Spina Bifida Flashcards
What is spina bifida?
Spina Bifida is a type of neural tube defect that occurs when one or more vertebrae fail to fuse at approximately 28 days of gestation, leaving the spinal cord unprotected in utero.
PREVALENCE:
-3 in 10,000 or 1 in 1,400 in the US
-Higher prevalence in Hispanics and Caucasians compared to African Americans and Asians
-90-95% have no family history of SB
Common co-morbidities
seizure
latex allergy
sensation decreased–> skin breakdown
hip subluxation, clubfoot, scoliosis
UE weakness
Most common level of spinal defect in spina bifida
L5-S1
** spina bifida can present with UMN and LMN signs –> higher lesions may have more UMN signs
When does development of the neural tube usually occur?
3-4 weeks gestation
Open spinal dysraphism
Meninges and/or nerve tissue are exposed to the external environment.
Most prevalent.
Closed spinal dysraphism
Meninges and nerve tissue are covered by skin.
Mildest form of the condition.
Myelomeningocele
The most common form of Spina Bifida but others forms of open and close lesions exist
-most severe form of the condition
Myelomeningocele is a severe form of spina bifida in which the spinal cord and nerves develop outside of the body and are contained in a fluid-filled sac that is visible outside of the back area.
Occulta meaning
hidden
Spina bifida occulta:
mildest and most common
one or more vertebrae is malformed
often no symptoms
common to have hair tuft growth over affected vertebrae
Meningocele
meninges protrude outside of spinal canal and are filled with spinal fluid
Lipomyelomeningocele
closed neural tube disorder
often requires surgery
fatty tissue protrudes into the spinal canal through an opening in the vertebrae
causes leg weakness and B/B issues
Myelomeningocele
most severe form of SB
portion of SC exposed through an opening in the spine
SC may or may not be covered by the meninges
Anencephaly
baby is born without parts of the brain and skull
type of neural tube defect
occurs when upper part of neural tube does not close properly during gestation
baby is born without forebrain and cerebrum
parts of the brain that the baby is born with are commonly not covered by skull or skin
prevalence: 1 in 4,600 infants born
Encephalocele
Neural tube defect→ lack of complete closure during pregnancy
Sac-like protrusion of brain matter and meninges through an opening in the skull
The opening may occur anywhere on skull from the nose to the back of the neck
—> most often on the back of the head, top of the head, or between the forehead and nose
Prevalence: 1 in 10,500 live births in the US
Etiology: the cause is generally unknown
Diagnosis prenatally:
13-15 weeks:
-blood lab test - AFP - 80% reliable
-The alpha fetoprotein test (AFP) is a blood test performed to measure, diagnose, or monitor fetal distress or fetal abnormalities. It can also detect some liver disorders and some cancers in adults.
16-24 weeks:
-fetal ultrasound, >90% reliable
16-18 weeks:
-amniocentesis: takes amniotic fluid from around your baby in the uterus
-100% accurate but more risky
Complexity of spina bifida:
-from minor to severe physical and mental disabilities
SEVERITY BASED ON:
-size/location of malformation
-open vs closed
-which spinal nerves are involved
**The higher the malformation occurs on the back, the greater the amount of nerve damage and loss of muscle function and sensation.
CAUSES AND RISK FACTORS OF SB
CAUSE: unknown but likely multiple factors
-genetic
-nutritional - maternal nutrition
-environmental -teratogens
-could be related to Folic acid–> reduces risk of neural tube defects by up to 70%
FOLIC ACID REC:
-0.4 mg of folic acid should be taken by women of childbearing age
-dark leafy greens, whole grains, legumes
MSK IMPAIRMENTS
foot abnormalities –> ex: clubfoot
shorter legs
decreased bone density
scoliosis
hip subluxation and dislocation
NEURO IMPAIRMENTS
loss of sensation
loss of muscle strength and control
loss of B/B control
muscle contractures
OTHER IMPAIRMENTS
hydrocephalus
Arnold Chiari Malformation
seizures
cognitive impairments
tethered cord syndrome
skin care - pressure sores, latex allergy
What is hydrocephalus?
