Download Functional Classification

CM 1- Neural Tube Defects
60% NTD’s prevented with folic acid supplement
Origin of the nervous system
 The nervous system develops from the Neural Plate
 Neural plate forms into the Neural folds, Neural tube and Neural crest
 Mesoderm causes endoderm to enfold, failure  NTD
 Neural tube  central nervous system consisting of brain and spinal cord
 Neural tube proceeds in cranial and caudal directions until only small area of the tube remain open at both
ends
 Around week 4: Cranial and caudal ends of the neural tube close
 Around 9th to 10th week: Lateral walls of the neural tube thicken, reducing the size of the neural
canalcentral canal of the spinal cord and ventricular system of the brain
NTD causes
 Failure of the neural tube to close spontaneously between the 3rd and 4th week
 The precise cause of NTDs remains unknown
o hyperthermia, drugs (valproic acid), malnutrition, chemicals, maternal obesity or diabetes,
o genetic determinants (mutations in folate-responsive or folate-dependent enzyme pathways)
o abnormal maternal nutritional state
o exposure to radiation before conception
The most common forms of birth defect, affecting 1 in every 1,000 pregnancies
Open Neural Tube Defects
 Anencephaly: exposed rudimentary brainsten due to failed closure of cephalic NT
 Myelomeningocele: herniation of SC through unfused portion
 Meningocele : herniation of meninges
Closed Neural Tube Defects
 Diastematomyelia
 Dermal Sinus
 Tethered Spinal Cord
 Lipomyelomeningocele
Spina Bifida Occulta
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Defect in posterior vertebral body fusion
Occurs in the L5 or S1 region
10% of otherwise normal people
No protrusion of the spinal cord or meninges
Most patients are asymptomatic and no neurologic signs
CM 1- Neural Tube Defects
Occult spinal dysraphism
Involves protrusion of spinal cord and/or meninges through the defect in the vertebral arches
Cutaneous manifestations such as a hemangioma, discoloration of the skin, pit, lump, dermal sinus, or hairy
patch
 Initial screening in the neonate may include ultrasonography.
 MRI– more reliable
Cutaneous lesions associated with OSD
 >50% of dimples diagnosed with OSD
 Imaging Indicating
o Subcutaneous mass or lipoma
o Dermal sinus, hairy patch
o Atypical dimples (deep, >5 mm, >25 mm from anal verge)
o Vascular lesion, e.g., hemangioma or telangiectasia
o Scar-like lesions
o Abnormal gluteal cleft
Dermoid sinus
 Midline defect-closed neural tube defect
 Small skin opening, leads into a narrow duct
 Pass through the dura, acting as a conduit for the spread of infection- Recurrent Meningitis
 Associated with tethered spinal cord syndrome and Diastematomyelia (SC divided into halves by bony or
cartilaginous septum)
Who needs further eval?
 Associated orthopedic findings
 clubfeet , arthrogryposis, hip dislocation, kyphosis or scoliosis
 Abnormal neurological findings
 chronic urinary tract infections
 lower limb deformity (foot drop, talipes equinovarus, dragging one foot)
 bowel/bladder dysfunction
 pain
 lower extremity spasticity or paresis.
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Spina Bifida with Meningcele
The cystic sac contains meninges and CSF
Spinal cord and spinal roots are in their normal position
Spina Bifida with Myelomeningocele
Most common birth defect compatible with life.
More severe than meningocele
More common than meningocele
Spinal cord and/or nerve roots are included in the sac.
Prevalence- approximately 60 per 100,000 births; Prevalences higher among Latino and female offspring.
The causes- both environmental and genetic factors
Exposure to alcohol
Valproic acid, carbamazepine, or isotretinoin
hyperthermia
Malnutrition (especially folate deficiency)
Diabetes and obesity
Myeloschisis
Most severe type of spina bifida
Spinal cord in affected area is open (failure of the neural folds to fuse)
Neonatal open lumbosacral myelomeningocele lesion that is leaking cerebrospinal fluid.
CM 1- Neural Tube Defects
Consequences- Brain abnormalities
 Hydrocephalus occurs in 60% to 95% of children
 more common with higher-level lesions
 Chiari type II malformation
 Agenesis of the corpus callosum
 Other anomalies such as hypoplasia of the cranial nerve nuclei and diffuse microstructural anomalies
o learning disabilities- nonverbal learning disorder
o attention-deficit/hyperactivity disorder (ADHD)
o problems with executive function
 Overall intelligence in the normal range
 Precocious puberty- related to a disorder of the hypothalamus
 Approximately 15% of individuals develop a seizure disorder (epilepsy).
o generalized tonic-clonic
o respond well to antiepileptic medications
o new-onset seizures may occur as a manifestation of shunt infection or, rarely, shunt failure.
