搜索
NeurologyMain201-211Q201A23-year-oldmanisfoundatthesceneofamotorvehicleaccidentwithlowerextremityfractures:abdominalbruising,andscalplacerations.Hecomplainsofpainandsomeshortnessofbreath.Initially,hisbloodpressureis95/60mmHgandpulseis120/minandregular.Hisspineisimmobilized,andperipheralintravenousaccessisobtained.Heisgiven1Lofintravenousfluids.Onthewaytothehospital,hebecomesprogressivelydrowsyanddevelopsprogressiveweaknessontherightsideofhisbody.Hisbloodpressureis160/90mmHgandpulseis50/min.Whichofthefollowingnervefunctionsismostlikelytobecompromisedonphysicalexamination?A.AbducensB.AccessoryC.FacialD.GlossopharyngealE.OculomotorA201Correctanswer:FSuddenlossofconsciousness(LOC):lossofposturaltone,anddelayedreturntobaselinementalstatusshouldraisesuspicionforseizure(eg,generalizedtonic-clonic).Somepatientsmayexperienceanaura(egrolfactoryhallucination)priortotheeventand/orlateraltonguelacerationsduringtheeventComparedtootheretiologiesofsuddenLOCtgeneralizedseizuresalmostalwayshaveadelayedreturntobaselineneurologicfunctioningduetoapostictalstateoftransientconfusion,lethargy,and/orfocalneurologicdeficits.Incontrast,syncopeisatransientLOGwithlossofposturaltonefollowedbyimmediatespontaneousreturntobaselineneurologicfunction.Themostcommoncauseofsyncopeisvasovagalsyncope,whichmaybeprecededbyaprodromeofnausea,warmth:lightheadedness,and/ordiaphoresis.Pallorandweakpulses(duetovagalnerveactivation)stronglysuggestsyncope.(ChoiceA)Thepatient'srecentpsychosocialstressorsraiseconcernforingestion,butacetaminophentoxicitycausesapredictablesequenceofnausea/vomiting,rightupperquadrantpainwithelevationofliverenzymes,andpotentialliverfailureanddeath.Seizuresarenottypical.(ChoicesBandC)OrthostatichypotensiorMscharacterizedbyasignificantdropinbloodpressureaftershiftingfromalyingtoastandingposition.Causesincludeintravascularvolumedepletion(duetobloodlossordehydration)andmedication-relatedautonomicinstability(egrbetablockers).Apositivestoolguaiactestindicatesoccultgastrointestinalbleeding,whichcanleadtoorthostatichypotensionandsyncopesecondarytohypovolemia.Mopostictalstateisseen,andahistoryofmelanoticstoolsorpalloronexaminationistypical.(ChoiceD)Pulsusparadoxusreferstoafallinsystemicbloodpressure10mmHgduringnormalinspiration.Itisacommonfindinginpatientswithcardiactamponade,whichcanpresentwithsyncopebuta!sowithtachycardia,hypotension,andelevatedjugularvenouspressure.(ChoiceE)Asystolicmurmurthatincreaseswithstandingischaracteristicofhypertrophicobstructivecardiomyopathy.Syncopeisoftenassociatedwiththisconditionandisusuallyinducedbyexertion.Returntoneurologicbaselineisimmediate.Educationalobjective:Seizuresarecharacterizedbysuddenlossofconsciousness,lossofposturaltone,andapostictalstatewithdelayedreturntobaselineneurologicfunctioning.Tonguelacerationscanoccurwithtonic-clonicmovements.Q202A2-month-oldgirlisbroughttotheofficebyherparentsforawell-childvisit.SheisexclusivelybreastfedandtakesvitaminDsupplements.Thepatientisabletoliftherheadwhenproneandsmilessocially.Shelivesathomewithhermother,father,andgrandmother.Thefatheroccasionallysmokescigarettesbutneverinthepresenceofthechild.Thegrandmotheroftenhelpstakecareofthechildovernightandsleepsinthebedwithher.Physicalexaminationresultsareappropriateforage.Thechildisdueforseveralroutinevaccinationstoday.Themotherbecomestearfulandmentionsthatthepatient’s3-month-oldcousinrecentlydiecHnhiscrib;thecauseremainsunexplainedafterautopsy.Sheasksforinformationabouthowtopreventsuchanincident.Inadditiontosleepinginthesupineposition,whichofthefollowingfactorsisassociatedwithdecreasedincidenceofunexplainedinfantdeath?A.Bed-sharingwithacaretakerB.Delaying2-monthvaccinationsC.Limitingsecond-handsmokeexposureD.Placingtheinfantinaside-sleeppositionE.UsingahomeapneamonitorF.UsingasoftmattressA202Correctanswer:EThispatientpresentsafterbluntheadtraumawithsigns/symptomsworrisomefortranstentorial(uncal)herniationsecondarytoaright-sidedepiduralhematoma.Epiduralhematomasresultfromruptureofthemiddlemeningealartery,andthishigherarterialpressurecanrapidlyexpandthehematomaandcompressthetemporallobe.ThefluidresuscitatiorMnthispatientlikelyincreasedtherateatwhichtheepiduralhematomaexpanded.Thepresenceofhypertension,bradycardia,andrespiratorydepression(Cushing'sreflex)indicateselevatedintracranialpressure.Theuncusistheinnermostpartofthetemporallobeandherniatesthroughthetentoriumtocausepressureontheipsilateraloculomotornerve,ipsilateralposteriorcerebralartery,andcontralateralcerebralpeduncleagainsttheedgeofthetentorium.Patientstypicallypresentwiththefocalneurologicsignsshowninthetableabove,(ChoiceA)Abducensnerve(i.e,hCHVI)injuryfromuncalherniationusuallyoccurslaterintheclinicalpresentation：withas/mptomofinabilitytoabducttheeye.(ChoiceB)Accessorynerve(ireMCNXI)dysfunctioncanbeduetolesionsinthemedulla,suchasocclusionoftheposteriorinferiorcerebellarartery.Theaccessorynervecanalsobeinjuredduringsurgicalproceduresinvolvingtheanterolateralneck.Injuriespresentwithparalysisoftheipsilateralsternocleidomastoidandtrapeziusmuscles.(Choice