134POSTGRADUATEMEDICALJOURNALMarch1950tothefrontalTumourshaveawayoftransgressingtheanatomicalboundariesoftraditionatumourmaybetemporalaswellasfrontaltemporalaswellasparietaloccipitalaswellasboth ID: 955614
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133TUMOURSOFTHEFRONTALLOBEByGEOFFREYJEFFERSON,M.S.,F.R.C.S.,F.R.C.P.,F.R.S.ProfessorofNeurology,UniversityofManchesterGeneralConsiderationsThedifficultiesindiagnosingfrontaltumourshavebeenwellrecognized,notonlybyallwritersonthesubject,butbyallclinicianswhethertheyhavecontributedtothewrittenwordornot.Thereasonsforthisarenothardtofind,andcentrechieflyroundthefactthatlargethoughthefrontallobesaretheycontainnostructurewhosedestruc-tionmustnecessarilycauseanobviousalterationinthepatient,analterationthatcouldnothavebeenproducedbyalesionelsewhere.Objectionstothisstatementcometomind,foritwillbere-memberedthatthemotorareaandthepre-motorareabothliewithinthefrontallobe.Theyde-marcate,however,itsextremeposteriorborderanditisclearthatunlessatumourissofarbackinthefrontallobethatitalmostceasestobeapurefrontaltumournodisturbanceofmotionwillresult.Ontheleftsidetheso-calledmotorspeechcentre,orBroca'sarea,comeswithintheanatomist'sdefinitionofthefrontallobe,sothatdifficultiesintheexteriorizationofspeechmightwellbefoundwithafrontaltumourfarenoughbacktoinvolvethesemechanisms.Wemustnotbeundulyimpressedwiththeimportanceofthegreymatterofthecortexattheposteriorendoftheleftthirdfrontalconvolution.Tumours,andfor-thatmatterotherlesionsaswell,morecom-monlyproducetheireffectsbyinterferencewiththewhitematter,bycuttingdeepassociationandprojectionfibres,thanbydestructionofthelayersofcellsinthecortex.Itismoreprobablethatdefectsofspeechareduetodamagetothesedeepfibresthantolossofcellswithaspecialfunctioninthecortex.Thisbeliefhasledinmorerecentyearstospeechdefectsbeingreferredtodamageof'theregionoftheinsula'(islandofReil),abrainareathatbelongsasmuchtothetemporallobeasSketchofarightfrontallobectomyshowingthebareflooroftheanteriorfossafalxandleftanteriorcerebralartery. 134POSTGRADUATEMEDICALJOURNALMarch1950tothefrontal.Tumourshaveawayoftrans-gressingtheanatomicalboundariesoftradition;atumourmaybetemporalaswellasfrontal,tem-poralaswellasparietal,occipitalaswellasbothtemporalandparietal.When,therefore,onewishestospeakofthesignsofatumourinanyareaitisbesttoconfinetheexamplestolesionswhichareentirelylocal.Hencefrontaltumoursofclassicaldescriptionwillonlyslightly,ifatall,en-croachonthemotorarea,norwillallofthoseevenontheleftsideleadtodeficiencyinspeech.Istherethenwithinthefrontallobenootherstruc-ture,isitanunbrokenmassofwhitematterwiththeusualgreymattercoveringit?Therelieswithinitthecaudatenucleusandthefrontendofthelateralventricle.ItmaybethatthetremortowhichGraingerStewartfirstdrewattentioninI906andhassincebeennoticedbymanyasapeculiarityoffrontaltumours,isduetopartialinvolvementofthecaudatenucleusandbasalganglia.Theanteriorhornofthelateralventriclecouldhavenoneurologicalsignificance,butitisimportantthattheforamenofMonrolieswithinthefrontallobeandifatumourissosituatedthatitcouldblockit,agreatriseinintracranialpressuremustfollow.Otherwisethepressurewithintheskulltendstobelowwithanteriorlyplacedtumours,asStopfordfirstpointedoutthoughnotforthereasonthatheadduced(absenceofpressureontheveinofGalen).Inthisreviewoftheneuralstructuresofthefrontallobe,inthesearchforareaswhosedestruc-tionmightleadtooutspokensignsorsymptoms,nomentionhasbeenmadeasyetofintellectualprocesses.Arenotthefrontallobesthe'organsofthemind,'theorganizersofpersonality,thecensorsofconduct,almostonemightsaytheseatofthesoul?Istherenorecognizableanatomicalcorticalareawhichhousesthemind?Althoughthefrontallobesareconcernedinthesethings,andprobablymoreconcernedthananyotherpartofthebrain,alltheevidencepointstothesequalitiesbeingmorediffuselyspreadthrough
