3. Primary neurolationPrimary neurolation
Occur in 3-4 week gestation
Neural tube (NT) internally (gives rise to
the CNS above S2 segment),
epidermis externally &
neural crest (NC) at the junction of NT &
Epidermis
mesoderm cells which migrate away from
the neural tube and give rise to the
PNS,skull, facial and jaw bones, pigment
cells, adrenal medulla
4.
5. Neural tube closureNeural tube closure
Start at the cervical area (cervico-
medularly junction)
Extend cranially and caudally
Cephalic neuropore close around day 25
Caudal neuropore closes around day 29
and correspond to S2 segment
7. Dermal sinus tractDermal sinus tract
result from incomplete disjunction of
neuroectoderm from cutaneous ectoderm
The sinus tracts extend deep into the
subcutaneous tissues, reaching the spinal
canal in one-half to two-thirds of cases.
it may be attached to the dura, causing
tenting of the thecal sac.
8. AnencephalyAnencephaly::
Failure of anterior neuropore to close
Brain and calvarium are absent &
Replaced by a cerebrovasculorum - a
tangle of glial and connective tissue
9. Spina Bifida OccultaSpina Bifida Occulta
Common anomaly
Midline defect of vertebral bodies without protrusion of
spinal cord or meninges
Asymptomatic
Spine X Ray
MRI
14. --Located anywhere esp. lumbosacralLocated anywhere esp. lumbosacral
--Low sacral region: no motor impairment, anesthesia inLow sacral region: no motor impairment, anesthesia in
perineal areaperineal area
--Mid lumbar region: saclike cystic structure covered withMid lumbar region: saclike cystic structure covered with
thin layer of partially epithelialized tissuethin layer of partially epithelialized tissue..
Remnant of neural tissue are visibleRemnant of neural tissue are visible
Flacid paralysisFlacid paralysis
Clinical MinifestaionClinical Minifestaion
15. EncephaloceleEncephalocele
Bony defects in midline
Brain tissue can protrude through hole
Most common in occipital region
Prognosis depends on quantity of
cerebral tissue that herniates into the
defect
Surgical repair is required
16. CHIARI MALFORMATIONCHIARI MALFORMATION
Herniation of post. Fossa contents throughHerniation of post. Fossa contents through
foramen magnumforamen magnum..
Normal: upto 5 mm of tonsillar descent throughNormal: upto 5 mm of tonsillar descent through
foramen magnumforamen magnum..
Classified into Chiari I and II based on amountClassified into Chiari I and II based on amount
of descentof descent..
17. CLINICAL FEATURESCLINICAL FEATURES
Presents in infants or young adultsPresents in infants or young adults..
Headache aggravated by coughing orHeadache aggravated by coughing or
strainingstraining..
Signs of brainstem compressionSigns of brainstem compression
19. CRANIOSYNOSTOSISCRANIOSYNOSTOSIS
Premature closure of cranial suturesPremature closure of cranial sutures..
May affect single or multiple suturesMay affect single or multiple sutures
Present with abnormal head shapePresent with abnormal head shape..
Associated with rare genetic abnormalitiesAssociated with rare genetic abnormalities..
Surgery is required to correct itSurgery is required to correct it..