Fetal CNS

Question 1

What is the Dandy-Walker malformation?

Answer 1

Nonspecific congenital brain malformation:
Hypoplasia of the cerebellar vermis
Cystic dilation of the 4th ventricle communicating with the cisterna magna
Enlarged posterior fossa

Question 2

How is mega cisterna-magna defined?

Answer 2

Greater than 10 mm

Question 3

What is Dandy-Walker variant?

Answer 3

Variable hypoplasia of the cerebellar vermis without enlargement of the posterior fossa

Question 4

What is a Blake’s pouch cyst?

Answer 4

Normal anatomic entity, formed from normal dorsal expansion of the 4th ventricle into the CM, detected by transverse lines/septa within the CM behind the cerebellar vermis

Question 5

When can a diagnosis of a cerebellar malformation be made?

Answer 5

After 18 weeks, bc before 18w development of the vermis may be incomplete

Question 6

Management of Dandy-Walker malformation/variant

Answer 6

Careful sono exam for concurrent abnl (found in 60% in one study)
Karyotype (abnl in 20%)
Remember that false-positives have been found (57% in one series)
Offer termination

Question 7

Genetic disorders associated with Dandy-Walker malformation?

Answer 7

Joubert-Boltshauser, Walder-Warburg, Meckel-Gruber, Aicardi, Smith-Lemli-Opitz

Question 8

Chromosome abnl associated w/ Dandy-Walker malformation?

Answer 8

Trisomy 9
Triploidy
45, X
49, XXX
T13/18

Question 9

Teratogens associated w/ Dandy-Walker malformation?

Answer 9

Rubella, CMV, Toxo, Coumadin, Alcohol, Isotretinoin, Maternal diabetes

Question 10

What are isolated choroid plexus cysts and how common are they?

Answer 10

What are isolated choroid plexus cysts and how common are they?

Question 11

What are the major clinical implications of an isolated choroid plexus cyst?

Answer 11

What are the major clinical implications of an isolated choroid plexus cyst?

Question 12

What is the association between choroid plexus cysts and aneuploidy?

Answer 12

What is the association between choroid plexus cysts and aneuploidy?

Question 13

When an isolated choroid plexus cyst is detected, how is counseling different for women with a normal screen versus those whose screening indicates increased risk?

Answer 13

When an isolated choroid plexus cyst is detected, how is counseling different for women with a normal screen versus those whose screening indicates increased risk?

Question 14

What is the vein of Galen?

Answer 14

A single, midline structure formed by convergence of the 2 internal cerebral veins and the basal veins of Rosenthal, posterior to the splenium of the corpus callosum; the vein courses posteriorly to empty into the straight sinus

Question 15

What is the vein of Galen malformation?

Answer 15

An extremely rare anomaly, a complex AV malformation affecting the vein of Galen

Question 16

How does vein of Galen malformation aneurysm?

Answer 16

Size of the aneurysm determines clinical presentation. A large aneurysm can result in as much as 50-60% of the cardiac output shunting thru the lesion that may cause high-output congestive heart failure -> hydrops or neonatal cardiac failure

Question 17

What cerebral anomalies can be associated with vein of Galen aneurysm?

Answer 17

Cerebral parenchymal injury including cerebral infarction, periventricular leukomalacia, and hemorrhagic infarction

Question 18

US findings of vein of Galen aneurysm?

Answer 18

Cystic or tubular mass is noted in the midline ofthe brain just above and behind the thalamus. Turbulent venous or arterial flow may be demonstrated using color Doppler within the draining vessel.Generalized cardiomegaly or right ventric- ular enlargement is commonly notedCoarctation of the aorta and transposition of the great vessels occur with increased frequency in infants with vein o fGalen aneurysm and may also be responsible for cardiomegaly Massive hydrops has been reported as early as 31 weeks ofgestation

Question 19

Differential diagnosis of vein of Galen aneurysm

Answer 19

Other midline cystic structures within the brain such as an arachnoid cyst or an interhemispheric cyst associated with agenesis ofthe corpus callosum.

Question 20

Antenatal management of vein of Galen aneurysm

Answer 20

Serial antenatal ultrasound examinations should be performed q 2w to determine a change in size of the aneurysm and to monitor for hydrocephalus or congestive heart failure. Joint management with a pediatric cardiologist and pediatric neurosurgeon is suggested.The approach to therapy for a patient with a vein of Galen aneurysm will depend on the age of the patient, the clinical symptoms, and the angiographic architecture of the malformation.