outthebrainthanwasthoughtasrecentlyas20yearsago.Itismorepossibleforapatienttohavealargefrontallesionwithoutalterationinhismemoryorper-sonalityormoralsense.Sometimesofcoursethesethingsaredisturbed,butmuchlesscom-monlythanwouldbethecaseifthefrontalcortexwasanexceedinglyhighlyspecializedmosaicwherethewholeofourintellectualand(forwantofabetterword)spiritualpotentialitiesorachieve-mentwerelodged.Thisfascinatingsubjectwillbedealtwithalittlemorefullybelow.SymptomsandSignsofFrontalLobeTumoursAstheresultoftheanalysisoffrontallobetumourswhichhavebeenmadeduringthepast30yearsacertainuniformityofdescriptionhasemerged.Writersdifferintheemphasiswhichtheyplaceonthisorthatsymptomorsign;suchemphasistendstobeindividualisticandwhathashelpedoneobservermaybethoughtunimportantbyanother,eventhoughheagreesthattheobserva-tioniscorrect.Howeverdesirableitmaybeforteachingpurposestoproduceasyndrome,aformula,somethingwhichshallrepresentthephotographiclikenessofadiseaseentity,weknowverywellthatinpracticetheresemblancewillbeafamilyratherthananexactone.Itisexceed-inglyrareforanycasetoshoweverysignwhichtheclosestscrutinyofalargenumberofcaseshasprovedtobeapossibility.Onlytoooftenbutoneortwoofthetheoreticallypossiblediagnosticcriticalpointsareallthereistoworkon.Wewillbeginwithalistofsymptomsandsigns,andfirstamongstthemwemustplacethoseofthatriseinintracranialpressurewhichisthegeneralruleinintracranialtumours.x.Signsofraisedintracranialpressure:head-ache,chokingoftheopticnerveheads,vomiting,paralysisofcranialnervesatadistance,usuallytheabducens,and(inlaterstages)drowsiness.2.Signsandsymptomsduetointerferencewiththebrainmassofthefrontallobes:(a)Epilepticfits.(b)Memorydefects,personalitychanges,in-continence,inertia,lossofpowersofconcentra-tionandofintrospection,facetiousness,un-warrantedgoodhumour(Witzelsucht,euphoria).(c)Weaknessofthecontralaterallimbs,per-hapsa'graspreflex.'(d)'Motor'aphasia,ifthelesionisleft-sidedinaright-handedperson.(e)Tremorofthearms,oftenipsilateral.(f)Pseudo-cerebellarsigns-dizziness,ataxia,nystagmus.(g)Electro-encephalographicevidenceofafocalorgeneraldisturbanceofcorticalactivity.3.Neighbourhoodsigns,duetocompressionofnearbystructures:(a)Anosmia,uni-orbilateral.(b)Opticatrophy,especiallywhenitisuni-lateral.Centralscotomata.FosterKennedy-Patonsyndrome.4.X-rayevidenceof:(a)Calcificationinthebenignfrontalgliomas.(b)Hyperostosisoftheflooroftheanteriorfossaorofthevault,associatedwithsome,butnotall,meningiomas.(c)Increasedlocaldiploicvascularity.DiscussionIfallthesignsmentionedaboveoccurredalwaysweshouldhaveaveryclearpictureindeed,unless March1950JEFFERSON:TumoursoftheFrontalLobe135ANALYSISOFTHESYMPTOMSOF50FRONTALLOBETUMOURS20Casesof30CasesofMeningiomaGliomaPercent.Percent.i.Pressuresigns:Headache,vomiting,visualdisturbances,etc...........90772.Symptomsandsignsattributabletothefrontallobe:(a)Epilepticattacks:Generalized..................2050Localized..................027Minor............5I3(b)Contralateralpareses................2027(c)Otherpyramidalsigns..............2523(d)Earlyapathy,lossofconcentration,memorydefects,euphoria,personalitychanges..................3020(e)Graspreflex............3(f)Aphasia....................25I0(g)Hypersomnia..................33.Pseudo-cerebellarsigns:(a)Ataxia....................250(b)Tremoro...................I07(c)Vertigo..............2520(d)Nystagmus..................534.Neighbourhoodsigns:(a)Anosmia....................257(b)Opticatrophy,andFosterKennedy-Patonsyndrome......2575.X-rayevidences:Calcification,hyperostosis..............4033thecerebe
