Myelodysplasia (Spina Bifida) - (Exam 2) Flashcards
What is the general definition of Myelodysplasia?
- Defective development of any part (especially the lower segments) of the spinal cord
- Congenital neural tube defect (NTD)
What is the pathophysiology of Myelodysplasia?
- Embryo (20 days after conception) neural groove –> neural crest –> closure of neural tube
- Day 23 completely closed except for hole at top –> brain & hole at bottom –> spinal cord
- Also errors in development of vertebral architecture
The degree of dysfunction of Myelodyplasia is related to what?
Anatomic level of the defect
Patients with Myelodysplasia usually present with loss of (BLANK) below the level of the lesion
Neurologic function (sensory & motor)
What is the etiology of Myelodysplasia?
Possible environmental & genetic factors:
- Folic acid deficiency
- Lower SES
- Teratogenic agents
- Hyperthermia during early pregnancy
- Vitamin A deficiency
- Rh factor
- Alcohol ingestion
- Genetic Link? (parent w/ one child with myelodysplasia have 50x higher chance of having a sibling)
How is Myelodysplasia detected pre and postnatally?
Pre-natal:
- Ultrasonic scanning is able to detect NTD prenatally
- Serum alpha- fetoprotein (AFP) testing
Post-natal:
- Observation (except occulta)
Myelodysplasia - Occulta is a result from what?
Failure of one or more vertebral arches to meet and fuse in 3rd month of development
In Myelodysplasia - Occulta (BLANK) & (BLANK) are unharmed and remain in vertebral canal
- (BLANK) defect is covered by skin
In Myelodysplasia - Occulta Spinal Cord & meninges are unharmed and remain in vertebral canal
- Bony defect is covered by skin
Where is Occulta most common at?
in Lumbosacral area
Occulta has no disturbance in (BLANK) or (BLANK) function
Occulta has no disturbance in neurological or musculoskeletal function
What physical features may be present with Occulta?
- Depression or dimple
- Cafe au lait spot
- Soft fatty deposit
- Tuft of hair midline over area
How does Aperta-cystica occur?
Neural tube & vertebral arches fail to close appropriately
In Aperta- cystica there is a (BLANK) protrusion of material through (BLANK)
In Aperta- cystica there is a cystic protrusion of material through defective arches
What are the two types of aperta-cystica?
- Meningocele
- Myelomeningocele
Describe Meningocele
- Protrusion of meninges and CSF into cystic sac
- Spinal cord remains within vertebral column
- May exhibit some abnormalities but less common
What is Myelomenigocele?
Protrusion of both spinal cord & meninges into cystic sac
What is a closed Myelomenigocele?
Covered with a combination of skin & membranes
Where are meningoceles and closed myelomeningoceles most common?
At thoracic & lumbosacral areas
What is an open myelomenigocele?
Nerve roots & spinal cord may be exposed with dura & skin at edge of lesion
Where do open Myelomenigocele occur?
2/3 of open type occur at T-L junction
What is Myelodyplasia: Lipoma?
Fatty tumor on spinal cord
What is Myelodyplasia: Myelocytocele?
Cystic like tumor of spinal cord
What is Myelodyplasia: Anencephaly?
- Failure of closure of cranial end of neural tube
- Some brain tissue may be evident but forebrain usually absent
- Lack of sustained life
What is the clinical picture of Occulta?
- Usually does not cause neurologic dysfunction
- Occasional disturbances in bowel & bladder function or foot weakness (Most common in LS area)
