Embryology of Nervous System

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Transcript of Embryology of Nervous System

MarwanAlhalabiMDPhDProfessorinReproductiveMedicineFacultyofMedicineDamascusUniversity&ClinicalMedicalDirectorOrientHospitalAssistedReproductionCenterDamascus,Syria.

Thehumanbrainisthemostcomplex

massofprotoplasmonearth-perhapseveninourgalaxy.

6

BrainDevelopment

• The spinalcorddevelopsfromthecaudal2/3 oftheneuraltube

Caudal portion

Rostral portion

mesencephalon

metencephalon

myelencephalon

6 weeks4 weeks

• Pinealgland:sleep-wakecycle,secretesmelatonin.

• Epithalamus:masticatoryandswallowingfunctions.

• Thalamus:majorrelayofsensoryinputtocerebralcortex.

Diencephalon

2

Microcephaly

Anencephaly

Chiari0Malforma3on

Chiari MalformationChiari MalformationClinical IssuesClinical Issues AFP,AFP, High morbidity &mortalityHigh morbidity &mortality 4%aneuploidy rate4%aneuploidy rate CS at delivery termCS at delivery term 80% need ventriculoperitoneal 80% need ventriculoperitoneal

shuntshunt Can reverse with in utero surgeryCan reverse with in utero surgery Preventive threatment with folic Preventive threatment with folic

acidacid

Imaging FindingsImaging Findings Posterior fossa Posterior fossa „„banana banana

signsign““ Calvarial lemon signCalvarial lemon sign VentruculomegalyVentruculomegaly CM obliterationCM obliteration Head normal or smallHead normal or small

Diagnostic ChecklistDiagnostic Checklist AmniocentesisAmniocentesis Cranial findings easier to Cranial findings easier to

see than ONTDsee than ONTD Compressed CM may be Compressed CM may be

only finding!!only finding!!

14 +4 weeks

Hydrocephalus , T 21Hydrocephalus , T 21Ventriculomegaly

HydrancephalyHydrancephaly

Hydranecphaly

Encephalocele

Occipital EncephaloceleOccipital EncephaloceleImaging FindingsImaging Findings Herniated brain tissueHerniated brain tissue „„cyst within the cystcyst within the cyst““ Ventriculomegaly 70Ventriculomegaly 70--

80%80% Microcephaly 25%Microcephaly 25% PolyhydramniosPolyhydramnios OligohydramniosOligohydramnios

CAVE:CAVE: Associated with multiple Associated with multiple

syndroms ( Meckelsyndroms ( Meckel-- Gruber )Gruber )

HoloprosencephalyHoloprosencephaly

Pilu

Holoprosencephaly

Hemimegalencephaly Arachnoid0cyst

ACC

SOP

SchizencephalySchizencephalySchizencephaly

PFAFluidACyst

Yong seok et al.

Vascular0Malforma3ons

Circle of Willis MallformationCircle of Willis Mallformation

Sunday, July 28, 13

Sonography&of&the&CNS

Basic0Examination “Neurosongram”

Sunday, July 28, 13

Planes0of0Basic0Examina3on

Axial0Planes Sagibal0Planes

Sunday, July 28, 13

Axial0Planes

Sunday, July 28, 13

Axial0Planesa:0Transventricular

Sunday, July 28, 13

Axial0Planesa:0Transventricular

b:0Transthalamic0

Sunday, July 28, 13

Axial0Planesa:0Transventricular

C:0Transcerebeller0

b:0Transthalamic0

Sunday, July 28, 13

The0Transventricular0plane

Sunday, July 28, 13

The0Transventricular0plane

Frontal0hones

Sunday, July 28, 13

The0Transventricular0plane

Frontal0hones

Atrium

Sunday, July 28, 13

The0Transthalamic00Plane

Sunday, July 28, 13

T

T

The0Transcerebeller00plane

Sunday, July 28, 13

Cavum0Sep30Pellucidi

T

T

The0Transcerebeller00plane

Sunday, July 28, 13

Cavum0Sep30Pellucidi

Frontal0hones

T

T

The0Transcerebeller00plane

Sunday, July 28, 13

Sagibal0Planes00

Sunday, July 28, 13

Sagibal0Planes00

A:0The0Midsagittal0Plan

Sunday, July 28, 13

Sagibal0Planes00

b:0Parasgittal0plane

A:0The0Midsagittal0Plan

Sunday, July 28, 13

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Corpus0Callosum

Lateral0Ventricles

Third0Ventricle

midbrainPituitary

Splenium

Thalamus

hypothalamus

Fourth0ventricle

The0Corpus0Callosum

Sunday, July 28, 13

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ParaHSagiGal&Plane&

Sunday, July 28, 13

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Basic Examniation ChecklistBasic Examniation Checklist

