医学院神经解剖学教案小脑损伤

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1、神经解剖学选修课教程4-1-2小脑损伤lesionsofthecerebellumReview1:Threefunctionaldivisionsofthecerebellum:spinocerebellum(paleocerebellum)cerebrocerebellum(neocerebellum)vestibulocerebellum(archicerebel-lum)spinocerebellum(paleocerebellum):importantincontrollingthepostureandmovementofthetrunkan

2、dlimbscerebrocerebellum(neocerebellum):participatesintheplanningofmovemnetvestibulocerebellum(archicerebellum):helpsustomaintainbalanceandcontrolheadandeyemovementReview2:ConnectionsandfunctionsofthefunctionaldivisionsSpinocerebellarpathways(1)Spinocerebellarpathways(2)Spinocer

3、ebellarpathways(3)Cerebrocere-bellarpathwayVestibulocere-bellarpathwayClinicalCorrelationsDamagetothecerebellumproducesneurologicalsignsonthesamesideasthelesionKnowledgeoftheanatomyofthedescendingprojectionsystemiscrucialforunderstandingwhycerebellardamagetypicallyproducesipsil

4、ateralmotorsigns.Thisisbecauseboththecerebellarefferentprojectionsarecrossedaswellasthedescendingpathways,whicharethetargetsofcerebellaraction.Thecombineddecussationsresultinasystemofconnectionsthatis“doublycrossed”.Damagetocerebellarinputfromthespinalcordalsoproducesipsilatera

5、lsignsbecausetheprincipalspinocerebellarpathways,thedorsalspinocerebellarandcuneocerebellartracts,ascendipsilaterally.Thus,whetherdamageoccurstoeithercerebellarinputsoroutputs,ortothecerebellumitself,neurologicalsignsarepresentontheipsilateralside.Signsandsyndromesofcerebellarl

6、esionsTherethreeclassicneurologicalsignsofcerebellardamage:Ataxiaisinaccuracyinthespeed,force,anddistanceofmovement.Nystagmusisarhythmicinvoluntaryoscillationoftheeyes.Tremorisinvoluntaryoscillationofthelimbsortrunk.Theflocculonodularlobesyndrome(caudalvermissyndrome)consistsof

7、theinabilitytomaintaintheuprightpostureduetotruncaldystaxia.Nystagmusmayalsobepresent.ThissyndromeoccursmostcommonlywithtumorofthevermisThecerebellarhemispheresyndromeconsistsofdystaxiaandhypotoniaoftheipsilateralextremities.Themostcommoncausesareneoplasmaandinfarctsofacerebell

8、arhemisphere.