Fetal brain pathology registry review Flashcards
Ventriculomegaly/hydrocephalus
Enlargement of the ventricles
Most common brain abnormality
Ventriculomegaly
Ventriculomegaly due to obstruction
Hydrocephaly
Criteria for ventriculomegaly
Lateral ventricle >10mm at atrium and “dangling choroid” sign
*severe cases look for rim of cerebral tissue
Aqueductal stenosis
Narrowing of cerebral aqueduct causing dilation of 3rd and lateral ventricle
Most common cause of hydrocephalus
Aqueductal stenosis
Criteria for aqueductal stenosis
Ventriculomegaly + dilated 3rd ventricle (circle in midline)
Hydranencephaly
Cerebral tissue is replaced by fluid. No cerebral hemispheres only brain stem/basal ganglia present (fluid, no brain)
*no rim of cerebral tissue seen within cranium
Holoprosencephaly
Varying degrees (3) of absence of midline and fusion of non midline brain structures starting anteriorly
*associated with midline facial defects
*strong associated with T13 (Patau)
Hydr-
Fluid
-Anencephaly
No brain
Holo-
Whole/complete
-Pro
Forebrain
Lobar holoprosencephaly
Minimal fusion. Absent CSP/CC, fused frontal horns. Rest intact, “heart shaped” frontal horns
Semilobar holoprosencephaly
Partial fusion lateral ventricle and thalami, partial falx, absent CSP/CC
*butterfly shaped LV
Alobar holoprosencephaly
Most severe form, NO lobes = no midline separation of hemispheres
-Midline brain structures are absent (CC. CSP, 3rd vent, falx)
-Non midline brain structures are fused
-Horseshoe shaped monoventricle, fused thalami
*FATAL
Dandy-Walker malformation
Absence or defect of the cerebellar vermis causing 4th ventricle to dilate and cisterna magna to enlarge
Associations of dandy-walker malformation
Midline brain defects- agenesis of CC, holopros, ventriculomegaly, cephaloceles
Criteria for dandy-walker malformation
Cisterna magna >10mm, dilated 4th ventricle, splayed cerebellar lobes
*key hole appearance
Enlarged cisterna magna
> 10mm but no keyhole sign (normal 4th ventricle)
Vein of galen aneurysm
Connection between an artery and vein, anechoic tubular mass midline brain with turbulent color flow patterns
Agenesis of corpus collosum
If CSP is absent, CC is likely absent because they develop at the same time and are adjacent structures
Anomalies associated with agenesis of corpus collosum
Holopros, DWM, T18, T13
Criteria for agenesis of corpus collosum
Absent CSP, colpocephaly, sunburt/radial pattern sulci
Colpocephaly
Splayed and teardrop shaped lateral ventricle
Choroid plexus cyst
Frequently seen on routine sonos. Usually regress by 3rd trimester
*soft marker for T18 (Edwards)
Hydrocephaly fluid shape
Both sides with rim/dangling choroids
Hydranencephaly fluid shape
Fluid filled cranium with no rim
Alobar holoprosencephaly fluid shape
Horseshoe
Semilobar holoprosencephaly
Butterfly
Lobar holoprosencephaly
Heart frontal horns
Dandy-walker malformation
Key-hole
Vein of galen
Central tube with color
Schizencephaly
Fluid filled clefts within cerebrum
Porencephaly
Cyst that communicates with ventricular system caused by hemorrhage, ischemia, vascular occlusion
Lissencephaly
“Smooth brain” No sulci/gyri within the cortex= agyria. Diagnosed 3rd trimester
Teratoma
Most common intracranial tumor.
