Imaging Neurologic Emergencies:Imaging Neurologic Emergencies:When and Where Radiology Makes a DifferenceWhen and Where Radiology Makes a Difference

James G. Smirniotopoulos, M.D.James G. Smirniotopoulos, M.D.Radiology and Radiological SciencesRadiology and Radiological Sciences

Uniformed Services UniversityUniformed Services UniversityBethesda, MDBethesda, MD

Learning ObjectivesLearning Objectives

Choose the best imaging for each patientChoose the best imaging for each patient

Develop a Develop a ““checklistchecklist”” for imaging to for imaging to improve your ability to identify significant improve your ability to identify significant findingsfindings

Recognize imaging findings that will Recognize imaging findings that will acutely change patient managementacutely change patient management

Clinical Assessment

History– Headache, Seizure, Weakness, Visual– Traumatic, non-trauma, “found down”

Level of Consciousness– Glasgow Coma Scale (GCS)

Neurologic Examination– Cranial Nerve Exam (CNN 2-12)– Extremities – moving all four?

Imaging Assessment

What tests are on the “menu”?– CT scans

w/o contrastwith contrast

– MR scansw/o contrastwith contrast“Special” MR (e.g. Diffusion, Perfusion, etc.)

What test should I get?– Almost always a non-contrast CT scan

Imaging Assessment

What should I look for?– Global Assessment for abnormalities– Mass Effect, Brain Shift or Herniation– BWH?

Diagnosis and Etiology– Traumatic– Non-Traumatic

Vascular (e.g. “stroke”)Toxic/MetabolicNeoplastic

Treatment Decisions– Surgical vs. “Conservative” or “Medical Management”

MR and CT Imaging ChecklistsMR and CT Imaging Checklists

Anatomic LocationsAnatomic Locations–– SagittalSagittal ImagesImages

Sup. Sag. SinusSup. Sag. SinusCorpus CallosumCorpus CallosumSellaSella RegionRegionClivusClivus

–– Axial ImagesAxial ImagesSkull, Skull, EpiEpi/Sub Dural/Sub DuralSASSASCortical Gray MatterCortical Gray MatterWhite MatterWhite MatterDeep Gray MatterDeep Gray MatterVentriclesVentricles

Morphologic FeaturesMorphologic Features–– Mass EffectMass Effect

Yes, proportionalYes, proportionalLess than expectedLess than expectedNo mass effectNo mass effect

–– Abnormal WM SignalAbnormal WM SignalVasogenic EdemaVasogenic EdemaDemyelinationDemyelinationInfiltrating neoplasmInfiltrating neoplasm

–– Enhancing Ring LesionEnhancing Ring LesionNecrotic NeoplasmNecrotic NeoplasmReactive (e.g. abscess)Reactive (e.g. abscess)Fluid or InflammatoryFluid or Inflammatory

History of Imaging Acute CNS

AutopsySkull series plain filmsAngiography– Gross mass lesions (EDH, SDH)

Computed Tomography– EDH, SDH, Contusion, some DAI

Conventional Spin Echo MRI– More of the above

GRE/MSI, DTI, MRS, fMRI– Even more

CNN 2: BlindnessCNN 2: Blindness

45 45 y.oy.o. man with acute onset of right. man with acute onset of right--sided sided homonymous hemianopsiahomonymous hemianopsia

Where would the lesion be?

L R

LR

What we see What we see -- FindingsFindings

Axial CTAxial CTAbnormal Cortex and WMAbnormal Cortex and WM–– Where?Where?

