腰椎穿刺和脑脊液（CSF）检查

腰椎穿刺和脑脊液（CSF）检查 腰椎穿刺和脑脊液(CSF)检查 MedicineInternationaI LumbarPunctureand CSFExamination MohammadSharief CSFanalysisisvaluableifltheinvestigationofmanyneurolog— icaldisorders,includinginflammatory.infectiousanddegenera— tivediseasesoftheCNS.BecauseCSFisindirectcommunica— tionwiththeextracellularspaceofthebrainandspinalcord, pathologicalchangesintheCNSareoftenreflectedinthe CSF.Inaddition,studiesofCSFproteinsoftenprovidecrucial infonnationaboutCNSdisorders. Lumbarpuncture Themainindicationsforlumbarpunctureareto: ?obtainasampleofCSFfordiagnosticpurposes ?measureCSFpressure ?reduceCSFvolumefortherapeuticpurposes(e.g.inbenign intraeranialhypertension) ?administertherapeuticmaterials(e.g.antibiotics,chemo— therapy) ? injectradiopaquematerials(e.g.myelography) Lumbarpunctureisusuallyasimpleandsafetechnique,but thereisariskoffataltentorialorcerebellarherniationwhen theCSFpressureishigh,particularlyifthisiscausedbyall intracranialmass.Lumbarpunctureshouldthereforenotbe performedimmediatelyinpatientswithpapilloedemaorother featuresofraisedintracranialpressure,butshouldbepreceded occupyinglesions. byCTorMRIofthebraintoexcludespace— Theriskofbrainherniationislessinpatientswithintracranial hypertensionorsubaraclmoidhaemorrhage. Skininfectionaroundthelumbarpuncturesiteisacontra— indication.becauseinfectionmaybeintroducedintothein— trathecalcompartment.Lumbarpunctureisalsocontraindicated inpatientswithbleedingdiathesisandinthosetakingoralan— ticoagulants. Preparation Mostpatientsareapprehensivebeforelumbarpuncture,and 朋l韬,,1n砑dS『llisConsultantNeurologistandSeniorLectureratGuy’ s.King’sandStThomas’Hospitals,London,UK.?妇inedinneurolo— gYandneur~immunologyattheInstituteofNeurology,theRoyalLondon HospitalandStBartholomew’sHospa|.London.Hisresearchinterests includetheimmunopathologyofdemyelinatingdiseaseandCSFabnormali- tiesinneurologicaldisorders. MEDlClNE 19 benefitfromreassuranceandadescriptionofwhatisaboutto happen.Itishelpfultoobtainthepatient’scooperation,be— causetheprecedureissimpleinrelaxedindividualspositioned suchthatthelumdarinterspinalspacesremainopen.Sedation ~vithdiazepammaybenecessaryinanxiouspatients.Thepa— tientshouldliehorizontallyontheleftsidewiththeneck flexedfirmly,thekneesdrawnuptothechinandtheback flexed.Theshouldersandpelvisshouldbeverticalonafirm support,preferablythehardedgeofthebedoralloperatingta— ble. BASlCSClENCE Anat~andphysioIogyofCSF CSFiscontainedwithintheventriclesandthesubarachnoid