Table Of Content18
Schriftenreihe Neurologie
Neurology Series
Herausgeber
H.IBauer,Gottingen .H.Ganshirt,Heidelberg· P.Vogel,Heidelberg
Beirat
H.Caspers, Munster· H.Hager, GieBen· M.Mumenthaler, Bern
A.Pentschew, Baltimore· G.Pilleri, Bern· G.Quadbeck, Heidelberg
F.Seitelberger,Wien .W.Tonnis, KOln
Erlo Esslen
The Acute Facial Palsies
Investigations on the Localization and Pathogenesis
of Meato-Labyrinthine Facial Palsies
With a Foreword by U. Fisch, Zurich
With 127Figures
Springer-Verlag
Berlin Heidelberg New York 1977
Privatdozent Erlo Esslen, M.D.
DivisionofNeurology, KantonsspitalAarau,Switzerland
The investigations were performed at the University Hospital of Neurology, Zurich,
Switzerland.
ISBN-13:978-3-642-66536-3 e-ISBN-13:978-3-642-66534-9
DOl: 10.1007/978-3-642-66534-9
LibraryofCongressCatalogingin Publication Data. Esslen, Erlo.Theacute facial palsies. (Schriftenreihe Neuro
logie). Bibliograpby:p. Includesindex.!. Paralysis, Facial-Etiology. 2. Facial nerve-Diseases-Diagnosis. 3. Facial
nerve-Surgery.4.EIectrodiagnosis.I. Title. II.Series. [DNLM: I.Facial paralysis-Etiology.2. Facial nerve-Patho
logy. 3. Constriction, Pathologic-Complications. 4. Herpes zoster-Complications.5.Labyrinth. 6. Petrous bone.
WISC344Bd. 18/WL330E78a]. RC418.E87. 616.8'7. 67-55687.
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Softcoverreprintofthehardcover1stedition 1977
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v
Foreword
IhavebeenprivilegedtoworkwithDr. Esslenfor more thantenyearsand to have
witnessedhowsurgicalprogresscombinedwithaccurate clinicaland electrophysiological
investigationshave revolutionized the diagnosticand therapeuticapproachto the para
lysed face.
Thelongjourneyofthe VIIthnerve throughthe temporalbonehasbeenconsid
ered for years responsible for the particularliabilityofthisnerve to acutepalsies. The
disappointingresults obtainedwithsurgicaldecompressionconfined ofnecessity to the
mastoidand tympanicsegmentsofthefallopian canalledusinthesixtiesto apply
modernotoneurosurgicaltechniquesinorderto achieve totalexposure ofthe intra
temporalcourseofthe facial nerve. At that time Esslenstartedto recordwithsurface
electrodesthe compoundactionpotentialevoked bymaximalpercutaneousstimulation
in representativeareasofthe facial muscles. Withthismethod,calledelectroneurono
graphy,exactdeterminationotthe percentageofdegenerated nerve fibers couldbe
achieved in theearlystagesofthe palsy.Precise electroneuronographiccriteriafor the
selectionofpatientsrequiringsurgeryinorderpossiblyto improvethe outcome oftheir
disfiguringparalysiswere workedout. At surgeryd¥ectstimulationofthe totally
exposedintratemporalportionofthe facial nerve wasused for the first time incombina
tionwithelectroneurographyinorderto determineobjectivelythe degreeofthe lesion.
Incontrastto whathasbeenbelieved for yearsthe pathologyrelatedwithacute facial
palsyhasbeenfound to besituated inthemajorityofthe casesat theentrance and not
towardthe exitofthe fallopian canal.Althoughfurther studiesarenecessaryto establish
withoutquestionthevalueoftimelysurgery,the presentmonographestablisheswith
outdoubtthat, inordertobeeffective,ithastobeperformed in themosthidden
labyrinthineand meatalportionsofthefacial nerve.Inanycase,theelectroneurono
graphiccriteriaindicatethatlessthan 5%ofthe patientscanbe considered ascandidates
for surgery. Inviewofthelocalisationofpathologyfamiliaritywiththe most modern
otoneurosurgicalprocedureisanessentialprerequisitefor asuccessfuloperation.
The workofEsslenhasdeeplyextendedourknowledge onthe naturalhistoryof
the mostcommonacutefacial palsiesandhasestablishedvalidcriteriafor surgical
will
indications. Thereis no doubtthat Esslen'smonograph remainfor yearsto come
the basisfor alogicaltherapeuticapproachto the acutelyparalysedface.
