病理学 神经系统疾病

DiseasesoftheNervousSystem神经系统病理1感染性疾病感染途径血源性感染：脓毒血症局部扩散：如中耳炎直接感染：如创伤或医源性经神经感染：单纯疱疹病毒沿三叉神经入侵细菌性疾病病毒性疾病海绵状脑病2细菌性疾病脑脓肿(brainabscess)脑膜炎(meningitis)

硬脑膜炎(pachymeningitis)：继发于颅内感染软脑膜炎(leptomeningitis)：蛛网膜、软脑膜及脑脊液的感染化脓性脑膜炎：细菌为主淋巴细胞性脑膜炎：病毒感染慢性肉芽肿性脑膜炎：由结核杆菌等引起3EPIDEMICCEREBROSPINALMENIGITIS(流行性脑脊髓膜炎）Definition:Acutepurulentinflammationofleptomeningitis,subarachnoidspaceandthespinalmeningescausedbymeningococcus（脑膜炎双球菌,Neisseriameningitidis)4EtiologyGenerally,pyogenicmeningitismaybecausedbyMeningococcus(脑膜双球菌）,pneumococci（肺炎双球菌）,streptococci（链球菌）,Staphylococci（葡萄球菌）,influenzabacilli（流感细菌）,actinomyces（放线菌）,andrarely,colonbacilliininfants.Themostimportantoftheseisthemeningococcus.5脑膜炎双球菌（学名Neisseriameningitidis），又名脑膜炎奈瑟菌或脑脊髓膜炎双球菌，简称为脑膜炎球菌，是一种革兰氏阴性菌，1887年Weichselbaum首次从脑脊液中分离出内毒素细菌表面成分菌毛：粘附器感染性强，但对外界的抵抗力较弱，存活能力差。本菌含自溶酶，如不及时接种易溶解死亡对寒冷、干燥较敏感，低于35℃、加温至50℃或一般的消毒剂即可杀死6EpidemicfeaturesSourceofinfection:PatientindiseasePathogencarrierwithoutsymptoms50%innormalpersonscouldbefoundwithNeisseriameningitidisinepidemicseason.Routeoftransmission:Airtransmission,e.g.bycough,sneezingIntimatetouch,e.g.kiss,breast-feedingSusceptiblepopulation:6monthsold–2yearsoldinpeaksusceptiblepopulation.Epidemicseason:mostinspringandwinter7Pathogenesis89Pathogenesis（脑脊髓膜炎期）（败血症）期（上呼吸道感染期）（化脓性脑膜炎）（沃-弗综合征）10MorphologyGrossly:Anexudateisevidentwithintheleptomeningesoverthesurfaceofthebrain.Themeningealvesselsareengorgedandstandoutprominently.A.Pathologicalfeaturesofpurulentmeningitis11软脑膜及蛛网膜下腔可见大量脓性渗出物，血管扩张充血12MicroscopicallyThesubarachnoidspacecontainspurulentexudateswithvaryingamountsoffibrin.Inmostseverecases,theentiresubarachnoidspaceisfilledwithpurulentexudates.Inlessseverelyaffectedcases,onlythetissuearoundtheleptomeningealbloodvesselscontainscells.13蛛网膜下腔间隙增宽，毛细血管扩张，大量炎性渗出物积聚14炎性渗出物以大量中性粒细胞和纤维蛋白渗出为主

及少量淋巴细胞、单核细胞浸润15B.PathologicalfeaturesoffulminantmeningitisInfulminantinfections,apparentsepsissymptomand signsappearwiththelessseverelypurulentexudates aroundtheleptomeningealandsubarachnoidspace, evenwithoutmeningealinflammation.Fulminantmeningitiscouldbedividedinto: Shocktypeandmeningitis-encephalitistype16Pathologicalfeaturesoffulminantmeningitis1.Shocktype:WaterhouseFriderichsensyndrome（沃-弗综合征)：两侧肾上腺严重出血，肾上腺皮质功能衰竭，表现为周围循环衰竭、休克和皮肤大片紫癜。机制：大量内毒素释放引起的DICAgroupofshocksymptoms:HighfeverandchillHeadacheandvomitingSkineruption(petechiaandecchymosis)ThecoldextremitiesandpalenessWeakpulseandlowpressureDIC(disseminatedintravascularcoagulation)1718Pathologicalfeaturesoffulminantmeningitis2.Meningitis-encephalitistype

脑膜脑炎Agroupofsymptomsinvolvingdamagesofcentralnervoussystemaccompaniedwiththetri-signsininfectiousdiseases:heavyheadache,highpyrexiaandvomiting脑实质损害的临床症状明显患者迅速进入昏迷，嗜睡，惊厥频繁锥体束征常阳性，两侧反射不等血压持续升高，眼底可见视乳头水肿部分病人发展为脑疝瞳孔明显缩小或散大，或忽大忽小191)Signsofmeningealirritation(脑膜刺激症状）2)Increasedintracranialpressure（颅内压升高症状）3)Changesofcerebrospinalfluid(CSF)（脑脊液改变）Clinicopathologicassociation20Clinicopathologicassociation1)SignsofmeningealirritationHeavyheadacheOpisthotonus（角弓反征）Kernigsign+（屈髋伸膝征阳性）Stiffneck（颈项强直）Cloudingofconsciousness21Stiffneck22Clinicopathologicassociation2)Increasedintracranialpressure

