CNRN Practice Samples Questions and Answers Updated 2026

CNRN Practice Samples Questions
and Answers Updated 2026
WhichMofMtheMfollowingMtumorMtypesMwillMhaveMaMhigherMincidenceMinMpediatricMpop
ulationsMandMhaveMaMdecreasedMincidenceMwithMage?

A.MGlioblastoma

B.MPilocyticMastrocytoma

C.MCentralMnervousMsystemMlymphoma

D.MMetastaticMbrainMtumorM-MAnswerMB

Rationale:MBothMpilocyticMastrocytomaMandMmedulloblastomaMbrainMtumorsMareMmoreMc
ommonlyMfoundMinMtheMyoungerMpopulation.MTheMincidenceMofMtheseMtumorsMwillMdec
reaseMwithMage.MGlioblastomasMareMmoreMfrequentlyMfoundMinMyoungMadults.MCNSMlym
phomaMandMmetastasisMwillMhaveManMincreasedMincidenceMwithMage.



AMpatientMpresentsMwithMprogressiveMneurologicalMdeficitsMandMhasMaMrecentMhistoryM
ofMtransientMneurologicalMattack.MThisMpatientMisMmostMlikelyMexperiencingMwhichMofMt
heMfollowingMtypesMofMstroke?

A.MThromboticMstroke

B.MEmbolicMstroke

C.MSubarachnoidMhemorrhage

D.MVasospasmsM-MAnswerMA

Rationale:MThromboticMstrokesMfrequentlyMpresentMasMaMworseningMneurologicalMstatusM
overMaMshortMperiodMofMtime.MPatientsMmayMhaveMexperiencedMepisodesMofMtransient
MischemicMattacksM(TIAs)MbeforeMtheMonsetMofMtheMischemicMstrokes.MEmbolicMstrokes
MtendMtoMhaveMaMmoreMsuddenMonsetMwithoutMprogressionMinMsymptoms.MSubarachno
idMhemorrhagesM(SAHs)MareMaMsuddenMonsetMofMheadacheMwithoutMtheMhistoryMofMtr
ansientMneurologicalMdeficits.MVasospasmsMareMassociatedMwithMSAH,MandMsymptomsMoc
curMmostMcommonlyMbetweenM7MandM10MdaysMafterMtheMSAH.



WhichMofMtheMfollowingMbestMdescribesMaMcoupMinjury?

A.MInjuryMoccursMatMtheMpointMofMimpact.

B.MInjuryMoccursMonMtheMcontralateralMsideMofMimpact.

C.MItMisManMaccelerationMinjury.

D.MItMisMaMdecelerationMinjury.M-MAnswerMA

Rationale:MAMcoupMinjuryMoccursMatMtheMpointMofMimpact,MandMaMcontracoupMinjuryM
occursMonMtheMcontralateralMside.MTheMmechanismMofMinjuryMforMaccelerationMinjuriesM

,isMcommonlyMdefinedMasMaMmovingMobjectMhittingMaMstationaryMhead,MwhereasMaMdec
elerationMinjuryMinvolvesMaMmovingMheadMhittingMaMstationaryMobject.



AMpatientMisMadmittedMtoMtheMICUMwithMpersistentMepilepticMseizuresMlastingMbeyondM
90Mminutes.MWhichMofMtheMfollowingMbestMdescribesMtheMseizureMactivity?

A.MEpilepticMseizure

B.MEpilepsy

C.MRefractoryMseizure

D.MNonepilepticMseizureM-MAnswerMC

Rationale:MAnMepilepticMseizure,MwhichMpersistsMforMgreaterMthanM90MminutesMdespiteM
administrationMofManticonvulsantsMisMcalledMaMrefractoryMseizure.MAnMepilepticMseizureMi
ndicatesMtheMpresenceMofMEEGMwaveMchangesMduringMtheMseizureMactivity.MEpilepsyMre
fersMtoMrepetitiveMseizuresMwithoutMaMreversibleMcauseMsuchMasMhyponatremia.MNonepil
epticMseizureMisMtheMpresenceMofMseizureMactivityMwithoutMtheMEEGMchanges.



