FacialNerveParalysis May 24, 2007 v. Rothholtz

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Facial Nerve Paralysis

Vanessa S. Rothholtz, M.D., M.Sc.

UCI Department of Otolaryngology -Head and Neck Surgery

May 24, 2007



Chief Complaint

My Starbucks caramel macchiatto dribbled

down my chin this morning, and it ruined

my white coat. Now my face isn’t working.Do I need a face lift?



History

Unilateral left-sided otalgia (TMJ)

Fever, chills

Headache Generalized fatigue

Conjunctivitis two weeks ago (resolved withantibiotics)

“My eczema acted up again last week, but itlooked a little different.”

Travel – Sonoma County for a friend’s wedding alast month



Physical

Eyes: Left eye with injected conjunctiva, pupils equaland reactive

Ears: EAC patent, TM c/m/i

Nares: Patent, clear

OC/OP: Dentition intact, tongue midline / mobile, Notonsillar hypertrophy

Face:

Normal tone and symmetry at rest

Obvious facial asymmetry with effort

No perceptible forehead movement

Incomplete eye closure

Asymmetrical motion of mouth with maximal effort



What grade of paralysis is this

based on the House-Brackmann

facial nerve grading scale?

IV



House-Brackmann Facial Nerve

Grading ScaleI Normal

II Normal tone and symmetry at rest

Slight weakness on close inspection

Good to moderate movement of forehead

Complete eye closure with minimum effort

Slight asymmetry of mouth with movement

III Normal tone and symmetry at rest

Obvious but not disfiguring facial asymmetry

Synkinesis may be noticeable but not severe

+/- hemifacial spasm or contractureSlight to moderate movement of forehead

Complete eye closure with effort

Slight weakness of mouth with maximumeffort

IV Normal tone and symmetry at rest

Asymmetry is disfiguring or results inobvious facial weakness

No perceptible forehead movement


Asymmetrical motion of mouth withmaximum effort

V Asymmetrical facial appearance atrest

Slight, barely noticeable movement

No forehead movement


Asymmetrical motion of mouth withmaximum effort



Differential DiagnosisV Anomalous sigmoid sinus, benign

intracranial hypertension, intratemporal

aneurysm of internal carotid artery,embolization for epistaxis (external carotid

artery branches)

I Malignant otitis externa, otitis media,

cholesteatoma, mastoiditis, meningitis,

parotitis, chicken pox, Ramsay Hunt

syndrome, encephalitis, poliomyelitis (typeI), mumps, mononucleosis, leprosy,

HIV/AIDS, influenza, Coxsackie virus,

malaria, syphilis, scleroma, TB, botulism,

mucormycosis, Lyme disease

T Cortical injuries, basilar skull fractures,

brainstem injuries, penetrating injury to

middle ear, facial injuries, altitude paralysis

(barotrauma), SCUBA diving (barotrauma)

A Temporal arteritis, periarteritis nodosa,

Multiple sclerosis, myasthenia gravis,

sarcoidosis, Wegener granulomatosis,

eosinophilic granloma

M Paget disease, osteopetrosis, diabetesmellitus, hyperthyroidism, pregnancy,

alcoholic neuropathy, bulbopontine paralysis, oculopharyngeal muscular dystrophy

I Bell palsy, Melkersson-Rosenthal syndrome(recurrent facial palsy, furrowed tongue),hereditary hypertrophic neuropathy,(Charcot-Marietooth disease, Dejerine-

Scottis disease), Landry-Guillain-Barresyndrome, Sarcoidosis, Kawasaki disease,surgery, embolization

N Acoustic neuroma, glomus jugulare tumor,leukemia, meningioma, hemangioblastoma,hemangioma, pontine glioma, sarcoma,hydradenoma, gacial nerve neuroma,

teratoma, fibrous dysplasia, vonRecklinghausen’s disease, carcinomatousencephalitis, cholesterol granuloma,carcinoma (invasive or metastatic)

C Molding, forceps delivery, myotoicdystrophy, Moebius syndrome

D Vaccine for rabies, Antitetanus serum,

mandibular block anesthesia



Course of the Facial Nerve Intracranial – Arises at the pontomedullary junction and

courses with CNVIII to the internal acoustic meatus - 12mm Meatal – Anterior to the superior vestibular nerve and

superior to the cochlear nerve – 10mm

Intratemporal –

Labyrinthe segment Passes through narrowest part of fallopian canal -

12mm

Narrowest part of facial nerve. The most susceptible tocompression secondary to edema.

