3. Anatomy of Facial nerveAnatomy of Facial nerve
The facial nerve contains approximately 10,000 fibersThe facial nerve contains approximately 10,000 fibers
7000 myelinated fibers innervate the muscles of facial7000 myelinated fibers innervate the muscles of facial
expression, stapedius muscle, postauricular muscles,expression, stapedius muscle, postauricular muscles,
posterior belly of digastric muscle, and platysmaposterior belly of digastric muscle, and platysma
3000 fibers form the nervus intermedius3000 fibers form the nervus intermedius ((Nerve ofNerve of
WrisbergWrisberg))
sensory fiberssensory fibers ((tastetaste)) from the anterior 2/3 of the tonguefrom the anterior 2/3 of the tongue
taste fibers from soft palate via palatine and greater petrosaltaste fibers from soft palate via palatine and greater petrosal
nervenerve
parasympathetic secretomotor fibers to the parotid,parasympathetic secretomotor fibers to the parotid,
submandibular, sublingual, and lacrimal glandsubmandibular, sublingual, and lacrimal gland
6. Nuclear segmentNuclear segment
Facial motor nucleusFacial motor nucleus
lower 1/3 of Ponslower 1/3 of Pons
abducent nucleusabducent nucleus
Out from brain stem at pons recess betweenOut from brain stem at pons recess between
olive andolive and inferior cerebellar peduncleinferior cerebellar peduncle
7.
8. Nervous intermediusNervous intermedius
Parasympathetic secretory fibers arise fromParasympathetic secretory fibers arise from
superior salivatory nucleussuperior salivatory nucleus
These preganglionic fibers travel to theThese preganglionic fibers travel to the
submandibular ganglion via the chordasubmandibular ganglion via the chorda
tympani nerve to innervate thetympani nerve to innervate the
submandibular and sublingual glandssubmandibular and sublingual glands
And to sphenopalatine ganglion via greaterAnd to sphenopalatine ganglion via greater
superficial petrosal nerve to innervatesuperficial petrosal nerve to innervate
lacrimal, nasal, and palatine glandlacrimal, nasal, and palatine gland
9. Nervous intermediusNervous intermedius
Secretory fibers of lesser superficialSecretory fibers of lesser superficial
petrosal nerve tranverse tympanic plexus,petrosal nerve tranverse tympanic plexus,
synapse in otic ganglion, and travel viasynapse in otic ganglion, and travel via
auriculotemporal nerve to innervateauriculotemporal nerve to innervate
parotid glandparotid gland
Taste fibers from anterior 2/3 of tongueTaste fibers from anterior 2/3 of tongue
reach geniculate ganglion via chordareach geniculate ganglion via chorda
tympani nerve and from there travel to thetympani nerve and from there travel to the
nucleus of the tractus solitariusnucleus of the tractus solitarius
12. Cerebellopontine angleCerebellopontine angle
The facial nerve and nervus intermedius exit theThe facial nerve and nervus intermedius exit the
brain stem at the pontomedullary junction andbrain stem at the pontomedullary junction and
travel with CN VIII to enter the internaltravel with CN VIII to enter the internal
acoustic meatusacoustic meatus
14. Labyrinthine segmentLabyrinthine segment
Fallopian canalFallopian canal
Shortest & Narrowest partShortest & Narrowest part
Temporal boneTemporal bone
Facial nerve enter fallopian canal until middle earFacial nerve enter fallopian canal until middle ear
First genuFirst genu
Geniculate ganglionGeniculate ganglion
BranchesBranches
Greater superficial petrosal nerveGreater superficial petrosal nerve lacrimallacrimal
glandgland
Lessor superficial petrosal nerveLessor superficial petrosal nerve parotid glandparotid gland
15.
16. Tympanic segmentTympanic segment
FirstFirst genugenu above oval windowabove oval window stapesstapes
Second genu beyond middle earSecond genu beyond middle ear
Out of cranium through stylomastoid foramenOut of cranium through stylomastoid foramen
17. Mastoid segmentMastoid segment
Stylomastoid foramenStylomastoid foramen
BranchesBranches
Motor nerve to stapedius muscleMotor nerve to stapedius muscle
Chorda tympani nerve betweenChorda tympani nerve between malleus andmalleus and
incusincus
secretomotor : Submandibular & Sublingual glandsecretomotor : Submandibular & Sublingual gland
taste fiber : anterior 2/3 of tonguetaste fiber : anterior 2/3 of tongue
18.
