中英中枢病变引起的偏侧咀嚼肌痉挛H

临沂白癜风医院 http://baidianfeng.39.net/a_zzzl/190525/7168767.html
SECTION1第一部分

A57-year-oldmanpresentedwithspasmsofhisleftjaw.Twoyearsprior,hehaddevelopedleft-sidedfacialnumbnessfollowedbydevelopmentofleft-sidedshock-likepainandtheninvoluntaryandrepetitivemovementsofthejaw-closingmuscles.Jawmusclecontractionswereepisodic,interferedwithchewingandtalking,andledtofrequenttonguebiting.Individualspasmsvariedfromsecondstominutesandhereportedthatfunctioninbetweenepisodeswasnormal,althoughhiswifefelthespokewithreducedmouthopening.Hesometimesawokewithabloodytongue,suggestingthatcontractionsoccurredduringwakingandsleep.Hehadnohistoryofpremonitorysensationorreliefassociatedwiththespasms.Hereportednodifficultyswallowing.

57岁男性，表现为左侧下颌痉挛。两年前，患者左侧面部出现电击样疼痛，之后左侧面部麻木感，随后出现不自主的重复闭口肌运动。下颌肌肉收缩是阵发性的，影响咀嚼和谈话，并导致频繁舌咬伤。每次痉挛时间持续数秒钟到数分钟，患者诉发作间期功能正常，但其妻子感觉患者说话时口张开的小。患者有时醒来时发现舌出血，提示在清醒和睡眠期间发生痉挛。患者病史中痉挛发作或缓解没有先兆，无吞咽困难。

Neurologicexaminationdemonstrateddecreasedsensationinall3trigeminaldivisionsontheleftandareducedcornealreflexontheleft.Masseterbulk,tone,andstrengthwerenormalbilaterally.Contractionswerenotedinthejaw-closingmuscles.Mouthopeningwaslimitedduringspeech.Therewasnofacialweakness.Therewasnopalataltremor.Headrotation,shouldershrugging,andtonguemovementswerenormal.Withtheexceptionofmild-to-moderatedistalsensorydeficit,theremainderoftheneurologicexaminationwasunremarkable.

神经系统查体发现左侧三叉神经所有3个分支分布区都感觉减退，左侧角膜反射减弱；双侧咀嚼肌肌容积、张力和力量均正常；可看到下颌闭口肌收缩；讲话时张口受限；无面瘫，无上颚震颤；转头、耸肩、舌运动正常；除了轻度到中度的远端感觉减退外，其它神经系统查体无明显异常。

Questionsforconsideration:

1.Whatisthelocalization?

2.Whatarepotentialetiologies?

思考问题：

1.定位？

2.潜在的病因？

SECTION2第二部分

Thispatient’sexaminationrevealed2localizingabnormalities:decreasedleftfacialsensationwithdiminishedcornealreflexandfrequentcontractionsoftheleftjawmuscles.Bothfindingslocalizetothetrigeminalnerve.Thesensoryfibersofthetrigeminalnerveoriginateatthetrigeminalnucleusintheponsandthemotorfibersofthetrigeminalnerveoriginateintheponsinanareacloseto,butnotin,thetrigeminalnucleus.Sensoryfibersprojectfromthetrigeminalnucleustothetrigeminalganglion,atwhichpointtheysplitinto3branchdistributions:ophthalmic(V1),maxillary(V2),andmandibular(V3).Motorfibersprojectfromthepons,decussate,trackadjacenttothetrigeminalnucleus,andeventuallyexitthecraniumadjacenttoV3throughtheforamenovale.Fromtheforamenovale,motorfibersseparatefromsensoryfibersandradiatetothemasseterandotherjaw-movingmuscles.

这个病人的查体发现2处异常：左侧面部感觉减退伴角膜反射减退、左侧下颌肌肉频繁的收缩。两处异常定位于三叉神经。三叉神经的感觉纤维起源于脑桥三叉神经核，运动纤维起源于临近脑桥三叉神经核的区域，但不在这个三叉神经核内。感觉纤维从三叉神经核投射到三叉神经节，在这里分为3支：眼支（V1）、上颌支（V2）、下颌支（V3）。运动纤维从脑桥交叉到对侧，紧邻三叉神经核走行，最后紧邻下颌支（V3）通过卵圆孔出颅。出卵圆孔后，运动纤维与感觉纤维分开，支配咀嚼肌和其它下颌运动肌肉。

