An encephalocele is when part of the fetal brain pokes out of a hole in the fetal skull in a sac. How much and what kind of tissue pokes out is different in each case, and what that means for the fetus will be determined via special imaging studies, such as MRI. This rare defect is caused by failure of the neural tube to close completely. It often occurs in families with a history of spina bifida and anencephaly.
Surgery can be performed during infancy to put the protruding tissues back into the skull, and some affected children may have normal intelligence. Prognosis varies between individuals depending on what kind of brain tissue is affected, the location of the sacs and any accompanying brain malformations.