Herniation: Compartment Syndrome of the Head Connie Chen, MD Neurology Consultants of Dallas.

Herniation:Herniation: Compartment Compartment

Syndrome of the Syndrome of the HeadHead

Connie Chen, MDConnie Chen, MDNeurology Consultants of DallasNeurology Consultants of Dallas

GoalsGoals

Understand Understand RecognizeRecognize TreatTreat

TheoryTheory

Compartment = skull contentsCompartment = skull contents Fixed volume:Fixed volume:

Brain (80%), blood (10%), csf (10%)Brain (80%), blood (10%), csf (10%) Stable pressure: CPP=MAP-ICPStable pressure: CPP=MAP-ICP

TheoryTheory Autoregulation of increased intracranial Autoregulation of increased intracranial

pressure (cough/valsalva):pressure (cough/valsalva):

Increased ICPIncreased ICP

Increase MAPIncrease MAP

Compartment’s goal: Maintain CPP!!Compartment’s goal: Maintain CPP!!

Another lookAnother look

Perfusion of a compartment:Perfusion of a compartment:

CPP= MAP- ICPCPP= MAP- ICP

If MAP cannot increase:If MAP cannot increase: Increased ICP = Decreased CPPIncreased ICP = Decreased CPP Decreased CPP = Tissue ischemiaDecreased CPP = Tissue ischemia Tissue ischemia = EdemaTissue ischemia = Edema

Another lookAnother look

Edema = Further increased ICPEdema = Further increased ICP Further decreased CPP = Tissue Further decreased CPP = Tissue

deathdeath

What Else?What Else?

Monro-Kellie doctrine:Monro-Kellie doctrine:

- Skull is a fixed volume- Skull is a fixed volume

- increase in one volume leads to - increase in one volume leads to decrease in others.decrease in others.

Brain> blood, csfBrain> blood, csf

What Else?What Else?

Increased ICP (via increased Increased ICP (via increased volume)volume)

Displace blood/csfDisplace blood/csf

**Displace brain** !!!!**Displace brain** !!!!

TheoryTheory

Increased ICP via increased volumeIncreased ICP via increased volume

Displaces blood, CSF, then brainDisplaces blood, CSF, then brain

&&

Reduces CPP causing brain ischemiaReduces CPP causing brain ischemia

RecognizeRecognize

Looking at a Head CT is not Looking at a Head CT is not recognitionrecognition

RecognizeRecognize

Displaced brain will cause neurologic Displaced brain will cause neurologic signssigns

SignsSigns

Where does Where does displaced brain go?displaced brain go? Side to side: Side to side:

subfalcinesubfalcine Side to bottom: uncal Side to bottom: uncal

(transtentorial) (transtentorial) Top to bottom: Top to bottom:

central tentorialcentral tentorial Bottom to top: Bottom to top:

“upward”“upward” Bottom thru the Bottom thru the

“hole”: tonsillar“hole”: tonsillar

falx

tentoriumforamen magnum

SignsSigns SubfalcineSubfalcine

ACA compression: ACA compression: contralateral leg paresiscontralateral leg paresis

SomnolenceSomnolence

Uncal (transtentorial)Uncal (transtentorial) Anisocoria to “blown Anisocoria to “blown

pupil”pupil” Midbrain and PCA Midbrain and PCA

compression: compression: SomnolenceSomnolence, , Contralateral Contralateral

hemiparesis, occipital hemiparesis, occipital infarctinfarct

Decerebrate posturing Decerebrate posturing (extensor)(extensor)

midbrain

SignsSigns Central tentorialCentral tentorial

Somnolence/comaSomnolence/coma Bilaterally “blown” Bilaterally “blown”

pupilspupils Decorticate/Decorticate/

decerebrate posturingdecerebrate posturing Bilateral midbrain, Bilateral midbrain,

PCA compressionPCA compression

Upward (rare)Upward (rare) Midbrain compressionMidbrain compression ““Blown” pupilsBlown” pupils Somnolence/comaSomnolence/coma

midbrain

SignsSigns

TonsillarTonsillar SomnolenceSomnolence QuadriparesisQuadriparesis Cardiac arrythmiasCardiac arrythmias Respiratory failureRespiratory failure

midbrainmedulla

Foramen magnum

More SignsMore Signs

Vital sign changes Vital sign changes (brainstem is being (brainstem is being crushed):crushed):