Hydrocephalus
Cause: disturbance of formation, flow, or absorption of CSF
fluid accumulation in ventricles
common among children born with myelomeningooele
Prevalence: 15-25% at birth, increases to 80-90% that will require a ventriculoperitoneal shunt
S/S:
headaches
nausea
lethargy
vision problems
hoarse cry
swallowing issues
cocktail party personality - articulate and verbose but contents include jargon and cliches
Synringomyelia- a fluid filled central cavity (spinal cord) often associated with hydrocephalus
(5-40% incidence) –> change in motor and sensory function, increased reflexes, pain
–> may require localized shut in the spinal cord
Arnold Chiari Malformation Type II
leading cause of mortality in children with spina bifida
portion of the brainstem descends into the cervical spinal canal due to increased CSF pressure
S/S:
changes in breathing pattern
swallowing problems
ocular muscle palsies
lateral rectus weakness (CN VI)
weakness/spasticity in arms
bradycardia- can be severe
Club foot and SB
in 30-50% infants with spina bifida
more common with T spine and lumbar lesions
Associated with:
-muscle imbalance
-contractures
-intrauterine positioning
-spasticity
Tethered cord syndrome and SB
20-50% of children with myelomeningocele
caused by spinal cord becoming tethered to part of vertebral column → abnormal stretch of the spinal cord with the child’s growth
SIGNS/SYMPTOMS
weakness
scoliosis
pain –with vertebrae palpation
orthopedic deformity
abnormal gait and balance
–gait analysis indicated
urologic dysfunction
TREATMENT
surgical- to detach SC from vertebrae
Re-tethering occurs 10-15%
Activity and Participation outcome measures
Alberta Infant Motor Scale- Motor function
-0-18 months
PEDI- goal setting –> parent/caregiver report
demonstrate change in function over time
–>higher scores means greater functionality
WeeFIM
-validated for use with children with spina bifida
-18 items, 7 levels
-6 months to 7 years
–> higher scores=more indepedence
-assessing self care, mobility, and cognition
School Function Assessment- Participation in school
SB Helath Related QOL-
–impact of impairment on life satisfication
BFS outcome measures
Goniometry
American Spinal Injury Association impairment scale (ASIA) - ISNCSCI
–sensory and motor function
Hand held dynamometry or MMT
Gait and movement analysis
Common stages of motor development
-in first 6 months - close to typical
-rolling: thoracic SB usually roll by 18 months with compensatory strategies –> many will crawl
-sitting: children with mid-lumbar SB can sit with support with delay and increased lordosis, typical with L4-L5 lesion
-pull to stand/cruise: can be done among children with low lumbar lesions, may progress to ambulation with assistive devices around age 2
positive predictors of ambulation
low motor level
no history of shunt
no history of hip or knee contracture surgery
What other muscles other than hip abductors are commonly weak in those that walk with a Tredelenburg pattern?
-hip extensors
-plantar flexors
Medical management of SB
FIRST
-fetal or post-natal surgery
—fetal is higher risk
-can lead to improved mobility and fewer surgeries needed for shunt placement
SECOND
surgery to place shunt → to help drain CSF from brain
–may need additional surgery based on growth, clogged shunt, or infection
Orthopedic considerations
Scoliosis or kyphosis
-common with lesions above L2
-may need surgery with Cobb Angle >40 degrees
—->fusion, growing rods
Hip subluxation and dislocation
-fractures 11-30% most common in the distal femur and femoral neck related to osteopenia
-watch out for warmth of skin or low-grade fever
-often present subacutely
Early Intervention
Monitor joint alignment, muscle imbalance, and development of contractures
-stretching, orthoses, splints
-serial casting
-surgery
Tummy time
-to strengthen neck and mm. for crawling,
-improve sensory processing and motor planning
Bracing for ambulation
-soon after pull to tall kneel or pull to stand
-protects the lower limbs from torque and shear forces
Power mobility
-can start at 24 months of age
ensure proper fit, posture, technique
PBWSTT
-high repetition
-functionally relevant
-strength and control of muscles is improved
—motor development
-increases bone density
-increased amount of sensory input → more steps
Motor function across the lifespan
-average age of onset for those that walk: age 3
–> most likely with a mobility support device
-many children will lose capacity later in life (around 11)
Independent living: 30-60%
Employment rate: 25-50%
Interventions 1-5 years old
monitor any changes in neuro level, strength, gait, sensation, B/B, MSK changes
consider using standing frame or mobility device to encourage upright standing and WB
discuss/emphasize mobility options
use appropriate bracing to facilitate weak muscles and protect limbs from shear or torque forces
ensure proper wheelchair fit, posture, and technique
Interventions 6-12 years old
focus on strength of the upper extremities to improve wheelchair mobility, ambulation, and functional activities
educate patient on how to don and doff orthoses independently
promote physical activity and weight-bearing through conversations with family and patient about adapted PE or adaptive sports
Concerns across life span
ADULTHOOD CONCERNS:
-increased body size
-joint degradation
-decreased bone density
-poor control and painful movement
-motivation
*consider low impact activity