Consequences- Spinal Cord abnormalities
 Loss of Sensation
o decubitus ulcers
 Common pressure points include the ischial tuberosities , the coccyx, bony prominences of the
feet and ankles
 may lead to osteomyelitis
o method of promoting healing is to remove the pressure
 Loss of efferent nerve stimuli
o neurogenic bowel and bladder
 Loss of motor function
o Loss of mobility
o musculoskeletal deformities such as flexion contractures or torsion of a bone
o scoliosis and kyphosis
 Loss of efferent fibers in sexually mature males leads to impotence as well as to retrograde ejaculation
CM 1- Neural Tube Defects
Tethered SC
Abnormal attachment of lower end of the SC to surrounding structure (SC in most children who have myelomeningocele
is positioned lower in the spinal column than other individuals)
New onset might be due to increased intracrainial pressure from ventricular shunt failure
o Weakness in lower extremities, deterioration of gait
o Pain in back or legs and local swelling in the back
o Atrophy of muscles in lower extremities
o Sensory loss or change in lower extremities
o Change in deep tendon reflexes
o Change in bowel or bladder function
o New orthopedic contracture, such as pes cavus or foot- or leg-length discrepancy
o Rapidly progressive scoliosis and new decubitus ulcer
Bladder Dysfunction
o Occur in virtually all children who have myelomeningocele
o Categorized as failure to store urine or failure to empty urine
o May be related to the bladder, external sphincter, or both
o Increases the risk of urinary tract infections
o Leads to urinary reflux and hydronephrosis  renal damage and failure over time
o Infection leads to renal damage and failure over time
Renal failure remains a common cause of death in adults born with myelomeningocele
Treatment
o Clean intermittent catheterization (CIC)
o Ultrasonographically at regular intervals
o Cystometrography (urodynamics)
o Vesicostomy- urine to drain directly into the diaper
opening the bladder and sewing on a piece of small intestine- older children and teens
o Regular care from a urologist
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Neurogenic bowel
Constipation and rectal prolapse may occur
o timed toileting
o high in fiber diet
o stool softeners or laxatives
Surgical procedure- the antegrade colonic enema
o daily boluses of liquids are pushed into the colon, evacuating it and preventing fecal incontinence.
In this procedure, a hole is made in the abdominal wall that can be connected directly to a hole in the colon. A
gastrostomy feeding button is placed through the hole on the abdominal wall into the colon, daily
boluses of liquids are pushed into the colon, evacuating it and preventing fecal incontinence.
Latex allergy
 50% of children who have myelomeningocele
o The risk of allergy increases as the child gets older and may be life-threatening
o Avoiding latex-containing products from the time of birth is recommended.
CM 1- Neural Tube Defects
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Prenatal screening
Alpha-fetoprotein
screening at 16 to 18 weeks of gestation
High-resolution ultrasonography
Amniocentesis- AFP and acetylcholinesterase
Chromosomes study
A woman carrying a fetus that has a myelomeningocele should be referred for delivery to a tertiary medical
center that specializes in the care of these children
Newborn Care
Routine care in the delivery room, but the lesion on the back should be protected from contamination
Parenteral antibiotics until surgical closure
o closed surgically within 72 hours
 Neurologically evaluation to determine the level of lesion- U/S or MRI
 Ventricles Shunt- hydrocephalus (think seriously about it!)
 Orthopedic evaluation
 Urologic evaluations- creatinine and BUN, renal U/S, and voiding cystourethrography
Cranial imaging using ultrasonography or MRI is performed to evaluate for hydrocephalus and structural evidence of the
Chiari II anomaly. Daily measuring of head circumference, monitoring of neurologic signs such as irritability,
and repeated cranial imaging are used to guide the management of hydrocephalus. If the cerebral ventricles
are enlarging significantly, surgery to shunt the ventricles is performed. Family support, financial counseling,
and genetic counseling are provided.
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Prevention of NTD
The second most prevalent congenital anomaly in the United States
Substantial morbidity and mortality
Folic acid supplementation and dietary fortification decrease the occurrence and recurrence of these anomalies
Periconceptional folic acid supplementation can prevent 50% or more of NTDs
 Folate is a water-soluble B vitamin (B9) that occurs naturally in foods such as beef liver, leafy green
vegetables, oranges, and legumes, whereas folic acid is the synthetic form of folate that is found in
supplements and added to fortified foods . The bioavailability of folic acid from supplements and folic acid
fortified foods appears to be substantially higher than folate bioavailability from consumption of natural
foods.
 Adequate folate is critical for cell division due to its essential role in the synthesis of nucleic and certain
amino acids. Folate deficiency may impede adequate cell turnover during a critical point in the closure of the
neural tube, thereby resulting in incomplete formation. Genetic etiology — MTHFR and MTHFD1 are key
players in folate metabolism. Polymorphisms of genes for folate-dependent enzymes have been associated
with development of NTDs, as well as some other complex diseases.
AAP, CDC, USPHS Recommendations
All women capable of becoming pregnant consume 400 microgram of folic acid daily
Previous NTD-affected pregnancy, 4000 microgram per day beginning at least 1 month before conception and
continuing through the first trimester