脑白质病变PPT课件.ppt

脑白质病变CerebralWhiteMatterDisease,1,脑白质病变定义,脑白质病变病因,血管源性白质病变,白质病变与认知损害,2,脑白质病变临床常见，多种疾病累及神经系统白质,分原发、继发性两大类.,病理过程：髓鞘形成延迟、髓鞘形成障碍、脱髓鞘,诊断：临床+MRI+病理,脑白质病变,AnnNYAcadSci.Oct2008;1142:266309.,3,Genetic,2,Demyelinative,3,Infectious,4,Inflammatory,5,Toxic,EtiologyofCWMDisorders,6,1,7,8,9,10,11,Metabolic,Vascular,Traumatic,Neoplastic,Hydrocephalic,Degenerative,4,5,MRIofX-ALD,MLD,GLD,VWMD,(A)X-连锁的肾上腺脑白质营养不良(X-ALD),T1image;(B)异染性脑白质营养不良(MLD),FLAIRimage;(C)球形细胞脑白质营养不良(GLD),T2-weightedimage;(D)白质消融性脑白质病(VWMD),T1-weightedimage.X-ALD:impairedpsychomotorspeed,spatialcognition,memory,andexecutivefunctions;MLD:psychosis,behavioraldisturbances,anddementia;GLD:hemiparesis,intellectualimpairment,cerebellarataxia,andvisualfailure;,AnnNYAcadSci.Oct2008;1142:266309.,6,神经轴索球样细胞脑白质营养不良,(A)FLAIRMRIintheaxialplaneshowingconfluenthighsignalintheperiventricular,deep,andsubcorticalwhitematterofthefrontalandparietallobesextendingthroughthespleniumofthecorpuscallosum.(B)Grosspathologyofacoronalsectionofthecerebralhemisphere,showinggliosisinthecentrumsemiovale(arrow)andinternalcapsule(arrowhead).Thedisorderusuallypresentswithexecutivesystemdysfunctionandotherneurobehavioraldeficits,progressingtodementia.,7,MRIinpatientswithMELAS,Criteriafordiagnosisarestrokelikeepisodesbeforeage40(notconfinedtovascularterritories);encephalopathycharacterizedbyseizures,dementia,orboth;withlacticacidosisand/orragged-redfibers.Recurrentheadacheorvomitingmaybepresent.PeriventricularanddiffuseWMhyperintensities,aswellasareasofcorticalinfarctionandcerebraledema,areseenonMRI,8,脆性X相关震颤和(或)共济失调综合征,Whitematterpallorisseeninthecerebellarparenchyma(A),aswellasinthemiddlecerebellarpeduncles(B).Progressivecognitivedeclineischaracterizedbyimpairedexecutivefunction,workingmemory,intelligence,declarativelearningandmemory,informationprocessingspeed,temporalsequencing,andvisuospatialfunctioning,butlanguageisspared.,9,10,FLAIRMRIinmultiplesclerosis,(A)Whitematterhyperintensityperpendiculartothelateralventricle(Dawsonsfinger),shownbythearrow.(B)Inasecondcase,thefocalareaofhyperintensity(arrow)correspondedtotheinitialclinicalpresentationCognitiveimpairmentsinMSalsoincludeawiderangeoffocalneurobehavioralsyndromesandneuropsychiatricdisturbances,11,MRIfeaturesofADEM,(A)CoronalT1-weightedpostgadoliniumimageshowingenhancinglesionsintherightmorethanlefthemispheres.(B)Axialzero-BMRIdemonstrationofthemultiplelesions.(C)FLAIRMRI6monthsaftermarkedclinicalrecoveryshowsmuchimprovedareasofhyperintensity.,12,13,HIV,FLAIRMRIshowinghyperintensitiesinprefrontalwhitematterinapatientwithHIVandcognitiveimpairment,SchmahmannJD,PandyaDN.FiberPathwaysoftheBrain.OxfordUniversityPress;NewYork:2006,14,PML,(A)T2-WIshowsinvolvementofwhitematteroftherightoccipitalregion(arrow),accountingforthehemianopsiainthisHIV-positivepatient.