Spinal Pathology Flashcards
Each vertebra will develop how many different ossification centres?
3
The centrum forms what?
The central portion of the vertebral body
The two neural processes of the vertebra will form what? 5
- Pericles
- Transverse processes
- Laminar
- Spinous process
- Posterolateral part of the vertebral body
In terms of the 3 ossification centres, how visible is each ossification centers?
Only parts of the fetal spine are visible
Ossification is not complete in the laminae until when?
18 weeks
Potentially a small spina bifida could be missed when?
Prior to 18 weeks
What are the chances of getting NTD?
1/1000 births
What increases risk of NTD? 4
- Valproic acid
- Maternal diabetes
- Folic acid deficiency
- History of spinal defects
What is valproic acid used for?
Medication for seizure
What history of spinal defects are important? 2
- Previous pregnancy
- Family history of NTD
What is spina bifida? 3
Defect in structure of the spinal canal that ma result in the herniation of its contents.
1. Meninges
2. CSF
3. Neural tissue
What kind of defect is spina bifida?
NTD
Besides spinal bifida what are other examples of NTD? 2
- Encephalocele
- Anencephaly
What is Encephalocele?
Brain herniating through defect in cranium
What is anencephaly?
Missing cranium and brain
What are two types of spina bifida?
- Occulta
- Aperta
What does spina bifida involve?
Only the deeper layer
What may we see with spina bifida?
May only see a skin dimple or patch of hair on the skin
What is spina bifida occulta look like?
Closed defect
How many cases of spinal bifida are occulta?
15-20% of cases
What does Occult mean?
Hidden or concealed
What is spina bifida aperta? What does it involve?
- Open defect
- Involves all layers from dura to skin
How many cases are aperta cases in terms of spina bifida?
80-85%
What are two types of spina bifida aperta?
- Meningococcal
- Myelomeningocele
What is spina bifida aperta Meningocele?
Spina bifida aperta which contains meninges and CSF
What is spina bifida aperta Myelomeningocele?
Contains meninges, CSF and neural tissue
What does Spinal NTD look like on U/S? 2
- Splayed laminae
- Protruding mass or cyst
When looking for spinal NTD what should we look for association with? What are the signs?
Arnold Chiari II malformation, ventriculomegaly. These signs are
1. Obliterated cisterna magna
2. Banana sign with cerebellum
3. Lemon sign
When is screening for MS AFP done?
Quad screen which is at 16 weeks
AFP is produced where in the fetus?
Fetal liver
Can AFP cross the placenta?
Yes
Gestational age must be considered as AFP level. Why?
The MS AFP level varies with gestational age