An encephalocele is a congenital neural tube birth defect that occurs when the tissue covering the brain and a portion of the brain itself stick out through an opening in the skull. This forms a skin-covered sac outside the skull. This sac is typically covered by skin, although in some cases it is only covered by a thin membrane, making it more vulnerable to injury and infection.
At UPMC, treatment is surgical and usually performed shortly after birth. Our neurosurgeons specialize in skull base and pediatric neurosurgery, using advanced minimally invasive techniques when possible to repair the skull, reposition viable brain tissue, and optimize neurological outcomes.
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What Is Encephalocele?
Encephaloceles occur when the neural tube fails to close completely during fetal development, leaving a skull defect. This forms a skin-covered sac outside the skull.
Less frequently, only a thin membrane covers the sac, increasing its vulnerability.
The contents of the sac can vary, and may include:
- Blood vessels.
- Meninges (the protective coverings of the brain).
- Neural tissue (brain tissue).
The exact contents vary with size and location. Some infants may have only fluid and meninges in the sac, while others may have more extensive brain tissue involvement.
What are the types of encephalocele?
Encephaloceles are classified by location. Anterior encephaloceles occur in the front of the head, and posterior encephaloceles occur in the back of the head.
Types of encephaloceles include:
- Frontoethmoidal (sincipital) — Located near the forehead and nose, often associated with facial deformities.
- Occipital — At the back of the head, the most common type in Western countries.
- Parietal — Located in the top back of the head. This type is less common.
- Sphenoidal — Near the skull base, behind the eyes, and in front of the ears.
How common is encephalocele?
According to the U.S. Centers for Disease Control and Prevention (CDC), encephaloceles occur in about 1 in 10,000 live births in the U.S. They account for 10% to 20% of all cranial neural tube defects. Prevalence varies by geographic region and maternal health factors.
What causes encephalocele?
Encephaloceles are neural tube defects, and their exact cause is not fully understood.
Factors may include:
- Environmental exposures (high maternal fever, teratogens, hot tub/sauna use during pregnancy).
- Family history of neural tube defects.
- Folate deficiency before and during early pregnancy.
- Genetic predisposition.
- Use of antiseizure medications during pregnancy.
Most cases are sporadic, though some syndromic associations exist, such as in Meckel-Gruber syndrome.
Encephalocele risk factors
Risk factors for encephalocele include:
- Becoming too hot during pregnancy, which can be caused by hot tub use or having a high fever.
- Lack of folic acid before and during pregnancy.
- Personal or family history of neural tube defects.
- Taking antiseizure medications during pregnancy.
Complications of encephalocele
Even with surgical treatment, children with encephaloceles may face complications, including:
- Hydrocephalus.
- Developmental or intellectual delays.
- Vision or craniofacial abnormalities.
- Motor impairments.
A child's prognosis is strongly influenced by encephalocele size, location, and how much brain tissue is involved.
How can I prevent encephalocele?
You may not be able to prevent encephalocele. However, ensuring that you are getting plenty of folic acid during early pregnancy may reduce your child’s risk of developing encephalocele.
What Are the Signs and Symptoms of Encephalocele?
The main symptom of encephalocele is a sac of brain tissue that sticks out of an opening in a newborn’s skull. In some cases, this can cause fluid buildup in the brain (hydrocephalus).
Other symptoms may include:
- A smaller-sized head at birth (microcephaly).
- Facial malformations.
- Headaches (in older children).
- Nasal blockage or cerebrospinal fluid (CSF) leakage from the nose or ear.
- Vision problems or ataxia (unsteady movements).
- Weakness or coordination difficulties.
How Do You Diagnose Encephalocele?
Encephalocele is often diagnosed during a routine prenatal ultrasound and is confirmed after your baby is born.
Tests to diagnose encephalocele
Tests to diagnose encephalocele include:
- Prenatal ultrasound — Common screening tool that can show cranial defects.
- Prenatal magnetic resonance imaging (MRI) — Provides more detailed information about brain tissue involvement and associated abnormalities.
- Genetic testing — May be offered if other congenital anomalies are suspected.
After birth, MRI and CT scans help define the lesion's size, contents, and surgical planning needs. An audiogram and ophthalmologic exam also may be performed, depending on location.
Encephalocele prognosis
Can a baby survive with an encephalocele?
Survival and developmental outcomes depend on size, location, and contents of the encephalocele.
- Babies with small anterior encephaloceles and minimal brain tissue involvement often do well after surgery.
- Large occipital encephaloceles containing significant brain tissue are associated with higher mortality and neurological deficits.
Ongoing rehabilitation, physical therapy, and special education support may be required for long-term development.
What is the survival rate for encephalocele?
The overall survival rate is around 55% to 70% for large encephaloceles; it is higher for smaller, surgically corrected lesions.
How Do You Treat Encephalocele?
Encephaloceles require surgical treatment soon after birth to repair the skull and remove or replace brain tissue that developed outside the skull. Timing may vary depending on the infant's condition. Complete treatment often requires multiple surgeries.
Surgery involves:
- Removing nonfunctional brain tissue in the sac.
- Reconstructing the skull defect to protect the brain.
- Preserving and repositioning viable neural tissue.
Hydrocephalus, if present, may require placement of a ventriculoperitoneal (VP) shunt. Craniofacial reconstruction also may be performed for associated deformities.
Why Choose UPMC for Encephalocele Care?
When you choose UPMC for encephalocele care, you will receive:
- Access to world-class neurosurgery expertise —Our world-renowned experts treat the full spectrum of skull base and neurosurgical conditions using the latest diagnostic and treatment techniques.
- A full range of treatment options — We offer nonsurgical care and noninvasive, minimally invasive, and traditional open surgical procedures. This allows us to effectively treat all types of disorders while reducing your risk of complications.
- Multidisciplinary care — Our neurosurgeons partner with neurologists, rehabilitation specialists, and other medical experts to provide complete care that optimizes your recovery and quality of life.
