facial paralysis - semmelweis...

© 2003 The American Academy of Otolaryngology – Head and Neck Surgery Foundation

Facial ParalysisFacial Nerve Subcommittee of the American Academy

of Otolaryngology-Head & Neck Surgery

Editor: Peter S Roland MD

Contributors: Peter S Roland MD, Larry Lundy MD, Jacques

Herzog MD, Fred Telischi MD & Gady Har-El MD

DISCLAIMER:

The American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNS/F)

is providing these resources for historical purposes only. The information is provided AS IS, and

the Academy makes no representations or warranties about the suitability of this information for

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created it at the time it was created, and does not necessarily represent the official views or

recommendations of the American Academy of Otolaryngology — Head and Neck Surgery

Foundation, Inc. All materials are subject to copyrights owned or licensed by the AAO-HNS/F,

and all rights are reserved. The names, trademarks, service marks, and logos of the AAO-HNS/F

may not be used by any other party without prior, express written permission of AAO-HNS/F.


Facial Paralysis

• Idiopathic 57%

• Trauma 17%

• Herpes zoster 7%

• Tumor 6%

• Infection 4%

• Birth trauma 3%

• Central etiology 1%

Etiology


Bell’s Palsy and Ramsay-Hunt

• Ramsay-Hunt

– Facial paralysis

– Otalgia

– Vesicular eruption on auricle

– Sensorineural hearing loss (SNHL) / Vertigo

– Varicella zoster virus

• Bell’s palsy

– Idiopathic and therefore a

diagnosis of exclusion

– Widely held to be viral

etiology


Diagnosis

• History and physical examination

• Audiometry

• Topognostic study

• Radiographic imaging

• Prognostic studies


History

• Sudden or gradual

• Associated hearing loss

– Tinnitus

– Pain

– Infection

– Trauma Chronic Suppurative Otitis Media


House-Brackmann Grading


Physical

• Hemotympanum

• Otitis media

• Cholesteatoma

• Middle ear mass

• Vesicular eruption

Otoscopy

Middle ear paraganglioma


Physical Examination

• Facial nerve

– Incomplete vs. complete

– LMN vs. UMN

• Other cranial nerves

Neurological


Topognostic Testing

• Tear test

• Stapedial reflex

• Taste test

• Salivary flow


Radiography

• Asymmetric SNHL

• Complete CN VII palsy

• MRI/CT

Metastatic mass in

Internal Auditory Canal

Air contrast CT


Etiology

• Viral

– Herpes simplex

– Herpes zoster

• Vasospasm

• Immunologic injury


Pathophysiology

• Entrapment

• Compressive neuropathy


Natural History

• Bell’s palsy

– Total paralysis 69%

– Complete recovery 71%

– Satisfactory outcome 84%

– Recurrence 6.8%

Early return = Good prognosis

• Ramsay-Hunt

– Greater degeneration

– Complete recovery 16%

– Satisfactory 40-50%


Prognostic Studies

• Salivary flow

• Electrodiagnostic studies

Identify within 14 days of onset


Prognostic Studies

• Identify reversible vs. irreversible injury

• Prevent progression from second-degree to

third-degree injury

• Timing 3-5 days

• ? Reinnervation


Prognostic Studies

• Minimal excitability > 3.5 mAmps

• ENOG > 90% degeneration

Poor prognosis


Medical

Treatment

• Prednisone 1 mg/kg/day X 5-14

days, slow taper

• Valcyclovir 1000 mg TID

• Famciclovir 500 mg TID


Treatment

• > 90% degeneration

• Within 14-21 days of onset

• Expose meatal foramen

Surgical


Electrophysiologic Testing

• Primary uses of testing

– Assists in prognosis

– Helps determine appropriate treatment options

– Monitors response to treatment


Nerve Injury - Sunderland Classes

• 1st degree – Neuropraxia

• 2nd degree – Axonotmesis

• 3rd degree – Endoneural disruption

• 4th degree – Perineurial disruption

• 5th degree – Neurotmesis



• Basic principles

– Facial nerve is tested distal to site of lesion

– Attempt to determine rate and degree of degeneration

– Need to assess facial nerve function frequently (daily

or every other day)

– Need normal function on uninvolved side for

comparison of test results



• Basic principles (cont’d)

– Only valid for clinically paralyzed, not paretic, facial nerve

– No value once response is lost or recovery begins

– Test results lag behind pathologic event by about 3 days



• Test battery

– NET - Nerve excitability test

– MST - Maximal stimulation test

– ENOG - Electroneuronography

– EMG - Electromyography



• NET – Nerve excitability test

– Lowest level of stimulation to get a twitch

– Compare this threshold with normal-side

threshold

– Difference of 3.5 mAmps indicates significant

and progressive degeneration

– ~ 40% of patients with 3.5 mAmps difference

still have complete, spontaneous recovery



• MST - Maximal stimulation test

– Increase stimulation level until maximal

response is seen

– Grade response (compared with normal side)

as:

• Equal

• Slightly decreased

• Markedly decreased

• Absent



• MST - Maximal stimulation test (cont’d)