(B)FLAIRMRIinapatientwithsystemiclymphomaandPML,demonstratingconfluentprefrontalwhitematterlesionspreadingacrossthegenuofthecorpuscallosum(arrow),andadditionallesionsaffectinglocalassociationfibersoftherightprefrontalandparieto-occipitalcortices(arrowheads).(C,D)AxialFLAIRimagesinanHIV-positivepatientshowingconfluentsubcorticalanddeepwhitematterinvolvementbyPML.,Cognitivepresentationsincludefrontallobesyndromesandaphasia,progressingtoquadriparesis,mutism,andunresponsiveness,15,16,17,ToxicLeukoencephalopathy,FLAIRMRIintheaxialplaneofapatientwithcognitivedeclineafterreceivingmethotrexate,T2-WMRIappearanceintheaxialplaneoftolueneencephalopathyintwopatientsadramaticsyndromeofdementia,ataxia,andotherneurologicsigns,18,Heroin,Clinicalmanifestationsincludecerebellarmotorfindingsofataxia,dysmetriaanddysarthria,bradykinesia,rigidity,andhypophonia,andthesyndromemayprogressoverweekstopseudobulbarpalsy,akineticmutism,decorticateposturing,andspasticquadriparesis.,MRIscansafterheroininhalation,knowncolloquiallyas“chasingthedragon.”FLAIRimagesintheaxialplane(AD).Inhalationofheatedheroinvapor(colloquiallytermed“chasingthedragon”)producesadevastating,progressivespongiformleukoencephalopathy.,19,20,Hypoxicischemicencephalopathy,AxialMRIindelayedleukoencephalopathyafterhypoxicischemicinsult.(A)FLAIRimageshowsextensive,symmetricwhitematterhyperintensitieswithrelativesparingofsubcorticalwhitematter.(B)Diffusion-weightedimagingshowsrestricteddiffusionofthewhitematterabnormalities,confirmedon(C),apparentdiffusioncoefficientmapping,21,22,23,Gliomatosiscerebri,FIG3.55M.A,AxialT2-weightedspin-echolocalizerimage(1900/80).B,Correspondingspectrum.Stereotacticbiopsysamplewastakenfromthedenotedvoxel,withamaximumCho/NAAratioofthelesionof8.9aswellasalactatedoubletat1.35ppm.FIG4.10yearoldboywithseizure.,24,朗格汉斯细胞组织细胞增多症,T2-weightedaxialMRIinapatientwithLangerhanscellhistiocytosis,showinghyperintensesignalabnormalityinthewhitematterofthecerebellum,25,26,B,C,A,WMlesions,Aging,脑白质病变,VascularDisease,27,白质高信号（WMHyperintensities）,Leukoaraiosisisvisibleas(A)whitematterhypodensityonCTand(B)whitematterhyperintensityonFLAIRMRIinthesamepatient.,28,02,03,04,01,70岁以上老人，95%在MRI上可以发现白质高信号，随年龄增加逐渐增多,危险因素：高血压、糖尿病、吸烟,、视网膜血管改变、肾脏血管改变；,内皮功能紊乱(血清同型半胱氨酸和细胞粘附分子1),血栓形成(血栓调节蛋白和纤维蛋白原）,炎性反应(CRP),氧化应激2,髓鞘脱失和胶质增生，破坏髓鞘和少突胶质细胞影像学发现和病理学显示的髓鞘脱失具有相关性,WMH的相关概念,1.JNeurolNeurosurgPsychiatry.2001Jan;70(1):9-14.2.Brain.2004Jan;127(Pt1):212-93.Neurology.2006Sep12;67(5):830-3.,29,01,WMH负荷与脑梗死以及卒中史相关,02,与脑血管病有共同的危险因素，如高血压等,03,利用ACEI和利尿剂降压治疗可以减缓WMH进展,04,CSVD导致血管狭窄、阻塞,破坏血管的反应性，导致白质低灌注,05,认知障碍病人WMH高负荷，局部脑血流量下降代谢水平降低,WMH的病理机制,30,脑白质病变与认知功能下降显著相关,脑白质病变越严重，认知功能下降越快,Stroke2005;36;56-61.,脑白质恶化级别,无,1级,2级及以上,初次MRI,随后的MRI,年,改良后的MMSE评分,9594939291908988878685,4567891011,31,高的WMH负荷与认知功能从正常转化到MCI，MCI转化到痴呆有关系,脑室周围的WMH与将来的痴呆特别是AD相关,在MRI上见到的白质高信号（WMH）同正电子发射断层扫描（PET）中使用的脑淀粉样标记物一样，可以独立预测AD诊断,WMH与认知改变,32,WMHs影响信息加工速度和执行功能，影响记忆的提取而不是编码,1,脑室周围白质区域为“远端供血区”，这种情况因为缺乏吻合更易受到中度血流降低的损害,2,脑室周围WMHs破坏联系较远皮质区域的联系性长束，执行功能受累较为突出,3,皮质下区域由致密的短回路U纤维组成，皮质下痴呆则主要是认知过程速度减慢,4,WMHs相关的认知改变,33,OttoBinswanger在1894年首先提出WMCs与痴呆之间可能存在关联；Alzheimer在1902年再次提到Binswanger的病例，以后提出Binswanger脑病（BD）这一名词。