中枢神经系统感染(2)ppt课件.ppt

VIRALMENINGITIS ENCEPHALITIS Viralmeningitisreferstomeningitiscausedbyaviralinfection Childrenandyoungadultsarefrequentlyaffected Viralmeningitisismostoftencausedbyenteric肠道的virusesViralencephalitisbychildhoodexanthems皮疹 arthropod borne节肢动物agents虫媒性病原体 andherpessimplextype1 Cause 最常见柯萨奇病毒ECHO病毒肠道病毒 其次流行性腮腺炎单纯疱疹病毒腺病毒 Pathology Viralinfectionscanaffectthecentralnervoussysteminthreeways血源性播散 hematogenousdisseminationofasystemicviralinfection eg arthropod borneviruses虫媒性病毒 轴突传播 neuronalspreadofthevirusbyaxonaltransport eg herpessimplex rabies狂犬病病毒 自身免疫性感染后脱髓鞘 autoimmunepostinfectionsdemyelination脱髓鞘 eg varicella水痘病毒 influenza Pathologicchangesinviralmeningitisconsistofaninflammatorymeningealreactionmediatedbylymphocytes 病毒性脑膜炎的病理改变是由淋巴细胞介导的炎性脑膜反应 Encephalitisischaracterizedbyperivascularcuffing lymphocyticinfiltration andmicroglialproliferationmainlyinvolvingsubcorticalgraymatterregions Internuclearorintracytoplasmicinclusionsareoftenseen 病毒性脑炎的病理改变特点是血管周围套袖样改变 淋巴细胞浸润 以及累及皮层下灰质的小胶质增生 并经常可见到核浆或细胞浆内包涵体 Clinicalfindings symptomsandsigns Clinicalmanifestationsincludefever headache neckstiffness photophobia畏光 painwitheyemovement andmildimpairmentofconsciousness Patientsusuallydonotappearasillasthosewithbacterialmeningitis Systemicviralinfectionmaycauseskinrash pharyngitis咽炎 lymphadenopathy淋巴结病 pleuritis胸膜炎 carditis心肌炎 jaundice黄疸 organomegaly器官肿大 diarrhea腹泻 ororchitis睾丸炎 andthesefindingsmaysuggestaparticularetiologicagent病原体 Becauseviralencephalitisinvolvesthebraindirectly markedalterationsofconsciousness seizures andfocalneurologicsignscanoccur Whensignsofmeningealirritation脑膜刺激征andbraindysfunctioncoexist共存 theconditionistermedmeningoencephalitis脑膜脑炎 Laboratoryfindings CSFanalysisisthemostimportantlaboratorytest CSFpressureisnormalorincreasedalymphocyticormonocyticpleocytosis脑脊液细胞数增多ispresent withcellcountsusuallylessthan1000 ml highercountscanbeseeninlymphocyticchoriomeningitis脉络丛脑膜炎orherpessimplexencephalitis Apolymorphonuclear多形核白细胞pleocytosiscanoccurearlyinviralmeningitis whileredbloodcellsmaybeseenwithherpessimplexencephalitis Proteinisnormalorslightlyincreased usually80 120mg dL Glucoseisusuallynormal butmaybedecreasedinmumps腮腺炎 herpeszoster带状疱疹 orherpessimplexencephalitis Gram sstainandbacterial fungal andacid fastbacillius AFB culturesarenegative Oligoclonalbands寡克隆区带andCSFproteinelectrophoresis电泳abnormalitiesmaybepresent Anetiologicdiagnosiscanoftenbemadebyvirusisolation polymerasechainreaction oracute andconvalescentphase恢复期CSFantibodytiters抗体滴度 Bloodcountsmayshowanormalwhitecellcount leukopenia白血球减少症 ormildleukocytosis白细胞增多 Serumamylase血清淀粉酶isfrequentlyelevatedinmumps腮腺炎 abnormalliverfunctiontestsareassociatedwithbothhepatitisviruses肝炎病毒andinfectiousmononucleosis单核细胞增多症 TheEEGisdiffuselyslow especiallyifthereisdirectcerebralinvolvement Diagnosis Differentialdiagnosis Thedifferentialdiagnosisofmeningitiswithmononuclearcellpleocytosisincludespartiallytreatedbacterialmeningitis治疗不彻底的细菌性脑膜炎aswellassyphilitic梅毒的 tuberculous结核性的 fungal parasitic寄生物的 neoplastic肿瘤的 andothermeningitides脑 脊 膜炎 EvidenceofsystemicviralinfectionandCSFwetmounts stainedsmears cultures andcytologicexamination细胞学检查candistinguishamongthesepossibilities Whenpresumedearlyviralmeningitisisassociatedwithapolymorphonuclear多形核白细胞pleocytosisoflessthan1000whitebloodcells mLandnormalCSFglucose oneoftwostrategiescanbeused ThepaitentcanbetreatedforbacterialmeningitisuntiltheresultsofCSFculturesareknown Treatmentcanbewithheldandlumbarpuncture腰椎穿刺术repeatedin6 12hours Ifthemeningitisisviralinorigin thesecondsampleshouldshowamononuclearcellpleocytosis Adisorderthatmaybeclinicallyindistinguishablefromviralencephalitisistheimmune mediatedencephalomyelitisthatmayfollowviralinfectionssuchasinfluenza measles麻疹 orchickenpox水痘 Progressiveneurologicdisfunctiontypicallybeginsafewdaysaftertheviralillness butcanalsooccureithersimultaneously同时发生oruptoseveralweekslater Neurologicabnormalitiesresultfromperivenous静脉周围的demyelination脱髓鞘 withoftenseverelyaffectsthebrainstem TheCSFshowsalymphocyticpleocytosis脑脊液细胞数增多 usuallywithcellcountsof50 150 mL