Congenital malformations Flashcards
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
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
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
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
Cervical spinal cord cyst should trigger search for what malformation?
Chiari I
What is always associated with chiari II?
What is the cause?
Myelomeningocele
Chronic CSF leak in utero causes collapse of developing brain
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
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)
Heart shaped cerebellum suggests what?
Chiari II
What is the geographic breakdown of encephalocele?
NA?
LAtin america/asia?
North america - occipital (80%), parietal (10%)
LA/Asia - syncipital (frontoethmoidal)
What is chiari III malformation?
Chiari II with low occipital/high cervical encephalocele
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)
What are the two syndromes associated with occipital/parietal encephaloceles?
Chiari III
Dandy walker
Who gets sincipital encephaloceles (anterior nasal)? What is always associated?
Which is more common - nasofrontal or nasoethmoidal
Latin american/Asian boys
hypertelorism
nasofrontal
What is the differential diagnosis of anterior encephalocele?
nasal glioma (brain heterotopia) and nasal dermoids
What is a nasal glioma
ISOLATED mass of brain tissue trapped in prenasal space
can grow
will enhance
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
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
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
What is joubert syndrome?
Ataxia, hyperpnea, apnea, seizures, abnormal eye movements, mental retardation, motor apraxia, hypotonia