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169 Cards in this Set

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THE NEAURAL TUBE IS IMPORTANT BECAUSE...?

IT GIVES RISE TO ALL STRUCTURES FOR NERVOUS SYSTEM

WHAT ARE THE PRIMARY BRAIN VESICLES THAT DEVELOP DURING WEEK 4?

Prosencephalon (forebrain)


Mesencephalon (midbrain)


Rhombencephalon (hindbrain)

ANY ANOMALIES RELATED W/ THE CNS MEANS WHAT?

Neural tube defect

WHAT IS THE MOST COMMON NEURAL TUBE DEFECT?

Anencephaly

WHAT IS ANENCEPHALY AKA?

Aprosencephaly and atelencephaly

IS ANENCEPHALY COMMON?

No, it only occurs approx 1 in 1000 pregnancies and is not common in US --- only in England

THERE IS A GREATER RISK FOR ANENCEPHALY WHEN...?

Woman has history w/ prior pregnancy with open neural tube

WHAT CAUSES ANENCEPHALY?

Failure of closure of neural tube @ cranial end

ANENCEPHALY IS MORE COMMON IN LADIES WITH WHAT?

Uncontrolled diabetes and high in zinc

WHAT IS THE RESULT OF ANENCEPHALY?

absenceof cranial vault, complete or partial absence of forebrain, presence of brainstem, midbrain, skull base, facial structures

WHAT IS INCLUDED IN PRENATAL DIAGNOSIS?

Prenataldiagnosis often made with sonographyfollowing referral for high maternal serum alpha-fetoprotein (AF) levels

WHAT IS ANENCEPHALY ASSOCIATED WITH?

Canbe associated with Meckel-Gubersyndrome, trimsoy13, trisomy 18, or Amniotic bandsyndrome

Ananencephalic fetus; absence of the brain and calvarium isidentified. Note the froglike appearance.

Aprofile of the anomaly.

Echogenicfoci were noted in the heart; amniocentesis revealed trisomy 13.

FIGURE59-2 Postmortemphotograph of anencephaly. The arrowpoints to the rudimentary brain (cerebrovasculosa).

WHAT ARE OTHER SONOGRAPHIC FINDINGS OF ANENCEPHALY?

Polyhydramnios


Coexistingspinabifida and/or craniorachischisis Cleftlip and palate


Hydronephrosis


Diaphragmatichernia


Cardiacdefects


Omphalocele


Gastrointestinaldefects


Talipes

WHAT IS ACRANIA?

Lethal anomaly aka exencephaly and manifestsas absence of cranial bones with presence of complete, although abnormal,development of cerebral hemispheres

WHEN WOULD ACRANIA OCCUR?

4th gestational week

HOW SHOULD YOU ESTABLISH DIAGNOSIS FOR ACRANIA?

Presenceof significant brain tissue and lack of froglike appearance should establishdiagnosis

Thepresence of brain tissue without the presence of a calvarium. FIGURE 59-4A Acrania.Patient presented with an elevated maternal serum alpha-fetoprotein. Note theamnion (arrows)along the back of the fetus. Amniotic band syndrome was the probable cause

FIGURE 59-5 Coronalfacial view showing absence of the parietal bones (arrows), withhighly visible brain tissue (arrows)representing acrania or exencephaly. c,Chin; N, nose; o,orbits

FIGURE 59-6 Inthe fetus shown in Figure 59-5, a transverse view shows the disorganized andfreely floating brain tissue (arrows). Thebrain anatomy is enhanced because of the absence of skull bones. Note theherniated ventricle (v) and sulcalmarkings

FIGURE 59-7 Sameneonate shown in Figures 59-5 and 59-6, with acraniashortly after birth. The infant died within a few hours.

WHAT IS A NEURAL TUBE DEFECT IN WHICH MENINGES ALONE OR MENINGES AND BRAIN HERNIATE THRU DEFECT IN CALVARIUM?

Cephalocele

WHAT TERM IS USED TO DESCRIBE HERNIATION OF MENINGES AND BRAIN THRU DEFECT?