spaces;inadults.thetotaIvolumeisabout140mI.111eventric— ularsystemcomprisestwoIateraIventricleswithinthecerebraI hemispheres.bothofwhichopenviatheinterventricularforam— inaofMonrointothesinglemidlinethirdventricle.whichcorn— municateswiththefourthventricleviatheaqueductofSylvius. ThefourthventriclecontinuesintothespinaIcordasthespinal carlaI.andterminatesinthrfllumterminale. TheprimaryfunctionsofCSFareto: .provideaprotectivecushioningeffectforthebrainandspi— naIcord .preserveastablechemicalenvironment .removethewasteproductsofcerebraImetabolism. CSFissecretedbythechoroidplexusesandabsorbedbythe arachnoidviiii.whichprotrudeintotheduraIvenoussinuses. ThevariousconstituentsoftheCSFareindynamicequilibrium withtheblood.Normally.CSFpressureisinequilibriumwith thecapillarypressureinthebrain.Inhealthyadults.CSFpres— sureis<18cmsaline;CSFpressure>20cmisconsidered hypertensive. Comix)nentsofno棚ICSF CSFSerum .Pressure8—12cmsaline一 .0H7.37.4 .Osmolality295mOsmol/litre295mOsmel/Iitre .Totalprotein0.1—0.45g/litre65—8og/litre Pre-albumin2—8%<1% Albumin45—75%50% “/-globulin1—10%15% . Glucose2.8—4.0mn’~l/litre3.5—5.5rr~mol/litre . Cells1—4x106/litre4—8x1/litre .Sodium135—148rrrnol/litre136—149rm~l/litre . Potassium2.5—3.3rm~l/litre23—30rnn3ol/litre 128rm~l/litre93—1o8rnn3ol/litre .Chloride116— .Bicarbonate23—30mmel/litre23—30rnn3ol/litre .Lactate1.1—1.9mmel/litre0.9—1.5rnn3ol/litre Lumbarpunctureshouldbeperformedunderfullsterilecondi— tions;thelowerlumbarareashouldbecleanedwithantiseptic solutionandtheareacoveredwithsteriledrapes.Theoperator shouldwearamaskandsterile0ves. 02000TheMedicinePublishingCompanyLtd MedicineInternationaI 1 Positionforlumbarpuncture ThelineconnectingthehighestpointsoftheiliaccreststraversestheL3一L4interspace Technique Lumbarpunctureiseasiesttoperformatthespacebetweenthe spinesofL3andIAorinthespaceabove.Alowerspace shouldbeusedininfantsandyoungchildren.inwhomthe spinalcordmayextendtotheleveloftheL3一L4space.The L3一L4interspaceistraversedbyalineconnectingthehigh. estpointsoftheiliaccrests(Figure1).Theoperatorshould identifytheL3andIAspinousprocessesandputthefingersof thelefthandoneachtomaintaintherelationshipwhileanaes. thetizingtheskin. Infiltratetheskinandsubcutaneoustissuewithlocalinjec. tionof2%lignocaine.waitforafewminutesfortheanaes. thetictotakeeffect.theninsertaspinalneedlewithitsstylet inpositionandpassithorizontallyinwardsinaslightlycepha— ladposition(towardstheumbilicus).Theneedlepasses