19. Extracranial segmentExtracranial segment
Posterior auricular nerve :Posterior auricular nerve : auricularisauricularis,, occipitalisoccipitalis
and sensation at auricular, post auricular areaand sensation at auricular, post auricular area
Branch to posterior belly of digastric muscle andBranch to posterior belly of digastric muscle and
stylohyoid musclestylohyoid muscle
TTemporalemporal branchbranch : muscle above: muscle above zygomazygoma
ZZygomaticygomatic branch :branch : orbicularisorbicularis occlioccli
BBuccaluccal branch :branch : buccinatorbuccinator and upper lipand upper lip
MMarginal mandibulararginal mandibular branch :branch : orbicularis orisorbicularis oris andand
lower liplower lip
CCervicalervical branch :branch : platysmaplatysma
20.
21.
22. PhysiologyPhysiology
EfferentEfferent fibersfibers : from the motor nucleus: from the motor nucleus
innervate muscles of facial expression, post-innervate muscles of facial expression, post-
auricular, stylohyoid, posterior digastric, andauricular, stylohyoid, posterior digastric, and
stapedius musclesstapedius muscles
EfferentEfferent fibersfibers : ANS: ANS ((preganglionicpreganglionic
parasympathetic fiberparasympathetic fiber))
sphenopalatine ganglion to lacrimal glands andsphenopalatine ganglion to lacrimal glands and
mucinous glands of nosemucinous glands of nose
submandibular ganglionsubmandibular ganglion toto submandibular andsubmandibular and
sublingual glandssublingual glands
23. AfferentAfferent fibersfibers convey taste from anteriorconvey taste from anterior
two-thirds of tongue to nucleus tractustwo-thirds of tongue to nucleus tractus
solitarius via lingual nerve, chorda tympani,solitarius via lingual nerve, chorda tympani,
and nervus intermedius.and nervus intermedius.
Afferent fibersAfferent fibers mediate sensation frommediate sensation from
posterior external auditory canal, concha, earposterior external auditory canal, concha, ear
lobe, and deep parts of facelobe, and deep parts of face
PhysiologyPhysiology
24. ClassificationsClassifications of facial nerve injuryof facial nerve injury
SeddonSeddon classification of nerve injuryclassification of nerve injury
NeuropraxiaNeuropraxia
AxonotmesisAxonotmesis
NeurotmesisNeurotmesis
25. ClassificationsClassifications
Sunderland classification of nerve injurySunderland classification of nerve injury
1° damage1° damage = Compression= Compression
2° damage2° damage = Interruption of axoplasm= Interruption of axoplasm
33° damage° damage = Disruption of myelin= Disruption of myelin
4° damage4° damage = Disruption of perineurium,= Disruption of perineurium,
myelin and axonmyelin and axon
5° damage5° damage = Transection of nerve= Transection of nerve
28. DegenerationDegeneration
Interruption of the continuity of the axonInterruption of the continuity of the axon
separates the distal axon from its metabolic sourseparates the distal axon from its metabolic sour
ce, the neuron or cell bodyce, the neuron or cell body
Wallerian degenerationWallerian degeneration of the distal axon andof the distal axon and
myelin sheath begins withinmyelin sheath begins within 2424 hourshours
Macrophages phagocytose degraded myelin andMacrophages phagocytose degraded myelin and
axonaxonss
29. RegenerationRegeneration
CompleteComplete
PartialPartial
Simple misdirectionSimple misdirection
Clinical expression: synkinesis or associatedClinical expression: synkinesis or associated
movementmovement
Complex misdirectionComplex misdirection
Clinical expression: mass movementClinical expression: mass movement
39. Evaluation of Facial paralysisEvaluation of Facial paralysis
Clinical featureClinical feature
CentralCentral VSVS Peripheral facial paralysisPeripheral facial paralysis
Complete head and neck examinationComplete head and neck examination
Cranial nerve evaluationCranial nerve evaluation
Electrodiagnostic testingElectrodiagnostic testing
Topographic diagnosisTopographic diagnosis
40. Central facial paralysisCentral facial paralysis
Upper motor neurone lesionUpper motor neurone lesion
Movements of the frontal and upper orbicularisMovements of the frontal and upper orbicularis
oculi tend to be sparedoculi tend to be spared
Because of uncrossed contributions fromBecause of uncrossed contributions from
ipsilateral supranuclear areasipsilateral supranuclear areas
Involvement of tongueInvolvement of tongue
Involvement of lacrimation and salivationInvolvement of lacrimation and salivation
41. Peripheral paralysisPeripheral paralysis
Lower motor neurone lesionLower motor neurone lesion
At rest :At rest :
less prominent wrinkles on forehead ofless prominent wrinkles on forehead of
affected side, eyebrow drop, flattenedaffected side, eyebrow drop, flattened
nasolabial fold, corner of mouth turned downnasolabial fold, corner of mouth turned down
Unable to :Unable to :
wrinkle forehead, raise eyebrow, wrinklewrinkle forehead, raise eyebrow, wrinkle
nasolabial fold, purse lips, show teeth, ornasolabial fold, purse lips, show teeth, or
completely close eyecompletely close eye
42.