llarsignswerealsooutspoken.Theremightthenbeaconflictintheobserver'smindastowhichsignswerethemorereliable.Itisbetternottogetinvolvedinthatproblematthisstage,sowewillgobacktothesignsofraisedpressure.Unlesstheseareinsistenttheideaofatumourbeingpresentisscarcelylikelytoarise.Thisis,alas,onlytootrueandmanyapatientwithafrontaltumourhasbeenthoughttobeahystericortobeatfaultinsomesystemotherthanthenervous.Itisagoodworkingruletoattributenervoussymptomstothenervoussystem.Thepractitionerisnotalwayssoreadytodosoasheshouldbe.Headachesareoftendismissedasbiliousormigrainous,vomitingasduetogastricorothersub-diaphragmaticdisorder,andthesymptomsotherwisegenerallyattributed,ifsexandagemakethatpossible,tomenopausaldis-turbances.Unlessthepatienthasafitorthedoctoranophthalmoscopethingsmaydragonindefinitelyinthiswayuntilthetumourisin-operable.Afatalityatthislatestagemaycon-firmthedoctor'simpressionthatbraintumoursareveryriskythingsandthatmostpatientsdieofthem.Althoughtheremustofcoursebeasub-stratumoftruthinsuchanopinion,otherwiseitwouldnothavearisen,themoreconscientiouswouldmoreproperlywonderwhetherthepicturewouldnotbedifferentiftumourswerediagnosedwhentheyweresmall.Theyneverwillberecog-nizedatthatstageunlessthepractitionerstowhomthe-patientsfirstgowiththeircomplaintsare'tumourconscious'andreadytosuspectabrainlesiononlittleevidence.Thelasttenyearshasshownaremarkableimprovementinthisdirectioninthiscountry,forwhichpraisemustbegiventohimtowhomitisdue,thefamilydoctor.i.Generalpressuresigns.Thereisnothingverynoteworthyabouttheheadachesfromwhichthesepatientssuffer.Theyareoftennotverysevere,buttheyarecontinuousandprogressive.Theydonothavetheparoxysmalqualitiesofthepainproducedbysometumoursintheposteriorfossa.Thepainmaybeunilateral,andthenitisgenerallyonthesamesideasthetumour.Ithastobedifferentiatedfrommigraineinwhichthepainiscommonlyunilateral,maybeaccompaniedbyfleetingvisualdisturbances(teichopsia)andbyvomiting,butitdatesbackcommonlyoveryears,iswellspacedintime,andperiodical.Itdoesnothavethecontinuouslyworryingcharacteroftumourheadache.Somepatientswithtumour,andevenwithveryhighpressure,havenohead-acheatall,butthankstotheworkofPickeringinEnglandandofHaroldWolffandhiscollaboratorsinNewYorkitappearsprobablethatheadacheiscausedbydistortionofbrain-meningealrelation-ships.Theonlystructureswithintheskullinwhichpaincanbeexperimentallyinducedarethebasaldura,thegreatvesselsandthecranialnerves;paincannotbecausedbystimulatingthebrainitself.Itappearsthereforethatatumourcausesheadachebyslightrotationsordragssuchasdistorttherelationshipofthebraintothepain- 136POSTGRADUATEMEDICALJOURNALMarch1950sensitivestructuresmentioned.Whenapatienthasnoheadacheandyethasatumourweassumethatinsufficientdisturbanceofintraduralrelation-shipshasoccurred.Changesintheopticdiscs,papilloedemaandcongestionofthenerve-headsarepresentinmostcases.Itisundoubtedlypossibleforatumourintheanteriorfossatoattainsomesizebeforeanypressuresignsarise.Thebraindoesnotsotightlyfillitsmembranesandbonycapsulethattheslightestencroachmentontheintracranialspaceleadstoclearlyrecognizablecerebralembarrassment.Asmalltumourintheposteriorfossawillcausetroublemuchearlierthanoneintheprefrontalregionbecauseitwillinterferewiththecirculationofthecerebrospinalfluid.Inthatcasethemassoffluidinthedilatedventriclesmustbeaddedtothatofthetumouritselfifwewishtocomparetumoursizeswithtumoureffects.Equallyasmallmeningiomaspringingfromthesphenoidalwing,buryingitselfinthebrainandhinderingtheout-flowofcerebrospinalfluidfromthelateralven-triclewill,intheend,causemoredisturbance