Medial Occipital LobeMedial Occipital Lobe

–– Minimal mass effectMinimal mass effect

Right Homonymous Hemianopsia:What the Patient Sees …

L R

L R

NonNon--Contrast CTContrast CT

PCA InfarctPCA Infarct

Lights up like a lightbulbon MRI DWI

Post. Cerebral A. InfarctPost. Cerebral A. Infarct

Imaging InfarctionImaging Infarction

CT abnormal in hoursCT abnormal in hoursMR abnormal in minutesMR abnormal in minutesInsular ribbon signInsular ribbon sign–– Increased waterIncreased water

Hyperdense MCAHyperdense MCAHyperintense MCAHyperintense MCAVascular (intravascular) enhancementVascular (intravascular) enhancement

DWI BrightDWI BrightADC DarkADC Dark

Intraluminalclot

Intracellular Cytotoxic Edema

Carotid Thrombosis => Carotid Thrombosis => MCA ClotMCA Clot

MCAACA

MCA

PCA

X

medpix20366.jpgThis 53 yo man presented to the Emergency Department reporting a several hour history of left-sided hemi-body weakness

Repeat CT scans, two hours after admission

Repeat CT: Hyperdense MCARepeat CT: Hyperdense MCA

DWI

Restricted Diffusion – or T2 Shine-

Thru?ADC Map

Matching DWI and ADC Images = Matching DWI and ADC Images = CytotoxicCytotoxic Edema = Acute InfarctEdema = Acute Infarct

CytotoxicCytotoxic EdemaEdema

Normal Na+ Normal Na+ K+ K+ pumppump–– K goes InK goes In–– Na goes OutNa goes Out

Energy DependentEnergy Dependent–– GlucoseGlucose–– O2O2–– ATPATP

Normal Neuron

Swollen Dead Neuron

Chronic Infarct

Atrophy

Two days after IA Thrombolysis

Complications of Complications of rTPArTPA

Whole MCA InfarctionWhole MCA Infarction

Acute Motor Acute Motor HemiplegiaHemiplegia

BP on presentation 185/105

Courtesy Doug Phillips, UVA

INTRAINTRA--CEREBRAL HEMORRHAGECEREBRAL HEMORRHAGEDense and HomogeneousDense and HomogeneousRound/oval shapeRound/oval shapeBasal ganglia/deep whiteBasal ganglia/deep whiteProportional mass effectProportional mass effectExtension into ventricleExtension into ventricle

Hypertensive HemorrhageHypertensive Hemorrhage

BP on presentation 210/110

Courtesy Doug Phillips, UVA

Hypertensive HemorrhageHypertensive Hemorrhage

Hypertensive “hit list”Basal GangliaInternal/External CapsuleThalamusDentate NucleusPonsLobar

Courtesy Doug Phillips, UVA

HeadacheHeadache

39 39 y.oy.o. woman with abrupt onset of the . woman with abrupt onset of the ““worst headache of my lifeworst headache of my life””

What we see What we see -- FindingsFindings

Axial CTAxial CTAbnormalAbnormalWhere?Where?–– Subarachnoid spaceSubarachnoid space

How?How?–– HyperdenseHyperdense

Worst HA: NonWorst HA: Non--Contrast CTContrast CT

Aneurysm and RuptureAneurysm and Rupture

Clinical Clinical HxHx::–– "Worst Headache of My Life"Worst Headache of My Life””–– NuchalNuchal RigidityRigidity–– PhotophobiaPhotophobia

Signs: Signs: KernigKernig’’ss, , Brudzinski'sBrudzinski'sDemographics:Demographics:–– Common Cause of Stroke in Young (< 40)Common Cause of Stroke in Young (< 40)–– Most pts. 40Most pts. 40--60yrs60yrs

Risk Factors: Hypertension, ADPCKD, CTD Risk Factors: Hypertension, ADPCKD, CTD (connective tissue)(connective tissue)

Subarachnoid HemorrhageSubarachnoid Hemorrhage

Subarachnoid HemorrhageSubarachnoid Hemorrhage

LP more sensitive than CTLP more sensitive than CTTrauma is most common cause for RBCTrauma is most common cause for RBC’’S S in CSFin CSF–– Not seen as easily or as often on CTNot seen as easily or as often on CTSAH on CTSAH on CT–– Blood clotBlood clot–– usually Aneurysm / AVMusually Aneurysm / AVM–– Uncommon from neoplasmUncommon from neoplasm–– Uncommon from spinal diseaseUncommon from spinal disease

