Summary

• A spectrum of birth defects that result from abnormal neurulation during the first 4 weeks of embryogenesis. Caused by interaction of genetic and environmental factors. Preventable with maternal folate supplementation or fortification.
• Can affect the brain (anencephaly, encephalocoele) or any level of the spinal axis, although most commonly involves the lumbosacral region. Not to be confused with spina bifida occulta, which affects the vertebral arches only and is a clinically insignificant radiological finding in 10% of the general population.
• Defects of the spinal cord are classified as open if both the spine and the meninges are affected (myelomeningocoele) or closed if involving meninges only (meningocoele), fatty tumours within the spine (lipomeningocoele), or intraspinal cartilage or bone (diastematomyelia).
• Results in variable paralysis and sensory loss in the legs, orthopaedic deformities, scoliosis, neurogenic bowel and bladder, hydrocephalus, and Chiari II malformation. Often associated with non-verbal learning disability and executive dysfunction, although intelligence is typically not impaired.
• Most neural tube defects are detected antenatally on ultrasound or clinically at birth.
• Treatment involves repair of the defect within 1 to 3 days of delivery and a multidisciplinary approach to care across the life span.