- 1 in 5,000 births.
- Cranial bone defect with herniated fluid-filled or brain-filled cyst.
- Usually occipital (85%), but can be parietal (15%) and rarely frontal.
- 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).
- Detailed ultrasound examination.
- Invasive testing for karyotyping and array.
- Follow-up should be standard.
- 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.
- 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.
- Isolated: 3-5%.
- Part of trisomies: 1%.
- Part of an autosomal recessive conditions: 25%.