Subarachnoid ClotsSubarachnoid Clots

AneurysmAneurysm

Round (Round (‘‘berryberry’’) shape) shapeVessel bifurcationVessel bifurcation–– natural weaknessnatural weakness–– exploited by high BPexploited by high BP

Common sites:Common sites:–– ACA <ACA <--> ACOMM> ACOMM–– MCA branchesMCA branches–– Basilar TipBasilar Tip

Angiography Angiography -- AngiogramAngiogram

AP Oblique

ICA AneurysmICA Aneurysm

MRAT2WMR

Pulsation Artifact

Phase-encoding direction

ICA AneurysmICA Aneurysm

““Found DownFound Down””34 34 yoyo marine stationed at Guantanamo Bay Cuba, marine stationed at Guantanamo Bay Cuba,

presenting w/ acute mental status changes, febrile.presenting w/ acute mental status changes, febrile.

T2WMR

Abnormal Gray MatterAbnormal Gray Matter

VascularVascular–– IschemiaIschemia–– InfarctionInfarction–– Hyperemia (Migraine, Seizures)Hyperemia (Migraine, Seizures)

InflammatoryInflammatory–– EncephalitisEncephalitis–– MeningoMeningo--EncephalitisEncephalitis–– VasculitisVasculitis

Abnormal Gray MatterAbnormal Gray Matter

Vascular – Follows territory of MCA, etc.

Infection – Multiple territories

T2WMR

NonNon--Vascular Vascular »» HSV EncephalitisHSV Encephalitis

MCA

ACA

MCA

ACA

MCA

AChoA

ACA

PCA

34 34 yoyo comatose woman, psychiatric pt. comatose woman, psychiatric pt.

Courtesy Aimee Hawley, M.D. MGAFMC

FindingsFindings

IntraaxialIntraaxialDiffuse Bilateral abnormalitiesDiffuse Bilateral abnormalities–– Low attenuation in Cortical Gray MatterLow attenuation in Cortical Gray Matter–– Low attenuation in Basal GangliaLow attenuation in Basal Ganglia

““EdemaEdema””–– What Kind?What Kind?

InterstitialInterstitialCytotoxicCytotoxicHydrostaticHydrostatic

Toxic/MetabolicToxic/Metabolic

Lab: Serum Na+ 121Lab: Serum Na+ 121

Psychogenic Psychogenic polydipsiapolydipsiaOverhydrationOverhydration–– Athletes drinking too much waterAthletes drinking too much water

IatrogenicIatrogenic–– D5W w/o saltsD5W w/o salts

TreatmentTreatment–– Hypertonic SalineHypertonic Saline–– 2% saline (not 4%)2% saline (not 4%)

Causes of Causes of HyponatremiaHyponatremia

Increased total body waterIncreased total body water–– Excessive water intakeExcessive water intake–– Iatrogenic (IV therapy)Iatrogenic (IV therapy)

Reduced Urine OutputReduced Urine Output–– ExerciseExercise–– Heat ExposureHeat Exposure–– Inappropriate ADHInappropriate ADH

Sodium LossSodium LossInadequate Sodium IntakeInadequate Sodium Intake

Treatment:

Correction by administration of IV Saline, or twice normal, or …

Treatment of Treatment of HyponatremiaHyponatremia

Rapid Correction of serum Na+Rapid Correction of serum Na+

T1W

T2W

DWI

Osmotic Osmotic MyelinolysisMyelinolysis

What do they have in Common?What do they have in Common?

