Encephalocele is a very rare birth defect in which a problem with fetal development causes part of the brain to herniate through the skull. This condition is classified as a neural tube defect, because it involves a problem with the development of the neural tube, the fetal structure which eventually develops into the brain, spinal cord, and associated skeletal material. The severity of an encephalocele can vary considerably, as can the prognosis. Around half of infants born with this condition die shortly after birth because the defect is so severe.
Thanks to the widespread use of prenatal ultrasound, encephalocele is often diagnosed during pregnancy, because the defect can be readily visible on an ultrasound. If a fetus appears to have encephalocele, a doctor may recommend more medical imaging studies such as a fetal MRI to learn more about the severity of this condition and to develop a treatment plan. Usually, this condition does not impact the course of the pregnancy, although a doctor may recommend a Cesarean section for delivery to avoid trauma to the herniated brain tissue.
An estimated 80% of fetuses with encephalocele die before delivery because the defect is so severe that it is incompatible with life. The treatment for patients who survive with this condition is surgery shortly after birth to correct the defect and repair the skull to prevent future herniation. The best prognosis is for patients who have encephalocele in the front of the skull, while patients with herniation at the back of the skull may experience severe developmental delays, quadriplegia, and other problems as a result of brain abnormalities.
Sometimes, a very mild encephalocele goes undiagnosed during pregnancy and is not noticed after birth because it is so subtle. In these cases, parents may notice developmental delays or the development of facial abnormalities, and a doctor may diagnose encephalocele after a thorough examination. Treatment for these infants and children also usually involves surgery to correct the condition before it becomes worse.
The causes of encephalocele are not fully understood. There appears to be a genetic link, as with many neural tube defects, but sometimes there is no clear genetic connection. Parents who receive a diagnosis of encephalocele should not blame themselves or wonder if they could have done something different, and instead focus on the care they can offer to their infant. It can help to consult a genetic counselor after a diagnosis to receive tests which may reveal a genetic predisposition for neural tube defects, as this information could be of use to parents who plan on future pregnancies.