brain herniation - smirniotopoulos (rsna 2007)

Click here to load reader

Post on 07-Nov-2014

135 views

Category:

Documents

3 download

Embed Size (px)

DESCRIPTION

Brain Herniation - Smirniotopoulos (RSNA 2007)

TRANSCRIPT

Learning ObjectivesRecognize Urgent Lesions Understand Acute Traumatic Lesions Describe four types of herniation Triage Acute Vascular Lesions Recognize Diffuse cerebral swelling

Essentials of NeuroradiologyJames G. Smirniotopoulos, M.D. Uniformed Services University Bethesda, MD And Armed Forces Institute of Pathology Washington, DC

2 y.o. with dilated pupil

EPIDURAL HEMATOMA

Significant trauma Fracture & concussion (l.o.c.)

Lucidpt

Interval

Wakes Up 40% pts.Delayed neurologic Sx (hrs. Later) Herniation, coma and deathMidline Herniation: Subfalcial and Downward Transtentorial

EPIDURAL HEMATOMATrauma -> fracture & concussion Tearing/stripping of both layers of dura away from inner table Laceration of outer periosteal layer of dura Laceration of meningeal vessels Inner (meningeal dura) intact Blood between naked bone and dura NORMAL arterial pressure continues to dissect

Epidural Hematoma

1

Brain Herniation Syndromesf

Brain Herniation SyndromesfC

t

t

t

U

M

tKernohans Notch: Cerebral peduncle contralateral to the mass lesion

T

T

Four Types of Brain HerniationTranscalvarial cerebral cortex Subfalcial Cingulate Gyrus Transtentorial

Downward Upward

fC

Uncus and Temporal Lobe Vermis

t

U M

t

Foramen Magnum Tonsils and MedullaT T

Calvarial Herniation

Subfalcial and Transtentorial

Left to Right Shift Subfalcial herniation Downward Transtentorial

2

Complex Subdural Hematoma

SDH: Subfalcial Herniation

1cm pineal shift, 3cm Right-to-Left shift and Subfalcial Herniation

Dural Baffles: Falx and TentoriumfC

Subfalcial Herniation Cingulate

t

UM

t

T

T

Subfalcial Herniation

SDH Brain Herniation

3

SDH Brain Herniation

Transtentorial Herniation

The PCA is compressed between the uncus and midbrain

Tentorial hiatus and MidbrainSuperior Cerebellar a. Oculomotor nerve (CN3) Posterior Cerebral a. Temporal Herniation Compresses

PCA Infarct Tentorial Herniation

CN3 Compresses PCA

Courtesy Mauricio Castillo, M.D. UNC

PCA Infarct from Herniation

Diffuse cerebral swelling

Anoxic Damage Loss of Autoregulation Commotio Cerebri Secondary herniation Duret Hemorrhage

4

30 y.o. man after motor cycle crash with facial swelling and facial fractures. Acute alteration in level of awareness.

Duret Hemorrhages

Downward displaced brainstem Kinks and compresses perforators Hemorrhagic Infarction

No sulci, no cisterns, low-attenuation both temporal lobes, brainstem (midbrain) hyperattenuating lesion.

25 y/o man from a helicopter crash. Upon arrival, patient was intubated and sedated

After reviewing this CT, what would you do next ?a. Suggest FLAIR MR b. Suggest Magnetic Susceptibility Image (MSI or SWI) c. Suggest Diffusion Weighted MR d. Make Diagnosis e. a, b, and c are ALL suggested

3 Reasons for Getting an MR CT CT CT

fails to explain Pts Condition fails to explain Pts Condition fails to explain Pts Condition

5

Findings

Shearing Injury

Intraventricular hemorrhage Torn Shearing

Choroid Plexus Injury

Shearing Injury

Corpus Callosum

MSI

T2W

SWI

Deep Lesions - Terminology Intermediate

SHEARING INJURIES Deep

Contusions Shearing Injury Diffuse WhiteWhite-matter Injury (DWI) Diffuse Axonal Injury (DAI)

lesions

High Velocity (MVA) Trauma Acceleration/Deceleration Especially CORONAL Side Impact (Running

angular momentum a Red Light)

Do not require an impact or Fx. SHEARING OF AXONS AXONS Breaks Actual force

connections may be tension

SHEARING SHEARING of Small WM VESSELS

Small (petechial) hemorrhages

6

DIFFUSE AXONAL INJURY Neurologic Some

Deep Lesions Coronal Forces

Sx Begin at Impact have Immediate L.O.C. Some have Persistent Vegetative State Pathology: foci of hemorrhage in corpus callosum, brainstem, etc. axon retraction balls (ARB) LongLong-Term Survivors: microglial clusters foci of demyelination

Angular momentum in the Coronal Plane: Running a Red Light T-Bone the cars

Corpus Callosum

WM Axonal Transection

Dense, compact, white matter, bundles of axons

Axon Retraction Balls Cytoplasm leaking from transected axons and disrupted axolemma.