MultipleMultipleBilateralBilateralSymmetricSymmetricAnatomicAnatomicBasal gangliaBasal ganglia

Toxic and/or Metabolic:

•Acquired

•Congenital

MetabolicMetabolic

IntrinsicIntrinsicDiabetic Diabetic KetoacidosisKetoacidosisHypoglycemic ComaHypoglycemic Coma

ExtrinsicExtrinsicToxic ExposuresToxic ExposuresCO and MethanolCO and Methanol

Carbon Monoxide Methanol Intoxication

Medial vs. Lateral LenticularMedial vs. Lateral Lenticular

Carbon Monoxide Methanol Intoxication

Medial vs. Lateral LenticularMedial vs. Lateral Lenticular

CO PoisoningCO Poisoning

Carbon Monoxide IntoxicationCarbon Monoxide Intoxication

CO IntoxicationCO Intoxication

CO binds to CO binds to HgbHgb 240X stronger than O240X stronger than O22making making carboxyhemoglobincarboxyhemoglobinSxSx: HA, Lethargy, weakness, dizziness, : HA, Lethargy, weakness, dizziness, nausea, confusion, and SOB nausea, confusion, and SOB TX is to displace CO with OTX is to displace CO with O22–– TT1/21/2 for CO is 320 min on room airfor CO is 320 min on room air–– 80 min on 100% O80 min on 100% O22

–– 23 min at 3 23 min at 3 atmatm 100% O100% O22

MetOHMetOH IntoxicationIntoxication

TxTx for for MetOHMetOH -- FomepazoleFomepazoleFomepazoleFomepazole ((AntizoleAntizole, 4, 4--methylperazole) is a methylperazole) is a synthetic synthetic alcohol alcohol dehydrogenasedehydrogenase inhibitor inhibitor for IV administrationfor IV administrationClear yellow liquid, mw 82.1, mp 25Clear yellow liquid, mw 82.1, mp 25ºº C (77C (77ºº F)F)INDICATIONS: Antidote for ethylene glycol, or methanol INDICATIONS: Antidote for ethylene glycol, or methanol poisoning or suspected EG ingestionpoisoning or suspected EG ingestionPRECAUTIONS: Dilute in > 100 PRECAUTIONS: Dilute in > 100 mLmL NS, follow NS, follow hepatic enzymes & WBC (hepatic enzymes & WBC (eoseos) during Rx, ) during Rx, interaction with ethanol (compete for ADH)interaction with ethanol (compete for ADH)DOSE: 15 mg/kg load, 10 mg/kg Q 12 h DOSE: 15 mg/kg load, 10 mg/kg Q 12 h xx 4 doses, 4 doses, then 15 mg/kg Q 12 h till EG < 20 mg/then 15 mg/kg Q 12 h till EG < 20 mg/dLdL

Anoxia During SurgeryAnoxia During Surgery

Diffuse and Bilateral Gray-matter hypointensities

Anoxia During SurgeryAnoxia During Surgery

Diffuse and Bilateral Gray-matter hypointensities

What we saw What we saw ……

TraumaTrauma–– Epidural Hematoma => Brain HerniationEpidural Hematoma => Brain Herniation–– Subdural Hematoma => Brain HerniationSubdural Hematoma => Brain HerniationVascular Vascular –– Acute Cerebral InfarctionAcute Cerebral Infarction–– Spontaneous Spontaneous ““hypertensivehypertensive”” HematomaHematoma–– SAH from Ruptured Cerebral AneurysmSAH from Ruptured Cerebral AneurysmInfectionInfection–– Herpes EncephalitisHerpes EncephalitisMetabolic/ToxicMetabolic/Toxic–– HyponatremiaHyponatremia–– CO and CO and MetOHMetOH ToxicityToxicity

SummarySummary

Brain HerniationBrain Herniation–– EpiduralEpidural–– SubduralSubdural

TraumaTrauma–– Ventricular bloodVentricular blood–– Shearing InjuryShearing Injury

Gray matterGray matter–– EncephalitisEncephalitis–– Ischemia/InfarctionIschemia/Infarction

Toxic/MetabolicToxic/Metabolic–– Co vs. MethanolCo vs. Methanol

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Thank You!Thank You!Muito ObrigadoEUXAPIΣTΩ !

Mahalo !Dank u wel !

Merci BeaucoupDanke Schön !

Go Raimh Maith Agat

Mil Gracias