Neural Tube Defects Flashcards
What is gastrulation?
The process of the single layered blastula turning into the 3 (ecto/endo/mesoderm) layers
What is the difference between open and closed NTD’s?
Open: Brain or spinal cord exposed at birth
Closed: Covered by skin
What is anencephaly?
An open NTD where the head of the NT fails to close, P born with no forebrain- no survival
What is an encephalocele?
Protrusion of the brain through the skull at birth
What is hydraencephaly?
Part of cerebrum is just CSF fluid (agenesis)
What is spina bifida occulta?
Affects 10% population. Outer part of vertebrae not completely closed, however gap is very small so no spinal cord protrusion
What is the cause of NTD’s?
Low folate (vit B9) or vitamin B12, needed for nucleic acid/ DNA synthesis
Name 5 risk factors for NTD’s?
Low folate (vit B9) or vit B12
Obesity
Uncontrolled diabetes
Antiseizure medication (valproate/ carbamazepine)
What is the female to male ratio in NTD’s?
F 4:1 M
In spina bifida cystica, what is the difference between a meningocele and a myelomeningocele?
Meningocele: Just meninges pushed out through opening in vertebrae (often no SC damage)
Myelomeningocele: SC also pushed out between vertebrae, leading to damage (most severe form)
Name 4 common symptoms seen in a patient born with a myelomeningocele?
Partial/ total lower limb paralysis
Bowel/ urinary incontinence
Loss of skin sensation
Cognitive sympt (caused by arnold chiari malformation)
What is a chiari malformation?
Where all or part of the cerebellum and brain stem has descended below the level of the foreamen magnum
What are the two main types of chiari malformation?
1- Only cerebellar tonsils below brainstem
2- (ka arnold-chiari malformation)- Part of cerebellum and medulla oblongata pushed down, often results in hydrocephalus (seen in 95% myelomeningocele)
What is the lemon sign?
Seen on ultrasound before 24wks, it is a bilateral concavity in the anterior skull (making it look like a lemon)- Highly indicative of spina bifida
In patients with spina bifida why is hydrocephalus also seen?
Due to a malformation (arnold-chiari) causing it to be misshapen and narrow area’s of the ventricular system to become blocked
What is checked on in a quadruple blood test and what would be seen in a baby with spina bifida?
AFP, hCG, uE3, inhibin A
High AFP could indicate spina bifida
(Low AFP plus high hCG could indicate downs)
What is the most common immediate treatment for spina bifida?
Surgery within 48hrs of birth to place cord and tissue back in and seal gap in vertebrae
Shunt for hydrocephalus
What long term treatment is given to patients with spina bifida?
Physio- prevent muscle waiting
OT- Boost self esteem and independence
Incontinence treatments
Spontaneous leg movements in the womb are often associated with what?
Damaged spinal cord (i.e. spina bifida)
Baby can’t kick itself round so many SB babies are born breech