Encephalocele

WHAT TERM IS USED TO DESCRIBE HERNIATION OF ONLY MENINGES?

Cranial meningocele

CEPHALOCELE OCCURS AT WHAT RATE?

1 to 3 in 10,000 live births

Prevalenceof 4:1 females over males; 6:1 prevalence of Caucasian over African-American describes what anomaly?

Anencephaly

WHAT PARTS ARE INVOLVED WITH CEPHALOCELE?

Occipitalbone


Parietal


Frontal


Temporalregions


Otherbones of calvarium

CEPHALOCELE MEANS...

PROTRUSION OF THE BRAIN ... a pouch

IF THE POUCH OF CEPHALOCELE CONTAINS MENINGES ONLY, WHAT IS IT CALLED?

Meningocele

IF THE POUCH OF CEPHALOCELE CONTAINS BRAIN TISSUE ONLY, WHAT IS IT CALLED?

Encephalocele

IF THE POUCH OF CEPHALOCELE CONTAINS MENINGES AND BRAIN TISSUE, WHAT IS IT CALLED?

Encephalomeningocele

IF THE POUCH OF CEPHALOCELE CONTAINS MENINGES, BRAIN TISSUE, LATERAL VENTRICLES, WHAT IS IT CALLED?

Encephalomeningocystocele

WHAT ARE US FEATURES OF CEPHALOCELE?

Extracranialmass, which may be fluid- filled (cranial meningocele) orcontain solid components (encephalocele)




Abony defect in skull




Ventriculomegaly; ismore commonly identified with encephalocele





Polyhydramnios

WHAT ARE CHROMOSOMAL ANOMALIES AND SYNDROME THAT HAVE BEEN ID'd WITH CEPHALOCELE INCLUDES...?

trisomy13 and Meckel-Grubersyndrome

WHAT IS SPINA BIFIDA?

Wide range of vertebral defects that result from failure of neural tube closure so there is a cleft, or opening in spine

WHAT MAY PROTRUDE THROUGH DEFECT W/ SPINA BIFIDA?

Meninges and neural elements

WHERE ALONG VERTEBRAL COLUMN DOES SPINA BIFIDA MOST COMMONLY OCCURS?

Lumbar and sacral regions

WHAT VARYING DEGREES OF NEUROLOGIC IMPAIRMENT IS SPINA BIFIDA ASSOCIATED WITH?

minoranesthesia, paraparesis,death

FETUSES WITH MYELOMENINGOCELE OFTEN PRESENTS WITH CRANIAL DEFECTS ASSOCIATED WITH...?

Arnold-Chiari(type II) malformation

IF YOU SEE A FETUS W/ SPINA BIFIDA... WHAT SHOULD YOU DO?

Scan the brain and if you see enlarge ventricles and if there is ventriculomegaly it means that fetus has Arnold Chiari Type II malformation and you will not call it spina bifida

WHEN YOU HAVE ARNOLD-CHIARI, SONOGRAPHIC FINDINGS INCLUDE...?

Banana shape of the cerebellum

TRUE OR FALSE: ARNOLD CHIARI LEADS TO OBLITERATION OF CISTERNA MAGNA.

True

WHAT DO CAUDAL DISPLACEMENT OF CRANIAL STRUCTURES IN ARNOLD CHIARI CAUSE?

Scalloping of frontal bones of skull making fetal head resemble a lemon

WHY WOULD FETUSES BE DELIVERED EARLY W/ SPINA BIFIDA?

Ventricular shunting is usually by c section to preserve motor function

WHAT ARE THE RISKS OF SURGICAL REPAIR OF DEFECTS IN UTERO?

premature delivery, maternalmorbidity, fetal mortality

WHAT DOES THE PROGNOSIS OF SPINA BIFIDA DEPENDING ON?

Type, size, and location of defect

WHAT MATERNAL FACTORS ARE ASSOCIATED WITH SPINA BIFIDA?

