Arteriovenous Malformation - Lecture 11 Flashcards
AVM is a
birth defect
who is more common to get AVM
20-30 yr olds
size of AVM
can be tiny to the size of a whole hemisphere
what are AVMs
masses of abnormal blood vessels
appear as a tangle of arteries and veins
high pressure arteries
connect directly to low pressure arteries instead of through capillaries
what do they all share
characteristic of an AV connection w/o an intervening capillary network
what is abnormal
lack of O2 or glucose to brain tissue within the fistula
scarred in result to
tiny hemorrhages
may not have been noticed except for headache
what occasionally occurs
focal deficits
what do focal deficits result from
shunting away blood from healthy brain into fistula
cerebral steal syndrome
what is AVM the result of
abnormal fetal development
risk of bleed with AVM
1-4% per yr
preceded by intense headache and/or seizure
smaller AVMs are more likely
to bleed than larger d/t elevated arterial pressure in small vessels
how can hemorrhages be
parenchymal or SA
bleeds are often
less devastating
why’re bleeds less devestating
bleeds are primarily into the malformation
only incidentally into the adjacent brain
long term prognosis
good
90% surviving the first bleed
treatment options
radiation
embolization
surgery
radiation
indicated for very small and deep AVMs
embolization
indicated for larger AVMs
what is used in embolization
angiogram
AVM is given agents which help decrease the blood supply to the malformation
surgery
complete resection
disallowing them from recurring again
completely removed
surgical interventions for hemorrhagic CVA
craniotomy and evacuation
craniectomy and evacuation if ICP is abnormally high
preoperative management of recurrent hemorrhage and vasospasm are important
factors associated with recovery –> HCVAs
poorer survivability
better fxnal recovery
factors associated with recovery –> ICVAs
good survivability
poorer fxnal recovery
recovery can occur d/t
reduction of swelling or edema
existence of collateral blood flow
neuroplasticity
lacunar CVA
relatively uncommon
lacunar CVA has
characteristics of both ischemic and hemorrhagic CVA
where do lacunar CVA occur
deep white matter of the brain where tiny arterioles branch off of larger vessels
vulnerable to hypertensive hemorrhage or the vessel may thicken or thrombose
syndromes tend to be either (lacunar CVA)
pure motor
facial weakness
pure sensory
pure motor
internal capsule - posterior limb
facial weakness
internal capsule - anterior limb
pure sensory
posterolateral thalamus
prognosis of lacunar CVA
tends to be good