Head + NeckHead + NeckMidline & FalxMidline & FalxCavum septi pellucidiCavum septi pellucidiLateral cerebral ventriclsLateral cerebral ventriclsChoroid PlexusChoroid PlexusCerebellumCerebellumCisterna magnaCisterna magna

Sunday, July 28, 13

• Head&Neck

• Midline&Falx

• Cavum septi pellucidi

• Lateralcerebralventricles

• Choroidplexus

• Cerebellum

• Cisternamagna

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Microcephaly

Anencephaly

Chiari0Malforma3on

Chiari MalformationChiari MalformationClinical IssuesClinical Issues AFP,AFP, High morbidity &mortalityHigh morbidity &mortality 4%aneuploidy rate4%aneuploidy rate CS at delivery termCS at delivery term 80% need ventriculoperitoneal 80% need ventriculoperitoneal

shuntshunt Can reverse with in utero surgeryCan reverse with in utero surgery Preventive threatment with folic Preventive threatment with folic

acidacid

Imaging FindingsImaging Findings Posterior fossa Posterior fossa „„banana banana

signsign““ Calvarial lemon signCalvarial lemon sign VentruculomegalyVentruculomegaly CM obliterationCM obliteration Head normal or smallHead normal or small

Diagnostic ChecklistDiagnostic Checklist AmniocentesisAmniocentesis Cranial findings easier to Cranial findings easier to

see than ONTDsee than ONTD Compressed CM may be Compressed CM may be

only finding!!only finding!!

14 +4 weeks

Hydrocephalus , T 21Hydrocephalus , T 21Ventriculomegaly

HydrancephalyHydrancephaly

Hydranecphaly

Encephalocele

Occipital EncephaloceleOccipital EncephaloceleImaging FindingsImaging Findings Herniated brain tissueHerniated brain tissue „„cyst within the cystcyst within the cyst““ Ventriculomegaly 70Ventriculomegaly 70--

80%80% Microcephaly 25%Microcephaly 25% PolyhydramniosPolyhydramnios OligohydramniosOligohydramnios

CAVE:CAVE: Associated with multiple Associated with multiple

syndroms ( Meckelsyndroms ( Meckel-- Gruber )Gruber )

HoloprosencephalyHoloprosencephaly

Pilu

Holoprosencephaly

Hemimegalencephaly Arachnoid0cyst

ACC

SOP

SchizencephalySchizencephalySchizencephaly

PFAFluidACyst

Yong seok et al.

Vascular0Malforma3ons

Circle of Willis MallformationCircle of Willis Mallformation

Sunday, July 28, 13

(<#10#mm#is#normal).##Independent#of#gesta7onal#age#

Mild&10&–&15&mmLow&Risk&

Severe&>&15&mm&High&Risk&

mean#=#6:8#mm

Ventriculomegaly0(hydrocephalus)

Sunday, July 28, 13

•Square0Shaped,0Interrupts0and0Fills0The0Space0Between0The0Frontal0Horns•The0CSP:0Becomes0Visible0At01600Weeks,0Obliterate0Near0Term

Absent0CSP

Sunday, July 28, 13

Blake’s&pouch&cyst Megacisterna&magna DHW&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Findings Upward0rotation0of0an0intact0vermis0with0normal0torcular

Cisterna0magna0>10mm0with0intact0and0normally0positioned0cerebellum

Upward0rotation0of0the0vermis0(normal0or0hypoplastic)0with

elevated0torcular

SagiGal&

Axial

Categoriza3on0of0posterior0fossa0fluid0collec3ons0(1)

Sunday, July 28, 13

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