congenital intracranial malformations Flashcards
what is cause of anencephaly
incomplete closur anterior neuropore betweeen closure 1 and 3- know as closure 2
what getstational day does anterior neuropore close
day 24
what primary brain malformations occure during primary neuralation
anencephaly
cephalocele
congenital dermal sinus tract
when does primary neuralation occur
3-4 weeks
when does holoprosencephaly occur
prosencephalic cleavage failure by 6 weeks, could be due to primitive sreak faulure gastrulation
what are common genes invovled and chromosome for holoprosencephaly
SHH, SX3- chromosome 13 followed by chromosome 18
what causes hydrancephaly
normal brain disrupted by vascular occlusions- drugs, cirgarete smoking
what defines septoptico dysplasia
optic
nerve hypoplasia, pituitary dysfunction, and midline brain defects,
particularly absence of the septum pellucidum- fewer than 1/3 have all three- all have optic nerve hpoplasia
genes invovles in SOD
sox, Hesx
microcephaly how is it defined
2 SD below the age matched mean
what are types of microcephaly
MV- microcephaly vera with normal gyral patter
mSG- simplified gyral pattern
what is definition of megalencephaly
volume greater than 2 sd above the mean
what are metabolic causes
gangliosidoses, mucopolysaccharidoses,
sphingolipidoses, maple syrup urine disease, Alexander disease,
and Canavan disease.
how do children with hemimegicephaly present
cranial asymmetry, hemiplegia, and intractable seizures
that star t soon after birth
what is FCD type 1
radial (FCD type 1a) or tangential (FCD
type 1b) dyslamination of the neocortex, microscopically identified
in one or multiple lobes
