中枢神经系统感染 (英文)

FocalCNSInfectionsAnatomicRelationshipsoftheMeningesBoneEpiduralAbscessDuraMaterSubduralEmpyemaArachnoidMeningitisPiaMaterBrain2AnatomicrelationshipsoftheBrainFrontalLobeFrontalandEthmoidalSinusesSellaTurcicaSphenoidalsinusesTemporalLobeMiddleEar,Mastoid,MaxillarySinusesCerebellum,BrainStemMiddleEar,Mastoid3BrainAbscess50%-LocalSourceotitismedia,sinusitis,dentalinfection25%Hematogenousspreadadults-lungabscess,bronchiectasisandempyemachildren-cyanoticcongenitalheartdisease(4-7%)pulmonaryAVM-Osler-Weber-Rendusyndrome(5%)rarelybacterialendocarditis10%trauma/surgery4BrainAbscess-pathologyLocationtemporal>frontal>otherlobes>10%aremultipleStages-basedonhistologicfindings1.Earlycerebritis-poorlydemarcatedfromsurroundingbrain2.Latecerebritis-reticularmarix(collagenprecursor)anddevelopingnecroticcenter3.Earlycapsuleformation-neovascularity,necroticcenter,developingcapsule4.Latecapsuleformation-collagencapsule,necroticcenter,gliosissurroundingcapsule5EarlyAbscess(Cerebritis)–Poorlylocalizedareaofdiscolorationandsoftening.6LaterCerebritic/EarlyAbscessStage–increasingnecrosisofcenterwithbeginningsofcapsuleformation7Matureabscess(LateStage)-densefibro-glioticcapsularwallandpurulentcenter8BrainAbscess-microbiologyStreptococcusmostfrequent(33-50%),Multipleorganisms(80-90%)ofcases,Mayalsoincludeanaerobes(Bacteroidessp.)Whensecondarytofrontal-ethmoidalsinusitis:Strep.Milleri,Strep.AnginosusWhenfromotitismedia,mastoiditis,orlungmultipleorganismsincludinganaerobicstrep.,bacteroides,enterobacter(proteus)PostTraumaticAbscessinclude:Staph.aureusandEnterobacteriaceae:9Abscesswall–innerportionformedbyalayerofneutrophilsandfibrin,middlelayerwithmainlyfibrin(Blueontrichromestain)andtheouterportionwithreactiveglia.10Pyogenicmeningitis–notetheneutrophilsarecollectedinthesubarachnoidspace.11BrainAbscess-ClinicalPresentationSymptomsarenon-specificforabscessandarenormallyduetoincreasedintracranialpressure/masseffect:Headache,Nausea/Vomiting,orLethargy.OccasionallySeizures.12Abscess–CTpresentationCTappeareancedependentonstageCerebriticstage–thickdiffuseringofenhancement,furtherdiffusiononcontrastintocentrallumenorlackofdecayofcontrastondelayedscan30-60minuteslater.Capsularstage–faintrimpresentonprecontrastCT.(Necroticcenterwithedematoussurroundingbrainmakesthecollagencapsuleeasiertosee.).Thinringonenhancementandthereisdecayofenhancementondelayedscans.13Abscess–MRIpresentationMRIpresentationalsovarieswithcapsuleformationEarlyCerebriticstage–hyperintenseinT2withpoorcontrastenhancementonT1.LaterCerebriticStage–centralregionofnecrosisishyperintensetobrainonT2,rimisisointensetomildlyhyperintenseonT1.Thecapsuleenhanceswithcontrast.EarlyandLateCapsuleStages–CapsuleiseasilyvisibleonunenhancedscansasawelldeliniatedisointensetoslightlyhyperintenceringwithbecomeshyperintensewithcontrastonT1.CapsuleishypointenseonT214Intraparenchymalabscess15InitialmanagementofBrainAbscessBloodCultures(rarelyhelpful)LProleisdubiousbecauseofriskoftranstentorialherniation.CSFistypicallyabnormalbutculturesareusuallynegative.initiateantibiotictherapy(preferablyafterbiopsyspecimenisobtained),regardlessofwhichmanagementmodeischosen.16BrainAbscessAntibioticsIfpathogenisunknownorSaureusissuspected:Vancomycin-Adult1gmq12hoursPLUS3rdgenerationcephalosporin(e.gClaforan)PLUSMetronidazoleAdult(30mg/kg/d)dividedq12orq6hoursORChloramphenicolAdult1gmIVq12hoursORforposttraumaticabscessuseporifampin9mg/kg/dqd17BrainAbscess-medicaltreatmentMedicaltherapyaloneismoresuccessfulif:ThetreatmentisbegunbeforecompleteencapsulationThelesionis0.8-2.5cmindiameterorless (3.0cmisthetypicalcutoff)Thedurationofsymptomsis<2weeksThepatientsshouldshowimprovementinthefirst2weeksoftreatment18BrainAbscess-surgicaltreatment,indicationssignificantmasseffectexertedbylesionproximitytoventriclepoorneurologicalconditionInabilitytoobtainweeklyCTscansInpatientundergoingmedicaltreatmentIntervention,ifneurologicaldeteriorationoccurs,anatomicprogressionofabscesstowardsventricles,orafter2weeksoftherapyifabscessisenlarged.Alsoconsiderifthereisnodecreaseinabscesssizeby4weeksoftreatment.19BrainAbscess-surgicaltreatmentmodernmethodsNeedleaspiration-recommendedforthinwalled(immature)ormultiplelesionsSurgicalexcision-onlycanbeperformedonmatureabscessHistoricalmethodsTubedrainage-34%moralitymarsupialiaztion-removeoverlyingcortexandpack-23%mortalityDecompressivecraniectomywithspontaneousmigrationofabscess20TreatmentofBrainAbscessin1895Ifsymptomsofabscessexist–trephinetheskillatonce.Iftherearelocalizingsymptomsopenoverthatregion.Ifpusisnotfoundintheepi/subduralspacesandthebrainbulgesverymuchandisnotseentopulsatetheninstertagrooveddirectorto2.5inches,ifnopustheredirectandreinsert.211895medicinecontinuedWhenpusisfound,incisethebrainoverlyinghecavity.Scrapeoutthegranulationtissueintheabscesscavity.Irrigatewithhotsaltsolution.Placearubberdrainagetubetoexternallydrain.Closeduraandskin.Slowlyremovetherubbertubeoverthenext4-7days.(Pennicillin–1943)22Mortality/Morbiditypre-CTera-40-60%moralitypostCTera-0-10%(Improvementduetobetterantibiotics,surgicalmethodsandabilitytodiagnoseearlier)neurologicdisability45%latefocalorgeneralizedseizures-27%hemiparesis-29%23Multipleabscessesina6yearold24Presumedsourceofpolymicrobialabscesses.25CerebellarAbscessfromopenskullfracture.26SubduralEmpyemaLocatedinthepotentialspacebetweentheduraandthearachnoid.Mayspreadrapidlyduetolackofanatomicalboundaries.LessmasseffectthanbrainabscessSurgicalEmergencyUsuallyfromalocalsourceofinfection>50%stemfromaparanasalsinusitis(fronto-ethmoidal)traumaorsurgeryprogressionofanepiduralabscess,ostermyelitis27EtiologiesofSDEparanasalsinusitis-67-75%otitis-14%postneurosurgical-4%trauma-3%meningitis(mainlypeds)-2%congenitalheartdisease-2%other7%28SubduralEmpyema-clinicalfever-95%focalneurologicaldeficit(mainlyhemiparesis)-80-90%nuchalrigidity-80%headache77%Seizures-50-60%Foreheadoreyeswellingfromemissaryveinthrombosis-30%Vomiting-20%Maletofemaleratio-3:129SubduralEmpyema-evaluationCTofheadbothwithandwithoutcontrastLP-hazardous-riskoftranstentorialherniationLocation- convexity70-80% falcine10-20%32/10,000autopsies30Subduralempyema-BacteriologyAerobicStreptococcus-30-50%Staphylococcus-15-20%Microaerophilicandanaerobicstrep-15-25%AnaerobicGmnegativerods-5-10%other5-10%31ManagementofSubduralempyemaCraniotomy-relativelyemergencytodebrideanddrainwidecraniotomyisusedbecauseofseptations/loculationsAntibiotics-initiallyVancomycinandchloramphemicolORCefotaximeandflagylModifybasedoncultureresults32Meningitisprogressiontosubduralempyema33SubduralEmpyema34IntracranialEpiduralAbscessLocalizedbetweenduraandbonesharplydefined-mainlybeduraladherencetoboneatsuturelinesfocalosteomyelitisassociatedwithsubduralempyemaManagementandetiologysameassubduralempyema35MixedAbscessLocation36SpinalEpiduralAbscessclinicalpresentationbackpainfeverspinetendernessmajorriskfactorsdiabetesIVdrugabusechronicrenalfailurealcoholism37SpinalEpiduralAbscess-Exammyelopathicdistaltolesiondeteriorationofexamwithtimeclassicpresentationofa“skinboil”in15%ofpatientsPatientscomplainofexcruciatingpainlocalizedtothespineAlsomaynotebowel/bladderdisturbances38SpinalEpiduralAbscessAveragetimecourseBackpaintorootproblems-3daysRootproblemstoweakness-4.5daysWeaknesstoparaplegia-24hours39SpinalEpiduralAbscessEpidemeology.2-1.2/10,000hospitaladmissions40-60yearsoldincidenceincreasing40SpinalEpiduralAbscess-sourceHematogenousspreadSkininfectionsParenteralinfections(IVDA)BacterialendocarditisUTIRespiratoryinfectionDentalabscess41SpinalEpiduralAbscess-sourcedirectdecubitusulcerpsoasabscesstraumapharyngealinfectionmediastinitispyelonephritis42SpinalEpiduralAbscess-sourceFollowingspinalproceduresopenprocedureforexampledisectomyclosedprocedureLPEpiduralcatheterNosourcein50%ofpatientsinsomeseries43SpinalEpiduralAbscess-locationCervical–15%Thoracic-50%Lumbar-35%PosteriortotheCord-82%44SpinalEpiduralAbscess-treatmentSurgerygoalistodeterminecausativeorganismanddebridementisnecessaryimmobilization-infectedsegmentsmaybecomeunstableNon-surgicalmanagementindications:patientswithprohibitiveoperativeriskfactorsinvolvementofanextensivelengthofthespinalcanalcompleteparalysisfor>3daysabsenceofneurologicaldeficit(controversial)45SpinalEpiduralAbscess-treatmentAntibiotics3rdgenerationcephalosporinPLUSVancomycin-untilMRSAisruledoutPLUSRifampinpoDurationoftreatment3-4weeksIVfollowedby4weeksofpomortality18-23%46Discitiswithlocalosteomyelitisandepiduralempyema47ParasiticInfections-CysticercosisMostcommonparasiticinfectioninCNSCausedbylarvalstageofTaeniasolium-porktapewormIncubationperiodfrommonthstodecades83%ofcasesshowsymptomswithin7yearsofexposureInfectionwiththeadultform-tapewormingutmanistheonlyknowpermanenthostforthewormeggsareexcretedinthefeces-doesnotcauseneurocysticercosis48ParasiticInfections-CysticercosisInfectionwiththelarvaanimals(pigs)serveasanintermediatehostlarvaburrowthroughthesmallboweltogainaccesstothesystemiccirculationmainlyinfectthefollowingsites:Brain(60-92%ofcases)SkeletalmuscleEyeSubcutaneousTissue49ParasiticInfections-CysticercosisCommonroutesofinfectionFood(usuallyvegetables)orwatercontainingeggsfromhumanfecesFecal-Oralautoinfection(poorsanitationhabits)Autoinfectionfromreverseperistalsis-(theorypossiblyofferedbypatientswhoautoinfectedthemselves)50ParasiticInfections-Cysticercosiscystercercuscellulosae-(3-20mm)regularroundthinwalledcyst,producesonlymildinflammationlarvaincystcystercercusracemosus-(4-12cm)activegrowinggrapelikeclustersintenseinflammationnolarvaincyst51ParasiticInfections-CysticercosisLocation:meningeal27-56%parenchymal30-63%ventricular12-18%(maycausehydrocephalus)mixed-23%Clinicalsymptomsofincreasedintracranialpressure52ParasiticInfections-Cysticercosisserologyantibodytiterssignificantif1:64intheserumand1:8intheCSFCTscanringenhancing/calcifiedlesions,multiple53ParasiticInfections-CysticercosisTreatmentSteroids-symptomaticreliefAntihelminticdrugsPraziquantal-(DOCforintestinalinfestation)- 50mg/kgdividedtidfor15daysAlbendazole-15mg/kgdividedbidpotidfor3monthsNiclosamide-maybegivenorallyforGIinfestation54Cystercercuscellulosae-(3-20mm)

regularroundthinwalledcyst,

producesonlymildinflammation

larvaincyst

55ParasiticInfections-Echinococcosis“HydatidCyst”-causedbyingestionofthedogtapeworm(Uruguay,Australia,NewZealand)Treatment-SurgicalexcisionwithoutcystruptureCystisfullofwormsAdjunctivetreatmentAlbendazole-400mgpoBIDfor28days56EchinococcusCyst–intraoperative57FungalInfectionsCryptococcosis-mostcommonfungalinfectioninCNSdiagnosedinlivepatientsCryptococcoma(mucinouspseudocyst)-occursalmostentirelyintheHIVpopulation3-10mm,mostcommonlyinthebasalgangliaCandidiasis-mostcommonfungalinfectioninCNSdiagnosedindeadpatientsrareinhealthyindividualsAspergillosisCoccidiomycosis-normallycausesmeningitis58Cryptococcosis59Aspergillosis–Abscessinthecentrumovale.(Alsomaycausediffusecerebriticinfections)Notemanysatellitelesionscommonamongfungalinfections.(Patientw