Zurich,March 1977 U. Fisch
VII
Preface
This treatise is the resultof10yearsofclosecooperationbetweenneurologistand
otologist. The cooperationbeganwith the questionofhowthe resultsof"decompres
sion"offacial nerve couldbe assessed. Thisinterventionhad then for more than
10yearsbeenpart ofthe repertoire ofotologic operations. Itimpliesthe openingofthe
tympanicormastoidal sectionofthe fallopian canalandslittingoftheepineurium.
Theindicationfor this interventionwas, however, rathervague and opinionsonthe
mostappropriate time varied considerablyamongotologicsurgeons.
We tried toanswer the questionofthe usefulnessofdecompression offacial nerve
bycombined clinicalandelectromyographicinvestigations. Severalyearsofwork on
this revealed that decompression ofthefacial nerve did not improvethe prognosis.
Thiswasconfirmed some timelaterbyotherinvestigators(Naumannet aI., 1968;
Adourand Swanson, 1971).
Thisdisappointingresultwasenhancedbythefact that theexploration ofthe facial
nerve afteropeningofitscanaldid notshowany impressive alterationofnerve tissue
suggestingthatonehadfound thesite oftheessentialpathogeneticprocessescausing
palsy. Forbothofthese reasons,the ineffectivenessofdecompressionaswell asthe
vanishingevidence ofthe underlyingpathogeneticconcept,thisinterventionwasgiven
up in 1967inZurich.
The new technique oftranstemporalopeningofthe internalauditorychannel and
ofthe fallopian canal,introducedinZurichin 1968,completelychangedthesituation.
The first probatory openingsofthe internalauditorychannelin casesofherpeszoster
oticus,laterofBell'spalsy aswell, revealedan enormousedemaandhemorrhage,
infarctionofthe facial nervejustbeforetheentrance to the fallopian canal,and asevere
strangulationofthe nerve at the transition ofthe relatively wide fundus ofthe internal
meatusacusticusandthe muchnarrowercanalofthe facial nerve. Thegrossly bulging
facial nerve couldnotenteritspropercanalwithoutatwo to threefold reductionof
itsdiameter. These observationsinducednewconceptsabout the localizationandthe
essentialpathogeneticfactors involvedindifferenttypes ofacute facial palsies.Con
sideringtheseveremorphologic alterationofthefacial nerve attheentrance to itscanal
itwasassumedthat thiswasalso thesite offunctional disturbance. Inordertotest this
assumption,the facial nerve waselectrically stimulatedalongitswholecoursethrough
the petrosalbone afteropeningofthe internal auditory channel andthe fallopian
canaland theevokedcompoundmuscle actionpotential offacial muscles was recorded.
The resultsoftheseinvestigationsand theintegration ofmorphologicandelectro
physiologic findings form partofthe first sectionofthe monograph.
In relation to the new operativetechnique andthe outlookofaverymuchim
provedmethodofdecompressionofthefacial nerve,an evergrowingneedformore
reliable methodsofpre-and postoperativeevaluationanddocumentationofthefunc
tionalandmorphologicstate ofthe facial nerve became obvious. Allelectrodiagnostic
VIII
methodshithertoapplieddid notallow theestablishmentofaprofIle ofthe day-to-day
alterationsofthe facial nerve and did notmake possible aclose follow-up ofthe natural
history offacial palsiesofdifferent genesis. The applicationofanelectroneurographic
methodadaptedespecially for thispurposehasled to the discoveryof"rules"ofthis
natural history.The knowledge ofthese ruleshascreatedanewbasisfor earlierand
more reliable prognosesinacute facial palsies. Furthermore ithasestablished anessen
tialsimilarity ofnaturalhistoryinfacial palsiesofdifferentetiology.
IamindebtedtoProf. Baumgartner,Headofthe University HospitalofNeurology,
Zurich,for kindsupportofthiswork.
