Neural Tube Defects Flashcards
Is used to describe many distinctly malformations of the neural tube
Neural Tube Defect
It is the developing brain & spine od the fetus at 3-4 weeks of gestation
Neural Tube
Why is the neural tube susceptible to malformations?
Because NT forms in utero firet as a flat plate and then molds to form the brain & spinal cord.
It is the process in which the neural plate bends up and later fuses to form the holloe tube that will eventually differentiate into the brain & the spinal cord of the CNS.
Neurulation
Risk Factors of NTDs
- Folic acid deficiency
- Family hx of NTDs
- Maternal age under 20 or over 40
- Maternal educaction
- Low socioeconomic status
- Maternal diabetes
- Maternal obesity
- Certain drugs such as valproic acid - used to treat seizure disorders
Two most common NTDs
- Anencephaly - brain defect
- Spina Bifida - spinal cord efect
When does neural folds fuses?
Around Day 21-28 (3-4 weeks of gestation)
Order or sequence of fusion of neural folds
- Begins midline
- Cranial
- Going downward to caudal
Two possible outcomes of neural fusion
- Complete fusion of neural tube
- Unfused neural tube segment (incomplete)
Is the most severe type of NTD in which both the brain and spinal cord remain open
Cranioachischisis
Is a condition in which major portions of the brain, skull, and scalp are absent or failed to develop
Anencephaly
How is Anencephaly diagnosed?
- Amniocentesis
- Prenatal UTZ
- Elevated MAFP (Maternal Alfa-fetoprotein)
Outcomes of anencephaly
An infant with this condition may die in utero or may survive for several days after birth but cannot survive further because they have little or no cerebral function
Treatment or cure for anencephaly
No known treatment or cure and no surgical management available
What happens if the condition is discovered prenatally?
Parents are offered the option of pregnancy termination
Degrees of Spinal Cord Abnormalities
- Spina Bifida Occulta
- Meningocele
- Meningomyelocele
It is the mildest form of all NTDs
- a malformation caused by the non-closure or incomplete closure of the posterior portion of the vertebrae
Spina bifida occulta
Assessment findings for spina bifida occulta
- May be first noticed as dimpling on the skin at the point of incomplete fusion
- Abnormal tufts of hair or discolored skin may also be present
How do nurses help in clarifying the degree of spina bifida occulta to parents?
Explain that this degree simply means a surface of bone is missing and the spinal cord is intact
Why do children with spina bifida occulta need no surgical correction?
No tissue protruding from the vertebrae
Surgery in children with spina bifida occulta is done in order to?
Prevent vertebral detorioration because of the unbalanced spina column
Three layers of meninges
- Pia mater
- Arachnoid
- Dura mater
Meninges herniate through an incompletely closed or unformed vertebrae, they will protude as a circular mass called…?
Meningocele
Meningocele is accompanied by no sensory or motor deficit unless?
Membrane sac ruptures
Why is immediate surgery necessary for meningocele?
To replace the meninges & to close the gap in the skin to prevent infection
When is surgery done for meningocele?
24-48 hours after birth to prevent infection & trauma to the exposed tissue
Most severe form of spina bifida
- Meninges protrude through the vertebrae & the spinal cord usually ends at the point of protrusion
Meningomyolocele
What happens to the nerves function?
Motor & sensory function will be decreased or absent beyond the point of protrusion
Why is talipes (club feet) a complication of meningomyelocele
Due to lack of innervation to the feet/ankles
Complications associated with meningomyelocele
- Loss of bowel & bladder control
- Permanent weakness or paralysis of legs
- Talipes (club feet)
- Hydrocephalus
Why is hydrocephalus a complication of meningomyelocele?
Due to obstruction of CSF circulation from the spinal deformity
- Higher the meningomyelocele occurs on the cord, the more likely it is that hydrocephalus will be present.
Therapeutic management for mingomyelocele
- Immediate surgery
- Simultaneous VP shunting during a primary meningmyelocele repair
VP shunting may not be necessary if meningomyelocele repair is done in?
Utero
After surgery, the child will continue to have partial or complete paralysis of the lower extremities & loss of bowel & bladder function. why is that?
Lesions on the back can be reparied but the absence of a lower cord cannot be replaced
How are NTDs diagnosed?
- Prenatal UTZ
- Fetoscopy
- Screening amniotic fluid for alpha-fetoprotein
- analysis of maternal alpha-fetoprotein
How can a lesion be closed if the condition is discovered in utero?
Thru fetoscopic surgery
Why is an infant with NTD can be born via C-section?
To avoid pressure & injury to the spinal cord.
Surgical closure of open lesion in an infant with myelomeningocele is usually recommended in the?
First 24 hours to reduce the incidence of infection & trauma to the exposed tissues
Plan of care after deliver of the baby with myelomeningocele is focused on?
Potential for infection
What is the baby’s position prior to surgery for a myelomeningocele?
Prone position
Why is the baby placed in prone position prior to surgery for a myelomeningocele?
To minimize pressure on the sac & reduces potential trauma to the area.
Why is maintaing skin integrity necessary in caring for an infant with myelomeningocele?
Because skin problems can develop due to limited movement, muscle weakness, poor sensation, bowel & bladder incontinence