Tympanic segment

From geniculate ganglion to pyramidal turn – 11mm

Mastoid segment

Exits the stylomastoid foramen – 13mm

Extracranial – From stylomastoid foramen to pes anserinus



The longest segment of the facial nerve is:

A. Vertical of mastoid portion

B. Cisternal portion

C. Tympanic portion

D. Portion in the IAC

Captier G. Organization and microscopic anatomy of the adult human

facial nerve: Anatomical and histological basis for surgery



Blood supply to facial nerve –

clinical relevance Courses between the epineurium and periosteum – making the blood supply

at risk when mobilizing at the first genu

Extrinsic

Stylomastoid artery (branch of the postauricular artery of external carotid artery)

Greater petrosal artery (branch of middle meningeal artery)

Internal auditory artery (branch of the AICA) Labyrinthe segment - lacks anastomosing arterial cascades thereby making

the area vulnerable to ischemia

* Parhizkar N, Hiltzik DH and Selesnick SH. Facial nerve rerouting in skull base

surgery. Otol Clin N Am. 2005; 38(4): 685-710



Work Up

Basic labs, thyroid function panel, Lyme titersELISA for antibodies

Audiogram Stapedial reflex

EKG

MRI with gadolinium / CT

Nerve Excitability Test, Maximal StimulationTest, Electroneuronography (EnoG) - Useful 72hours post-injury



Topognostic Testing

Schirmer test for lacrimation

Stapedial reflex test (stapedial branch)

Taste testing (chorda tympani nerve)

Salivary flow rates and pH (chorda

tympani)



Topognostic Testing

Schirmer Test

Greater superficial petrosal nerve

Filter paper is placed in the lower conjunctival fornix bilaterally

3- 5 minutes

Value of 25% or less on the involved side or total lacrimation less than 25 mm isconsidered abnormal.



Topognostic Testing

Stapedial Reflex

Stapedius branch of the facial nerve

Most objective and reproducible A loud tone is presented to either the ipsilateral or

contralateral ear evokes a reflex movement of thestapedius muscle changes the tension on the TM (whichmust be intact for a valid test) resulting in a change in theimpedance of the ossicular chain

If intact stapedial reflex, complete recovery can beexpected to begin within six weeks

Absence of the stapedial reflex during the first two weeks

in Bell’s Palsy is common



Topognostic Testing

Taste Testing

Chorda tympani

Extremely subjective

Papillae generally disappear within 10 days

post injury - middle 1/3 of the tongue is

most indicative, because the anterior 1/3

may receive bilateral input.



Topognostic Testing

Salivary flow rates

Chorda tympani

Cannulation of Wharton's ducts bilaterally

5 minute measurement of output

Significant if 25% reduction in flow of the

involved side as compared to the normal side Salivary pH Flow Rate



Nerve Excitability Test (NET)

Most predictive prognostic factor for recovery of facial nerve function*

Hilger nerve stimulator over stylomastoid foramen

Reflects elevated thresholds for neuromuscular stimulation due to degeneration / disruption of axons (comparison to contralateral side)

Difference > 2.5 milliamps - poor prognosis

* Ikeda M et. al. Clinical factors that influence the prognosis of facial nerve paralysis and the magnitudes of influence. Laryngoscope. 2005; 115:855-860.



Nerve Excitability Test (NET)

Benefits:

Easy to perform

More comfortable for patient

Drawbacks

Subjectivity (relies on operator’s visualdetection of response)

May exclude smaller fibers (current thresholdsare likely to selectively activate larger fiberswith lower thresholds and not those smaller fivers closer to stimulating electrode)



Maximal Stimulation Test (MST) Electrical impulse administered to saturate the nerve with

current and to compare it to contralateral side

Test is repeated periodically until definitive response

Response

Equivalent to contralateral side

Minimally diminished (50%)

Markedly diminished (< 25% of normal)

Absent

Symmetric response within first ten days – completerecovery in > 90%

No response within first ten days – incomplete recoverywith significant sequelae

Superior to NET - test becomes abnormal sooner, butdrawback is subjectivity



Evoked electromyography (EEMG) or

Electroneuronography (EnoG) Records compound muscle

action potential (CMAP) withsurface electrodes placedtranscutaneously in thenasolabial fold (response) andstylomastoid foramen(stimulus)

Waveform responses areanalyzed to compare peak-to-

peak amplit`udes betweennormal and uninvolved sideswhere the peak amplitude is

proportional to the number of intact axons



Evoked electromyography (EEMG) or

Electroneuronography (EnoG)

