Spina Bifida (Myelomeningocele)

Question 1

Description

Answer 1

Failure of fusion of the neural fold

During neurulation phase of embryonic development

Embryologic defect of bone, meninges, and spinal cord

Spectrum from anencepahly to spina bifida occulta

Question 2

Etiology

Answer 2

Multifactorial

Folate deficiency?

Environmental: socioeconomic, maternal age, hyperthermia, teratogens, seasonal

Familial

Question 3

Incidence

Answer 3

0.6/1000 in US

Prenatal diagnosis

Question 4

High incidence of Arnold Chiari II

Answer 4

Consists of downward displacement of the cerebellar tonsils through the foramen magnum (opening at the base of the skull)

As a result of obstruction, non-communicating hydrocephalus can result

Question 5

Hydrocephalus

Answer 5

Abnormal accumulation of CSF in the ventricles of the brain

Causes increased intracranial pressure

In non communicating, due to obstruction of CSF outflow

Can cause headaches, dizziness, impaired coordination, and in severe cases, paralysis

Question 6

Shunt hydrocephalus

Answer 6

in 90%

50% obstruct and require revision in 1st year of life

Risk of shunt infection 12%

Question 7

Other Symptoms

Answer 7

Neurogenic bladder and bowel

Question 8

Site of Defect, Percentages

Answer 8

Cervical level 1%

Upper Thoracic 1%

Lower Thoracic and Upper Lumbar 6%

Mid Lumbar 27%

Lumbosacral 42%

Sacral 21%

Entire lumbosacral 2%

Question 9

Neurologic Impairment, Percentages

Answer 9

Cervical and upper thoracic 1%

Lower thoracic 27%

Intact hip flexion but impaired quadriceps 23%

Lower lumbar and quadriceps sparing 45%

Lower sacral, leg strength, B&B abnormal 4%

Question 10

Neurological impairment

Answer 10

Typically flaccid paralysis

May have

Spasticity

Mixed paraplegia and spasticity

Asymmetry

Intact regions of voluntary control below regions of paralysis

Question 11

Hydromyelia

Answer 11

50-80%

abnormal widening of the central canal of the spinal cord

Creates cavity in which cerebrospinal fluid can accumulate

Build up of CSF can put pressure on spinal cord

Damage nerve cells

Weakness of upper limbs, spasticity, ascending motor changes

Scoliosis

Question 12

Tethered cord

Answer 12

11-15%

Traction of conus medullaris and cauda equina after repair

Progressive neurologic deficits

Impair strength, spasticity, back pain, B&B changes, scoliosis

May require surgical release

Question 13

Musculoskeletal deformity of the hip

Answer 13

Occurs in majority

Hip Extensors and Abductors most affected

Muscle imbalance leads to hip flexion contracture

50% subluxed or dislocated hips

May require surgery

Question 14

Musculoskeletal deformity of the knee

Answer 14

Flexion contracture most common

May be due to joint stiffness, spasticity in the knee flexors

Or Progressive crouched posture with weak quadriceps

More common L3 or higher

Question 15

Musculoskeletal deformity of the foot

Answer 15

Deformities occur in 85%

Abnormal bony cartilaginous growth

Lack of sensation and vasomotor instability
- skin injury and poor healing

Equinovarus

Pure Equinus

Pes Cavus

Cock-up toe deformity at great toe

May require surgery as well as bracing

Question 16

Musculoskeletal deformity of the spine

Answer 16

Scoliosis with lordosis

Kyphosis

Rigid congenital malformation

Question 17

Prevalence of scoliosis in spina bifida

Answer 17

100% with thoracic lesions develop scoliosis of at least 45 degrees

L4 lesions, 60%

Question 18

Scoliosis in spina bifida

Answer 18

high paraplegia, develops early, C-shaped, always progresses

with hydromyelia, usually S-shaped

kyphosis almost always progressive

may have rigid apex

treat to decrease pressure on abdomen, diaphragm and skin

treat before 180

Question 19

Other Complications

Answer 19

Fractures

Pressure Sores

Obesity

Latex Allergy