9149statlermentalstatus.doc.pdf
TRANSCRIPT
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DiagnosticApproachtoAlteredMentalStatusMichelStatler,MLA,PACTuesday,May26,2009
I. LearningObjectivesa. Interprettheabnormalitiesonphysicalexamfoundinapatientwithalteredmental
status.b. Recognizethesignsandsymptomsassociatedwithimpendingherniation.c. Selecttheappropriatediagnosticstudiestoevaluateapatientwithalteredmental
status.
II. Introductiona. Consciousnessisthestateofawarenessofselfandtheenvironment
i. Normalconsciousnessdependentupon:1. Intactcerebralhemispheresforcognition2. Reticularformationforalertness
b. Alteredmentalstatusresultsfromanimpairmentofarousalorcognitionc. Disordersofconsciousnesscanseeacuteconfusionalstatesordeliriumd. Disordersofcognitionleadtoimpairmentofmemoryorothercognitivefunction(i.e.
judgmentorabstractthinking)i. Dementiaaffectscognitionwithoutaffectingconsciousnessii. Focalneurologicdiseasecanaffectcognitionifcriticalcorticalareasofcognition
areinvolved.e. Comaduetodysfunctionofbothcerebralhemispheresand/ortheupperbrainstem
III. Etiologies
a. Metaboliccausesi. Hypoxiaii. Electrolyteand/orglucosedisturbancesiii. Uremiaiv. Hepaticfailurev. Drugssedatives,opiates,antidepressants,anticonvulsantsvi. Toxinsalcohol,carbonmonoxide,heavymetalsvii. Psychiatricdisorders
b. Intracranial/structuralcausesi. Traumadiffuseaxonalinjury,epiduralorsubduralhematomaii. Vascularischemicstrokewithmasseffect,brainstemstroke,hemorrhagic
strokeiii. Infectionmeningitis,encephalitis,abscessiv. Otherepilepsy,hydrocephalus
IV. ImportantHistoricalDetails
a. Dependentupontheobservationsofothersi. Onset/timelineofsymptomsii. Historyofrecentsystemicorneurologicsymptomsiii. Historyofheadtraumaiv. Pastmedicalhistoryrenalorhepaticdisease,diabetesv. Medications
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vi. Druguse,includingalcoholvii. Associatedsymptoms:fever,HA,stiffneck,seizureactivity
b. Historywithpossibleetiologiesi. Hxofheadachemeningitis,encephalitis,subarachnoidhemorrhage,
intracerebralhemorrhageii. Hxofpriorheadinjurychronicsubduralhematomaiii. Acuteonsetofsymptomsischemicorhemorrhagestrokeiv. Gradualonsetofsymptomsmasslesionormetaboliccausev. Hxoflimbtwitchingand/orincontinenceseizurewithpostictalconfusionvi. Hxofdiabeteshypoglycemiavii. Hxofmalignancyintracranialmetastasis
Case#1A73yearoldrighthandedmanisbroughtinbyhissonforincreasingforgetfulness.Hissonsaysthatheoftenlosesthingsandishavingahardtimerememberingdatesandfindingtherightwordsforthings.Recentlyhehasbeendroppinghiscoffeecupandhastroublefeedinghimselfandwriting.Alertandorientedx2;unabletorecalldate.Wordfindingdifficulty;abletoname3/5objects.Poorrecallatoneminute(1/3);cannotrecallnamesofpresidents;knowsdate/placeofbirth.Unabletodoserial7sorrepeatdigitspan.Abletowrinkleforeheadbilaterally,mildflatteningofthenasolabialfoldontheleftDecreasedhandgriponleft,4/5weaknessleftUE.