Maternal diabetes, maternal obesity, hyperthermia, folic acid deficiency have been associated with spina bifida

IF THERE IS A FAMILY HISTORY OF SPINA BIFIDA OR ANENCEPHALY, IS THAT A SIGNIFICANT RISK FACTOR FOR OCCURENCE OF SPINA BIFIDA?

Hell yes

Aneonate with a lumbar myelomeningocele

WHAT DOES DANDY-WALKER MALFORMATION MANIFESTS WITH?

a genesis or hypoplasia of cerebellar vermis withresulting dilation on fourth ventricle and enlargement of posterior fossa.

ALWAYS THINK OF THE POSTERIOR PART OF THE BRAIN WITH WHAT DEFECT?

Dandy-Walker Malformation

DIAGNOSIS OF DANDY-WALKER SHOULD NOT BE DONE BEFORE WHAT WEEK?

18

WHAT ARE CHROMOSOMAL ANOMALIES ASSOCIATED W/ DANDY-WALKER?

Trisomies 13, 18, 21, triploidy

WHAT OTHER SYNDROME IS DANDY-WALKER ASSOCIATED WITH?

Meckel-Gruber and Walker-Warburg

IF MOMMY HAS CONGENITAL INFECTION OR DIABETES, IS RISK HIGHER FOR DANDY- WALKER?

Yes

WHAT DOES THE PROGNOSIS OF DANDY-WALKER DEPEND ON?

Presenceor absence of associated anomalies and on degree of hypoplasia of cerebellar vermis, ascorrelates with severity of mental retardation

MANY INFANTS WITH ISOLATED DWM HAS WHAT KIND OF IQ?

Some may have subnormal IQ and some may have normal function

WHAT WILL YOU SEE ON US W/ DWM?

Posteriorfossa cyst




Splayingof cerebellar hemispheres as result of complete or partial agenesis ofcerebellar vermis




Enlargedcisterna magna caused by cerebellar vermisanomaly and posterior fossa cyst




Ventriculomegaly

WHAT IS THE CAUSE OF HYDROENCEPHALY?

Obstruction of internal carotid

IF OBSTRUCTION IS INSIDE BRAIN VENTRICLE, WHAT KIND OF HYDROENCEPHALY IS THAT?

Non communicating

PRESENCE OF SUBARACHNOID CYST MAY CAUSE WHAT?

Non communicating hydroencephaly

WHAT THREE TYPES OF SPINA BIFIDA ARE THERE?

1. Occult spina bifida


2. Meningocele spina bifida


3. Meningomyelocele spina bifida

WHAT TYPE OF SPINA BIFIDA HAS OPENING IN SPINE BUT NOTHING HAS BEEN PROTRUDED... THE OPENING IS COVERED BY SKIN AND HAIR AND CANNOT BE DETECTED ON US AND MOMMY'S AFP IS NORMAL?

Occult spina bifida

CAN OCCULT SPINA BIFIDA BE SURGICALLY SOLED?

Yes because the hole is small with everything else normal in the baby

WHAT TYPE OF SPINA BIFIDA INVOLVES ONLY PROTRUSION OF THE MENINGES?

Meningocele

WHAT SPINA BIFIDA IS MORE COMMON AND BOTH MENINGES AND NEURAL ELEMENTS PROTRUDE THRU DEFECT?

Meningomyelocele

WHAT IS TERMED FOR A SPINA BIFIDA DEFECT THAT IS VERY LARGE AND SEVERE AND INVARIABLY LETHAL?

Rachischisis

IN ARNOLD CHIARI II, WHAT WILL MAKE FETAL HEAD RESEMBLE A LEMON?

Caudal displacement of cranial structures which causes scalloping of frontal bones of skull

Splayingof the posterior ossification centers with a V or U configuration.

Alarge spinal defect at the thoracic level is seen in the fetus. The prognosiswas expected to be extremely poor

FIGURE 59-14A Sagittal(A) and transverse (B)views of the fetal spine (arrows)demonstrate this defect in the lumbar region consistent with a myelomeningocele

Meningomyelocele infetus with mild ventriculomegaly.Note the neural elements protruding into the sac.