Axon Retraction Balls

Diffuse axonal injury (Magnetic Susceptibility)

TSE T2

Turbo FLAIR

FLASH T2* TE: 15 ms

FLASH T2* TE: 35 ms

Ref. Parizel PM et al. Eur. Radiol. 1998; 8: 960-965

7

Corpus Callosum and BG

Unconscious Patient - CT

Thanks to Pam Schaefer

Diffuse Axonal Injury - FLAIR

Diffuse Axonal Injury - MSI

Thanks to Pam Schaefer

Thanks to Pam Schaefer

Trauma, Intraventricular Blood => MR

Blindness45 y.o. man with acute onset of homonymous hemianopsia

CT

SWI

8

Non-Contrast CT

What we see - Findings

Axial CT Abnormal Cortex and WM Where?

Medial Occipital Lobe

Minimal

mass effect

Imaging Infarction

CT abnormal in hours MR abnormal in minutes Insular ribbon sign Increased water Hyperdense MCA Intraluminal Hyperintense MCA clot Vascular (intravascular) enhancement DWI Bright ADC Dark Intracellular Cytotoxic Edema

Early MCA stroke

Insular Ribbon Sign

Carotid Thrombosis => MCA ClotMCA

PCA Infarct

ACA X PCA MCA

Lights up like a lightbulb on MRI DWI

9

medpix20366.jpg

Post. Cerebral A. Infarct

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

Repeat CT: Hyperdense MCA

Matching DWI and ADC Images = Cytotoxic Edema = Acute Infarct

Repeat CT scans, two hours after admission

DWI

Restricted Diffusion or T2 ShineThru?ADC Map

Cytotoxic Edema

Neuronal SwellingNormal Neuron

Normal Na+ K+ pumpK Na

goes In goes Out

Energy Dependent Glucose O2 ATP

Swollen Dead Neuron

10

Restricted Diffusion

Chronic Infarct Atrophy

Complications of rTPA

Whole MCA Infarction

Two days after IA Thrombolysis

Acute Motor Hemiplegia

INTRA-CEREBRAL HEMORRHAGE Dense

and Homogeneous Round/oval shape Basal ganglia/deep white Proportional mass effect Extension into ventricleBP on presentation 185/105 Courtesy Doug Phillips, UVA

11

Hypertensive Hemorrhage

BP on presentation 210/110 Courtesy Doug Phillips, UVA

Hypertensive Hemorrhage

Found Down68 year old man with confusion and acute hemiplegia.

Hypertensive hit list Basal Ganglia Internal/External Capsule Thalamus Dentate Nucleus Pons Lobar Courtesy Doug Phillips, UVA

NOTE: Vasogenic EdemaCourtesy Doug Phillips, UVA

Glioblastoma multiforme, WHO 4

Found Down

34 yo marine stationed at Guantanamo Bay Cuba, presenting w/ acute mental status changes, febrile.

Courtesy Doug Phillips, UVA

12

Abnormal Gray Matter

Abnormal Gray Matter

Vascular Ischemia Infarction Hyperemia

(Migraine, Seizures)

Inflammatory Encephalitis Meningo-Encephalitis Vasculitis

Vascular Follows territory of MCA, etc. Infection Multiple territories

Non-Vascular HSV EncephalitisACA MCA MCA ACA ACA MCA

AChoA PCA

HSV encephalitis

Courtesy Mauricio Castillo, M.D. UNC

13

HSV encephalitis

HSV encephalitis

HSV encephalitisCourtesy Mauricio Castillo, M.D. UNC Courtesy Mauricio Castillo, M.D. UNC

