Congenital malformations Flashcards by Alex Grushky

What are the spectrum of causes of aqueductal stenosis?

What are the associations?

Congenital narrowing of the aqueduct
Postinflammatory changes (post meningitis or hemorrhage)
Tumors

Chairi I/II, Dandy walker

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What is the appearance of aqueductal stenosis?

What physiologic dysfunction can be seen?

Thickened tectum can be seen

Will see narrowing of the aqueduct

Endocrine dysfunction in 20% due to compression of hypothalamus-pituitary axis

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What age group for type I chiari?

What is the etiology?

What distance for diagnosis? What else needed for diagnosis?

Adults

Mesenchymal malformation of craniocervical junction leading to hypoplasia of bones and dura

> 6cm is Dx, 3-6cm is tonsillar herniation

Need downward “pointing” tonsils for dx in indeterminate cases

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What are the symptoms with chiari I malformation?

What is the treatment?

Headache, neck pain, nystagamus, lower CN palsy, basilar invagination, odontoid defromities, scoliosis, spinal cord cysts

Klippel-feil

Tx: resection of the hypoplastic posterior arch of C1, dural resection with duroplasty and recreation of cisterna magna

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Cervical spinal cord cyst should trigger search for what malformation?

Chiari I

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What is always associated with chiari II?

What is the cause?

Myelomeningocele

Chronic CSF leak in utero causes collapse of developing brain

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What is are the skull and dura anomalies with chiari II?

Lacunar skull, scalloped petrous ridge and clivus, large foramen magnum, insufficient tentorial incisura, hypoplastic or fenestrated falx

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What are the brain anomalies with chiari II?

Inferiorly displaced vermis into the foramen magnum

heart shaped cerebellum displaced superiorly through insufficient tentorial incisura, lack of cerebellar sulcation

Absent aqueduct

Beaked tectum

Callosal agenesis, large massa intermedia

Interdigitation of cortical sulci in superior midline

Hydrocephalus and colpocephaly (dilated atria and occipital horns)

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Heart shaped cerebellum suggests what?

Chiari II

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What is the geographic breakdown of encephalocele?

NA?
LAtin america/asia?

North america - occipital (80%), parietal (10%)

LA/Asia - syncipital (frontoethmoidal)

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What is chiari III malformation?

Chiari II with low occipital/high cervical encephalocele

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What is an atretic parietal meningocele?

Form fruste of encephalocele

Small amount of meninges, gliotic brain and CSF can cross the superior sagittal sinus and associated with venous anomalies( persistent falcine sinus)

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What are the two syndromes associated with occipital/parietal encephaloceles?

Chiari III

Dandy walker

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Who gets sincipital encephaloceles (anterior nasal)? What is always associated?

Which is more common - nasofrontal or nasoethmoidal

Latin american/Asian boys

hypertelorism

nasofrontal

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What is the differential diagnosis of anterior encephalocele?

nasal glioma (brain heterotopia) and nasal dermoids

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What is a nasal glioma

ISOLATED mass of brain tissue trapped in prenasal space

can grow
will enhance

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What is a nasal dermoid?

may from anywhere from the tip of the nose to the nasal bones

Fatty appearance

Communicate with foramen cecum in front of a wide or bifid crista galli

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What is seen in dandy walker syndrome?

obstruction of the outlet foramina of the fourth ventricle which becomes dilated

Large posterior fossa with high insertion of the torcula herophilli

Hydrocephalus

Inferior vermian hypoplasia

corpus callosal agenesis

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What is the spectrum of dandy walker?

Mega cisterna magna - intact vermis, normal 4th ventricle, scalloping of inner table of bone

Variant - mild inferior vermian hypoplasia, enlarged vallecula that communicates with a mildly enlarged and keyhole shaped 4th ventricel and hydrocephalus

Full on disease

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What is joubert syndrome?

Ataxia, hyperpnea, apnea, seizures, abnormal eye movements, mental retardation, motor apraxia, hypotonia

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What is seen in joubert syndrome on imaging?

Hypoplastic/aplastic cerebellar vermis
Abnormal tracts in brainstem
Lack of decussation of superior cerebellar peduncles, which become thin and parallel

What is the molar tooth appearance? What is it seen with?