““Cushing Reflex” : Cushing Reflex” : Bradycardia/hypertensionBradycardia/hypertension

respiratory changerespiratory change

Somnolence/ComaSomnolence/Coma

EXAMINE PT: pupils, pupils, pupilsEXAMINE PT: pupils, pupils, pupils

Pupils?Pupils? Blown pupilsBlown pupils: (large unreactive): (large unreactive)

Not medication unless ophthalmology Not medication unless ophthalmology came came

Or if under GENERAL anesthesiaOr if under GENERAL anesthesia Compression of midbrainCompression of midbrain

Pinpoint pupilsPinpoint pupils: (small unreactive): (small unreactive) Often caused by medication (benzo’s, Often caused by medication (benzo’s,

opiates)opiates) Also from pontine damageAlso from pontine damage

Pupils?Pupils?

AnisocoriaAnisocoria:: Sometimes normal or surgicalSometimes normal or surgical Sometimes meds: nebulizerSometimes meds: nebulizer Compression of CN IIICompression of CN III

IrregularIrregular:: SurgicalSurgical Ongoing ischemia: “cat eye”Ongoing ischemia: “cat eye”

Exam SummaryExam Summary

Vital sign change is LATEVital sign change is LATE

Early exam change- somnolenceEarly exam change- somnolence Pupil change- anisocoria or less Pupil change- anisocoria or less

reactivereactive

Very late change: comatose, dilated Very late change: comatose, dilated pupils, posturingpupils, posturing

TreatmentTreatment

Head CT is not a treatmentHead CT is not a treatment

TreatmentTreatment

Herniation = Brain CODEHerniation = Brain CODE

Stabilize your pt first: ABC’s, then Stabilize your pt first: ABC’s, then BCBBCB

Then conduct “secondary survey”Then conduct “secondary survey”

TreatmentTreatment

Control your compartment (BCB)Control your compartment (BCB) BloodBlood CSFCSF BrainBrain

BloodBlood

Allow outflow:Allow outflow: Cut the tape off of the neckCut the tape off of the neck Head midlineHead midline Head of bed at 45 degreesHead of bed at 45 degrees

Constrict blood vessels:Constrict blood vessels: Hyperventilate: BAG!Hyperventilate: BAG! Goal is pH change- not pCO2Goal is pH change- not pCO2

CSFCSF

Drain CSF Drain CSF Intraventricular catheter placementIntraventricular catheter placement Spinal CSF removal will let you Spinal CSF removal will let you

herniate fasterherniate faster

BrainBrain

Steroids only work on tumorsSteroids only work on tumors

BrainBrain ShrinkShrink

Hyperosmolar agents: mannitol, hypertonic Hyperosmolar agents: mannitol, hypertonic salinesaline

Doses? Bolus vs infusion.Doses? Bolus vs infusion.

CutCut Surgical removalSurgical removal

Shut downShut down Neuroanesthetic agents: propofol, Neuroanesthetic agents: propofol,

thiopentalthiopental

How Long?How Long?

Hyperosmolar agents and Hyperosmolar agents and hyperventilation hyperventilation lasts 6 hours lasts 6 hours at best.at best.

Then what?Then what?

Your pt is betterYour pt is better

Your pt is not betterYour pt is not better

Then what?Then what?

Head CT verifies your diagnosis Head CT verifies your diagnosis

and identifies the problemand identifies the problem

Release Release

Release the compartment : “pop the Release the compartment : “pop the top”top”

Early vs. lateEarly vs. late

CaseCase 60 yo wm s/p acute right MCA 60 yo wm s/p acute right MCA

strokestroke

CaseCase

4 days later4 days later Pt becomes somnolent but arousablePt becomes somnolent but arousable There’s new anisocoriaThere’s new anisocoria

Plan?Plan?

CaseCase

12 hours later12 hours later Not arousable- comatoseNot arousable- comatose Still anisocoria, right pupil stops Still anisocoria, right pupil stops

reactingreacting

Plan?Plan?

CaseCase

Other options?Other options?

SummarySummary

Look outside your “box”Look outside your “box”

Herniation is reversibleHerniation is reversible

Treat before scanningTreat before scanning