Protrusionof a saclike structure that may be anechoic (meningocele) orcontain neural elements (myelomeningocele).

Spina Bifida


open cleft in the skin

“Bananasign” in21-week fetus with lumbosacral meningomyelocele.Note lemon-shaped frontal bones consistent with frontal bossing.




Flatteningof frontal bones, head “lemon”shape Obliterationof cisterna magnaInferiordisplacement of cerebellar vermis,giving cerebellum rounded, “banana”shapeVentriculomegaly

Lumbosacralmeningomyelocele (arrows)shownin a 21-week fetus, detected on a basic fetal scan. A,Abdomen;S, spine.

Lumbosacralmeningomyelocelemeasuring 6 cm (calipers) observed in a 33-week fetus during a basic fetalscan.

Dandy-Walkercyst. Note the splayed cerebellar hemispheres.

ThisDandy-Walker malformation was not associated with ventriculomegaly;amniocentesis revealed normal chromosomes.

DWM with ventriculomegaly

WHAT RESULTS FROM ABNORMAL CLEAVAGE OF PROSENCEPHALON (FOREBRAIN) AND ALSO FAILURE FOR IT TO DEVELOP INTO 2 HEMISPHERES?

Holoprosencephaly

TRUE OR FALSE: HOLOPROSENCEPHALY IS ASSOCIATED WITH SYNDROMES, GENETIC FACTORS, OR TERATOGENS AND MAY ALSO BE A SPORADIC EVENT.

True


WHAT IS A TERATOGEN?

Anything that exposes mom to have birth malformation such as radiation

WHAT ARE THE THREE FORMS OF HOLOPROSENCEPHALY?

Alobar - most severe


Semilobar - intermediate form


Lobar - mildest form

THE THREE FORMS ARE DEPENDENT ON WHAT?

The degree of failed hemispheric division

WHAT TYPE OF HOLOPROSENCEPHALY DO YOU GET WITH:


•Singularmonoventriclebrain tissue that is small


•Cup,ball, pancake configuration


•Fusionof thalamus


•Absenceof interhemisphericfissure


•Absenceof cavumseptum pellucidum


•Absenceof corpus callosum


•Absenceof optic tracts


•Absenceof olfactory bulbs

Alobar holoprosencephaly

WHAT ARE THE THREE MORPHOLOGIC TYPES OR CONFIGUARTION OF ALOBAR HOLOPROSENCEPHALY?

Pancake


Cup


Ball

3 types of alobar holoprosencephaly

WHAT TYPE OF HOLOPROSENCEPHALY DO YOU GET WITH:


Singularventricular cavity with partial formation of occipital horns


Partialor complete fusion of thalamus


Rudimentaryfalx and interhemisphericfissure


Absentcorpus callosum


Absentcavumseptum pellucidum


Absentolfactory bulbs

Semilobar

FIGURE 59-27 Aneonatal ultrasound in a newborn revealed semilobar holoprosencephaly.There was no history of a prenatal ultrasound because of the normal course ofthe pregnancy. The infant lived for only a few weeks.

WHAT TYPE OF HOLOPROSENCEPHALY WILL YOU GET WITH:


•Almostcomplete division of ventricles with corpus callosum that may be normal, hypoplastic, orabsent


•Cavumseptum pellucidum willstill be absent.

Lobar

WHY IN MOST SEVERE FORMS OF HOLOPROSENCEPHALY, FETUS DIES AT BIRTH OR SHORTLY THEREAFTER?

Prognosis is considered uniformly poor

IS SURVIVAL POSSIBLE FOR LEAST SEVERE LOBAR HOLOPROSENCEPHALY?

Yes, but with severe mental retardation

WHAT ARE FACIAL ANOMALIES THAT COME WITH HOLOPROSENCEPHALY?

•Thefacial anomalies include cyclopia,hypotelorism, anabsent nose, a flattened nose with a single nostril, and a proboscis.

