Spina Bifida P1 Flashcards
general definition of spina bifida
aka spinal dyspharism and neural tube defect
congenital malformation and VC and SC
failure of neural tube to close in 3rd-4th wk
epidemiology of spina bifida
whites
females
hispanic ethniity
etiology of spina bifida
inc risk:
low folic acid intake
if may anak na may spina bifida = higher chance
pregestational diabetes and obesity
teratogenic drugs - valproate and carbamazepine
drugs used to induce ovulation
inc age
midspring conception
recommended doses for folic acid
normal: 400 ug or 0.4 mg daily
previous NDT mother or high risk: 4000 ug or 4 mg daily (1-3 mo. prior to conception)
week 2 of development
gastrulation = 3 germ layers
primitive streak in epiblast
significance of ectoderm
outer most layer where nervous system is derived
week 3 of development
neurulation = forming of neural tube
- primary and secondary phse
notochord secretes growth factor = ectoderm –> neuroectoderm –> neural endplate
primary phase
week 3-4
neural plate thickens and bends –> folds to form hollow tube
cranial = brain
caudal = SC
secondary phase
week 4-7
caudal part of neural tube becomes lumbar, sacral and coccyx segment
upper part does not close: anencephaly
lower part does not close: spino bifida
discuss neural plate
forms by day 18 and becomes tube and crest
tube - CNS
crest - PNS
closure of cranial end
24th day
closure of caudal end
26th day
discuss anencephaly
most severe NTD - dead na
neural tube does not close at base of skull
discuss encephalocele
rare NDT - can be repaired surgically but c deficits
part of brain herniates through skull defect
day 53 of development
caudal regression c rostral ext = SC
kaya lesions are before day 53 and usually sa lumbar and sacral