43. HouseHouse--Brackmann grading systemBrackmann grading system
Grade IGrade I -- NormalNormal
Grade IIGrade II -- Mild dysfunction, slight weakness on closeMild dysfunction, slight weakness on close
inspection, normal symmetry at restinspection, normal symmetry at rest
Grade IIIGrade III -- Moderate dysfunction, obvious but notModerate dysfunction, obvious but not
disfiguring difference between sides, eye can bedisfiguring difference between sides, eye can be
completely closed with effortcompletely closed with effort
Grade IVGrade IV -- Moderately severe, normal tone at rest,Moderately severe, normal tone at rest,
obvious weakness or asymmetry with movement,obvious weakness or asymmetry with movement,
incomplete closure of eyeincomplete closure of eye
Grade VGrade V -- Severe dysfunction, only barely perceptibleSevere dysfunction, only barely perceptible
motion, asymmetry at restmotion, asymmetry at rest
Grade VIGrade VI -- No movementNo movement
44. Topographic DiagnosisTopographic Diagnosis
To determine the anatomical level of aTo determine the anatomical level of a
peripheral lesionperipheral lesion
LacrimationLacrimation Geniculate ganglionGeniculate ganglion
Stapedius reflexStapedius reflex motor nerve of stapediusmotor nerve of stapedius
musclemuscle
TasteTaste chorda tympanichorda tympani
45. Schirmer'sSchirmer's TestTest
Geniculate ganglion & petrosal nerve function testGeniculate ganglion & petrosal nerve function test
Schirmer’s test +veSchirmer’s test +ve whenwhen
Affected side showsAffected side shows less than halfless than half thethe
amount of lacrimation seen on the normalamount of lacrimation seen on the normal
sideside
Sum of the lengthsSum of the lengths of wetted filter paper forof wetted filter paper for
both eyesboth eyes less than 25 mmless than 25 mm
Lesion at or proximal to theLesion at or proximal to the geniculate gangliongeniculate ganglion
46. Stapedius reflexStapedius reflex
Nerve to stapedius muscle testNerve to stapedius muscle test
Impedance audiometry can record theImpedance audiometry can record the
presence or absence of stapedius musclepresence or absence of stapedius muscle
contraction to sound stimuli 70 to 100 dBcontraction to sound stimuli 70 to 100 dB
above hearing thresholdabove hearing threshold
AnAn absence reflexabsence reflex or aor a reflex less than half thereflex less than half the
amplitudeamplitude is due to ais due to a lesion proximal tolesion proximal to
stapedius nervestapedius nerve
47. Taste (Electrogustometry)Taste (Electrogustometry)
Chorda tympani nerveChorda tympani nerve testtest
Solution of salt, sugar, citrate, quinine or ElectricalSolution of salt, sugar, citrate, quinine or Electrical
stimulationstimulation
ComparesCompares amount of current require for a responseamount of current require for a response
each side of tongueeach side of tongue
Normal :Normal : difference < 20 uAmpdifference < 20 uAmp ((thresholds differening bythresholds differening by
more than 25%= abnormalmore than 25%= abnormal))
Total lack of Chorda tympani :Total lack of Chorda tympani : No response at 300No response at 300
uAmpuAmp
Disadvantage : False +ve in acute phase of Bell’sDisadvantage : False +ve in acute phase of Bell’s
palsypalsy
57. Idiopathic facial palsy (Bell's Palsy)Idiopathic facial palsy (Bell's Palsy)
Most common cause of facial paralysisMost common cause of facial paralysis (>50% of case)(>50% of case)
Most ageMost age 25-3025-30 yrs.yrs.