HOLPROSENCEPHALY FACIAL ANOMALIES

HOLPROSENCEPHALY FACIAL ANOMALIES

Cyclopia = one eye


Cebocephaly = monkey-like head, with a defective small, flattened nose with a single nostril or absent nose and closely set eyes


Ethmocephaly = absent nose



HOLOPROSENCEPHALY C-shaped monoventricle

HOLOPROSENCEPHALY with a proboscis which is a long nose think of an elephant

Holoprosencephaly

HOLOPROSENCEPHALY:Polydactyly wasalso identified on all four extremities, suggesting the possibility of trisomy13.

Fetuswith trisomy 13. Small eyes with hypotelorism. Probiscus seenabove the orbits.

What do you get when there is a complete or partial absence of the corpus callosum?

Agenesis of the corpus callosum

WHEN DOES AGENESIS OF CORPUS CALLOSUM OCCUR?

It occurs when the corpus callosum, the band of white matter connecting the two hemispheres in the brain, fails to develop normally

WHY IS THE NORMAL DEVELOPMENT OF THE CORPUS CALLOSUM SO IMPORTANT?

It aids in learning and memory

DYSGENESIS OF THE CORPUS CALLOSUM DESCRIBES WHAT?

Complete to partial absence of callosal fibers that cross the midline

WHAT ARE THE CHROMOSOMAL ANMALIES THAT MAY ACCOMPANY ACC?

Trisomies 21, 13, 18, and triploidy

WHAT ARE SYNDROMES THAT HAVE BEEN ASSOCIATED WITH ACC?

Aicardi, Apert, Opitz, Joubertsyndromes

WHAT ARE THE MATERNAL DISEASES THAT CONTRIBUTE TO ACC?

Diabetes


Infections


Alcohol abuse

IS EXTRACRANIAL OR INTRACRANIALS THAT ARE ASSOCIATED WITH ACC?

Extracranial

WHAT DOES THE PROGNOSIS OF ACC DEPEND ON?

High incidence of associated anomalies but many carry poor prognosis

ACC MAY BE AYMPTOMATIC OR ASSOCIATED WITH MENTAL RETARDATION AND OR SEIZURES. TRUE OR FALSE?

True

WHAT SONOGRAPHIC FEATURES DO THESE BELONG TO?


•Absenceof corpus callosum•Elevationand dilation of third ventricle•Widelyseparated lateral ventricular frontal horns with medial indentation of medialwalls•Dilatedoccipital horns (colpocephaly),giving lateral ventricles teardrop shape•Absenceof cavumseptum pellucidum

ACC

A,Agenesis of the corpus callosum is diagnosed in this fetus with an absent cavumseptum pellucidum



ACC: The occipital horn of the lateral ventricle also appears dilated

WHAT IS THE RESULT OF OBSTRUCTION, ATRESIA, OR STENOSIS OF AQUEDUCT OF SYLVIUS WHICH CAUSES VENTRICULOMEGALY?

Aqueductal stenosis

WHAT DOES THE AQUEDUCT OF SYLVIUS DO?

Connect the third and fourth ventricles and it also explains the enlargementof lateral ventricles and third ventricle in presence of normal fourthventricle

WHAT KIND OF INFECTION MAY RESULT FROM AQUEDUCTAL STENOSIS?

Intrauterine infections

WHAT KIND OF MASS AND HEMORRHAGE ARE ALSO CONTRIBUTING FACTORS OF ACQUIRED OBSTRUCTION?

Cranial masses and ventricular hemorrhage

Primary aqueductal stenosis is usually __-linked and has _______-__________ inheritance.

X-linked


Auto-somal recessive (both parents)

AQUEDUCTAL STENOSIS HAS A _______ PROGNOSIS AND VARIES WITH ASSOCIATED _____________.

Poor


Anomalies

APPROX 90% OF SURVIVORS OF AQUEDUCTAL STENOSIS HAVE AN IQ OF WHAT?

BELOW 70

INFANTS WITH X-LINKED AQUEDUCTAL STENOSIS ARE PROFOUNDLY WHAT?

