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