thanamuchlargertumouratthefrontalpole.Theoutflowofcerebrospinalfluidmaybeinterferedwithbythecrebraloedemawhichissocommonanaccompanimentofthegliomas,andwhichitselfaddstothebulkofthetumourproper.Itislesscommoninmeningiomas(thoughitcanoccurwiththeseaswell)andthusitcomesaboutthatafrontaltumourspringingfromthemeningesoftheconvexitymayattainaconsiderablesizeoveranumberofyearsbeforeitsbulkiscomparablewithaglioma.Someofthegliomas,tobesure,areveryslowgrowinganditisnotsorareasmightbeimaginedtohaveafive-year,aten-yearorevenlongerhistorywithtumoursofthissort.Nearlyalloftheseareastrocytomas.Andsincethistumourtendstoweaveitselfamongstthenormalneuralstructures,andeventopushthemononeside,disturbancesoffunctionarenotnearlysoobviousorsoearlyastheyarewiththemalignanttypesofglioma(especiallythedreadedspongioblastomamultiforme,still,inspiteofradiotherapy,anincurablelesion).Vomitingisarareandalwaysalatesymptom,aswillbededucedfromtheforegoingconsiderations,foritrequiresforitsproductioninvolvementofcentreseitherintheregionofthethirdventricle,thehypothalamusortheposteriorfossa.2.Signsandsymptomsduetointerferencewithlocalbrainmechanism.(a)Tremorhasalreadybeenmentionedandisrarelyanoutstandingsignorcomplaint.Muchmoreimportantareepilepticfits.Theseoccurinabout50percent.offrontaltumours,andtheyareoftenalmost,orevenquite,indistinguishablefromtheidiopathicvariety.Theyarecommoneringliomathaninmeningiomacases.Ifthetumourspreadsfarbacktowardsthemotorareathemyoclonicmovementsmaypre-ponderateinthecontralaterallimbsandmayrarelybeJacksonian.Mostoftentheconvulsionscomewithoutwarningorwithanuninformativeaura.Theimportanceofthisapparentlyidiopathiccharacteristicisthatthefitsmaybetheonlysignofatumourformonthsoryears.Howarewetodistinguishfitsofthiskindfromtheidiopathic?Onlybygeneralinferenceandbyauxiliarytests.Thevastmajorityofidiopathicepilepsiesbeginbeforethepatientis20yearsold.Asageadvancestrueidiopathicepilepsybecomesrarer,anditisourdutytosearchmostcarefullyforacauseinallpatientsinwhomitstartsduringthethird,fourth,fifthandlaterdecadesoflife.Thefactthatthefitbeginswithturningoftheheadtotheoppositesideisnotdiagnostic,becauseagreatmanyyouthfulepilepticsdothat.JamesCollier(1929)thoughtthatpointimportant,butsomethingelsethatheobservedseemstothewritermuchmoreso-thetendencyofthesefitstobemultiple,toapproachortoattain'statusepilepticus,'ifthereisatumourinthefrontallobe.Thishascertainlybeensoinsomeofmyowncases.If,therefore,amanorwomanintheforties,letussay,beginstohavegeneralizedfitsandatthesametimehead-acheandsomeunaccountablefallingoffinworkingpowersweoughtcertainlytosuspectthatafrontaltumourispresent.Ifthereisasyetnopapil-loedemathebestplanwillbetoexaminethecerebro-spinalfluidforpressureandforraisedalbumencontent,andtomakepneumogramsorelectro-encephalograms.(b)Lossofmemoryforrecentevents,somesubtlealterationinpersonality,lossofapplicationatworkandfailuretorecognizethatdutiesmustbecompleted,lossofreticenceanddecency,arefrequentlyencounteredinpatientswithfrontaltumours.Completemoralbreakdownsothatthepatientbecomesdelinquentorliabletoimprison-mentforhisactsisinthewriter'sexperienceveryuncommon(onecaseonly).Muchmorecommonisittofindthepatientgoodhumouredanddocile,thoughgivenattimestoperiodsofunreasonable-nessimpenetrabletopersuasionorargument.Fewofmyfrontaltumourserieshaverealizedtheseriousnessoftheircondition,fewhavebeenworriedattheprospectsofanoperation,whichtothelaymindisparticularlydangerous,fewhavebeenbotheredaboutmoneymatters,theexpenseordurationoftheirillnesshasbroughtnoanxietiesorquestionings.Theyhaveacer