Male : FemaleMale : Female = 1 : 1= 1 : 1
Left side : Right side = 1 : 1Left side : Right side = 1 : 1
Unilateral > bilateralUnilateral > bilateral
Increase risk inIncrease risk in
pregnancy 3.3 timespregnancy 3.3 times
DM 4.5 timesDM 4.5 times
Recurrent rate 10%Recurrent rate 10%
60% have previous URI60% have previous URI
59. DiagnosisDiagnosis
By exclusionBy exclusion
Criteria :Criteria :
Paralysis or paresis of all muscle groups ofParalysis or paresis of all muscle groups of
one side of the faceone side of the face
Sudden onsetSudden onset
Absence of signs of CNS diseaseAbsence of signs of CNS disease
Absence of signs of ear or CPA diseaseAbsence of signs of ear or CPA disease
60. Medical treatmentMedical treatment
CCorticosteroidsorticosteroids ::
prednisoloneprednisolone 11 mg/kg/day 7-10 daysmg/kg/day 7-10 days
CCorticosteroidsorticosteroids combine withcombine with antivirantiviralal
drug is betterdrug is better
AAcyclovircyclovir 400400 mgmg 55 times/daytimes/day
FFamcicloviramciclovir andand valacyclovirvalacyclovir 500500 mgmg bidbid
61. Surgical treatmentSurgical treatment
Facial nerve decompressionFacial nerve decompression
IndicationIndication
Completely paralysisCompletely paralysis
ENOGENOG less than 10% in 2 weeksless than 10% in 2 weeks
Appropriate time for surgery is 2-3 weeksAppropriate time for surgery is 2-3 weeks
after paralysisafter paralysis
62. Herpes Zoster OticusHerpes Zoster Oticus
((Ramsay Hunt SyndromeRamsay Hunt Syndrome))
33rdrd
most common of peripheral facial paralysismost common of peripheral facial paralysis
(10%)(10%)
AgedAged > 60 yrs.> 60 yrs. or low immune (low CMIR)or low immune (low CMIR)
Virus travels to the dorsal root extramedullaryVirus travels to the dorsal root extramedullary
cranial nerve ganglioncranial nerve ganglion
Infected of HZV at auricular, external canal orInfected of HZV at auricular, external canal or
faceface
Prodromal symptoms very similar to those seen inProdromal symptoms very similar to those seen in
Bell's palsyBell's palsy
but usually more severebut usually more severe
63. Herpes Zoster OticusHerpes Zoster Oticus
((Ramsay Hunt SyndromeRamsay Hunt Syndrome))
Symptoms include severe otalgia, facial paralysis,Symptoms include severe otalgia, facial paralysis,
facial numbness, and a vesicular eruption on thefacial numbness, and a vesicular eruption on the
concha, external auditory canal, and palateconcha, external auditory canal, and palate
Facial paralysis + hearing loss + vertigoFacial paralysis + hearing loss + vertigo
““canal paralysiscanal paralysis””
Pathophysiology & treatment liked in Bell ’sPathophysiology & treatment liked in Bell ’s
palsypalsy
64. Temporal bone fracturesTemporal bone fractures
Longitudinal fractureLongitudinal fracture
Transverse fractureTransverse fracture
Mixed fractureMixed fracture
65. Temporal bone fracturesTemporal bone fractures
SignsSigns
bleeding from the external canalbleeding from the external canal
hemotympanumhemotympanum
step-deformity of the osseous canalstep-deformity of the osseous canal
conductive hearing loss (longitudinal fracture)conductive hearing loss (longitudinal fracture)
sensorineural hearing loss (transverse fracture)sensorineural hearing loss (transverse fracture)
CSF otorrheaCSF otorrhea
facial nerve involvement (20% of longitudinalfacial nerve involvement (20% of longitudinal
fractures and 50% of transverse fractures)fractures and 50% of transverse fractures)
66. Longitudinal VS TransverseLongitudinal VS Transverse
Type ofType of
injuryinjury
LongitudinalLongitudinal TransverseTransverse
IncidenceIncidence 70-90%70-90% 10-20%10-20%
Site of injurySite of injury Temporal ,Temporal ,
Parietal areaParietal area
Occipital ,Occipital ,
Frontal areaFrontal area
67. Origin ofOrigin of
fracture sitefracture site
TemporalTemporal
squamasquama
ForamenForamen
magnummagnum
Direction ofDirection of
injuryinjury
PosterosuperiorPosterosuperior
of EAC crossof EAC cross
roof of middleroof of middle
ear alongear along
carotid canalcarotid canal
anterior toanterior to
labyrinthinelabyrinthine
capsulecapsule
Between variousBetween various
foramen Jugularforamen Jugular
F. HypoglosalF. Hypoglosal
F. LabyrinthineF. Labyrinthine
capsulecapsule
71. PrognosisPrognosis
IImmediate onset paralysismmediate onset paralysis : poor: poor prognosisprognosis
DDelayed onset paralysiselayed onset paralysis : good prognosis: good prognosis
All case ofAll case of paralysisparalysis electrical testingelectrical testing
72. TreatmentTreatment
SurgSurgery is treatment of choiceery is treatment of choice
Indications for facial nerve explorationIndications for facial nerve exploration
incomplete paralysisincomplete paralysis
iatrogenic paralysisiatrogenic paralysis
ContraindicationsContraindications :: any case have noany case have no
poor prognostic factorspoor prognostic factors
73. ComplicationsComplications
Complications of facial nerveComplications of facial nerve
decompressiondecompression
dural tearsdural tears
conductive or sensorineural hearing lossconductive or sensorineural hearing loss
vestibular function lossvestibular function loss
persistent CSF leakspersistent CSF leaks
meningitismeningitis
injury to the anterior inferior cerebellar arteryinjury to the anterior inferior cerebellar artery
(AICA) or its branches(AICA) or its branches