– If normal response for 10 days, then 85-90% chance of complete return of function

– If markedly decreased or absent, then ~ 85% chance of poor outcome with significant sequela

– If response slightly or markedly decreases, expect some synkinesis


ENOG - Electroneuronography

• Uses maximal stimulation

• Record compound

muscle action potential

(CMAP)

• Measure amplitude of

response

• Amplitude of waveform is

proportional to number of

functional axons


ENOG -Electroneuronography

• If amplitude of involved side is 10% or less than

normal side, then poor chance for spontaneous

normal or near normal recovery

• If amplitude of involved side is 10% or greater than

normal side, expect excellent recovery

NORMAL ABNORMAL LEFT



• EMG – Electromyography

– Requires needle insertion into facial muscles

– Need to test multiple muscle groups (3-5 recommended)

– Does not estimate percentage of degenerated facial nerve fibers



• EMG – Electromyography

– Primary use in acute phase of facial paralysis (first

2 weeks) is confirmatory for other tests

– If other tests (NET, MST, ENOG) show no or little

response, and EMG shows voluntary motor unit

potentials, then still have good prognosis

– Loss of voluntary motor unit potentials worsens

prognosis



• EMG - Electromyography (cont’d)

– Fibrillation potentials occur at earliest at 10-14 days

post onset, indicating degenerating motor units

– Polyphasic reinnervation potentials can occur as early

as 4-6 weeks post onset, indicating fair recovery (if

later, worse recovery)


Facial Paralysis Secondary to Otitis Media

• Acute otitis media

• Chronic suppurative

otitis media

• CholesteatomaAcute Otitis Media


Acute Otitis Media

• Pathophysiology:

– Natural dehiscences?? Hof has localized “block” to

dehiscence in 2 cases but 55% of t-bones have

dehiscences

– Bacteriology no different than for acute otitis media

– Direct involvement of the facial nerve by infection.

(Balance and Duel, 1932; May, 1982)


Acute Otitis Media


– Demyelination secondary to bacterial

toxins (Kettle, 1943; Joseph and Sperling, 1998)

– Ischemia secondary to thrombosis of the

vaso-vasorum (Antoni-Candela and Stewart, 1974; Graham,1977)

– Viral reactivation ( Joseph and Sperling, 1998)


Acute Otitis Media

• Clinical reports: Ellefsen

– 23 patients

– 12 presented with moderate palsy and 11 with severe

– 4 had mastoidectomy secondary to persistent infection @ 2-4 weeks

– 22/23 HB I. Onset of improvement within 3 weeks in 78%


Acute Otitis Media

• Clinical reports: May

– 36 cases

– 89% good recovery, 11% poor

– All Rxed with

antibiotics (abx) + myringotomy (myr)

– Surgery if complete paralysis plus no response to maximal stimulation or salivary flow or coalescent mastoiditis or meningitis

– Maximal stimulation testing predicted recovery


Acute Otitis Media

• Clinical reports: Elliot

– 10 cases, 8 patients incomplete and 2 complete

– 8/8 incomplete recovered with abx + myr

(1 protracted)

– The 2 complete had mastoidectomy and recovered


Acute Otitis Media

• Clinical reports: Hof

– 7 pts

– 5 recovered with abx + myr + tube

– 2 had mastoidectomy with decompression secondary to facial nerve FN deterioration, both recovered


Acute Otitis Media

• Incidence in preantibiotic era:

– 4 estimates by separate investigators all between 0.5% and 0.7%

• Incidence in postantibiotic era:

– 2 estimates by separate investigators between 0.005% and 0.16%


Acute Otitis Media

• Clinical reports: Bluestone

– 35 cases

– 22 partial and 13 complete

– All Rxed with abx + myr

– 7 needed surgery because of coalescent mastoiditis or ENOG evidence of denervation


Recommendations

• Consensus:

– Facial nerve paralysis secondary to acute

otitis media should be Rxed with appropriate

antibiotics

– Myringotomy if not already draining


Recommendations

• Debated:

– A tube should be inserted

– Electrophysiological tests should be

used to determine if surgery is

necessary

– Decompression should accompany

mastoidectomy

– Steroids


Chronic Suppurative Otitis Media

• Incidence:

– Preantibiotic

• 2.3% (Pollock)

– Postntibiotic

• May — 3 cases

• Harker — 5 cases




– Natural dehiscence ??

– Many of the same inflammatory

mediators found in cholesteatomas are

found in chronic suppurative otitis media



• Clinical reports: Harker

– 6 ears

– 4 partial, 2 complete

– Surgery within 10 days after onset

– 5 recovered to HB I and 1 to HB II



• Clinical reports: Hartley

– 1 case

– Immunosuppressed

– Required graft


Cholesteatoma

• Incidence:

– May: 13 ears over 20 yrs

– Sheehy: 1.0% of 1,024 Primary ear operations

– Hof: 2 cases in 3 yrs


Cholesteatoma


–Pressure

–Inflammation


Cholesteatoma

• Clinical reports:

– May: 7 pts with normal electrophysiology HB I pt with no response max. stimulation all had incomplete recoveries