tainamountofinsight,fortheymaybebroughttounderstandperfectlywhatisthematterwiththem,buteventhentheyseemtobesparedanxietiesofareallyworryingkind.Thereisnodoubtwhateverthatallofthemental March1950JEFFERSON:TumoursoftheFrontalLobe137troublessofirmlylinkedinourmindsuntilre-centlywithtumoursofthefrontallobesalsooccurwithtumourselsewhere.Astheresultofex-periencesintheunilateralremovalofthefrontallobesinmanthewriterhasbeendriventotheconclusionthatalthoughthefrontallobeshavemuchtodowiththeworkingsoftheintellect,andofallthefacultiessubsidiarytoit,thattheyarenotitsoneandonlyseat.Norcananydifferencesbedetectedwhetheritbetherightlobeortheleftthatisexcised.Ifafrontallobeisremovedthepatientisleftquantitivelywithlessneuraltissuethanhehadbeforetocarryonhislifeandthought,todirecthisconduct.Somuchisobvious.Butwhatcouldnothavebeenforetoldisthatthedeprivationmakesremarkablvlittledifferencetohim.Itisclearthatthoughtprocessesarenotsointensivelycultivatedinthefrontalcortexthatremovalofapartleadstopermanentlossofsuchandsuchafacultyofthemind.Itwouldhavebeenveryinterestingifitwereso,foracarefulcorrelationstudyofpathologicalmaterialandoftheobservedclinicalfactswouldhaveledtotheestablishmentofindividualhumanfacultiesindifferentareasofthecortex.Somemighthavebeenintherightlobe,someintheleft.Suchanarrangementwouldhavecompletelyjustifiedthephrenologists,GallandSpurzheim,thefirstlocalizersoffunction.Thefactsare,ofcourse,quiteotherwise.Functionisdiffuselysowninthebrain,thoughnoonewoulddenythatitisheavilyconcentratedincertainparts.Thegreatestmentaldefectsarecausedbybilateralfrontallesionsorbytumoursofthecorpuscallosum,whichbycuttingcorn-missuralfibresimpairtheactivitiesofbothlobes.Mesiallyplacedfrontaltumoursareveryapttoinvadethecorpuscallosum.Severesymptomswillalways,therefore,suggestcallosalinvolvement.Mentalpower,inFosterKennedy's(I91i)words,dependsontheexquisiteintegrationoftheentirebrain.Disturbancesofcommissuralfibresandtractsleadstoanupsetinthisintegrationfarmorethandoescorticaldamage,whichisinhumanpathologyrarelydiffuse.Itisworthmakingthegeneralizationthatthekindofmentalalterationwhichbraintumoursbringaredementias,thedetailedpatternsofwhichdependonthepreviouseducationandpersonalityofthesufferers.Butgenerallytheytaketheformoflossofpreviousabilities.Schizophreniccharactersdonotoccur-andwouldnotexceptinthosewhoarealreadyschizophrenes.Noisinessandrestlessnessaremostseeninfolkwhoarenoisyandrestlessbynatureandthisistrueofheadinjuriesaswell.Remarkabledisturbancesofpersonalitysome-timesfollowlefttemporallesions,neoplasticorotherwise.Highintracranialpressure,whereverthelesion,interferingasitdoeswiththeactionsofthebrainasawhole,iscapableofcausinggreatchangesinalertnessandinthought,andexamplescouldbebroughtforwardofaclearfrontallobesyndromewhenthetumourwaslaterprovedtobeelsewhere.Wemustthereforebewaryofacceptingmentalpeculiaritiesasincontrovertibleevidenceofafrontallesion.Ifthesechangesarepresentinapersonwithnosignsofhighpressurethatwouldbebetterevidence.Incontinence.Inthehighlycompressed,drowsyorstuporouspatientincontinenceiscommonwhereverthelesionis.Normallyfewindividualspastinfancymicturateatthefirstfeelingofdesiretodoso,theyhaveacquiredinhibition.Thedrowsypatientrevertstochildhood'sstateandmaywetthebedlikethesleepychild.Butforanadulttodosowhilstawakeisalwaysapositivesign,usuallyofafrontallesion-itisaspositiveapieceofevidenceaspapilloedemaorapositiveBabinski.Somepatientsaregreatlydisturbedbysucheventsbutexplainthatthebladderemptiesbeforetheycanpreventit,asiftheirpowersofinhibitionhavevanished.Web