V. PhysicalExama. Vitalsigns
i. Signsofinfectionorsepsisii. Respiratorypatterns
1. CheyneStokesrespirationsseenwithbihemisphericlesionsormetabolicencephalopathy
2. Centralneurogenichyperventilation(Kussmauls)seenwithmetabolicacidosisorherniation
3. Apneusticrespirationsseenwithpontinedamage4. Clusterbreathingseenwithpontineorcerebellardamage5. Ataxic(Biots)respirationsseenwithmedullarydamage
iii. Hypertensionwithbradycardiaassociatedwithhighintracranialpressureb. HEENTlookforsignsoftrauma
i. BattlesorRaccoonsignii. CSFotorrheaorrhinorrheaiii. Hemotympanum
c. Skinexamcherryredskinconsistentwithcarbonmonoxidepoisoningd. Neurologicexam
i. Levelofconsciousness1. Lethargicpatientmaybeconversantbutinattentiveandslowto
respond;cantperformsimpletaskslikecounting.2. Stuporincompletearousaltopainfulstimuli;little,ifanyresponseto
verbalcommands3. Comatoseunresponsivetoallstimuli
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4. Ifpatientresponsive,attempttoevaluatelanguage,memoryandconcentration
5. Folsteinminimentalstatusexamcanbeusedii. GlasgowComaScale15pointscaleusedtopredictmortality
1. Basedoneyeopening,motor,andverbalresponsesa. Decorticateposturingflexionandadductionofarmsand
extensionoflegs(flexorresponse)i. Reflectslesionincorticospinaltractfromcortexto
uppermidbrainb. Decerebrateposturingextension,adduction,andinternal
rotationofthearmsandextensionofthelegs(extensorresponse)
i. Reflectsdamagetocorticospinaltractatlevelofpoonsoruppermedulla
iii. AVPUalternateassessmenttool;usedprimarilybyEMS1. Alertness2. Verbalresponse3. Painfulstimulus4. Unresponsive
iv. RestingeyepositionGazepreference1. GazepreferenceAWAYfromthesideofthehemiparesisisconsistent
withalargecerebralhemisphericlesiona. Frontaleyefieldsnormallymoveeyestocontralateralsideb. Iflesionpresenteyeslookatthelesionandawayfrom
hemiparesis2. GazepreferenceTOWARDthesideofthehemiparesisisconsistentwith
alesioninthebrainstem(pons)a. Lateralgazemechanismintheponsmovestheeyestothe
ipsilateralsideb. Iflesionpresent,eyesdeviateawayfromthedamagedsideand
towardthehemiparesisv. Spontaneouseyemovement
1. Rovingeyemovementsa. Slow,conjugatehorizontalmovementsb. Indicatesbrainstemcontrolofeyemovementsisintactc. Seenwithbilateralhemisphericdysfunction(ieanoxia)
2. Ocularbobbinga. Downwardjerkingofbotheyesfollowedbyslowreturntomid
positionb. Seenwithpontinelesions;needtoruleoutlockedinstate
vi. Reflexeyemovements1. Oculocephalic(DollsEyes)2. Oculovestibular(Calorics)
vii. LockedInSyndrome1. Patientawakebutquadriplegicwithparalysisofhorizontaleye
movements2. Verticaleyemovementpreserved3. Abletocommunicatebylookingdownorblinking
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4. Associatedwithlargepontinelesion,ieaninfarctorhemorrhage5. Prognosisfavorable;recoverypossible
viii. Pupillaryresponses1. Midposition(25mm)andnonreactiveseenwithmidbrainlesions2. Pinpoint&reactiveseenwithpontinelesions3. Unilateraldilated&fixedseenwithaCNIIIlesion/uncalherniation4. Bilateraldilated&fixedseenwithcentralherniation,hypoxia
ix. Fundoscopicexamlookforpapilledema1. Usuallytakes12hoursbeforepapilledemapresent
x. MotorExamlookforspontaneousmovementsandpresenceoffocaldeficits(leftvs.right;uppervs.lowerextremity)
1. Usepronatordrifttoassessforsubtleweaknessesxi. CheckDTRs.corticallesionswillproducehyperactivereflexes,clonus,anda
positiveBabinskixii. Foradditionalcomponentsoftheneurologicexamtobereliable,youneedan
alertandcooperativepatient(i.e.sensoryandcerebellarexams,meningealsigns)
e. PsychogenicComadiagnosisofexclusioni. Patientsarephysiologicallyawakebutunresponsiveii. Suspectwheninconsistentexamfindingsiii. Pupillaryandoculovestibularreflexesareintactiv. EEGisnormal
Case#2A24yearoldWMsustainedaclosedheadinjuryinaMVC.TherewasabriefLOCatthescene,butthepatientwasawakeuponarrivaltotheED.Hewasorientedtonamebutnottoplaceortime.Hecouldmoveallfourextremitiesuponcommand.Pupilswereequal,roundandreactivetolight.12hourslater,hewasunresponsivetoverbalcommandsandwithdrewtopainfulstimuli.Therightpupilwas6mmandsluggishlyreactive;leftpupilwas3mmandbrisklyreactive.