throughtheinterpinousligamentsandthenencountersthere— sistantligamentumflavum.Afterpenetratingthisligament,re— sistancesuddenlylessensastheneedleentersthesubarach. noidspace. Oncethesubarachnoidspaceisentered.removethestylet fromtheneedletoallowCSFtodripoutslowly.Caremustbe takennottoinserttheneedletoofar.becausethismaydamage theintervertebraldiscorthevertebralvein.CSFpressureis measuredbyattachingamanometertotheneedle:theheightof thefluidcolumnismeasuredwhenCSFceasestoriseinthe tube.Ensurethatthepatientisstraightenedbeforethepres— sureisread——raisedintra??abdominalpressureinatightly rolled—uppatientsincreasesCSFpressure. Afterthepressurereadingistaken.thefluidinthemanom— eterandthatfromthespinalneedleisusuallycollectedinfour separatetubestodetermine: ?cellnumberandmorphology ?cellularcytology .proteinandglucoseconcentrations ?oligoclonalbandsorimmunoglobulincontent,whenappropri— ate. Bloodsamplesarecollectedatthesametimeasthelumbar puncturetodetermineucoseconcentrationandimmunoglobu— MEDlClNE lincontent.Incertainsituations,CSFsamplesarealsosentfor bacteriologicalcultures.viralisolationorbiochemicaltests. 珊1entheexaminationiscomplete.removethelumbar punctureneedlewithoutre—insertingthestylet,pressonthear— eatopreventlocalbleeding,andputasmalldressingoverthe puncturesite.Thepatientistheninstructedtoremain1)ring downforafewhours,preferablyinapronepositiontoreduce theriskofheadache. ComplicationsofIumbarpunctMrs Herniationofthebrainorspinalcordcanbeavoidedby excludingintracraniallesionsbeforeundertakinglumbarpunc. ture.Ifconsciousnessdeterioratesorrespirationfails,immedi. atesu哂caldecompressionisrequired.Meanwhile,theraised intracranialpressureshouldbereducedbyosmotictherapy with20%mannito1.1g/kgbodyweightrapidi.v.infusion. Spinalcordtumoursmaycauseherniationorimpactionof thecordafterlumbarpuncture.Thispresentswithurinaryre. tentionandlegweakness.andshouldbetreatedwithurgent surgicaldecompression. HeadacheisrelativelycommonfoUowinglumbarpuncture, andisprobablycausedbysubsequentleakageofCSFthrough theduralhole.Theriskofheadachemaybereducedifthepa. tientdoesnotsitupforafewhoursaftertheprocedure.Dural leakagecanbeminimizedbyusingafinespinalneedle,with itsbevelinthespinalaxis. FailuretoobtainCSF(arytap)oftenmeansthatthelum. barpuncturehasbeenperformedincorrectly.orvertebraldis. easemayhavenarrowedtheinterspace.Insuchcases.another attemptshouldbemadeintheinterspaceaboveorbelow. Agenuinedrytap.inwhichtheneedleisinthesubarach. noidspacebutnofluidcanbewithdrawn,suggeststhatthe