Most reliable in first 2-3 weeks post event (as neuropraxic fibersrecover or regenerate, they discharge asynchronously and theresponse is subsequently diminished)

Response < 10% of normal in first 3 weeks – poor prognosis Response > 90% of normal within 3 weeks of onset – 80-100%

probability of recovery

Testing every other day

Advantages: Reliable Disadvantages:

Uncomfortable

Cost

Test-retest variability due to position of electrodes



Electromyography (EMG)

Measures post-synaptic membrane di/triphasic(polyphasic) potentials with voluntary muscle contractionthat are present 6-12 weeks prior to visible return of function

Assesses reinnervation potential of muscles two weeksafter onset

Limited value early in evaluation because fibrillation potentials indicating axonal degeneration do not appear until 10 – 14 days post onset

Detection of motor units in 2 of 3 muscle groups – 87%satisfactory outcome

Detection of motor units in 1 muscle group – 11%satisfactory



More Methods

Antidromic (retrograde) Conduction – F-wavesrepresent activated motor neurons in facialmuscles.

Transcranial magnetic stimulation – Enablescentral activation via a transcranial application of induce current via an electromagnetic coil

Trigeminofacial Reflex – Records action potentials reflexively generated in the orbicularisoculi muscle in response to an electrical stimulusapplied to V1



Lyme Disease - Borrelia Burgdorferi

Ten percent of patients have facial nerve paralysisafter 1-4 weeks incubation period

ELISA to search for IgG and IgM antibodies

Facial paralysis resolves in 6 to 12 months

Treatment

Early antibiotics

• Reduce symptoms

• Event long-term sequelae

Children - IV penicillin, ceftriaxone or cefotaxime

Adults - tetracycline

Muscular therapy



Bell’s Palsy

60-70% cases

Pathophysiology – Impaired “axoplasmic” flowfrom edema of facial nerve within fallopian canal

Rapid onset and evolution < 48 hours

May be associated with acute neuropathies of cranial nerves V- X

Pain or numbness affecting ear, mid-face, tongueand taste disturbances

Recurrences are more likely (2.5x) in patients withfamily history, immunodeficiency or diabetes



Bell’s Palsy

Treatment

Oral antivirals - Acyclovir - 10mg/kg (500mg)q8hrs x 7 days

Corticosteroid taper 1mg / kg / day for 10 days

Eye protection - lacrilube

Follow progression with serial exams

Facial nerve decompression Progression to > 90% degeneration on ENOG

Performed before irreversible injury to the endoneural tubulesoccurs (two weeks), will allow for axonal regeneration to occur



Treatment of Bell’s Palsy with Steroids: A

controversial closer look Steroids may have the following effects:

Reduce risk of denervation

Preventing / lessening synkinesis Preventing progression to complete paralysis

Hastening recovery

Controversy:

Lack of randomization, controls and definitivedosing in most studies

Stankiewicz J. Steroids and idiopathic facial paralysis. Otlaryngol Head Neck Surg. 1983; 91: 672.

Wolf S. Wagner J. Davidson S. et.. al. Treatment of Bell’s palsy with prednisone: a prospective randomized study. Neurology. 1978; 28: 158.



Facial Nerve function recovers to HB gradeI function in what percentage of patients

with Bell’s Palsy?

A. 50%

B. 70%

C. 85%

D. 95%

* Ikeda M et. al. Clinical factors that influence the prognosis of facial

nerve paralysis and the magnitudes of influence. Laryngoscope.2005; 115:855-860.



Which of the following factors is a predictor of poor facial nerve outcome following

Bell’s Palsy?

A. Age over 50 years

B. Male Gender

C. Loss of lacrimation

D. Hypothyroidism

* Ikeda M et. al. Clinical factors that influence the prognosis of facial

nerve paralysis and the magnitudes of influence. Laryngoscope.2005; 115:855-860.



What is this Condition?

Ramsay Hunt Syndrome



Herpes Zoster Oticus

(Ramsay Hunt syndrome)

10-15% of acute facial palsy cases

Lesions may involve the external ear, the skin of EAC or soft palate

Associated symptoms – hearing loss, dysacusisand vertigo

Additional involvement of CN V, IX and X and

cervical branches 2, 3 and 4 Pathogenesis – Neural injury due to edema at

point between the meatal foramen and thegeniculate fossa in the labyrinthe segment



The most common etiology of facialnerve paralysis in children is:

A. Infection

B. Congenital

C. Trauma

D. Iatrogenic

* Evans AD et. al. Pediatric facial nerve paralysis: Patients, management

and outcomes. Int J Ped Otol. 2005; 69:1521-1528.