,1,WMC是痴呆的危险因素，与认知功能下降有关。头部CT检出的AD患者WMCs可占30%，VaD患者可占70%。WMC与AD密切相关，提示血管病因素在AD病变过程中的重要性。,2,皮质下白质缺血主要是少突胶质细胞和髓鞘破坏；皮质下U纤维的密度较高WMLs主要破坏由弓状U纤维组成的短的皮质-皮质联系；脑室周围WMLs则破坏联系较远皮质区域的联系性长束,3,脑白质改变（WMC）与AD,34,1,2,3,4,主要累及脑皮质小动脉、中动脉、微动脉及毛细血管，表现为血管壁A的进行性沉积,5,是老年人自发性颅内出血和认知损害的重要原因,临床表现主要包括：反复颅内出血，认知下降和痴呆等,约30%的脑血管淀粉样变性患者可以出现老年痴呆症状，如严重的记忆障碍、注意力、定向力和计算力减退，或精神异常,型的主要病理改变是皮质微血管内A的异常蓄积；型的A主要沉积于脑膜血管及皮质动脉、小动脉，偶尔会累及静脉。,脑淀粉样血管病(CAA),35,CAA的MRI表现,(A)GradientechoMRIdemonstratingmultiplepunctuateareasofhemorrhage(microbleeds,arrow)atthecorticosubcorticaljunctions.(B)MRIFLAIRsequenceinapatientwithlobarintraparenchymalhemorrhageintheleftoccipitallobe(doublearrows),aswellasperiventricularWMH(singlearrow)andsubcorticalWMH(arrowheads),36,1894年Binswanger首先报道该病例，并强调本病患者的两个主要特点：（1）患者的脑血管有重度粥样硬化。（2）大脑半球白质损害明显，而皮质几乎不受影响,01,深穿支动脉供血的脑室周围白质发生大面积缺血性损害，仅有皮质穿支动脉供血的皮层下U型纤维未见明显受损,02,痴呆是最显著的症状，主要表现为记忆障碍、计算力差，可伴有心情、人格的改变，无欲、淡漠、精神错乱,03,Binswangers脑病,37,BinswangersMRI,Hyperintensesignalabnormalityisseenatperiventricularzones,whitematterimmediatelybeneathcortex,spleniumoftheCC,andinternalandexternal/extremecapsuleregions.Multiplehypodensitiesconsistentwithlacunarinfarctsarealsoseeninthebasalgangliaandthalamus,SchmahmannJDFiberPathwaysoftheBrain.OxfordUniversityPress;NewYork:2006,38,CADASIL,39,CADASILMRI,(A,B)FLAIRMRIinanasymptomatic39-year-old,notch3genepositivewithfamilyhistoryofearlystroke,whoseimagingfindingswereincidentallynoted.Characteristictemporallobewhitematterinvolvementishighlighted(arrows).(C)FLAIRMRIinapatientwithclinicallyestablishedCADASIL.(D)T2-weightedMRIinapatientwithnotch3geneandpathologicallyprovendisease.,40,神经行为综合征,神经精神综合征,白质性痴呆,脑白质病变与神经精神综合征,41,A,B,C,局部的白质病变导致失语,失用症(apraxia),失认症(agnosia),胼胝体分离综合征(callosaldisconnection)等,主要病因是卒中，肿瘤和脱髓鞘病也可以发生,病变部位：顶下小叶、颞顶交界、前额叶、基底节、丘脑、扣带回等，以非优势半球多见,NeurobehavioralSyndromes,42,FocalWMlesionswithneurobehavioralmanifestations,(A)Lacuneinthegenuoftherightinternalcapsule(arrow)onCTpresentingwithhemineglect.(B)DiagramoftheWMlesionresponsibleforparietalpseudothalamicpainsyndrome,thoughttodisruptthesecondsomatosensorycortexfromthalamus.(C)FLAIRMRIofposteriorreversibleencephalopathysyndromeproducingvisualloss.(D,E)FocalWMlesionconsistingofmetastaticmelanomawithsurroundingedema,producingalexiawithoutagraphia.,43,03,神经精神综合征是一组与神经系统疾病相关的行为和精神症状，可以分为情感障碍和精神行为障碍两类,02,白质病变对情感情绪、精神行为等非认知功能等产生影响，从而导致精神行为异常。,01,精神行为障碍指的是大脑机能活动紊乱，导致认知、情感、行为和意志等精神活动不同程度障碍的总称，包括幻觉、妄想、异常行为等,情感障碍以心境或情感异常改变为注意临床特征，包括抑郁、焦虑、情感淡漠、躁狂等；,04,神经精神综合征,44,请在此处输入您的文本，或者将您的文本粘贴到此处。,1,白质性痴呆,请在此处输入您的文本，或者将您的文本粘贴到此处。,1,请在此处输入您的文本，或者将您的文本粘贴到此处。,