elievethatthecorticalinhibitorypathwaystothebladderarechieflysubfrontal,linkingthefrontallobestocentresinthehypothalamus.Incontinenceisacommonhappeningafterthedeepbifrontaltransactionsofcompleteleucotomy,rareafterlimiteddorsalfrontalcuts.Butalthoughthereisprobablyananatomicalbasisinfibre-tractdis-connectionsinfrontaltumours,thethoughtfulmaybeinterestedtopursuetheirownreflectionsonthesubjectofinhibitionofmicturitionandtheeffectsthatsleepinessalonemightexerciseuponit.Butitcannottoooftenberepeatedthatincon-tinenceduringwakefulnessisasignwithlocalizingvalue.Inthehighlycompressed,drowsyorstuporouspatientthiscallsfornospecialcomment.Butitisanothermatterifitoccurswhenthepatientisconscious.Itisthenstronglysuggestiveofafrontallesion.Intheanalvticaltableof50frontaltumoursitwillbeobservedthatmentalandmemorydefectsoccurasanearlysigninlessthanone-thirdofthepatients.Asalatesigntherearefewpatientswhodonotshowsomealterationfortheymustalleventuallybecomedrowsyandin-continent.Thesealterationsareduetohighpressureandareverysimilarwhateverpartofthebrainthetumouraffects.(c,d)Betterstillwouldbetheadditionalpresenceofanaphasia,adifficultyinsayingwhatthepatientwishesthoughhedeclaresthatheisperfectlyclearheaded.Thiscanonlyoccurwhenthetumourisontheleftside(withtheusualreservationofrighthandedness)andfarback.Similarlyslightpyramidalsigns,absentabdominalreflexes,maysuggestthesideofthetumourifnot I38POSTGRADUATEMEDICALJOURNALMarch1950itssite.Sachshasstressedparticularlyweaknessofthefaceontheoppositeside;thiscertainlyoccursbutitisasfrequentwithtemporaltumours.NonethelessSachs'studiesoffrontaltumoursareimportant;heregardsfits,mentalchanges,andnystagmusasmostimportantsigns.Agraspre-flexmaybepresent,thatreflexactionbywhichthepatientwillalwaysclenchholdofanythingwhichsotoucheshispalm.IthasbeenadmirablydescribedbyAdieandMacdonaldCritchley(1927).Weaknessofthelegisrareinfrontaltumourpatients,becausethemotorareaslantsforwardofferingthefaceareamostreadilytothetumour.(e)Thecerebellarsignsshownbysomefrontaltumourswillbestbedealtwithinthedifferentialdiagnosis.3.Neighbourhoodsigns.Theolfactorytractsaresocloselyappliedtotheundersurfaceofthefrontallobesthattheircompressionbysub-frontaltumoursiswellimaginable.Completeanosmia,ononeorbothsides,israreunlesstheolfactorybulbsaredisorganized,ashappenschieflywhenthereisanolfactorygroovemen-ingioma.Elsberghasintroducedmoredelicatetestsforestimatingdepressionofthesenseofsmellshortofcompleteloss.Special,eventhoughsimpleapparatus,isnecessaryandoutsidehospitalitwillsufficeiftheclinicianteststhesenseofsmellwithwhatevereasilyidentifiableodourshecanfindtohand.Thesetestsmustberemem-bered,forespeciallyifthelossisunilateral,thepatientmaybeunawareanddoesnotmentionit.Whenitisbilateral(intheabsenceofnasaldisease)itisalwaysimportant,alwaysorganic,thoughitcanbeafalselocalizingsign(Cushing,I9I6).Unilateralopticatrophycausedbythepressureofafrontaltumourbearingheavilyonthenerveofthesamesideisanextremelyimportantsign.ItwasfirstgivendiagnosticsignificancebyLesliePaton,andworkedupwithillustrativecasesinanimportantpaperbyFosterKennedy,whosenameisusuallyattachedtothesyndromeofatrophyoftheopticnerveonthesideofthetumour,papilloedemaintheuncompressednerveoftheoppositeside.Ofrecentyearsthesignifi-canceofunilateralopticatrophyhasmoreandmoreimpresseditselfonophthalmologistsandneurologists.Itisanorganicsignofthefirstorder,andnevermoresothanwhentheoppositediscisoedematous.Itspresencemeansexactlywhatthefactsindicate.(Thepresentwriterhaspublishedastudyofcompressionoftheopticchiasmabygliomasanddiscu