Mentally retarded

WITH AQUEDUCTAL STENOSIS, US FEATURES OF THE LATERAL VENTRICLES ARE...?

Enlarged!


And may be a sign of severe aqueductal stenosis

TRUE OR FALSE: WITH AQUEDUCTAL STENOSIS, THE FOURTH VENTRICLE IS DILATED.

False, you get third ventricular dilation

IN X-LINKED FORM OF AQUEDUCTAL STENOSIS, YOU GET WHAT OF THE THUMB?

Flexion and adduction

Ventricularview in a fetus with acquired aqueductalstenosis caused by parvovirus infection. Dilatation of the ventricular system (v)resultedfrom inflammation, causing obstruction to the flow of cerebrospinal fluid. Thefetus was severely hydropic.Note the significant scalp edema (E

Inthe same fetus, third ventricle (3v) dilatation is demonstrated. Cordocentesis wasperformed to find a cause for the severe nonimmune hydrops, andparvovirus was detected within the fetal blood. The fetus died shortly afterbirth. E, Scalp edema.

Asagittal image of a fetus with severe hydrocephaly that was thought to resultfrom aqueductalstenosis.

WHAT IS THE CONDITION WHERE THERE IS DESTRUCTION OF CEREBRAL HEMISPHERES BY OCCLUSION OF INTERNAL CAROTID ARTERIES?

Hydranencephaly

WHAT IS DESTROYED AND REPLACED BY CSF IN HYDRAENCEPHALY?

Brain parenchyma

WHAT IS STILL PRESENT IN HYDRANENCEPHALY?

Midbrain and cerebellum

TRUE OR FALSE: THERE IS COEXISTING STRUCTURAL OR CHROMOSOMAL ANOMALIES ASSOCIATED.

False, there is no coexisting structural or chromosomal anomalies are associated

WHAT IS THE PROGNOSIS OF HYDRANENCEPHALY?

Grave with death occurring at birth or shortly thereafter

ARE THERE POSSIBLE SURVIVORS OF HYDRANENCEPHALY?

Some long-term survivors have been reported

WHAT DO THE FOLLOWING DESCRIBE?


•Absenceof normal brain tissue with almost complete replacement by cerebrospinal fluid •Absentor partially absent falx•Presenceof midbrain, basal ganglia, cerebellum•Choroidplexus may be identified.•Macrocephalymay occur.

US features of hydranencephaly

WHAT MAY HYDRANENCEPHALY BE CONFUSED WITH?

Hydrocephaly

WHAT MAY HELP IN DIFFERENTIATING HYDRANENCEPHALY FROM HYDROCEPHALY?

Presence of intact falx and surrounding rim of brain parenchyma may

Hydranencephaly (c) in afetus at 33 weeks’gestation showing a massive collection of cerebrospinal fluid. Note the braintissue in the occipital region (m)

Ina different fetus at 37 weeks’gestation, hydranencephaly isidentified. The head measurements were greater than the 95th percentile, so theinfant was delivered by cesarean section

WHAT REFERS TO DILATION OF VENTRICLES WITHIN BRAIN

Ventriculomegaly

WHAT OCCURS WHEN VENTRICULOMEGALY IS COUPLED WITH ENLARGEMENT OF FETAL HEAD?

Hydrocephalus

WHAT IS THE OCCURENCE OF HYDROCEPHALUS?

0.3 to 1.5 per 1000 live births

WITH VENTRICULOMEGALY (HYDROCEPHALUS), ENLARGEMENT/DILATION OF VENTRICLES OCCURS WITH OBSTRUCTION OF....?

CSF flow

WHEN IS A VENTRICLE CONSIDERED TO BE DILATED?

When its diameter exceeds 10 mm

WHEN HYDROCEPHALUS OCCURS WITH OBSTRUCTION THAT MAY BE CAUSED BY VENTRICULAR DEFECT LIKE AQUEDUCTAL STENOSIS, WHAT IS THIS REFERRED TO AS?