spaceisblockedatahigherlevelorthatthelumbarsacisin. filtratedbyacompressivelesionoradhesivearachnoiditis. Othercomplicationsoflumbarpunctureinclude: ?meningitisorepiduralabscess,causedbypoorasepsis 02000TheMedicinePublishingCompanyLtd MedicineInternationaI 2 UsualCSFfindingsinmeningitis Brcte~aI Tuberculous Fungal VimI Normal<51ymphocytes (8—16cmH20) Protein(g/litre)Glucose(mmol/litre) <04>50%bloodglucose level PurulentRaised>1000>0.8 (>60%neutophils) Viscous,mayclotRaised onstanding ClearorcloudyNormalorraised ClearorcloudyRaised MalignantClearorcloudyRaised 5—4OO0.8—04 (>8O%lymphocytes) <40O.mixedinflarT1ma一<1.2 torycells 10—1OO0<06 (>8O%lymphocytes) <2O0.mixedinflarT1ma一<1.5 toryandmalignantcells ?intrathecalbleeding,spinalorintracerebralsubduralhaema— tomas ?damageorinfectionoftheintervertebraldisc ?intraspinaldermoidcyst. CSFexamination AriseiflCSFpressureiscausedbyincreasedintracranialvol- unle,resultingfrom: ?space—occupyinglesionsoracutebrainswelling ?highvenouspressure.asinduralsinusthrombosis ?benignintracranialhypertension. DisturbancesofCSFpressurearealsoseeninhydrocephalus finwhichexcessCSFwithintheventriclesissecondarytoob— structionofCSFflow),impairmentofCSFabsorptionandex— cessiveCSFproduction. Grossappearance 而7ofCSFsuggestsneutrophilpleocytosis. Xanthochromia(yellowdiscoloration)isoftenseenfollow— ingsubarachnoidhaemorrhageorinCSFwithahighprotein content.Ifsubarachnoidhaemorrhageissuspected,spectropho— tometryshouldbeundertaken.Xanthochromiaisalsoseenin somepatientswithsubduralhaemorrhageandinthosewhoare jaundiced. BloodyCSFmayresultfromtraumaticpunctureofaverte— bralvein.inwhichcasethecontaminationoftheCSFlessens asitflows.Incontrast,uniformlybloodstainedCSFindicates subarachnoidbleeding. Cellcount Inhealthyadults,CSFcontainsuptofivemonocytes/ffl;the countmaybehigherinchildren.IncreasedWBCimpliesin— fectionorinflammationofthemeninges,whichcanbeprimary (asinmeningitis)orsecondarytoencephalitis.0thercauses oflymphocyticpleocytosisincludeparanleningealinfections, MEDICINE 21 <50%bloodglucose level,maybeabsent <50%bloodglucose level,maybeabsent <50%bloodglucose level >50%bloodglucose level,maybelowin measles <50%bloodglucose leveI cerebralabscess,poliomyelitis,multiplesclerosis,duralsinus thrombosis,post—infectiveencephalomyelitisandstroke.Pres— enceofneutrophilsinCSFisabnormal.oftenindicatingpyo— genicinfection. CSFmaycontainasmallnumberofRBCsasaresuhofthe traumaoflllmbarpuncture.butRBCspersistinginseveral specimensmaysuggestcerebralinfarction,ahaemorrhage印- proachingthesurfaceofthebrain,subduralbleedingorin— tracranialaneurysm. RaisedproteincontentisacommonabnormalityofCSF.A