This document discusses symptoms of facial nerve injury based on the level of injury and methods for surgically identifying the facial nerve. It describes symptoms associated with injuries at different levels along the nerve pathway. It also outlines three methods used in surgery to identify the facial nerve, including following tissue planes and exposing bony landmarks. Furthermore, it compares and contrasts upper motor neuron and lower motor neuron lesions, describes Bell's palsy symptoms, and mentions other causes of facial nerve lesions like compression and lacerations.

1. SYMPTOMS ACCORDING TO
LEVEL OF INJURY
1.AT INTERNAL ACOUSTIC MEATUS
 LOSS OF LACRIMATION
 LOSS OF STAPEDIAL REFLEX
 LOSS OF TASTE SENSATION FROM ANTERIOR 2/3RD
OF TONGUE
 LACK OF SALIVATION
 FACIAL MUSCLE PARALYSIS

2. 2.BETWEEN GREATER PETROSAL NERVE & NERVE TO
STAPEDIUS OR BELOW GENICULATE GANGLION
 LOSS OF STAPEDIAL REFLEX
 LOSS OF TASTE SENSATION FROM ANT2/3RD OF TONGUE
 LACK OF SALIVATION
 FACIAL MUSCLE PARALYSIS
3.B/W NERVE TO STAPEDIUS & CHORDAE TYMPANI
 LOSS OF TASTE FROM ANTERIOR 2/3RD OF TONGUE
• FACIAL MUSCLE PARALYSIS
4. BELOW STYLOMASTOID FORAMEN
 PARALYSIS OF MUSCLE OF FACIAL EXPRESSION

3. SURGERY OF FACIAL NERVE
• TO IDENTIFY FACIAL NERVE 3 METHODS ARE USED
1.BLOOD FREE PLANE IMMEDIATE IN FRONT OF
CARTELAGENOUS EXTERNL ACOUSTIC MEATUS
CAN BE OPENED BY BLUNT DISSECTION
LEADS SURGEON TO SKILL BASES JUST BELOW
STYLOID PROCESS & STYLOMASTOID FORAMEN
OPENED UP IN INFERIOR DIRECTIONBY BLUNT
DISSECTION TILLL TRUNK IS ENCOUNTERED

4. 2.EXPOSURE OF ANTERIOR BORDER OF STM
JUST BELOW ITS INSERTION IN MASTOID PROCESS
RETRACT MUSCLE POSTERIOR TO EXPOSE POST
BELLEY OF DIGASTRIC

5. LESION OF FACIAL NERVE
1. UMN LESION
2. LMN LESION
3. BELLS PALSY
4. COMPRESSION OF FACIAL NERVE
5. CHEEK LACERATION

6. UMN LESION
• LESION IN UPPER MOTOR NEURON
C/F
1. PATIENTS CAN MAKE FURROWS ON LOOKING
UPWARDS
2. LOWER PART OF FACE IS INVOLVED IN SIDE
OPPOSITE TO LESION IS INVOLVED
3. THIS IS LESION ABOVE PONS

7. LMN LESION
• LESION IN LOWER MOYOR NEURON
• LESION IN PONS OR ITS PATHWAY
C/F
1. FURROWS ARE LOST ON LOOKING UPWRDS
2. WHOLE OF FACE & FORE HEAD IS INVOLVED IN
SAME SIDE OF LESION
3. ISOLATED LESION
4. ASSOCIATED WTH HEMIPLAGIA

8. BELL’S PALSY
• DRIBBLING OR DROOPING OF SALIVA FROM ANGLE
OF MOUTH ON AFFECTED SITE
• CREASE ON FACE OR SKIN FOLDS ARE EFFECTED
OR BLUNTED ON AFFECTED AREAS
• FOREHEAD IS UN FURROWED
• DIFFFICULT IN CLOSURE OF EYES
• FOOD COLLECTION B/W TEETH AND CHEEK
• ANGLE OF MOUTH DROOPS ON AFFECTED SITE
• NASOLABIAL FOLD IS EFFACED IN AFFECTED SITE
• UN ABLE TO BLOW CHEEK
• LOSS OF TASTE