What do they have in Common? Multiple Bilateral

Toxic and/or Metabolic: Congenital

Symmetric Acquired Anatomic Basal

ganglia

Toxic/Metabolic

Metabolic

Medial vs. Lateral Lenticular

Intrinsic Diabetic Ketoacidosis Hypoglycemic Coma

Extrinsic Toxic Exposures CO and Methanol

Carbon Monoxide

Methanol Intoxication

14

CO Poisoning

Carbon Monoxide

Methanol Intoxication

Medial vs. Lateral Lenticular

Carbon Monoxide Intoxication

CO IntoxicationCO binds to Hgb 240X stronger than O2 making carboxyhemoglobin Sx: HA, Lethargy, weakness, dizziness, nausea, confusion, and SOB TX is to displace CO with O2

T1/2 80

for CO is 320 min on room air min on 100% O2 23 min at 3 atm 100% O2

MetOH Intoxication

Tx for MetOH - Fomepazole

Fomepazole (Antizole, 4-methylperazole) is a synthetic alcohol dehydrogenase inhibitor for IV administration Clear yellow liquid, mw 82.1, mp 25 C (77 F) INDICATIONS: Antidote for ethylene glycol, or methanol poisoning or suspected EG ingestion PRECAUTIONS: Dilute in > 100 mL NS, follow hepatic enzymes & WBC (eos) during Rx, interaction with ethanol (compete for ADH) DOSE: 15 mg/kg load, 10 mg/kg Q 12 h x 4 doses, then 15 mg/kg Q 12 h till EG < 20 mg/dL

15

34 yo comatose woman, psychiatric pt.

Findings

Intraaxial Diffuse Bilateral abnormalities Low attenuation Low attenuation

in Cortical Gray Matter in Basal Ganglia

Edema Edema What

Kind?

Interstitial Cytotoxic Hydrostatic Courtesy Aimee Hawley, M.D. MGAFMC

Diagnosis: Cytotoxic Edema

Lab: Serum Na+ 121

Cytotoxic Edema Cerebral

ischemia Metabolic PoisonsCN Triethyl Tin Hexachlorphene Hypoglycemia

Psychogenic polydipsia Overhydration Athletes

drinking too much water

Iatrogenic D5W

w/o salts

Treatment Hypertonic 2%

Gray matter > White matter

Saline saline (not 4%)

Causes of Hyponatremia

Rapid Correction of serum Na+Treatment: Correction by administration of IV Saline, or twice normal, or

Increased total body water Excessive Iatrogenic

water intake (IV therapy)

Reduced Urine Output Exercise Heat Inappropriate

Exposure ADH

T1W T2W DWI

Sodium Loss Inadequate Sodium Intake

16

Osmotic Myelinolysis

Anoxia During Surgery

Diffuse and Bilateral Gray-matter hypointensities

Anoxia During Surgery

Headache39 y.o. woman with abrupt onset of the worst headache of my life

Diffuse and Bilateral Gray-matter hypointensities

What we see - Findings

Worst HA: Non-Contrast CT

Axial CT Abnormal Where? Subarachnoid

space

How? Hyperdense

17

Aneurysm and Rupture

Subarachnoid Hemorrhage

Clinical Hx: "Worst

Headache of My Life Rigidity Photophobia Nuchal

Signs: Kernigs, Brudzinski's Demographics: Common Most

Cause of Stroke in Young (< 40) pts. 40-60yrs

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

Subarachnoid HemorrhageLP more sensitive than CT Trauma is most common cause for RBCS in CSF

Not

seen as easily or as often on CT

SAH on CT Blood

clot Aneurysm / AVM Uncommon from neoplasm Uncommon from spinal disease usually

Subarachnoid Clots

18

Aneurysm

Angiography - AngiogramRound (berry) shape Vessel bifurcation natural exploited

weakness by high BP

Common sites: ACA

ACOMM branches Basilar Tip MCA

AP

Oblique

ICA Aneurysm

Pulsation Artifact Phase-encoding direction

ICA Aneurysm

Summary

Brain Herniation Epidural Subdural

fC

Trauma Ventricular Shearing

blood Injury tU M

Gray matter Encephalitis Ischemia/Infarction

t

Toxic/Metabolic Co

vs. Methanol

T

T

19

Thank You!

Go Raimh Maith Agat

Muito Obrigado Mahalo ! Dank u wel !

EUXAPIT !

Merci BeaucoupDanke Schn !Mil Gracias

20