modcrateriseto0.6g/litreormoreisusuallycausedbyin. flammatoryorinfectivedisordersofthemeningesorbrain(e. g.meningitis,encephalitis,cerebralabscess).Asimilarmoder— ateincreaseiscommoninpatientswithmultiplesclerosis,ce- rebraltumours(primaryandmetastases),cerebralinfarctionor duralsinusthrombosis.Amarkedincreaseinproteincontent (oftenupto6g/litre)isseeninGuillain—Barresyndromeand spinalblock,usuallycausedbyspinaltumours. Otherconstituents Glucose—reducedorabsentCSFglucoseisseeninmenin. gitisofbacterial,tuberculousormalignantorigin(Figure2). C/aerateismoresensitivethanglucoseindistinguishing bacterialmeningitis(highlactate)fromviralmeningitis. Gramstainingandcultureareimportantinthediagnosis ofbacterialmeningitis. Oligoclonalbandsaredetectedinallpatientswithadreno— leukodystrophyorsubacutesclerosingpanencephalitis,andin mostpatientswithmultiplesclerosis,neurosyphilis,neuro- AIDSorneuro—Lymedisease.Oligoclonalbandsareoftenab. sentinmeningitis.encephalitisandbraintumoms. Polymerasechainreactionanalysisisusedtodiagnosevi— ralinfectionsoftheCNS.? 02000TheMedicinePublishingCompanyLtd 腰椎穿刺和脑脊液(CsF)检查国际内科双语杂志2001,Vol1,No.3 腰椎穿刺和脑脊液(CSF)检查 Moha?ln1adSharie产 MEDICINE,2000,28(6):36—38 CSF分析在很多神经系统疾患的诊断中都很有价 值,包括中枢神经系统(CNS)炎症,感染和退行性 变.因为CSF与脑和脊髓的细胞外间隙直接交通,所 以各种CNS的病理改变经常通过CSF反映出来.此 外,对CSF蛋白的检查常常为CNS疾患提供重要信 息. 腰椎穿刺 腰椎穿刺的主要指征为: ?为诊断目的获取CSF标本 ?测CSF压力 ?为治疗目的减少CSF体积(如良性颅内高压) ?应用治疗药物(如抗生素,化学疗法) ?注射放射对比剂(如脊髓造影). 禁忌证 腰椎穿刺通常是一种简单而且安全的技术,但是 当CSF压力增高时,会有致命的天幕疝或小脑疝的危 险,尤其是当颅内肿物引起CSF高压时.所以对有视 盘水肿或有其他颅内压增高特征的病人不应立即进行 腰椎穿刺,而应该先进行脑CT或MRI检查以除外占 位性病变.在颅内高压(译者注:可能有误)或蛛网 膜下腔出血的患者,发生脑疝的危险相对小些. 附近皮肤感染是腰椎穿刺的禁忌证,因为感染可 能被带入鞘内.有出血倾向和口服抗凝药物的病人也 禁忌做腰椎穿刺. ?MohammadSharief是英国伦敦Guy’s,King’s和StThomas’医院的神 经病会诊医师和高级讲师.他曾在神经病研究所,皇家伦敦医院和st Barthlomow医院接受神经病学和神经免疫学培训.他的研究方向包括脱 髓鞘疾病的免疫病理学和神经疾病的CSF异常. 22 准备 大部分患者在腰椎穿刺前都会紧张,安慰并向他 们描述如何进行会有好处.获得病人的配合很有帮 助,因为只要病人放松,将体位保持在椎间隙开放的 位置,整个过程是十分简单的.焦虑的患者应用安定 可能是必需的.病人应取左侧卧位,颈部尽量前屈, 膝盖尽量贴近下颏,背部屈曲.肩部和骨盆在固定支 持物上保持垂直,最好是在病床或手术床较硬的边 缘. 腰椎穿刺应在完全无菌的条件下进行;下腰部应 用消毒液清洗并铺上消毒巾.操作者应戴口罩和消毒 手套. 基础知识 CSF的解剖和生理 CSF存在于脑室和蛛网膜下腔,在成人总体积约 14Oral.脑室系统包括双侧大脑半球中的两个侧脑室, 通过脑室间孔(Monro孔)通向中线的单个第三脑室, 再通过Sylvius导水管与第四脑室交通,第四脑室延续 入脊髓成为脊髓中央管,并终止于脊髓终丝. CSF的主要功能为: ?为脑和脊髓提供保护性缓冲作用 ?维持稳定的化学环境 ?清除大脑代谢废物. CSF由脉络丛分泌,被突入于硬膜静脉窦的蛛网 膜颗粒吸收.CSF的各种成分处于与血液的动态平衡 中.一般而言,CSF压力与脑毛细血管压力平衡.在 健康成人中,CSF压力<18cm(盐水柱);CSF压力> 20cm就认为是高压. 技术 在脊椎的【3,L4间隙或上一间隙进行腰椎穿刺 国际内科双语杂志2001,Vol1,No.3腰椎穿刺和脑脊液(CSF)检查 最容易.