Thesensoryandmotorbranchesofthispatient’snervewerebothaffected.Wethereforeinferthatanintracraniallesionofthetrigeminalnervemustbecausingthepatient’sdifficulties.Possibleetiologiesofthelesionincludevascular,infectious,autoimmune,trauma,oramass.Theslowonsetofthispatient’sdifficultiesdecreasesthelikelihoodofvascularlesionsandtherewasnohistoryoftrauma.Alesionisolatedtothetrigeminalnervewouldbeanunusualpresentationofaninfectiousorautoimmuneetiologysuchasmultiplesclerosis,Devicdisease,orListeria,andthepatienthadnocurrentorpastsymptomsconsistentwiththeseillnesses.Consideringthesefactors,themostlikelyetiologyofthispatient’sisolatedtrigeminalnerveproblemisacentraltumorormass.

该患者三叉神经的感觉和运动分支都受累。因此，我们推测患者的症状一定是三叉神经颅内病变所致。可能的病因包括血管性、感染性、自身免疫性、外伤或占位。患者起病缓慢，血管性病因可能性小，无外伤史，孤立于三叉神经的病灶不是感染性或自身免疫性疾病（如多发性硬化、视神经脊髓炎或李斯特菌感染）的常见临床表现，并且患者既往和当前没有符合这些疾病的症状。考虑这些因素，该患者孤立的三叉神经病变最可能的病因是中枢神经肿瘤或占位。

Questionsforconsideration:

1.Whattestingwillnarrowthisdifferential?

2.Whatcanbedonetohelpthepatient’ssymptoms?

思考问题：

1.做什么检查会缩小鉴别诊断范围？

2.给予什么处理有助于患者的症状改善？

图磁共振和草图说明患者的颅内病变

（A）脑桥轴位T2序列层面见左侧脑桥占位病变，呈爆米花样外观，低信号的黑环源于含铁血黄素沉积，符合血管瘤诊断。（B）草图说明颅内病变（红色）如何影响三叉神经的感觉和运动分支。

SECTION3第三部分

EMGrecordingsdemonstratedfasciculationpotentialsintheleftmassetermuscle.Spasmsintheleftmasseterwerecharacterizedbyincreasingfrequencyoffasciculationdischarges,ofteninbursts,followedbyhigh-frequencydischargesofmultipleunits.Individualmotorunitsfiredatfrequenciesupto80Hz(onlyidentifiablewithcertaintyatthebeginningandendofspasms).Nospasmsorabnormaldischargeswereseenontheright.TheseEMGresultsconfirmedexcessactivityofthelefttrigeminalmotornerve.

肌电图检查发现左侧咀嚼肌肌束震颤电位。左侧咀嚼肌痉挛以频率逐渐增加的肌束震颤放电为特征，经常是在多个运动单位高频放电后爆发。个别的运动单位发射频率达80Hz（只有在痉挛发作开始和结束时才能明确辨认）。右侧没有见到痉挛或异常放电。这些肌电图结果证实左侧三叉神经运动支过度活动。

Blinkreflexwaselicitedbystimulatingthesupraorbitalnerve,andblinkreflexandjawjerkstudieswerenormalbilaterally.Themassetericinhibitoryreflexwaselicitedbystimulatingtherightmentalnerveatthementalforamenwitha1-cmbipolarstimulatorwitha0.2-msecdurationstimulusat28.6mA.Massetericinhibitoryreflexesweretestedduringvoluntaryactivationandinvoluntaryspasms.Duringvoluntaryactivationofthemasseter,normalS1andS2silentperiodswereevokedbymentalnervestimulation.Duringinvoluntaryspasms,whenthesamestimulationwasgiven,therewerenosilentperiods.Occasionally,high-frequencymotorunitpotentialscouldbeelicitedbyvoluntarymuscleactivation.

瞬目反射通过刺激眶上神经被引出；双侧瞬目反射和下颌反射正常。以一个1cm双极刺激器，刺激时程为0.2毫秒，电流28.6毫安，刺激右侧颏孔内的颏神经引出咬肌抑制反射。在随意运动和不自主痉挛期间检测咬肌抑制反射。咀嚼肌随意运动期间，通过刺激颏神经引出正常的S1和S2静息期。不自主痉挛期间给予同样的刺激，没有静息期。偶尔，随意肌肉活动引出高频运动单位电位。

BrainMRIrevealedahemangiomalocatedadjacenttotheleftponsintheareaofthetrigeminalnerveexitingzone(figure,A).Thelesionwasconsideredinoperable,butthepatientexperiencedsubstantialreliefwitha

转载请注明：http://www.kmyoc.com/xglhl/11218.html