Superior cerebellar peduncles become thin and parallel

Joubert

What is holoprosencephaly? What are the types?

midline cleavage of the face and a failure of the diverticulation of the brain

Alobar
Semilobar
Lobar
Midline

Which types of holoprosencephaly have hypotelorism and facial midline clefts

alobar and semilobar

What corpus callosal abnormality is seen with holoprosencephaly?

Agenesis of the anterior aspect

What is the most severe type of holoprosencephaly? What is seen?

Alobar monoventricle, absent septum pellucidum falx cerebri and interhemispheric fissue are also absent fused thalami

What is seen with semilobar holoprosencephaly?

Monoventricle with rudimentary occipital and temporal horns absent septum pellucidum thalami are fused

What is seen with lobar holopsrocencephaly?

Mild, lateral ventricles are almost normal but frontal horns point inferiorly absent septum pellucidum no thalamic fusion indistinguishable from septooptic dysplasia can have a solitary anterior cerebral artery

What is seen with midline holoprosencephaly?

Grey matter cleft extending through both hemispheres fused frontal lobes mid portion corpus callosum is absent

How does the corpus callosum form? how does it myelinate

Forms anterior to posterior Myelinates posterior to anterior

What is also seen with a complete callosal agenesis?

absent cingulate gyrus and sulcus, high riding third ventricle rostral interhemispheric arachnoid cyst colpocephaly (dilation of atria and occipital horns of lateral ventricles) can have isolated dilation of the temporal horns of the lateral ventricles hippocampal malrotations

What are the associated anomalies with dysgenesis of the corpus callosum?

``` Chiari II Dandy walker Holoprosencephaly Interhemispheric lipoma Migration anomalies Azygous anterior cerebral artery Abnormalities of the optic chiasm and pituitary gland ```

What is septo-optic dysplasia? What is it indistinguishable from?

Absent septum pellucidum Hypoplastic anterior optic pathways (chiasm and nerves) Flat roof of lateral ventricles Inferiorly pointed frontal horns Lobar holoprosencephaly

What are the associations with septo optic dysplasia?

``` Maternal diabetes Quinidine ingestion Antiseizure medication Drug abuse CMV Chiari II/aqueductal stenosis ```

What is meant by the term septo optic dysplasia plus?

Septo optic dysplasia schizencephaly remnant septum pellucidum and normal visual apparatus

What physiologic abnormality is seen with septo optic dysplasia?

Endocrine dysfunction secondary to hypoplastic pituitary

Ectopic pituitary bright spot should prompt a search from what?

Septo optic dysplasia

What is a schizencephaly?

Transcerebral cleft (extending from cortex to ventricle) lined by abnormal gray matter - some have overlying CSF-filled cyst that may grow

What are the types of schizencephaly?

Open lip - contain CSF in cleft Closed lip - walls of cleft are in apposition

What are the associated findings in schizencephaly?

Malrotated hippocampi Absent septum pellucidum Septo optic dysplasia

What are the symptoms with schizecephaly? Which type gets symptoms?

Seizures and hemiparesis Open lip

What is lissencephaly? What is the imaging?

smooth brain with no sulcations Thick grey matter with insufficient neurons, shallow sylvian fissures, lack of sulci, colpocephaly

What are the syndromes with lissencephaly?

Miller-dieker Walker-warburg Fukuyama

What is the double cortex sign? What sex is it seen in?

Band heterotopia seen with lissencephaly band o grey matter between subcortical and periventricular white matter seen in females

What is the differential for nodular foci of grey matter along the ependymal surface?

Tuberous sclerosis Grey matter heterotopia

What is the imaging of grey matter heterotopia?

Do not enhance, follow grey matter on all sequencing

What is cortical dysplasia?

Nonlissencephalic cortical dysplasia/Polymicrogyria Smooth argyric grey matter can have anomalous venous drainage

What is the cause of cortical dysplasia? Where do they occur usually?

Ischemia or CMV MCA distribution

Which synostosis is more common in boys? females?

F - coronal | M - sagittal

What is the classification of synostosis?

Simple - one suture r part of it Compound - more than one suture, may be syndromic Bony/cartilaginous

What is the normal time period for closure of sutures? posterior fontanelle? anterior?

18-24 months (metopic 6-9 months) 2 months Anterior - 7-9 months