婴儿和年龄较小的儿童则应向下一个间隙, 因为他们的脊髓可能延续到L3,L4水平.L3,L4椎 间隙处于双侧髂嵴最高点的连线上(图1).操作者应 找到L3和L4的棘突并在皮肤局部麻醉时用左手手指 按住两个棘突以保持准确位置. ?压力 ‘pH ? 渗透压 ? 总蛋白 前一白蛋白 白蛋白 7一球蛋白 ? 葡萄糖 ?细胞 ?钠盐 ? 钾盐 ? 氯化物 ? 碳酸氢盐 ?乳酸盐 正常CSF成分 血清 7.4 295mOsml/L 65—80g/L <1% 50% 15% 3.5—5.5mmol/L (4—8)×109/L 136—149mmol/L 3.8—5.0mmol/L 93—108mmol/L 23—30mmol/L 0.9—1.5mmol/L 用2%的利多卡因进行皮肤和皮下组织浸润麻醉, 等几分钟让麻药发挥作用,然后插入带有针芯的腰椎 穿刺针,略偏向头侧(朝向脐部)水平进针.穿刺针 经过棘间韧带后碰到坚韧的黄韧带.针突破这层韧带 进入蛛网膜下腔后阻力会突然减小. 进人蛛网膜下腔后抽出针芯,让CSF缓慢滴出. 一 定要小心不要进针太深,因为那样可能会损伤椎间 盘或椎静脉.将液压计与针接上测CSF压力,当压力 计中的液面不再升高时读取液面高度.读数前确认病 人处于平直体位——用力蜷缩的病人腹压会升高,导 致CSF压力升高. 测定压力后,收集压力计以及针管里的CSF,通 常分装4个小瓶,测定: ?细胞数和形态 ?细胞学 ?蛋白和葡萄糖浓度 ?视情况测定寡克隆区带或免疫球蛋白成分. 腰椎穿刺同时留取血样测定葡萄糖浓度和免疫球 23 蛋白成分.在某些情况下,CSF标本还要送细菌培养, 病毒分离或生化检查. 检查完毕,不需重新插入针芯直接拔出穿刺针, 按压穿刺部位防止局部出血并覆上一小块敷料.嘱咐 病人平卧几个小时,最好是俯卧以减少发生头痛的机 会. 腰椎穿刺的并发症 脑疝或脊髓疝进行腰椎穿刺前除外颅内病变就 可避免.如果发生意识水平恶化或呼吸衰竭则必须立 即进行外科减压.同时,必须用20%甘露醇进行渗透 压疗法以降低升高的颅内压,用法为1kg体重,快 速静脉点滴. 脊髓肿瘤可能会在腰椎穿刺后引起疝或脊髓压 迫,表现为尿潴留和下肢无力,必须紧急外科减压. 头痛腰椎穿刺后相对常见,可能是因为穿刺后 CSF从硬膜孔漏出而引起.如果病人在穿刺后几小时 内不坐起来,可能会降低头痛的危险性.用较细的针 穿刺并且针尖斜面与脊柱方向一致可能减少硬膜漏. 无法获得CSF(干穿)这经常意味着腰椎穿刺 操作不正确,或是存在椎体病变使椎间隙变窄.在这 种情况下应在上或下一个间隙再试一次. 真正的干穿,即穿刺针在蛛网膜下腔中但没有液 体流出,提示椎管在穿刺部位以上有堵塞或硬膜囊被 压迫性病变浸润或粘连性蛛网膜炎. 其他并发症包括: ?由消毒不当引起的脑膜炎或硬膜外脓肿 ?鞘内出血,脊髓或脑内硬膜下血肿 ?椎间盘损伤或感染 ?髓内皮样囊肿. CSF检查 压力 CSF压力升高是由颅内容积增加引起的,原因有: ?占位性病变或急性脑肿胀 ?静脉压升高,如硬膜窦血栓形成 ?良性颅内高压. CSF压力改变还见于脑积水(这种情况下CSF循 环阻塞继发引起脑室中CSF过多),CSF吸收障碍和 CSF生成过多. 外观 混浊提示CSF含中性粒细胞过多. 一,,埘一一,,,,,,,螂? 腰椎穿刺和脑脊液(CSF)检查国际内科双语杂志2001,Voi1,No.3 临床类型 正常 细菌性 结核性 真菌性 病毒性 恶性 外观 清亮 脓性 表1脑膜炎CSF检查的常见结果 压力 正常 (8,16cn1H2O) 升高 粘稠,静置后可有凝块升高 镜检(细胞) <5淋巴细胞 >1o0O (>60%中性粒细胞) 5,400 (>80%淋巴细胞) 清亮或浑浊正常或升高<400,混合炎性细胞 清亮或浑浊 清亮或浑浊 升高 升高 黄染常见于蛛网膜下腔出血后或CSF蛋白含量 过高.如怀疑蛛网膜下腔出血,则必须做分光光度计 分析.CSF黄染也见于一些硬膜下出血的患者和黄疸 患者. 血性CSF可能是穿刺损伤椎静脉的结果,在这 种情况下血色会随着CSF的流出而减轻.相反,如果 CSF持续血性则提示蛛网膜下腔出血. 细胞数 健康成年人的CSF不超过5个单核细胞/;在儿 童可能较多.WBC数升高提示脑膜感染或炎症,这可 以是原发的(如脑膜炎)或是继发于脑炎.其他导致 淋巴细胞增多的原因包括类脑膜炎球菌感染,脑脓 肿,脊髓灰质炎,多发性硬化,硬膜窦血栓形成,感 染后脑脊髓炎和卒中.CSF中出现中性粒细胞属于异 常情况,常提示化脓性感染. CSF可以因穿刺创伤而含少量RBC,但是在几瓶 样本中都持续存在RBC则可能提示有脑梗死,接近脑 表面的出血,硬膜下出血或颅内动脉瘤. 蛋白浓度 蛋白浓度升高是常见的CSF异常.中度升高到 0.6g/L或更高常由脑膜或脑的炎症性或感染性疾病引 起(如脑膜炎,脑炎,脑脓肿).类似的升高也常见 10,1000 (>80%淋巴细胞) <200,混合炎性细胞 和恶性细胞 24 蛋白(g/L)葡萄糖(mmol/L) <0.4>50%血糖水平 >0.8 0.8—4.0 <1.2 <0.6 <1.5 <50%血糖水平 可能测不到 <50%血糖水平 可能测不到 <50%血糖水平 >50%血糖水平, 在麻疹可能会低 <50%血糖水平 于多发性硬化,脑肿瘤(原发或转移瘤),脑梗死或 硬膜静脉窦血栓形成的患者.蛋白浓度显着升高(通 常高到6g/L)则见于格林一巴利综合征以及椎管堵 塞,后者多由脊髓肿瘤引起. 其他成分 葡萄糖CSF糖含量减低或消失见于细菌性脑膜 炎,结核或恶性病变(表1). CSF乳酸对鉴别细菌性脑膜炎(乳酸含量高) 与病毒性脑膜炎比糖含量更敏感. 革兰染色和培养在诊断细菌性脑膜炎时十分重 要. 寡克隆区带见于所有肾上腺白质营养不良或亚 急性硬化性全脑炎的患者,也见于大多数多发性硬 化,神经梅毒,神经一AIDS病变或神经Lyme病变的 患者.在脑膜炎,脑炎和脑肿瘤患者的CSF中常没有 寡克隆区带. 聚合酶链反应分析用于诊断?