Prevalence:

• 1 in 5,000 births.

Ultrasound diagnosis:

• Cranial bone defect with herniated fluid-filled or brain-filled cyst.
• Usually occipital (85%), but can be parietal (15%) and rarely frontal.

Associated abnormalities:

• Chromosomal defects, mainly trisomies 13 or 18, are found in about 10% of cases.
• Cerebral and non-cerebral defects and genetic syndromes are found in >60% of cases. The most common genetic syndromes are: Meckel-Gruber syndrome (autosomal recessive; polydactyly, multicystic kidneys, occipital cephalocele), Walker-Warburg syndrome (autosomal recessive; type II lissencephaly, agenesis of corpus callosum, cerebellar malformations, cataract) and amniotic band syndrome (sporadic; single or multiple abnormalities of the extremities, craniofacial region and trunk due to the presence of amniotic bands).

Investigations:

• Detailed ultrasound examination.
• Invasive testing for karyotyping and array.

Follow up:

• Follow-up should be standard.

Delivery:

• Place: hospital with neonatal intensive care and pediatric neurosurgery.
• Time: 38 weeks.
• Method: cesarean section at 38 weeks to avoid trauma to the exposed brain tissue.

Prognosis:

• Depends on the size, content and location of the encephalocele.
• Mortality for posterior encephalocele is >50% and for posterior meningocele and anterior encephalocele is about 20%.
• Neurological handicap in >50% of survivors.

Recurrence:

• Isolated: 3-5%.
• Part of trisomies: 1%.
• Part of an autosomal recessive conditions: 25%.