脑动静脉畸形.ppt

CEREBRAL
ARTERIOVENOUS MALFORMATIONS
AVM: a TLA for S
Incidence
% at autopsy
Slight male preponderance ( to )
Congenital lesions (although rarely familial)
Embryology
First half of third week of gestation
epiblastic cells migrate to form mesoderm
mesodermal cells differentiate to arterial and venous vessels on the surface of the embryonic nervous system
Embryology
First half of third week of gestation
epiblastic cells migrate to form mesoderm
mesodermal cells differentaite to arterial and venous vessels on the surface of the embryonic nervous system
Seventh gestational week
vessels sprout branches & rate developing brain
reach the gray-white interface, either loop back to pial surface or traverse entire neural tube, thus epicerebral & transcerebral circ'n
eventually connect arterial and venous systems by around the twelfth week
Pathology & Pathophysiology
absence of normal capillary system
Pathology & Pathophysiology
absence of normal capillary system
usual function displaced
Pathology & Pathophysiology
absence of normal capillary system
usual function displaced
asymptomatic at birth
Pathology & Pathophysiology
absence of normal capillary system
usual function displaced
asymptomatic at birth
vessels change with time
may develop aneurysms
parenchymal changes within and around the lesion
Pathology & Pathophysiology
absence of normal capillary system
usual function displaced
asymptomatic at birth
vessels change with time
may develop aneurysms
parenchymal changes within and around the lesion
site frequency is proportional to brain volume
Pathology & Pathophysiology
absence of normal capillary system
usual function displaced
asymptomatic at birth
vessels change with time
may develop aneurysms