An encephalocele is a very rare congenital defect in which nervous tissue protrudes through openings in the skull, resulting in a skin-covered sac outside the skull. Less frequently, the sac may be covered only by a membrane, increasing its vulnerability. The contents of the sac can vary, and may include meninges (the membranes that surround the central nervous system), blood vessels, and neural tissue from the underlying area of the brain. Encephaloceles typically can be seen during a prenatal ultrasound or at birth.
The prognosis for this condition depends upon the location of the sac and its contents, with the outlook being most favorable when no functional neural tissue is contained in the sac.
The preferred surgical approach at UPMC for encephaloceles of the skull base is the Endoscopic Endonasal Approach (EEA). This innovative, minimally invasive technique uses the nose and nasal cavities as natural corridors to access hard-to-reach or previously inoperable tumors. EEA offers the benefits of no incisions to heal, no disfigurement to the patient, and a faster recovery time. If complementary treatments, such as radiation therapy, are needed, those therapies can begin soon after surgery.
Ultrasound images of the fetus can reveal the presence of a herniated, fluid-filled sac outside the skull. Other developmental anomalies usually accompany encephalocele, so a positive diagnosis should be followed by a search for other conditions or abnormalities, such as hydrocephalus, microcephaly (abnormally small head), and paralysis. Encephaloceles that go undetected during gestation usually are diagnosed at birth by observation of the deformity.
In rare cases, a small encephalocele in the nasal cavity can remain undetected for years, even into adulthood.
An MRI is the preferred test to identify the contents of the encephalocele, which is essential for determining the best treatment process.
Surgery to remove the herniated tissue and repair the opening in the skull is the only treatment. If the encephalocele is covered by normal skin rather than a thin membrane, surgery may be postponed until the child is older. In most cases, any neural tissue contained in the sac is abnormal and is removed. However, if healthy neural tissue is present in the sac, one of the goals of surgery is to preserve it.
The surgical approach depends upon the location and contents of the encephalocele. If the sac does not contain vital nervous tissue, the encephalocele is simply removed and the opening in the skull is repaired. Encephaloceles of the skull base can be directly approached through the Endoscopic Endonasal Approach (EEA). This state-of-the-art, minimally invasive surgical procedure uses the nose as a natural corridor to reach and remove these lesions. There are no incisions in the face or skull.
At UPMC, we take a 360° Approach to treatment when evaluating each patient—looking at their conditions from every direction—to find the path that is least disruptive to the patient's brain, critical nerves, and ability to return to normal functioning. Our neurosurgical team may recommend a combination of surgical and non-surgical approaches to maximize the benefits of surgery while minimizing risks.