头痛、喷射性呕吐、脑疝形成、小儿前囟饱满Somedegreeofacuteinternalhydrocephalusresultsfromanincreasedpermeabilityofthechoroidsplexus,anoutpouringofexudatesintotheventricular.Thiscondition,alongwithedema,congestionofbloodvessels,andsubarachnoidexudates,increasestheintracranialpressure,whichcausestri-signsinintracranialpressure:heavyheadacheanddizziness,jetting-vomitingandherniaformation侧卧位脑脊液压超过2.0Kpa（正常：0.6-0.8Kpa）23Infulminantinfection,bacteriamaysometimesbevisibleonsmearorbereadilyculturedforafewhours beforepolymorphosappear.24结局和并发症脑积水脑神经受损麻痹：III,IV,V（三叉神经）,VI（展神经）和VII（面神经）动眼神经（III）麻痹表现为上睑下垂，眼球外斜，向上外、上内、下内、同侧方向运动障碍，瞳孔散大，对光反应及调节反应消失

滑车神经（IV）麻痹表现为眼球不能向下外方向运动，伴有复视，头呈特殊位，呈下颏向下头面向健侧的姿势脑缺血和梗死2580%以上的中枢神经系统病毒感染是由肠道病毒(enteroviruses)引起的包括柯萨奇病毒（Coxsackievirus）、埃可病毒(ECHOvirus)、脊髓灰质炎病毒(polio-virus)等其次是疱疹病毒（herpesvirus）,水痘-带状疱疹病毒（varicella-zostervirus）巨细胞病毒（cytomegalovirus,CMV）等呼吸道病毒（respiratoryvirus）、麻疹病毒(measlesvirus)风疹病毒(rubellavirus)、狂犬病病毒(rabiesvirus)、腮腺炎病毒(mumpsvirus)和虫媒病毒等也可引起病毒性疾病26中枢神经系统病毒感染的特点：绝对细胞内寄生：不同病毒定位于不同细胞或核团疱疹病毒：颞叶及顶叶眶部病毒感染的细胞出现：细胞溶解、小胶质细胞增生形成结节、多核巨细胞形成包涵体：胞质或胞核中，狂犬病毒时的Negri小体炎症细胞以淋巴细胞、巨噬细胞和浆细胞为主，形成袖套现象(vascularcuffing)27TypeBEpidemicEncephalitis

（流行性乙型脑炎）

乙型脑炎病毒感染所致的急性传染病，多在夏秋季流行高热、嗜睡、抽搐、昏迷等10岁以下儿童多见，约占50-70%全国乙脑报告病例数每年在5000～10000例之间，但局部地区时有暴发或流行。而全世界病例数每年高达50000例，死亡数15000例28Agreatmanyvirusesmaycauseepidemicencephalitis.InChina,India,SoutheastAsiaandKorea,aswellasJapan,epidemicencephalitisiscausedbeaflavirus(黄病毒),Japaneseencephalitisvirus.InordertodistinguishitfromvonEconomo’s(A)typeencephalitis,itwasnamedJapaneseencephalitisBorepidemicencephalitisB乙型脑炎病毒属披膜病毒科黄病毒属第1亚群，呈球形，直径20～40nm为单股RNA病毒Etiology29Sourcesofinfection Routeoftransmission Susceptiblepopulation EpidemicseasonPigs,cows,sheep,dogs,chicken,duckandgooseinfectedVector:mosquito[库蚊(Culex)、伊蚊(Aedes)和按蚊(Anopheles)]Ithasaseasonalincidenceandmosquitovector,mainlyoccurringinsummerandoftenaffectingthechildren(mostof2-7yearsofage).Epidemics3031Morphology

MainlyinvolvescerebrospinalparenchymaGrossappearance:softeningareaincerebralparenchyma,especiallyincortical粟粒或针尖大小的半透明软化灶皮质深层、基底核、视丘等处最严重，其次是小脑皮质、延髓及脑桥，脊髓病变最轻32软化灶33MorphologyMicroscopically:Degenerationandnecrosisofneurocyte（神经细胞变性坏死）Softeningareaformation（软化灶形成）Perivascularinflammatorycellinfiltration（脑血管改变）Proliferationofmicrogliacyte（胶质细胞增生）341.Degenerationandnecrosisofneurons:

Neuronophagiaphenomenon(噬神经细胞现象):individualneuronnecrosisandphagocytosisbymicroglialcells.小胶质细胞或血源性巨噬细胞包围吞噬坏死神经元后，可形成泡沫细胞或格子细胞

Satellitephenomenon(神经细胞卫星现象）：1个神经元由5个或以上少突胶质细胞（oligodendrocyte)围绕Microscopically35Necrosisofneurons神经元肿胀、尼氏小体消失、胞质内空泡形成、核偏位或固缩/溶解/消失3637383940噬神经细胞现象412.Softeningareaformation:Focalneuronalnecrosisandshowaloose,light-stainsievestructure软化灶：灶性神经组织坏死、液化形成镂空状筛网状结构具诊断价值42软化灶433.Perivascularinflammatorycellinfiltration

Themostcharacter