Congenital malformations Flashcards
What is anencephaly
Failure of anterior neurospore to close Skull fails to form Brain tissue degenerates Incompatible with life 4 times more common in females
What is encephaloceal
Failure of anterior neural tube to close
Leads to herniation of brain tissue through skull
Most frequent in occipital region
What is the cause for spina bifida
Failure of caudal neurospore to close
Affects tissue overlying spinal cord
=Non-fusion of vertebral arches
Severity ranges from minor abnormalities to major clinical symptoms
Different types of spina bifida
Spina bifida occulta Spina bifida cystica: -meningocele -meningomyecele -Myeloschisis
Spina bifida occulta
- Least severe form
- Unfused vertebral arches
- At L5/L6
- No clinical symptoms
- Presents as a dimple with a small dimple of hair
Spina bifida cystica cause
Protrusion of the spinal cord/ meninges through the vertebral arches
Meningocele
protrusion of meninges and CSF
Meningomycele
Nerve roots and spinal cord in the sac
Loss of sensation and muscle paralysis at level of lesion
Often associated with hydrocephalus
Myeloschisis
spinal cord in affected area is open due to inability of neural folds to fuse
How to prevent NTDS
Folic acid supplements Pre-natal screening: -Maternal blood screening: High levels of alpha-fetoprotein in serum -Amniocentesis : High AFP -Ultrasound
Risk factors for NTDS
- Genetic
- Environmental predisposition (drugs/hyperthermia)
- Genetic predisposition ( too little folate/vitamin A)
What is lissencephaly?
- Smooth brain: sulci and gyrus do not form
- Children under the age of 10 tend to die
- Failure to thrive, mental impairment, decreased muscle tone
What are the main causes for intellectual impairment?
- Rarely associated with brain abnormalities
- Head trauma
- Infectious disease
- Radiation
- Maternal alcohol consumption
