Myelomeningocele Flashcards
what is the etiology of Myelomeningocele?
Nervous system develops from a portion of the ectoderm called the neural plate
- Neural plate → neural tube → brain and spinal cord
what is the incidence of myelomeningocele?
2/1000 births
when and where does the neural tube close?
begins in cervical region and proceeds cranially and caudally
completed by 26th day
what is spina bifida?
defect in neural tube closure and the overlying prosterior vertebral arches
what is the cause of spina bifida?
- no definitive cause, but there may be genetic predisposition that is enhanced by environmental factors
- genetic risk factors:
- celtic orgin
- previous spina bifida births
- environmental risk factors:
- lower SES
- deficiences
prenatal testing that indicates spina bifida
- AFP at abnormally high level in amniotic fluid past 14 weeks gestational age, compared with US results
list the types of spina bifida
- Occulta
- Cystica
- Meningocele or myelocele
- Myelomeningocele
- Anencephaly
What is Occulta Spina Bifida
failure of vertebral arches to meet and fuse in 3rd month
describe Occula Spina Bifida
- overlying skin may be marked by dimble, pigmentation, or patch of hair
- lumbosacral area a common site
- usually associated with no neurological or musculoskeletal dysfunction
- however, there in a higher incidence than normal of urinary tract disorders
what is Cystica Spina Bifida
failure of neural tube and vertebral arches to close with cystic protrusion of meninges with or without spinal cord
describe meningocele/myelocele
- spinal cord remains in vertebral canal but it may be abnormal
- lipomeningocele
- superficial fatty mass in low lumbar or sacral area
- high incidence of B&B dysfunction due to tethered cord
describe myelomeningocele
- extensive spinal cord abnormalities
- most common in thoracic and lumbosarcal regions
describe anencephaly
cranial end of neural tube does not fuse
Clinical manifestation of Myelomeningocele
- loss of sensory and motor function
- orthopedic abnormalities
- hydrocephalus
- brain/spinal cord abnormalities
- B&B dysfunction
- cog impairments/learning issues
- integumentary impairment
- disturbed growth and development
- psychosocial issues
Loss of sensory and motor function in myelomeningocele is dependent on what?
- degree of spinal cord abnormality
- traction or stretch on spinal cord
- trauma to exposed neural tissue during delivery
- postnasal damage resulting from drying or infection of the neural plate
describe sensory impairment in spina bifida
- sensation below level of lesion is impaired
- may not exactly match level of lesion
- includes:
- kinesthetic
- proprioceptive
- somatosensory
what are the two main types of motor dysfunction in spina bifida?
- Type 1 → complete loss of function below level of lesion resulting in flaccid paralysis, loss of sensation, and absent reflexes
- Type 2 → mixture of flaccidity and spasticity
List several orthopedic problems that can result from spina bifida
- deformity/contractures
- osteoporosis
what can be the cause of deformities in spina bifida?
due to
- muscle imbalance
- effect of stress
- posture and gravity
- congenital malformations
- decreased sensation
- neurological complications
list typical congenital malformations found in spina bifida
- hemivertebrae
- deformed vertebral bodies and ribs
- missing ribs
- lumbar kyphosis
- club feet
- rocker bottom feet
- gibbus deformity
describe hydrocephalus
- present in 80-90%
- blockage of normal flow of CSF
- signs
- increased head size
- bulging fontanelles
- irritability
- lethargic
- sunset eyes
- typically develops following closure of sack
- watch for signs of shunt malfunction in child w/shunt
interventions for hydrocephalus
VA/VP shunt
shunt revision