Which of the following infections is mostlikely to cause facial paralysis in a

pediatric patient?A. Acute otitis media

B. Mastoiditis

C. Mycobacterium infection

D. Disseminated herpes

infection

* Evans AD et. al. Pediatric facial nerve paralysis: Patients, management

and outcomes. Int J Ped Otol. 2005; 69:1521-1528.



Acute Otitis Media

History and physical exam make the diagnosis

Palsy is progressive over 2 to 3 day period

Infectious agent – Staphylococcus non-aureus,Propionobacterium

CT temporal bone

Treatment

Myringotomy

Otic antibiotic drops containing topical steroids

IV antibiotics and steroids

If not improved… mastoidectomy



Möbius Syndrome

Most frequently sporadic Congenital facial weakness

with impairment of ocular

abduction

Dysfunction of other cranial nerves – III, IV, IX,

X, XII

Skeletal abnormalities

(orofacial, limbmalformations)

Pathogenesis – Genetic

cause vs. Ischemic cause



Melkersson-Roenthal syndrome

Triad Recurrent orofacial edema

Recurrent facial palsy (50-90%)

Lingua plicata (fissuretongue) – 25%

Lips become chapped,fissured and red-brown inappearance

Biopies identifygranulomatous changes

Facial nerve decompressionmay be indicated if facial

paralysis is severe andrecurrent

N l ti



Neoplastic

About 5% of cases of facial nerve paralysis are

caused by tumors Characteristics of facial nerve palsy

Slow developing

Additional cranial nerve deficits

Recurrent ipsilateral involvement

Adenopathy

Palpable neck or parotid mass

Most common benign tumor - facial nerveschwanomma

Most common malignant tumors - mucoepidermoidcarcinoma and adenoid cystic carcinoma of the

parotid gland.



Temporal Bone Fractures

Longitudinal fractures

80% incidence but 10-20% with facial nerveinjury

Transverse fractures

20% incidence, but 50% with facial nerveinjury

Most common site of fracture

Perigeniculate region



Temporal Bone Fractures

Penetrating injury to extratemporal facial nerve

branches

Injuries medial to a line perpendicular to thelateral canthus do not need to be explored because

they recover spontaneously (draw please)

Immediate paralysis after injury lateral to this line

needs to be explored and repaired with an end-to-end anastomosis 48-72 hours after the initial

injury



Sunderland Nerve Injury Classification

I Neuropraxia

Conduction block from compression and loss of axonic flow

Complete recovery II Axonotmesis

Axon disrupted but endoneurium preserved

Wallerian degeneration occurs distal to site of injury Complete recovery

III Neurotmesis

Complete disruption of axon including its surrounding myelin

and endoneurium Wallerian degeneration

Unpredictable outcome – High risk for synkinesis

IV Complete disruption of perineurium

V Complete disruption of epineurium

Risk of a neuroma from nerve sprouts outside of nerve sheath



A patient with facial nerve injury following a

gunshot wound to the temporal bone typically

presents with which of the following symptoms?

A. Midface branch paralysis

B. Complete facial paralysis

C. Forehead paralysisD. Partial weakness of the facial nerve

* Bento RF and de Brito RV. Gunshot wounds to the facial nerve. Otol

Neurotol. 2004; 25: 1009-1013.



Following surgical repair of facial nerve injurydue to a gunshot wound, the typical facial

nerve function outcome is House Brackmanngrade:

A. I or II

B. III or IV

C. V

D. VI

* Bento RF and de Brito RV. Gunshot wounds to the facial nerve. Otol

Neurotol. 2004; 25: 1009-1013.



A patient presents to the trauma bay after a

closed head injury. He has a unilateral facial

nerve paralysis and a CT scan confirms a

temporal bone fracture. The family wants

your expert opinion on the prognosis and

return of facial nerve function.

Immediate onset – as above

Delayed onset

94%-100% complete recovery

Patients with > 90% degeneration of

neural integrity – poor recovery



What if the facial paralysis

doesn’t resolve? End-to-End Anastomosis

Cable Nerve Graft

Hypoglossa-Facial Nerve Anastomosis

(Crossover or Jump Graft)

Muscle transposition (Gracilis)

Static Suspension (Gortex, Threads)



Complications

Keratitis

Emotional/Social Issues

Synkinesis



THANK YOU

FacialNerveParalysis May 24, 2007 v. Rothholtz

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