1、CEREBRALARTERIOVENOUS MALFORMATIONSAVM: a TLA for the CNSIncidencen0.52% at autopsynSlight male preponderance (1.09 to 1.94)nCongenital lesions (although rarely familial)Embryologyn First half of third week of gestationepiblastic cells migrate to form mesodermmesodermal cells differentiate to arteri
2、al and venous vessels on the surface of the embryonic nervous systemEmbryologyn First half of third week of gestationepiblastic cells migrate to form mesodermmesodermal cells differentaite to arterial and venous vessels on the surface of the embryonic nervous systemn Seventh gestational weekvessels
3、sprout branches & penetrate developing brainreach the gray-white interface, either loop back to pial surface or traverse entire neural tube, thus epicerebral & transcerebral circneventually connect arterial and venous systems by around the twelfth week Pathology & Pathophysiologynabsence of normal c
4、apillary systemPathology & Pathophysiologynabsence of normal capillary systemnusual function displacedPathology & Pathophysiologynabsence of normal capillary systemnusual function displacednasymptomatic at birthPathology & Pathophysiologynabsence of normal capillary systemnusual function displacedna
5、symptomatic at birthnvessels change with timenmay develop aneurysmsnparenchymal changes within and around the lesionPathology & Pathophysiologynabsence of normal capillary systemnusual function displacednasymptomatic at birthnvessels change with timenmay develop aneurysmsnparenchymal changes within
6、and around the lesionnsite frequency is proportional to brain volumePathology & Pathophysiologynabsence of normal capillary systemnusual function displacednasymptomatic at birthnvessels change with timenmay develop aneurysmsClinical presentationn95% have symptoms by age of 70 yearsClinical presentat
7、ionn95% have symptoms by age of 70 yearsnpeak presentation second to fourth decadeClinical presentationn95% have symptoms by age of 70 yearsnpeak presentation second to fourth decadehigh output failure, neonate, vein of Galenhydrocephalus, first decadeheadache, hemorrhage, seizures, 2nd & 3rdClinica
8、l presentationnfactors contributing to symptomsvessel walls, flow and pressuresClinical presentationnfactors contributing to symptomsvessel walls, flow and pressuresenlargement and encroachmentClinical presentationnfactors contributing to symptomsvessel walls, flow and pressuresenlargement and encro
9、achmentdural sinusesClinical presentationnfactors contributing to symptomsvessel walls, flow and pressuresenlargement and encroachmentdural sinusesischaemiaClinical presentationnfactors contributing to symptomsvessel walls, flow and pressuresenlargement and encroachmentdural sinusesischaemiacardiac
10、outputClinical presentationHemorrhagenAVM rupture not a function of sizenAneurysm rupture related to aneurysm sizeHemorrhagenAVM rupture not a function of size no marked increase with exercise, pregnancy, traumanAneurysm rupture related to aneurysm size increase with trauma exercise, end pregnancyHe
11、morrhagenAVM rupture not a function of size no marked increase with exercise, pregnancy, trauma arteriovenous, therefore less severenAneurysm rupture related to aneurysm size increase with trauma exercise, end pregnancy arterial, therefore more severeHemorrhagenAVM rupture not a function of size no
12、marked increase with exercise, pregnancy, trauma arteriovenous, therefore less severe mortality 6 to 13.6%nAneurysm rupture related to aneurysm size increase with trauma exercise, end pregnancy arterial, therefore more severe mortality 30-50%HemorrhagenAVM rupture not a function of size no marked in
13、crease with exercise, pregnancy, trauma arteriovenous, therefore less severe mortality 6 to 13.6% lower rebleed mortality rate (1%)nAneurysm rupture related to aneurysm size increase with trauma exercise, end pregnancy arterial, therefore more severe mortality 30-50% higher rebleed mortality rate (1
14、3%)HemorrhagenAVM rupture not a function of size no marked increase with exercise, pregnancy, trauma arteriovenous, therefore less severe mortality 6 to 13.6% lower rebleed mortality rate (1%) vasospasm rarenAneurysm rupture related to aneurysm size increase with trauma exercise, end pregnancy arter
15、ial, therefore more severe mortality 30-50% higher rebleed mortality rate (13%) vasospasm commonHemorrhage - AVMnNonetheless, risk of major, incapacitating, or fatal hemorrhage in untreated lesion is 40 to 50% Hemorrhage - AVMnNonetheless, risk of major, incapacitating, or fatal hemorrhage in untrea
16、ted lesion is 40 to 50%nYearly risk of initial hemorrhage 3%nRebleed in first subsequent year 6-18%, reducing to 3% again thereafternPediatric prognosis worse than adult Spetzler & Martin Grading SystemCriteria ScoreSize of NidusSmall (6cm) 3Eloquence of Adjacent BrainNo 0Yes 1Deep Vascular ComponentNo 0Yes 1Treatment OptionsHSurgical ResectionTreatment OptionsHSurgical ResectionHEndovascular Embolisation
