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