ssedthissyndromefully,DoyneLecture,Trans.Ophth.Soc.,45,I945.)Theopticatrophycanbeaswellpro-ducedbyatemporaltumouras-byafrontal(seeFig.I24inW.R.Henderson'sessayontheanteriorbasalmeningiomas,1938).Alsoonemustbewareofbeingdeceivedbyanatrophyconsecutivetoseverechokingofthediscswhichhasbecomemorecompleteononesidethantheother.4.NospecialcommentisrequiredbytheX-rayevidencesexcepttosaythatanumberofthebenigngliomascalcifyandthatthepatternsofthesecalcificationsneedanexperteyetorecognize.Theymaybeveryfaintandeasilyoverlooked.Ofrecentyearsangiographyhasprovedofgreatuseinthefinaldiagnosisofbraintumours,itsadvantagebeingthatitwilloftenenoughgiveevidencenotonlywhetheratumourispresentandwhereitis,butwillalsoindicateitsnature.Itisparticularlysuccessfulwiththemeningiomasbecausetheirself-containedfinecapillaryshadowmakesawell-definedmassintheX-rayfilm.Equally-itmaydemonstrateanunsuspectedangiomaorthewildvascularpatternofamalignantglioma.DifferentialDiagnosisWewillassumethatthefitsandmentalchangesfromwhichourhypotheticalpatientcouldsufferhavebeenprovednon-syphiliticbyanegativeWassermannreaction.Thechiefdifferentiationnecessarywillbebetweeneithertemporalorcerebellartumours.Temporaltumoursequallyproduceraisedpressure(onlymoreearlybecausetheytendtocompressthethirdventricle),facialweaknessandfits.Therearetwopointspeculiartotemporallobetumours-uncinatefitsandhomonymousvisualfielddefects.Ifneitheroftheseispresent,differentialdiagnosiscanonlybearrivedatbymechanicalmeans.Thepossibilityofcerebellarsignsinfrontaltumourshasalreadybeenmentionedonceortwice.Thispossibilityofconfusionisbroughtaboutbytheimportantpathwayswhichleavethefrontallobesandruntothepontinenuclei,theretoberelayedtothecerebellumandlabyrinthineapparatus.Butitcanbesaidatoncethatafull-fledgedcerebellarpictureisnevergivenbyfrontaltumours.Thesymptomsandsignsaresuggestiveandnomore.Whythenshoulddiffi-cultieseverarise?Thereasonisthatcerebellartumoursthemselvesfrequentlygiverisetosymp-tomsandsignswhicharescarcelymoreobtrusiveorclassical.TheclinicalpicturewhichGordonHolmes(1922)hasmadesowellknownisbestseenininjuriesorvascularinsultsofthecerebellum.Itcan,ofcourse,occurinpatientswithtumours,too,butnotsooftenasmightbethought.Evennystagmusitselfmay,ifrarely,beminimalorabsentincerebellarlesions.Itisquitecertainthatthecoarse,unmistakablenystagmusofsomecerebellartumnoursneveroccurswithfrontal. March1950JEFFERSON:TumoursoftheFrontalLobe139Beforehavingrecoursetoangiographyorventriculographythecorticalpotentialsshouldbestudiedelectronically.Sometimesextremelyac-curatelocalizationcanbegivenbythesemeansbyalterationsofpotentials,phasereversalsandsoforthasGreyWalter,DenisWilliamsandGeorgeDawsonhaveshown.Electro-encephalographyhasbecomeanessentialexplorationoforganiccerebrallesions.Furtherinformationcanbeobtainedbyangiographyorventriculography.OperationsonFrontalTumoursIngeneraltheattackonafrontaltumourfollowsthelinesgenerallyadoptedinneurosurgery.Itisassumedthattheaimistheremovalofthetumour.Thiscansometimesbeeffectedbyenucleation,inothercasestheextentandpositionofthetumourmakethesacrificeofthelobeunavoidable.Thelobemayhavetobeexcisedtogiveaccesstoatumourbeneathit.Thestepsoftheoperationareasfollows.Anincisionismadeinthemid-linebackwardsfromapointjustabovetheglabellatooneinsidethehairline.Thecosmeticresultissuperioriftheincisionisveryaccuratelyplacedinthemid-line.Havingreachedthehigherpointtheincisioncurvesoverthescalptofallverticallytowardstheearwhichitshouldreach.Thescalpflapshouldbefirstmarkedoutwithiodineandthenwithascratch.Novocaine-adrenalinsolu
