Module 11.1 Fetal spinal pathology Flashcards
Each vertebra will develop how many ossification centers?
Three
The centrum forms the ______ portion of the vertebral body
Central
The two neural processes will form what 5 things?
- Peduncles
- Transverse processes
- Laminae
- Spinous process
- Posterolateral part of the lateral body
Ossification is not complete until which weeks?
18 weeks
Potentially a small spinal bifida could be missed prior to what week?
18
How many will be at risk for NTD?
1/1000
What increases risk of NTD? 4
- Valproic acid
- Maternal diabetes
- Folic acid deficiency
- History of spinal defects
In terms of spinal bifida, Defects in the boney structure of the spinal canal may result in the herniation of what contents? 3
- Meninges
- CSF
- Neural tissue
What are other forms of NTD? 2
- Encephalocele: Brain herniation through defect in skull
- Anencephaly: Missing all brain and skull
What does this picture demonstrate?
Encephalocele
What does these two images demonstrate?
- Left normal spine
- Right Spina bifida occulta
What does these two pictures demonstrate?
- Left Spina bifida with meningocele
- Spina bifida with myelomeningocele
What is spinal bifida occulta? what does it involve? What might we see?
- Involves only the deepest layers
- May only see skin dimple or patch of hair on the skin
- Closed defect
How many spinal bifida cases are occult?
15-20%
What is involved with Spina bifida aperta? What kind of defect is it? And what are the percentage of cases?
- Involves all layers from dura to skin
- Open defect
- 80-85% of cases
Which is the most intense case of spina bifida?
Myelomeningocele with meningocele coming in second
What does meningocele contain?
Meninges and CSF
What does myelomeningocele contain? 3
- Meninges
- CSG
- Neural tissue
When is screening done for spina bifida? What is abnormal?
1.16 weeks
2. AFP is elevated
What are other causes of elevated MS AFP? 6
- Abdominal wall defects
- Multiple fata pregnancies
- Fetal death
- Urinary obstruction
- Cystic hygroma
- Incorrect dates
What is the most common location for NTD?
Lumbosacral spine
What is NTD usually associated with? 6
- Meckel gruber syndrome
- Encephalocele
- Polycystic kidneys
- Polydactyly
- Trisomy 18
- Triploidy
What is spinal dysraphism?
Abnormal closure of the spine
What is rachischisis? What is it another name for?
- Another name for spinal dysraphism
- Failure of fusion of the vertebral arches
What are radiological landmarks for NTDs? 3
- t12 most distal rib
- L5 superior margin of iliac wing
- S4 most caudal ossification center in 2nd trimester
What are some other systems affected by NTD?
lefts (clubfoot, hip dislocation)
Legs are affected by NTD how? 2
- Imbalance of muscular activity due to nerve involvement
- Nerves exposed to amniotic fluid results in damage to these nerves
What should look for on U/S for NTD? 5
- Obliterated cisterna magna
- Banana sign with cerebellum
- Lemon sign
- Splayed laminae
- Protruding mass or cyst
What does this image demonstrate?
Spinal NTD
Where is the best plane to do an assessment of meningocele?
Transverse
When assess Meningocele what must we ensure we do?
Assessment of the skin surface away from the uterine wall
What is the prognoses of NTD? 2
- Depends on location
- More superior = greater disability
What is Iniencephaly?
Special case of dysraphism involving the back of the cranium and c- spine
What is iniencephaly also known as?
Star gazing position
What cerebral condition can inencephaly also be associated with?
Anencephaly
What are some segmentation errors of iniencephaly?
Shortens neck and head becomes dorsiflexed
What is scoliosis?
Lateral curvature of the spine
What kyphosis?
Exaggerated curvature of the spine in the sagittal plane
What does this image demonstrate?
Scoliosis
What is the VACTERL sequence?
Vertebral
Anal
Cardiovascular
Tracheo- Esophageal
Renal
Limb
What is VACTERL sequence often associated with ?
Caudal regression
What is the prognosis of VACTERL sequence?
Depends on severity and extent of involvement
What is caudal regression?
Range of anomalies of the spine
What maternal condition increases the risk of caudal regression?
Maternal diabetes
What is sirenomelia?
- Absence of sacrum
- Fusion of legs
- Rectal atresia
- Renal dysgenesis or agenesis
- Oligohydraminos
What is the prognosis of sirenomelia?
- All die in infancy
What is the most severe form of caudal regression?
Sirenomelia (mermaids syndrome)
What is a sacrococcygeal teratoma? What elements does it contain?
- Mass adjacent to distal spine
- Contains elements of many tissues
How rare is sacrococcygeal teratoma?
1/ 35,0000 births (very rare)
Teratomas can arise from what areas? 4
- Sacrum
- Coccyx
- Brain
- Gonads
What are four types of sacrococcygeal teratomas?
By location
1. External mass predominant 47%
2. External mass with internal components 34%
3. Internal mass predominant with smaller external component 5%
4. Presacral mass (internal only) 10%
What is this an image of?
Type 1 Sacrococcygeal Teratoma
What is this an image of?
Type 2 Sacrococcygeal teratoma
What is this an image of?
Type 3 Sacrococcygeal teratoma
What is this an image of?
Type four sacrococcygeal teratoma
What is this an image of?
Sacral teratoma
What is the prognosis of sacral teratoma? What of a solid one? What happens if it is >4.5 cm?
- Depends on size of mass and severity of structure displacement
- Solid mass has a malignant tendency
- If >4.5 cm C section is indicated
What is the DDX for sacral teratoma? 3
- Rectal duplication
- Anterior myelomeningocele
- Sarcoma