WhichMofMtheMfollowingMwouldMbeMtheMbestMtechniqueMtoMuseMtoMassessMforMcerebr
ospinalMfluidMinMbloodyMdrainageMfromMtheMnoseMfollowingMaMtraumaticMbrainMinjury?

A.MGlucoseMtest

B.MHaloMtest

C.MSendMtoMlabMforMhemoglobinMlevel

D.MLitmusMtestM-MAnswerMB

Rationale:MHaloMtestM(aMpositiveMresultMproducesMaMyellowMring)MisMmoreMaccurateMth
anMaMglucoseMtest,MespeciallyMwithMtheMpresenceMofMbloodyMdrainage.MAMglucoseMtest
MhasMbeenMusedMtoMdistinguishMbetweenMsinusMdrainageMandMcerebrospinalMfluidM(CSF
)MbecauseMCSFMhasMglucoseMbutMsinusMdrainageMdoesMnot.MButMinMthisMscenario,Mthe
MdrainageMwasM"bloody,"MandMbloodMhasMglucose.MBloodyMdrainageMmayMgiveMaMfalse
MpositiveMwithMaMglucoseMtest.MTestingMforMhemoglobinMinMtheMdrainageMdoesMnotMd
etermineMtheMpresenceMofMCSF.MLitmusMtestMisMusedMtoMtestMaMpHMofMaMfluidMand
MisMnotMusedMtoMdistinguishMCSFMfromMnasalMdrainage.



WhichMofMtheMfollowingMisMtheMmostMcommonMcauseMofManMembolicMstroke?

A.MAtrialMseptalMdefect

B.MAtrialMfibrillation

C.MCalcifiedMlesion

D.MAngioplastyM-MAnswerMB

,Rationale:MAtrialMfibrillationM(AF)MisMtheMmostMcommonMcauseMofManMembolicMstroke.
MAtrialMsepticMdefectM(ASD)MandMcalcifiedMlesionsMcanMalsoMresultMinMembolicMstrokes
MbutMareMsignificantlyMlessMcommonMthanMAF.MAMcomplicationMofMangioplastyMcanMbe
MdistalMembolizationMbutMagainMisMnotMtheMmostMcommonMcauseMofManMembolicMstr
oke.



CranialMnerveM(CN)MVIIM(facialMnerve)MisMcommonlyMinvolvedMwithMBell'sMpalsy.MWhere
MdoesMthisMCNMoriginate?

A.MPons

B.MMedulla

C.MMidbrain

D.MBasalMgangliaM-MAnswerMA

Rationale:MCranialMnerveM(CN)MVM(trigeminalMnerve),MVIM(abducensMnerve),MVIIM(facialM
nerve),MandMVIIIM(acousticMnerve)MoriginateMfromMtheMpons.MCNsMIXM(hypoglossalMnerv
e),MXM(vagus),MXIM(spinalMaccessoryMnerve),MandMXIIM(hypoglossalMnerve)MoriginateMfro
mMmedulla.MCNsMIIIM(oculomotorMnerve)MandMIVM(glossopharyngealMnerve)MoriginateMfro
mMtheMmidbrain.MNoMcranialMnervesMoriginateMfromMtheMbasalMganglia.



WhichMofMtheMfollowingMelectrolyteMabnormalitiesMisMLESSMlikelyMtoMresultMinMaMseizur
e?

A.MHyponatremia

B.MHyperkalemia

C.MHypocalcemia

D.MHypomagnesemiaM-MAnswerMB

Rationale:MHyponatremiaMisMoneMofMtheMmostMcommonMelectrolyteMabnormalitiesMthatM
canMcauseMaMseizure.MHypocalcemiaMandMhypomagnesemiaMcanMalsoMcauseMseizures.MP
otassiumMisMmoreMlikelyMtoMaffectMtheMmyocardialMelectricalMsystem,MresultingMinMarrh
ythmias.



