Please note that some guidelines may be past their review date. The review process is currently paused. It is recommended that you also refer to more contemporaneous evidence.
The neural tube normally closes between 15 and 28 days after conception, failure of closure results in a neural tube defect (NTD). A meningomyelocele is the most common NTD. It is a sac-like structure protruding through a defect in the vertebral arches, containing meninges, CSF and spinal cord +/- nerve roots.
Detection and referral
Some points to note about detection and referral for neural tube defects:
- The detection of neural tube defects frequently occurs before birth as a result of maternal alpha-fetoprotein measurement or ultrasound examination.
- Referral to a multidisciplinary team for family counselling and management plan development is then appropriate.
- Genetics Health Services Victoria provides services throughout Victoria and can be contacted via (03) 8341 6201.
- Occasionally affected infants will deliver unexpectedly.
Prognosis
Prognosis for survival and extent of the disability depends on:
- the level of the lesion
- the degree of involvement of the spinal cord fibres
- presence of infection
- the presence of associated anomalies:
- central nervous system (such as hydrocephalus and Arnold-Chiari malformation)
- cardiac
- oesophageal
- intestinal
- genitourinary.
Differential diagnosis
Meningocele
Differential diagnosis includes:
- Herniation of meninges without associated neural tissue through the bony defect.
- Following surgical repair there is a good prognosis.
- Diagnosis is made by appropriate imaging studies (for example, ultrasound).
Investigation
Detailed clinical examination is required to assess:
- site and level of lesion
- motor and sensory level involvement
- presence of clinical hydrocephalus:
- palpate the fontanelle/sutures for evidence of raised intracranial pressure
- symptoms of hindbrain herniation:
- presence of musculoskeletal deformity or anomalies of other organ systems:
- assess anal tone
- urine output
- dribbling
- palpable bladder.
Further investigations (undertaken at tertiary centre)
- Neurosurgical assessment
- MRI brain and spine
- Sequential OFC measurements and cranial USS
- Renal tract assessment
- Renal tract USS
- Urine MCS
- Urology consultation, need for clean intermittent catheterisation
- Orthopedic assessment
- Hip USS
- Microarray
Management
Management issues include:
- Infants need referral and transport to a tertiary neonatal centre for assessment by a coordinated team of specialists experienced in dealing with these lesions.
- A treatment policy can be formulated and discussed with the parents.
- Before and during transport:
- the lesion, especially if ruptured, should be covered with a sterile non-adherent dressing such as cling wrap
- the infant should be nursed in the prone position and the defect protected, for example, by foam rubber cut into a doughnut
- IV access is required to provide antibiotics such as penicillin and gentamicin (preferably after blood is taken for culture).
- IV fluids are required if an excessive delay before oral feeds can commence is anticipated, respiratory difficulty or hypoglycaemia is present.
- In some infants, intermittent urinary catheterisations may be required.
- Multidisciplinary follow up is required.
Areas of uncertainty in clinical practice
Intrauterine surgery to close the defect has been associated with reduction of shunt dependent hydrocephalus and long-term neurological complications.
Caesarean section before the onset of labour is often the desired mode of birth since this has been associated with improved neurological outcomes.
More information
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References
- Ellenborgen R.G., Neural tube defects in the neonatal period eMedicine Journal, July 3 2001, Vol.2, No. 7
- Merrill DC, et al, The optimal route of delivery for fetal meningomyelocele, Am J Obstet Gynecol. 1998 Jul;179 (1):235-40.
- First World Congress on Spina Bifida Research (2009) Conference papers
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Version history
First published: February 2015
Review by: February 2018