andmildproteinelevation Treatment Exceptforherpessimplexencephalitis whichisdiscussedseparatelynospecifictherapyforviralmeningitisandencephalitisisavailable Corticosteroidsareofnoprovenbenefitexceptinimmune mediatedpostinfectioussyndromes Headacheandfevercanbetreatedwithacetaminophen醋氨酚 butaspirinshouldbeavoided especiallyinchildrenandyoungadults becauseofitsassociationwithReye ssyndrome Seizuresusuallyrespondtophenytoin苯妥英钠orphenobarbital苯巴比妥 Supportivemeasuresincomatose昏睡的patientsincludemechanicalventilationandintravenousornasogastricfeeding鼻饲 Prognosis Symptomsofviralmeningitisusuallyresolvespontaneouslywithin2weeksregardlessofthecausativeagent althoughresidualdeficits后遗症maybeseen Theoutcomeofviralencephalitisvarieswiththespecificvirus forexample herpessimplexvirusinfectionsareassociatedwithseveremorbidityandhighmortalityrates Mortalityratesashighas20 havealsobeenreportedinimmune mediatedencephalomyelitis脑脊髓炎followingmeasles麻疹infections Herpessimplexvirus HSV encephalitis HSVisthemostcommoncauseofsporadic散发的fatalencephalitisintheUnitedStates Abouttwo thirdsofcasespatientsover40yearsofage Primaryherpesinfectionsmostoftenpresentasstomatitis口炎 HSVtype1 oravenereally性交的transmittedgenital生殖器eruption出疹 HSVtpye2 Thevirusmigratesalongnerveaxons轴突tosensoryganglia神经节 whereitpersistsinalatentformandmaybesubsequentlyreactivated ItisnotclearwhetherHSVtype1encephalitis themostcommontypeinadults representsaprimaryinfectionorareactivationoflatentinfection Neonatal新生儿的HSVencephaltisusuallyresultsfromacquisition获得oftype2virusduringpassagethroughthebrithcanalofamotherwithactivegenital生殖器的lesions CentralnervoussysteminvolvementbyHSVtype2inadultsusuallycausesmeningitis ratherthanencephalitis Pathology HSVtpye1encephalitisisanacute necrotizing引坏死的 asymmetric不对称的hemorrhagic出血性的processwithlymphocyticandplasmacell浆细胞reaction Usuallyinvolvesthemedialtemporalandinferiorfrontallobes Intranuclearinclusions核内包涵体maybeseeninneurons神经元andglia神经胶质 Patientswhorecover康复期mayshowcystic囊的necrosis坏死oftheinvolvedregions 32 可编辑 嗜酸性CowdryA型包涵体 ClinicalFinding ASymptomsandSigns Theclinicalsyndromemayincludeheadache stiffneck vomiting behavioraldisorders memoryloss anosmia嗅觉丧失 aphasia hemiparesis轻偏瘫 andfocalorgeneralizedseizures Activeherpeslabialis唇疱疹isseenoccasionally butdoesnotreliablyimplicateHSVasthecauseofencephalitis HSVencephalitisisuauallyrapidlyprogressiveoverseveraldaysandmayresultincomaordeath Themostcommonsequelae后遗症inpatientswhosurvivearememoryandbehaviordisturbances reflectingthepredilection嗜好 偏爱ofHSVforlimbicstructures LaboratoryFindings LaboratoryFindings CSF TheCSFinHSVtpye1encephalitismostoftenshowsincreasedpressurelymphocyticormixedlymphocyticandpolymorphonuclear多形核白细胞pleocytosis 50 100whitebloodcells mL mildproteinelevation andnormalglucose Redbloodcells xanthochromia黄变 anddecreasedglucoseareseeninsomecases LaboratoryFindings VIRUS ThevirusgenerallycannotbeisolatedfromtheCSF butviralDNAhasbeendetectedbythepolymerasechainreaction聚合酶链反应insomecases HSV抗体检定 ELASA是现今国际上通用的HSV抗体检测方法 本方法采用双份血清和双份脑脊液作HSV 1抗体的动态检测 诊断标准 双份CSF抗体有增高趋势 滴度1 8以上 双份CSF抗体4倍以上升高 血与CSF的抗体比值 40 LaboratoryFindings EEG TheEEGmayshowperiodic周期的slow wavecomplexesarisingfromoneorbothtemporallobes LaboratoryFindings CTMRI CTscansandMRImayshowabnormalitiesinoneorbothtemporallobes Thesecanextendtofrontalorparietalregions顶区andaresometimesenhancedwiththeinfusion注入ofcontrastmaterial造影剂 However imagingstudiesmayalsobenormal Diagnosis DifferentialDiagnosis Thesymptomsandsignsarenotspecificforherpesvirusinfection ThegreatestdiagnosticdifficultyisdistinguishingbetweenHSVencephalitisandbrainabscess脑脓肿 andthetowdisordersoftencannotbedifferentiatedonclinicalgroundsalone brainabscess brainabscess OtherCNSinfectionsandvasculitis血管炎canalsomimicHSVencephalitis Deginitivediagnosiscanbemadebybiopsyofaffectedbrainareas withthechoiceofbiopsysiteguidedbytheEEG CT orMRIfindings However becausetreatmentismosteffectivewhenbegunearlyandiscomparativelysafe themostcommonapproachistotreatpatientswithpossibleHSVencephalitisasdescribedbelowandtoreservebiopsyforthosewhofailtoimprove Treatment Themosteffe