AMpatientMinMtheMICUMfollowingMaMsevereMtraumaticMbrainMinjuryMsuddenlyMdemonstra
tesMprofuseMsweating,MsustainedMtachycardia,Mhypertension,MandMfever.MWhichMofMtheM
followingMisMtheMmostMlikelyMcause?

A.MNeurogenicMfever

B.MDiencephalicMseizure

C.MParoxysmalMsympatheticMhyperactivity

D.MCerebralMsaltMwastingMsyndromeM-MAnswerMC

, Rationale:MTraumaticMbrainMinjuryM(TBI)MpatientsMcanMexperienceM"sympatheticMstorms"M
calledMparoxysmalMsympatheticMhyperactivity.MTheMsymptomsMincludeMfever,Mtachycardia,
Mhypertension,MprofuseMsweating,Magitation,MandMincreaseMrespiratoryMrate.MTheM"storm
"MisMthoughtMtoMbeMdueMtoMintermittentMstimulationMofMtheMsympathoexcitatoryMcente
rsMlocatedMinMupperMbrainstemMandMdiencephalon.MDiencephalicMseizureMisManMincorrec
tMtermMforMtheMsymptomsMbecauseMtheMEEGMisMnegative.MNeurogenicMfeversMcanMocc
urMfollowingMTBIMbutMisMnotMassociatedMwithMtheMotherMsymptomsMofMhypertensionMa
ndMtachycardia.MCerebralMsaltMwastingMsyndromeM(CSWS)MisMtheMlossMofMsodiumMthrou
ghMtheMkidneysMandMresultsMinMhypovolemicMhyponatremia.



InMsevereMcasesMofMcerebralMpalsy,MthereMmayMbeMaMdelayMinMgrowthMandMdevelopm
ent.MWhichMofMtheMfollowingMconditionsMcanMoccurMinMtheseMcases?

A.MCoagulopathy

B.MImmunocompromise

C.MFailureMtoMthrive

D.MLocked-inMsyndromeM-MAnswerMC

Rationale:MFailureMtoMthriveMisMaMcomplicationMofMmoderateMtoMsevereMcerebralMpalsy
M(CP).MItMcanMresultMinMmalnutritionMandMdeath.MCPMisMnotMassociatedMwithMimmuno
compromiseMorMcoagulopathies.MCPMinvolvesMabnormalMmotorMmovementsMassociatedMwi
thMspasticityMorMflaccidity,MbutMdoesMnotMdevelopMlocked-inMsyndrome.



WhichMofMtheMfollowingMbestMdescribesMtheMpenumbraMinManMischemicMstroke?

A.MIrreversiblyMdamagedMtissue

B.MNormalMhealthyMtissue

C.MPresenceMofMvasogenicMcerebralMedema

D.MReversibleMischemicMtissueM-MAnswerMD

Rationale:MTheMpenumbraMisMtheMareaMsurroundingManMinfarctionMthatMisMischemicMor
MreversibleMischemicMtissue.MIrreversiblyMdamagedMtissueMisMtheMareaMofMtissueMinfarcti
onMandMisMtheMcoreMofMtheMinfarction.MVasogenicMcerebralMedemaMisManMincreaseMin
MinterstitialMedemaMorMfluidMandMisMtypicallyMfoundMsurroundingMtheMpenumbra.MNorm
al,MhealthyMtissueMisMtheMareaMofMbrainMtissueMnotMaffectedMbyMtheMischemiaMorMinj
ury.



AMpatientMisMadmittedMtoMtheMtraumaMICUMfollowingMaMtraumaticMbrainMinjuryMdueMt
oMvehicleMrollover.MTheMpatientMisMhypotensiveMandMtachycardic.MWhichMofMtheMfollow
ingMisMtheMmostMaccurateMstatement?

A.MHypotensionMfollowingMtraumaticMbrainMinjuryM(TBI)MindicatesMpresenceMofMepiduralM
hematoma.