Non communicating hydrocephalus

WHEN OBSTRUCTION IS OUTSIDE OF VENTRICULAR SYSTEM SUCH AS WITH ARACHNOID CYST, WHAT KIND OF HYDROCEPHALUS IS THIS?

Communicating hydrocephalus

VENTRICULOMEGALY (HYDROCEPHALUS) COMMUNICATING TYPE withMultiplearachnoid cysts.

WHY IS IT CALLED NONCOMMUNICATING HYDROCEPHALUS?

Because the obstruction occurs within the ventricular system, the ventricles and subarachnoid space do not communicate

WHY IS IT CALLED COMMUNICATING HYDROCEPHALUS?

The obstruction occurs outside the ventricular system so the ventricles and the subarachnoid space communicate.

WHAT WILL CAUSE VENTRICULAR EXPANSION WITH VENTRICULOMEGALY (HYDROCEPHALUS)?

The increase in pressure within the ventricular system

WHY DOES IRREVERSIBLE BRAIN DAMAGE OCCUR WITH VENTRICULOMEGALY/HYDROCEPHALUS?

The enlarged ventricles may exert pressure on brain tissue

Periventricularcalcifications (arrows) and ventriculomegaly (v)ina 20-week fetus. An infectious cause was suspected. All testing had provednegative.

Inthe same fetus at 30 weeks’gestation, persistent periventricular calcifications (arrows)withventriculomegaly (v)wereobserved. No other anomalies or complications were present.

WHAT IS VENTRICULOMEGALY/HYDROCEPHALUS A MANIFESTATION OF?

Syndrome or chromosomal abnormality

WHAT ARE COMMON CAUSES OF VENTRICULOMEGALY?

Spina bifida and encephaloceles

VENTRICULAR ENLARGEMENT HAS BEEN LINKED TO WHAT?

Congenital infections such as toxoplasmosis and cytomegalovirus

SONOGRAPHIC FEATURES OF VENTRICULOMEGALY/HYDROCEPHALUS INCLUDE:


1. Lateral ventricular enlargement > ____ mm


2. "______ ______ _____," as gravity-dependent choroid plexus falls into increased ventricular space


3. Possible dilation of _____ and ____ ventricles


4. Fetal head enlargement when biparietal and HC mrasurements __________ those for established ga.



1. 10


2. Dangling choroid sign


3. 3rd and 4th


4. exceed

Proximalventricle measured 28 mm in diameter. Note the asymmetry between theventricles.




Topone more than 8 mm is considered to be dilated (v)Downstream needs to be more than 10 mm to be dilated

Theanterior choroid plexus “dangles” intothe posterior ventricle.

WHAT IS TERMED AN ABNORMALLY SMALL HEAD THAT FALLS TWO STANDARD DEVIATIONS BELOW THE MEAN?

Microcephaly

WHY DOES MICROCEPHALY OCCUR?

Brain is reduced in size

TRUE OR FALSE:


Isolatedmicrocephaly occurs in 1 per 1000 births; more commonly caused by associatedanomaly

True

IS MICROCEPHALY A RESULT FROM INHERITANCE OF AUTOSOMAL-DOMINANT OR AUTOSOMAL-RECESSIVE PATTERN?

Could be both!

WHAT TERATOGENS ARE LINKED WITH MICROCEPHALY?

congenitalinfections (rubella, toxoplasmosis, cytomegalovirus), maternal alcohol abuse,heroin addiction, mercury poisoning, maternal phenylketonuria, radiation, andhypoxia.

WHAT PERCENTAGE OF MICROCEPHALY ARE MENTALLY RETARDED?

85%

WHAT ARE SONOGRAPHIC FEATURES OF MICROCEPHALY?

•Small biparietaldiameter


•Smallhead circumference


•Abnormalhead circumference/abdomen circumference and head circumference–to–femurlength ratios

Microcephalyis demonstrated in this fetus with semilobar holoprosencephaly.

Inthe same fetus, the profile shows the small head; the fetus also had abilateral cleft lip.(shadowing from the nose/mouth is cleft palette)