Question 21

4 subtypes of vein of Galen aneurysm

Answer 21

1. Neonates with severe heart failure and cranial bruit.2. Children with mild heart failure and cranial bruit.3. Children younger than 1year of age with cranial bruit and hydrocephalus.4. Patients with headaches and syncope.

Question 22

Postnatal treatment of vein of Galen aneurysm

Answer 22

Transvenous and transarterial embolization techniques have been increasingly described in the literature. In the infant with congestive heart failure the initial procedure of choice appears to be endovascular, with a venous approach, either transfemoral or transtorcular. The immediate goal is to increase resistance in the aneurysm to right ventricular output.

Question 23

Long-term outcome of vein of Galen aneurysm

Answer 23

Little information is available on the long-term follow-up of prenatally diagnosed cases of vein of Galen aneurysm. In one series of 18 patients diagnosed prenatally, 13 infants survived the immediate neonatal period and 12 underwent embolization of the aneurysm. Total occlusion ofthe aneurysm was obtained in eight cases. Sixty-seven percent of the surviving newborns were neurologically normal when assessed with Denver Development Tests. Infants who require shunting for hydrocephalus with vein of Galen aneurysm appear to have a less favorable neurologic outcome.

Question 24

What is the vein of Galen?

Answer 24

A single, midline structure formed by convergence of the 2 internal cerebral veins and the basal veins of Rosenthal, posterior to the splenium of the corpus callosum; the vein courses posteriorly to empty into the straight sinus

Question 25

What is the vein of Galen malformation?

Answer 25

An extremely rare anomaly, a complex AV malformation affecting the vein of Galen

Question 26

How does vein of Galen malformation aneurysm?

Answer 26

Size of the aneurysm determines clinical presentation. A large aneurysm can result in as much as 50-60% of the cardiac output shunting thru the lesion that may cause high-output congestive heart failure -> hydrops or neonatal cardiac failure

Question 27

What cerebral anomalies can be associated with vein of Galen aneurysm?

Answer 27

Cerebral parenchymal injury including cerebral infarction, periventricular leukomalacia, and hemorrhagic infarction

Question 28

US findings of vein of Galen aneurysm?

Answer 28

Cystic or tubular mass is noted in the midline ofthe brain just above and behind the thalamus. Turbulent venous or arterial flow may be demonstrated using color Doppler within the draining vessel.Generalized cardiomegaly or right ventric- ular enlargement is commonly notedCoarctation of the aorta and transposition of the great vessels occur with increased frequency in infants with vein o fGalen aneurysm and may also be responsible for cardiomegaly Massive hydrops has been reported as early as 31 weeks ofgestation

Question 29

Differential diagnosis of vein of Galen aneurysm

Answer 29

Other midline cystic structures within the brain such as an arachnoid cyst or an interhemispheric cyst associated with agenesis ofthe corpus callosum.

Question 30

Antenatal management of vein of Galen aneurysm

Answer 30

Serial antenatal ultrasound examinations should be performed q 2w to determine a change in size of the aneurysm and to monitor for hydrocephalus or congestive heart failure. Joint management with a pediatric cardiologist and pediatric neurosurgeon is suggested.The approach to therapy for a patient with a vein of Galen aneurysm will depend on the age of the patient, the clinical symptoms, and the angiographic architecture of the malformation.

Question 31

4 subtypes of vein of Galen aneurysm

Answer 31

1. Neonates with severe heart failure and cranial bruit.2. Children with mild heart failure and cranial bruit.3. Children younger than 1year of age with cranial bruit and hydrocephalus.4. Patients with headaches and syncope.

Question 32

Postnatal treatment of vein of Galen aneurysm

Answer 32

Transvenous and transarterial embolization techniques have been increasingly described in the literature. In the infant with congestive heart failure the initial procedure of choice appears to be endovascular, with a venous approach, either transfemoral or transtorcular. The immediate goal is to increase resistance in the aneurysm to right ventricular output.

Question 33

Long-term outcome of vein of Galen aneurysm

Answer 33

Little information is available on the long-term follow-up of prenatally diagnosed cases of vein of Galen aneurysm. In one series of 18 patients diagnosed prenatally, 13 infants survived the immediate neonatal period and 12 underwent embolization of the aneurysm. Total occlusion ofthe aneurysm was obtained in eight cases. Sixty-seven percent of the surviving newborns were neurologically normal when assessed with Denver Development Tests. Infants who require shunting for hydrocephalus with vein of Galen aneurysm appear to have a less favorable neurologic outcome.