temporal bone fracture
Battle sign
After surgery of parotid gland sudden onset facial palsy occurs. How to manage?
Immediate exploration
After surgery of parotid gland late onset facial palsy occurs. How to manage?
Steroids
Graft for facial nerve
a ) most common
b) Long graft
a greater auricular C2C3
b) sural
Aberrant regeneration can cause?
Synkinesis
Crocodile tears
What are crocodile tears
Where is the site of injury
Tearing with salivation
Before the origin of gspn i e labyrinthine segment or cp angle
What is frey syndrome
Gustatory sweating
Cause of frey syndrome
Injury to auriculotemporal nerve in parotid surgery
Aberrant regeneration
Nerve fibers Supplies sweat gland overlying parotid
Management of freys
Botox
Surgical - implantation below skin
Tympanic neurectomy
Incision for parotid surgery
Lazy S incision aka modified blaires incision
