Fetal Spine Part 1 Flashcards
When scanning the fetal spine, what is very important to see?
intact skin line
Most congenital spinal problems are the result of defective closer of the neural tube during what week of embryonic development?
4th
Neural tube defects are associated with elevated ______.
AFP
Spinal dysraphism is a broad term given to a group of anomalies related to:
any abnormalities of the dorsum of the embryo
or
neurological disorders related to malformations of spinal cord (NTD fall under this group)
Spinal dysraphism can be divided into 2 pathological entities:
open spinal dysraphism
closed spinal dysraphism
What are examples of open spinal dysraphism?
meningocele
myelomenigocele
What are examples of closed spinal dysraphism?
spinal dermal sinus lipomyelomenigocele diastematomyelia neurentric cysts thickened filum terminale
What is spinal dermal sinus
an epithelium-lined tract from the skin to the spinal cord, cauda equina or arachnoid
What is lipomyelomeningocele
usually presents as a subcutaneous fatty mass just above the intergluteal cleft
What is diastematomyelia
split cord malformation
What is neurentric cysts
type of foregut duplication cyst, associated either with vertebral or CNS abnormalities
most commonly occur in thoracic region
Tight filum terminale syndrome is associated with what?
vertebral body deformities and spina bifida
Tight filum terminale syndrome:
incomplete involution to distal spinal cord
results in neurological deficiencies, pain, bowel dysfunction
What will be seen sonographically for tight filum terminale syndrome?
abnormally thickened filum terminale
sometimes with cysts/lipoma
For tight filum terminale syndrome, the diameter of the filum terminale should not exceed:
2mm
Tethered spinal cord is
attached to surrounding tissue
Neural tube defects involving ___________ _______ are referred to as
vertebral arches, spina bifida
What is common to all types of spina bifida?
non-fusion of the embryonic halves of the vertebral arches
The majority of spina bifida occurs where?
lumbosacral region
Severe spina bifida involves the
spinal cord
What is the most severe form of spina bifida
myelomenigocele
What is the mildest form of SB
occulta
one or more vertebrae are malformed and covered with skin
Many children with SB also have
hydrocephalus
What’s the difference between open and closed SB?
closed is covered by skin, open is not
Meningocele
meningeal membrane and CSF protrude through defect in vertebral arch (skin is mostly intact)
Myelomeningocele
meningeal membrane, CSF, and neural tissue (spinal cord) protrude through defect (skin partly covers defect)
Myeloschisis and rachischisis are often interchangable terms. True or false
True
Myeloschisis
open, flattened spinal cord, exposed through a wide defect in the posterior neural arch and defect in musculature and skin (no skin or meningeal covering)
Rachischisis
complete SB. cleft through entire spine from cervical to sacral region- open, flattened spinal cord (entire spinal cord is exposed)
SB occulta (or closed)
minor and insignificant abnormality
no clinical symptoms
rarely diagnosed prenatally
What are indications of SB occult?
dimple, tuft of hair or red mark on the back
Most spina bifida cases are what classification? How much?
Open – 80%
What type of spina bifida is most common?
Myelomeningocele (also most severe.. myeloschisis is most severe form of myelomeningocele)
Spina Bifida Aperta– Cystica involves
protrusion of the meninges and spinal cord through the defect in the posterior vertebral arch
If a mass contains only meninges with CSF, the anomaly is called
SB w/ meningocele.
spinal cord and roots are in their normal position, but there may be spinal cord anomalies
Meninges protrude _____ _____ _____ through the cleft in the malformed _________ _________.
under the skin, vertebral arch
Spina bifida apeta- cystica. If the spinal cord and/or nerve roots protrude in the mass, the defect is called
SB w/ myelomeningocele
What’s the most severe form of myelomeningocele?
myeloschisis
The more ______ the level of defect, the more severe the associated nerve dysfunction and paralysis may be.
cranial
There is a small skin layer covering the nerve tissue with myeloschisis. True or false
False- the nerve tissue is fully bare and a dermal or meningeal covering is absent
Many individuals with SB have an associated abnormality of the cerebellum, called:
Arnold Chiari II malformation
The cerebellum is larger in those individuals with SB. True or false.
False- cerebellum is smaller, especially those with higher lesion levels
What is abnormally developed in individuals with spina bifida myelomeningocele? What percentage?
corpus callosum
70-90%
What are some sonographic signs of spina bifida seen in the head?
nonvisualization of cisterna magna deformation of cerebellum (banana sign) concave frontal bones (lemon sign) dilation of lateral ventricles Chiari II malformation (97%) BPD lower than expected
