Spina Bifida Flashcards
spina bifida definition
- various degrees of congenital malformations involving the vertebral column, the meninges, the spinal cord and nerve roots
- Static, non- progressive lesion however secondary problems may result in deterioration of function
etiology of SB
- Associated with but not completely understood:
– Low levels of maternal folic acid prior to conception
– Maternal use of valproic acid (Depakote) and Accutane
– Increasing maternal age
– Maternal alcoholism
– Parental exposure to Agent Orange
Linked to environmental factors, pollution and lower socioeconomic levels
Possible genetic link – parents with 1 child are 30x more likely
Greater risk in people of Irish descent; lower risk with African or Japanese descent
spina bifida occulta
- Nonunion of vertebral arches at 1 or more segmental levels
- Usually in lumbosacral region
- Often present with surface hair tuft or skin dimple
- **Asymptomatic
meningocele
- **Least common form
- Pouch or cyst of meninges and CSF protrudes through vertebral defect
- Spinal cord and nerve roots are intact and in normal position
- *Asymptomatic; although child may have issues later in life with tethered cord
myelomeningocele
- **Most serious and common form
- Herniation of meninges, CSF, spinal cord and nerve roots through vertebral defect
- Disruption of sensation and motor deficits occur below lesion
- Loss of bowel and bladder control
- Most often in lumbosacral region but can occur anywhere along the spine
embryological origins
- Non-fusion of the neural tube
(Proximal closes at day 24 gestation, Distal closes at day 26 gestation)
Rupture of an already closed neural tube
diagnosis
Prenatally most common – prenatal care
– Alpha-fetoprotein (AFP): substance normally present in developing fetus and found in amniotic fluid
Screening test and many false positives
– Ultrasound: can identify lesion/level
– Amniocentesis: detects AFP and acetylcholinesterase in amniotic fluid
Plan for schedule c-section for delivery
• Options for parents
• Termination
• In-utero repair
At birth- limited or no prenatal care
– Recognized due to external sac or lesion on back
Lesion is usually surgically closed within 24-72 hours following birth to prevent infection or further damage
clinical manifestations
Loss of sensory and motor function – Complete vs. Incomplete lesion Complete: – Loss of function below lesion – Flaccid paralysis – Loss of sensation – Absent reflexes Incomplete: – Areas of spasticity – Hyperactive reflexes – Areas of volitional control
causes
– Primary: dysfunction is direct result of primary spinal lesion
Motor level is assigned according to last intact nerve root found
Classified on critical motor function that is present
– Secondary: dysfunction due to factors other than original lesion
related issues
- bladder and bowel dysfunction: catheterization
- hydromyelia: accumulation of CSF in spinal cord causes necrosis of peripheral nerves, results in weakness
- tethered spinal cord
- hydrocephalus: pressure in brain, shunt may be needed
Arnold Chiari malformation
Occurs in almost all children with myelomeningocele.
• involves the lower brainstem and bottom portion of the cerebellum
• the brainstem is elongated and displaced into the opening of the base of the skull and into the top of the spinal canal. The brainstem, cranial nerves and lower portion of the cerebellum may be stretched or compressed. This means that any of the functions controlled by these areas may be affected.
• no obvious symptoms, the most common are a weak or absent cry, stridor (noisy breathing), arching of the neck, breathing problems, color change, failure to thrive and feeding or swallowing difficulties.
shunts
– Ventriculoatrial (VA)
– Ventricuoloperitoneal (VP) - most common
*Shunts have 1-way valves and are placed in the lateral ventricle. A tube is passed just under the skin from the origin, under the clavicle, and into the peritoneum or right atrium.
• Shunts may become infected or clogged resulting in increased intracranial pressure
s/s shunt malformation
Infants: Bulging fontanelles, Vomiting, Change in appetite, Sunsetting eyes, Edema, redness along shunt track, High pitch cry, Irritability, Lethargy, Seizures, Head circumference increases
Toddlers: Persistent vomiting, Irritability, Headaches, Edema, redness along shunt track, Lethargy, Seizures
•* New nystagmus
•* New squint
School-aged Children: Headaches, Lethargy, Irritability, Edema, redness along shunt track, * Handwriting changes, Vomiting, Seizures, Decreased school performance, * Personality changes, * Memory changes
s/s shunt infection
- Fever
* Elevated WBC
other clinical manifestations
- impaired intellectual function
- speech and language impairments
- impaired fine motor and perceptual skills
- lack of independent mobility and self care skills
- orthopedic problems