VI. ImpendingHerniationa. Potentiallylifethreateningcomplicationthatcanbeenseenwithamasslesion,
traumaticinjury,orCNSinfectionb. Increasingunresponsivenesstostimulic. Changesinpupillaryresponsesd. Unilateralfixedanddilatedpupilsareconsistentwithuncalherniatione. Changesinrespiratorypatterns
i. CheyneStokes,apneustic,orclusterrespirationsf. Changesinmotorexam(withdrawingtopain,posturing)
VII. DiagnosticEvaluationa. ThebasicsABCsb. Intubateifpatienthasrespiratorycompromiseordeeplycomatosec. StartanIVd. Insertfoleycathetere. Checklabs:CBC,comprehensivemetabolicpanel,arterialbloodgas,PT/PTT,urinalysis,
fingerstickglucose,toxicologyscreen/bloodalcohollevel
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f. Mayalsogetthyroidfunctiontests,serumcortisol,andammonialevelg. NeuroimagingCT/MRI
i. NoncontrastCTgeneralfirstlineii. Includecontrastiftumororabscesssuspected
h. LumbarpuncturewithCSFanalysisruleoutCNSinfectionorsubarachnoidhemorrhage
i. EEGifdiagnosisunclear,EEGcanruleoutpostictalstate,nonconvulsivestatusepilepticus,ormetaboliccause
VIII. Puttingitalltogether
a. Patientwithnonfocalexamandintactbrainstemreflexes:i. Characterizedbyreactivepupils,fulleyemovementsandsymmetricmotor
responsesii. Mostlikelyetiologytoxic/metaboliccause,CNSinfectionorhydrocephalus
b. Patientwithfocalhemisphericsignsi. Characterizedbycontralateralhemiparesis,gazeparesisii. Mostlikelyetiologystructurallesion
1. Forexamplestroke,tumor,orsubduralhematomac. Patientwithfocalbrainstemsigns
i. Characterizedbyabnormalpupillaryresponses,cranialnervepalsies,orposturingonmotorexam
ii. Mostlikelycausebrainstemlesion(strokeortumor)oramasslesionwithherniation
IX. PearlsofPractice
a. StructuralcausesofAMSareassociatedwithfocaldeficitsonexamb. Focalfindingsonexamareanindicationforneuroimaging
i. CTgoodfortrauma´cerebralischemiaii. MRIgoodfortumorsorotherstructuralabnormalities
c. Bemindfulofchangesconsistentwithimpendingherniationobtainanemergentneurosurgicalconsultation
X. References
a. Gabriely,H,Leu,JP,andBarzel,US.BacktoBasics.TheNewEnglandJournalofMedicine2008;358:19521956.
b. Kanich,W.etal.AlteredMentalStatus:EvaluationandEtiologyintheED.AmericanJournalofEmergencyMedicine2002;20(7):613617.
c. Lehman,RK,andMink,J.AlteredMentalStatus.ClinicalPediatricEmergencyMedicine2008;9:6875.
d. Mistovich,JJ,Krost,WS,andLimmer,DD.BeyondtheBasics:InterpretingAlteredStatusAssessment.EMSAugust2008:9097.
e. Washburn,LA.AlteredMentalStatus:CauseDeterminesTreatment.JAAPA2005;18(2):1622.
f. Wilber,ST.AlteredMentalStatusinOlderEmergencyDepartmentPatients.EmergencyMedicineClinicsofNorthAmerica2006;24:299316.
g. Wong,J,Traub,SJ,Macnow,L,andKullchycki,LK.CasePresentationsoftheHarvardAffiliatedEmergencyMedicineResidencies.JournalofEmergencyMedicine2008;35(4);445448.