An encephalocele is a protrusion of nervous tissue and meninges through a skull defect. Many can be repaired surgically.
An encephalocele is caused by incomplete closure of the cranial vault (cranium bifidum).
Encephaloceles usually occur in the midline and protrude anywhere along a line from the occiput to the nasal passages but can be present asymmetrically in the frontal or parietal regions.
Encephaloceles may also occur internally, eg, at the anterior pole of the temporal lobe, and may be discovered only later in life during evaluation for associated neurodevelopmental symptoms such as epilepsy.
About 50% of affected infants have other congenital anomalies. Hydrocephalus often occurs with encephalocele.
DR M.A. ANSARY/SCIENCE PHOTO LIBRARY
Symptoms and Signs of Encephalocele
Symptoms and signs of encephalocele include the visible defect, seizures, and impaired cognition, including intellectual and developmental disability.
Diagnosis of Encephalocele
Prenatal ultrasonography
Diagnosis of encephalocele may be made by routine prenatal ultrasonography.
Small encephaloceles may resemble cephalohematomas, but x-rays show a bony skull defect at the base of the encephalocele.
Treatment of Encephalocele
Surgical repair
Most encephaloceles can be repaired. Even large ones often contain mostly heterotopic nervous tissue, which can be removed without worsening functional ability.
When other serious physical malformations coexist, the decision to repair may be more difficult. Neurodevelopmental symptoms that result from an encephalocele often persist even after its surgical removal because the normal developmental sequence of brain structure and neural network formation was disrupted.
Prognosis for Encephalocele
Prognosis depends on the location and size of the lesion.