Encephalocele

Encephalocele is a neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull. 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. Encephaloceles are often accompanied by craniofacial 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. File:Encephalocele of a newborn.JPG|A neonate with a large encephalocele. File:Encephalocele2.jpg|Encephalocele on the head of a two-year-old. File:Baby with encephalocele.jpg|Baby with encephalocele. File:Encephalocele picture.jpg|Encephalocele. File:A neonate with a large encephalocele.jpg|Neonate with encephalocele File:Congenital tumour.jpg|1-year-old with encephalocele and possible microcephaly, 1928 Since its earliest cited case in the 16th century, many generations of scientists have attempted to explain the cause. 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. Some studies have revealed a higher occurrence in female embryos, suggesting a genetic cause. Research has indicated that teratogens (substances known to cause birth defects), trypan blue (a stain used to color dead tissues or cells blue), and arsenic may damage the developing fetus and cause encephaloceles.