tion(ipercent.)istheninjectedalongtheproposedlineofsection.Thewholescalpflapisdissecteddownwardsandforwards,freefromthebone.Greatcaremustbetakenbyfingercompressiontokeeptheblood-lossduringthecuttingofthescalpflapdowntoafewcubiccentimetres.Suitablepointsarenowchosenformakingdrillholes,avoidingthefrontalairsinus.Thebonedustobtainedinmakingtheholesissavedforreplace-mentatthecloseoftheoperation.Theholesaremostsafelymadebybraceandperforatorandburrworkedbyhand.AfterseparationoftheduramaterfromthebonetheholesareconnectedwiththeGiglisaw.ThebaseoftheboneflapinthetemporalfossamaybenarrowedwithdeVilbissforceps;itisthenbrokendown,hingedonthetemporalmuscle.Thebleedingfromtheexposedduraisusuallynegligible,andiswellcontrollablewithwetcottonorlintine.Ifbleedingissevereeitherthereisameningiomabeneaththedurawithawideattachmenttoit,ortheanaestheticiswrongortheairwayimperfect.Itisagreathandicaptogoodsurgerytohaveahighintra-cranialpressure,hencetheneedforearlydiagnosis.Thepatient'schancesofrecoveryaregreatlyen-dangeredifthebraintendstobulgeirresistiblythroughaduralincision.Ifthepressurecannotbeloweredbypunctureofanintracerebralcystoroftheventricleitwillbewisertobreakofftheoperationbeforemoreharmisdoneandtryagainunderlocalanaesthesiaalonelater.Supposingthattheduracanbesafelyopenedthisisnextdone,cuttingitbelow,infrontandbehind.Thecortexisnowinspectedforevidenceoftumour,whichmaybeveryclear.Ifnotitwillbefoundbypuncture.Therecognitionofthepresenceofatumour,ofitsextentandespeciallyofitsnatureneedsconsiderableculture.Itisonthisvitalpointthatthegeneralsurgeonwassoconstantlydefeated.Ifexcisionofthefrontallobeisdecideduponthecorticalveinsenteringthesuperiorlongitudinalsinusarefirstcoagulatedsothatthefalxisclear.Thisnecessitatesaboneincisionexactlyonthemid-line.Ahalf-orone-inchover-hangwillgreatlyhamperthesecuringoftheseveins.Whenclearlyseentheyareeasilydia-thermizedanddivided.Thelineofcorticalin-cisionis-nextplannedonthesurfaceofthebrain,theveinstobecutcoagulatedandthearteriesoccludedwithsilverclips.Thelineofthissectionwillcommencebelow,asarule,atthejunctionoftheanteriorandmiddlefossae.Theincisionintothebrainisbestmadewithanarrowbluntdissector,whichallowstherecognitionofdeepvessels.Theanteriorhornofthelateralventriclemaybecutacrossifthetumourhasnotpushedittoofarback.Thisdoesnotmatter.Theonlydifficultymaybetheclippingoftheanteriorcerebralarteryonthemesialsurfacedeepin.Aftertheorbitalsurfaceofthebrainhasbeencutthrough,thewholelobeisliftedout.Allbleedingpointsaresecured,thelargecavityfilledwithRinger'ssolutionandtheduraclosed.Asmalldraincanbeleftinbetweenboneanddurafor24hours,butitiscertainthatdailyaspirationsoffluidwillhavetobemadeduringthenextweekortendays.Thedeadspaceeventuallysettlesdown,itmaypermanentlycommunicatewiththeventricle.Lobectomygivesthepatientthebestchanceoflongsurvivalandobeysthesurgicalmaximofblockremovalofnon-enucleabletumours.Innoneofthewriter'scaseshastherebeenanyimportantmental,moralor-otherdisabilityastheresultofit.Theprognosisdependsonthenatureofthetumour.Itisexcellentinthemeningiomasandangiomas,hopelessinthemalignantgliomasandintermediateinthemorebenigngliomas(astro-cytomas).Thewriterhashadseveralpatientswithastrocytomaswhohavesurvivedfiveyearsandafewwholivedusefullyforovertenyearsafterfrontallobectomy.Thegreatadvantageoftheoperationisthatitleavessolargean'internaldecompression'thatgivenaveryslowlygrowingtumourthespaceservesthemwell. 140PENNYBACKER:Pituitary,PinealandThirdVentricleTumoursMarchI950'....-}............FI.ii-CacfctonRtkocuorihl.Ntlocnouinltinnfvutadsprtoofsu