Encephalocele is aneural tube defect characterized by sac-like protrusions of thebrain and themembranes that cover it through openings in theskull. These defects are caused by failure of the neural tube to close completely during fetal development. Encephaloceles cause a groove down the middle of the skull, or between the forehead and nose, or on the back side of the skull. The severity of encephalocele varies, depending on its location.[1]
Encephaloceles are often accompanied bycraniofacial abnormalities or other brain malformations. Symptoms may include neurologic problems,hydrocephalus (cerebrospinal fluid accumulated in the brain),spastic quadriplegia (paralysis of the limbs),microcephaly (an abnormally small head),ataxia (uncoordinated muscle movement), developmental delay, vision problems, mental and growth retardation, and seizures.[citation needed]
A neonate with a large encephalocele.
Encephalocele on the head of a two-year-old.
Baby with encephalocele.
Encephalocele.
Neonate with encephalocele
1-year-old with encephalocele and possible microcephaly, 1928
16-year-old hydrocephalic female patient with occipital encephalocele, 1917
Since its earliest cited case in the 16th century, many generations of scientists have attempted to explain the cause.[2] Little has been revealed in the centuries to follow. Although the exact cause is unknown, encephaloceles are caused by failure of the neural tube to close completely during fetal development. Both environmental and genetic factors have been seen to contribute to the cause of encephaloceles.[3] Some studies have revealed a higher occurrence in female embryos, suggesting a genetic cause.[4] Research has indicated thatteratogens (substances known to cause birth defects),trypan blue (a stain used to color dead tissues or cells blue), andarsenic may damage the developingfetus and cause encephaloceles.[citation needed]
Proper levels offolic acid have been shown to help prevent such defects when taken before pregnancy, and early in pregnancy.[citation needed]
Occipital encephaloceles are frequently accompanied byhydrocephalus, as seen in 60-90% of patients.[5]
Usually encephaloceles are noticeable deformities and are diagnosed immediately after birth, but a small encephalocele in the nasal or forehead region can go undetected. Various physical and mentaldevelopmental delays can indicate the presence of encephaloceles.[citation needed]
Encephaloceles of the face are generally classified as nasofrontal, nasoethmoidal, or naso-orbital, however, there can be some overlap in the type of encephalocele. They can also appear along any part of the cranial vault, as they result from abnormal closure of cranial bones; the most common location for encephaloceles is the occipital region. If the bulging portion contains onlycerebrospinal fluid and the overlying membrane, it may be called ameningocele. If brain tissue is present, it may be referred to as a meningoencephalocele.[6] When the head size or occipitofrontal circumference is smaller than the herniating sac, then it is termed as giant encephalocele.[7]
Separation of the neural and surface ectoderm causes apoptosis in the midline. A disturbance in this separation process at the final closure due to the lack of apoptosis is considered to be a critical aspect of nasofrontal and nasoethmoidal encephalocele.[8]
It is recommended that women take a multivitamin with 400 micrograms of folic acid daily to reduce the likelihood of any type of neural tube defects before and during the first 28 days after conception.[9]
A series of steps involved in reconstructive surgery of a frontal encephalocele. The same child is in all the images.
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Currently, the only effective treatment for encephaloceles is reparative surgery, generally performed duringinfancy. The extent to which it can be corrected depends on the location and size of the encephaloceles; however, large protrusions can be removed without causing major disability. Surgery repositions the bulging area back into the skull, removes the protrusions, and corrects the deformities, typically relieving pressure that can delay normal brain development. Occasionally,shunts are placed to drain excess cerebrospinal fluid from the brain.[citation needed]
The goals of treatment include:
closure of open skin defects to prevent infection anddesiccation of brain tissue
removal of nonfunctional extracranial cerebral tissue with water-tight closure of thedura
total craniofacial reconstruction with particular emphasis on avoiding the long-nose deformity (nasal elongation that results from depression of thecribiform plate andnasal placode). Without proper management, the long-nose deformity can be more obvious after repair.[10]
Recovery is difficult to predict prior to surgery, and depends on the type of brain tissue involved and location of the encephaloceles. If surgery is successful, and developmental delays have not occurred, a patient can develop normally. Whereneurologic and developmental damage has occurred, the specialists will focus on minimizing both mental and physical disabilities.[citation needed]
In general, when the bulging material consists of primarily cerebrospinal fluid, a complete recovery can occur. When a large amount of brain tissue is present in the encephaloceles, there is a higher chance of perioperative complication.[citation needed]
Encephaloceles occur rarely, at a rate of one per 5,000 live births worldwide. Encephaloceles of the back of the head are more common in Europe and North America, while encephaloceles on the front of the head more frequently occur in Southeast Asia, Africa, Malaysia, and Russia. Ethnic, genetic, and environmental factors, as well as parental age, can all affect the likelihood of encephaloceles. The condition can occur in families with a family history ofspina bifida.[11]
The Facemakers:Operation Smile is a documentary co-produced by theDiscovery Channel andBBC 1 in conjunction withcentury films aired on 21 June 2000.[12] The Facemakers documents the remarkable changes that occurred in the lives of three children as a result of Operation Smile's visit toDavao City in thePhilippines in 1999. One child in particular, Abel Gastardo, had a condition too severe to be treated during the time of the mission. Abel had a rare nasofrontal facial encephalocele, an extreme protrusion of brain tissue from the front of his skull. The documentary follows Abel to theUnited States seven months later to receive corrective surgery. He was brought over by Operation Smile to receive the major surgery inVirginia, at theChildren's Hospital of the King's Daughters. The other facial defects within the fifty-minute programme consisted of children withfacial cleft andcleft lip and palate which may be associated with encephalocele.[13]
In November 2006, there was an hour-long documentary on theBritish television networkChannel 4 aboutFacing the World, an organization that helps children with severe facial disfigurements in developing countries. One of the children featured on the documentary was Ney, aCambodian boy who had a severe form of encephalocele, wherein part of his brain protruded through his face.[citation needed]
On December 4, 2012, Dr. Meara again led a cranio-facial surgical team to remove the encephalocele of an infant, Dominic Gundrum, the son of aWisconsin Court of Appeals judge and his wife. The surgery also closed the baby's skull, repaired a Tessier facial cleft, and brought the baby's facial features together.[14]
