Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month of pregnancy, often before a woman even knows that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly.

1. NEURAL TUBE DEFECTS
SWETAPARNA SUCHISMITA PRADHAN
M.SC NURSING (PAEDIATRIC)

2.  Neural tube defects are birth defects of the brain, spine, or spinal cord. They
happen in the first month of pregnancy, often before a woman even knows that
she is pregnant. The two most common neural tube defects are spina bifida and
anencephaly.
 In spina bifida, the fetal spinal column doesn't close completely. There is usually
nerve damage that causes at least some paralysis of the legs.
 In anencephaly, most of the brain and skull do not develop. Babies with
anencephaly are usually either stillborn or die shortly after birth

3. ETIOLOGY
 The exact cause of neural tube defects are not known.
 Genetic
 Maternal radiation exposures
 Drugs( valproic acid)
 Exposures to radiation
 Nutritional factors
 Environmental factors
 Poor intake of folic acid
 Obsess women
 Intake of antiepileptic medication during pregnancy.
 Getting enough folic acid, a type of B vitamin, before and during pregnancy prevents
most neural tube defects.

5. TYPES OF NEURAL TUBE DEFECTS
 SPINA BIFIDA
 SPINA BIFIDA OCCULTA
 MENINGOMYELOCELE
 ANENCEPHALY
 ENCEPHALOCELE

6. SPINA BIFIDA
 It is the congenital defect of the spinal column due to failure of the fusion of vertebral arches with
or without protrusion of the meninges & dysplasia of the spinal cord.
 It is the malformation of the spine in which the posterior portion of the lamina of the vertebra
fails to close.
 It can be only a small deformed lamina separated by a midline gap or may be a complete
absence of lamina.
 It can be broadly divided in to two groups
 SPINA BIFIDA OCCULTA
 SPINA BIFIDA CYSTICA( commonly found as meningocele & meningomyelocele)

7. SPINA BIFIDA OCCULTA
 Spina bifida occulta is the mildest type of spina bifida.It is somethings called ‘’hidden’ ’spina bifida.
With it, there is a small gap in the spine ,but no opening or sac on the back. The spinal cord & the
nerve usually are normal.
 It occur due to defective closure of the posterior arch and laminae of the vertebra , usually L5 &
S1.
 Some children present with cutaneous lesions over the defect ,as tuff of hairs ,nerves , lipoma ,dermal
sinus or as dimple in the skin.
 There may be intraspinal lesions like dermoid cyst, intramedullary lipoma etc. which produce
neurological defect.
 The symptomatic children usually present after 6 to 8 yrs. of age.
 Progressive deformity of the foot
 Changes in micturition pattern
 Alternation in the gait
 Tropic ulcers on the toes & feet
Operation can be done even before neurological deficit appears in selected cases.
Mylo – CT scan & MRI help to confirm the diagnosis before operation.

8. MENINGOCELE(Only involvement of Meninges)
 A meningocele is a birth defect where there is a sac protruding from the spinal column. The sac
includes spinal fluid, but does not contain neural tissue. It may be covered with skin or with meninges
membranes that cover the central nervous system). The sac often is visible from the outside of the back.
 Commonly located in the lumbosacral region in the vertebral arches.
 It may also be found in the thoracic region & in the skull ( cranial meningocele).
 The sac of the meningocele consist of both arachnoid & Dural meninges & contains cerebrospinal fluid.
 There is no dysplasia of the spinal cord & the child may found asymptomatic.
 Symptomatic child may present weakness of the legs or lack of sphincter control.
 As the skin or membranes covering is thin,CSF leakage may present & there is chance of infection.

9.  Head circumference should be measured daily & anterior fontanel to be checked for bulging or
widening .These help to detect the development of hydrocephalus.
 The meningocele sac should be protected from the infection & injury. If the sac is not covered with the
skin .It should be protected with the sterile moist dressing .
 x-ray ,spine & skull ,CT scan can be done to determine the defect & associated the anomalies.
 Surgical closure of the sac should be done as early as possible to provide infection.

10. MENINGOMYELOCELE(MYELOMENINGOCELE)
 Meningomyelocoele occurs due to Failure of closure of the neural tube during the third week of
gestation.
 abnormal differentiation of the embryonic neural tube.
 In Meningomyelocoele, a cystic swelling occurs over the site of the spinal defect which contains
meninges, nerve roots, and the spinal cord itself which has left the vertebral canal .
 Most common site of lumbosacral area.
 It can be found in 2 types
 1) Myelocele ( open type)
 2) Myelomeningocele ( close type)
 Postural abnormalities like club foot , subluxation of hips may present. Spasticity & hyperactive reflexes may
present in thoracic or cervical mylomen.
 Musculoskeletal deformity & hydrosyringomyelia may occur in neonates.
 Later contractures of joints, scoliosis & Kyphosis may develop.
 Risk of infection of CNS & rupture of sac.

11. ETIOLOGY
 Poor nutrition - Folic acid deficiency .
 Genetics
 Chromosome abnormalities: – Trisomy's 13 and 18 – Triploidy – Single gene mutations
 Maternal obesity, hyperthermia
 pregnancies complicated by diabetes at conception
 Drugs: valproate, carbamazepine and drugs to induce ovulation
 Maternal exposures to fumonisins, electromagnetic fields, hazardous waste sites, disinfection by-
products found in drinking water and pesticides.
 DIAGNOSIS
 X-ray, CT scan, MRI & complete neurological assessment.
 Routine blood & urine examination
 Prenatal diagnosis can be amniocentesis & estimation of alpha fetoprotein .

12.  MANAGEMENT
 Surgical correction of defect & essential care.
 Correction of musculoskeletal deformities & regulation of bowel & bladder function.
 Prevention of injury & infection of the sac by appropriate positioning & protecting covering.
 Monitoring vital sign
 Monitoring of sign of hydrocephalus (HC ,frontanel,feeding behavior).
 Adequate nutrition & prevention of leg or hip deformities & other complications. Perioperative
care, promotion of growth & development ,emotional & psychological support ,heath
regarding care of the child.

15. ANENCEPHALY
 Congenital absence of cranial vault with the cerebral hemisphere completely missing or
reduced to small masses.
 This condition is incompatible with life ,death usually occurs with a week or two of birth.

16. ENCEPHALOCELE
 It is sac like protrusion of meninges with brain substance ( cerebral cortex, cerebellum, or part of
brainstem )herniating through a congenital bony detect in skull.
 Commonly found in midline & in the occipital or parietal area & also found on frontal bone ,in the orbit or
in the nose.
 The size may vary from small to as big as size of head.
 Survival child may suffers hydrocephalus ,visual problem ,seizures,microcephalaly & mental retardation.
 Associated congenital anomalies are usually present i.e. cleft lip & palate, abnormal genitalia,congenital
nephrosis.
DIAGNOSIS:-
 Prenatal diagnosis ( alpha fetoprotein,USG),Postnatal period (X-ray & CT scan)
MANAGMENT:-
Surgical repair of the defect.
Hydrocephalus can be treated with shunt.
Prevention of infection & injury.
Outcome depends upon the extent & location of encephalocele with available treatment facilities.

17. ENCEPHALOCELE