– Magliulo: 10 pts with facial paralysis secondary to very large cholesteatomas. 7 had grafts, 1 7-12. 2 had compression only — partial recovery


Recommendations

• CONSENSUS:

– Urgent surgical intervention is the most appropriate therapy for facial nerve paralysis secondary to cholesteatoma or chronic suppurative otitis media

• DEBATED:

– CWU versus CWD; decompression


Facial Nerve Trauma

General considerations

• Most commonly injured cranial nerve

• Protected by longest bony nerve canal

• Second leading cause of facial paralysis after Bell’s palsy

• Location (intra- vs. extratemporal facial nerve)

• Timing of paralysis


Facial Nerve Trauma

Iatrogenic injury

• Anticipated or not

• Knowledge of anatomy

• Intraoperative monitoring

• Local anesthetic effects

• Early exploration

• ENOG for delayed paralysis


Facial Nerve Trauma

Diagnosis

• Mechanism of injury

• Paralysis vs. paresis (HB grading scale)

• Immediate vs. gradual paralysis

• Electrical testing

• Imaging


Facial Nerve Trauma

Temporal Bone Fracture

• Occipital or temporal impact

• Associated findings• Hearing loss

• Cerebrospinal fluid (CSF)

otorrhea

• Mastoid ecchymosis (Battle’s

sign)

• Hemotympanum

• External canal disruption

Fracture through mastoid cortex


Facial Nerve Trauma


• High-resolution CT

• Transverse vs. longitudinal orientation

• Mechanisms of injury• Stretch (50%)

• Transection (30%)

• Compression (20%)



Transverse

Longitutdinal


Longitudinal Fractures

• 4 times more common than

transverse

• Facial nerve injury in 20% of

cases

• Stretch or bony compression

more common

• Perigeniculate area most

common site

• Conductive hearing loss typicalLongitudinal fracture


Transverse Fractures

• Frequent severe brain

injury/mortality

• 50% associated with facial

nerve injury

• Labyrinthine segment most

common site

• Transection common

• Sensorineural hearing loss

typical

Transverse fracture


Facial Nerve Trauma


• Paralysis only

• After 3 days

• ENOG appears most accurate initially

• EMG during recovery for prognostication

• Nerve conduction for peripheral injuries


Facial Nerve Trauma


• Steroids

• Decompression

• Exploration

• Removal of bone fragments

• Neurorrhaphy


Penetrating Injuries

• Early exploration

• Neurorrhaphy

• Grafting

• Mobilization

• >30-50% injury

Bullet lodged in Temporal Bone


Facial Nerve Trauma

Repair Technique

• No tension (grafting when necessary)

• As soon as possible

– Barring infection/contamination

• Fresh nerve endings

• Approximation in fallopian canal or with

several sutures


Facial Rehabilitation

after Facial Nerve Paralysis

• Total facial rehabilitation – neural

procedures

• Segmental rehabilitation


Neural Procedures (nerve-muscle junction must be functionally intact)

• Primary neurorrhaphy (+ rerouting)

• Cable grafting

• Crossover procedures

• Cross-face nerve grafts


Prereanimation/After interposition graft

Prereanimation After interposition graft


Nerve Crossover

• Distal nerve function?

• Neuromuscular junction function?

• Muscle atrophy?

Types

• Hypoglossal - Facial

• Spinal accessory - Facial

• Phrenic - Facial


1 year After 12-7 Crossover

1 yr after 12-7 crossover


Rehabilitation By Site

• Upper face

• Midface

• Lower face


Exposure Keratitis


Upper Eyelid

• Tarsorrhaphy

• Gold weight

• Spring

• Cartilage

• Blepharoplasty

• Silastic encircling

• Temporalis muscle transposition

• Free muscle transfer

(+ Cross-face nerve graft)


Gold Weight

Gold weightIntraop after surgery Good eye closure post-op


Lower Eyelid

• Tarsorrhaphy

• Lid shortening

• Lateral canthoplasty

• Medial canthoplasty (+ adhesion)

• Cartilage graft augmentation

• Temporalis muscle transposition



Lid Shortening/Canthoplasty

Lid shortening Canthoplasty


Eyebrow


Midface

• Cosmesis

• Breathing

• Static

• Dynamic


Dynamic Midface

Rehabilitation

• Temporalis muscle transfer

• Masseter muscle transfer

• Cross-face nerve graft



Static Midface

Rehabilitation

• Facelift

• Suspension procedures (fascia, palmaris

longus, Alloplastic materials)

• Rhinoplasty

• Nasal valve reconstruction (+ grafts)

• Alar suspension to orbital

• Springs, dilators


Dynamic Lower Face Rehabilitation

• Temporalis muscle transfer

• Masseter muscle transfer

• Digastric muscle (anterior belly) transfer


• Cross-face nerve graft


The Lower Face/Smile


Before and After Temporalis Muscle Transfer Procedure


Static Lower Face Rehabilitation

• Facelift

• Oral commissuroplasty (primary, secondary)

• Lip wedge resection

• Suspension procedures (fascia, tendon, Alloplastic materials)

• Anti-drooling procedures

facial paralysis - semmelweis...

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