Zurich, March 1977 E. Esslen
IX
Contents
1. Introduction ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1. AnatomicalConsiderations 3
1.1.1. Course ofthe FacialNerve in thePetrosal Bone . . . . . . . . . . . 3
1.1.2. Compositionand FiberSpectrumofFacialNerve 7
1.1.3. IntraneuralTopographyofFacialNerve .. . . . . . . . . . . . . . . . . . . . . 7
1.2. EvaluationofPresent ViewsonEtiologyand PathogenesisofAcute Facial
NervePalsy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2.1. IdiopathicFacialPalsy(Bell'sPalsy) 8
1.2.2. HerpesOticuswithConcomitantFacialPalsy(RamseyHunt Syndrome) 12
1.2.3. Bilateral FacialPalsies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
2. Investigations,PartI: Intratemporal StimulationofFacial Nerve for
LocalizationofConduction BlockinIdiopathicFacialPalsy,HerpesOticus,
andMelkersson-RosenthalSyndrome . . . . . . . . . . . . . . . . . . . . . . .. 15
2.1. Operative Access to the InternalAuditoryChannel and OtherIntrapetrosal
Sections ofthe FacialNerve , 17
2.1.1. Intraoperative Stimulationand RecordingTechnique 17
2.1.2. ResultsofIntraoperative StimulationofFacialNervein the Internal
AcousticMeatusand FacialCanal. Aspectofthe FacialNerve Under
the OperativeMicroscope 18
2.2. Findingsin FavorofaRevisedConceptionofthe RelevantPathogenetic
Factorsin Acute FacialPalsies 25
2.2.1. Histopathologic FindingsinIdiopathic FacialPalsy 25
2.2.2. Histopathologic FindingsinHerpesOticus 29
2.2.3. IntegrationofMorphologic and Electrophysiologic Findings 35
3. Investigations,PartII: ElectrophysiologicInvestigationson the Natural
HistoryofAcute FacialPalsies 39
3.1. Electrodiagnosisofthe FacialNerve 41
1. GeneralConsiderations 41
2. SpecialProblemsofElectrodiagnosisofthe FacialNerve 42
3. ElectrodiagnosticMethodsHitherto Applied for Diagnosisin
FacialPalsy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 43
4. ANew Method for the Determinationofthe DegreeofDegeneration
ofFacial Nerve 45
3.2. Remarks onSome Clinical FeaturesofAcute FacialPalsies 50
3.2.1. ImplicationsofTopical Diagnosis 51
3.3. Case Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 53
3.3.1. Discussion ofthe GraphicalPresentationofResults 55
x
3.4. Results . 57
3.4.1. IdiopathicFacialPalsy (Groups 1-9) . 57
3.4.2. GeneralPrinciplesthat Emerge from theHistoriesofIdiopathic
FacialPalsy . 66
1. Nerve FiberDegeneration . 66
2. Conduction Blockand the BeginningofitsRecovery . 71
3. Latency . 74
4. CompletionofRecovery from Conduction Block . 78
5. Degree ofNerve Regeneration . 81
6. Degree ofFunctional Recovery . 83
7. Age . 90
3.4.3. HerpesOticus(Groups I and 2) . 92
3.4.4. PrinciplesofDiseaseEvolutionin FacialPalsyAssociated with
HerpesOticus . 93
3.4.5. BilateralFacialPalsies: Case Reports . 98
3.4.6. Bilateral FacialPalsies: Principles ofEvolution . 100
3.4.7. Acute FacialPalsiesofDifferentEtiologies . 105
3.4.8. FacialPalsiesinPetrosalBone Fractures . 107
3.5. Prognosis ofAcute FacialPalsies . 108
3.6. Operationin Acute FacialPalsy: TranstemporalDecompression . 110
3.6.1. EvolutionofOperatedCases . 111
3.7. Indicationsfor TranstemporalDecompression ofthe FacialNerve . 113
3.8. OnDrugTherapy ofIdiopathicFacialPalsy . 115
Summary 117
References 119
Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 125-163
Author'sPostscript 164
1. Introduction
3
1.1. AnatomicalConsiderations
1.1.1.Courseofthe FacialNerveinthePetrosalBone(Fig. 1)
Semilunargang!. Tympanica. Genicgangl.
Maj. uperlic.
petIosal n.
Entry to
facial canal
Internal ochleara. Ve tibulnrn.
acousticmeans
Fig. 1. Middle cerebralfossa. Dissectionofinternalacoustic meatusafterremoval of
its roof
On openingthe roofofthe internal acoustic meatus, routinely done in transtemporal
decompression(see2.1.0),the first structure tobeseenis the facial nerve. Alittle
behindthis nerve and deeper onehalfofthe vestibularnerve canbe recognized,while
the otherhalfofthe nerve,coveredbythe facial nerve, cannot be seen. Betweenthe
two nerveslies the intermediusnerve(orparsintermedia),notvisible from above. The
