Meningoencephalocele involves a sac of fluid and brain tissues, specifically the meninges, protruding from a newborn’s head. Meningoencephalocele is a type of encephalocele. Encephalocele occurs when the brain and spinal cord do not fully develop before birth. This can result in either the brain tissue, protective membranes of the brain, or protective fluid surrounding the brain and spinal cord being enveloped in a sac outside the head. In meningoencephalocele, it can result in all three being enveloped in a sac outside of the head. The sac most commonly forms at the back of the head, the forehead, or between the forehead and the nose.
Meningoencephalocele specifically involves the meninges being included in this protrusion of tissue. The meninges are the three protective covers surrounding the brain and the spinal cord. Meningoencephalocele most commonly occurs between the forehead and the nose or at the back of the head.
Meningoencephalocele is very rare.
Common symptoms of meningoencephalocele include:
Sometimes, meningoencephalocele will be detected at a routine ultrasound. However, the first time meningoencephalocele is visible and the first time the baby and parents have to deal with any of these symptoms may be right after birth.
Meningoencephalocele is what is known as a neural tube defect. The neural tube is a small channel that closes around the 3rd or 4th week of pregnancy to form what will become the brain and spinal cord. If the neural tube does not close all of the way, the brain and spinal cord cannot form properly. Other neural tube defect disorders include spina bifida.
It’s uncertain what causes neural tube defects at all. However, there are a few known risk factors.
Genetics plays a part in meningoencephalocele. Babies who are related to people with neural tube defects are more likely to have neural tube defects themselves, including meningoencephalocele. Other risk factors include the mother’s exposure to toxic chemicals during pregnancy and the mother having diabetes while pregnant. Research also shows that premature babies, babies with multiple birth defects, and Black children are more likely to have meningoencephalocele.
While these risk factors are associated with meningoencephalocele, it is an extremely rare disease. More research is needed into what causes it and what puts a foetus at risk for developing meningoencephalocele.
Meningoencephalocele will either be diagnosed during or after pregnancy. If it shows up on a foetal ultrasound, a doctor may perform magnetic resonance imaging (MRI) on the foetus to get a better image of the organs and brain of the foetus. They may also perform a foetal echocardiogram to examine the heart closely. These tests will help confirm a diagnosis in utero and give the parents a better idea of what to expect when the baby is born.
Other testing may include foetal DNA testing, amniocentesis, and chromosomal studies once the baby is born. Amniocentesis is a routine procedure that many mothers elect to have done in the second trimester. During amniocentesis, a sample of the amniotic fluid is taken to look for any genetic abnormalities in the foetal DNA.
Sometimes, neural tube defects are caused by defects in the chromosomes. After the baby is born, a blood sample might be taken so that a doctor can examine the chromosomes for any abnormalities.
The only complication of meningoencephalocele is stillbirth. Parents and patients with meningoencephalocele can expect less severe symptoms if the meningoencephalocele is on the front of the head, between the forehead and the nose, than if it’s on the back of the head.
Treatment for meningoencephalocele depends on the severity of the symptoms and what the long-term prognosis looks like for the baby. Surgery is often required. Many parents and care providers create long-term treatment plans to ensure optimal quality of life for the child. Others opt for providing the best quality of life for their child for as long as he or she lives. It’s a highly personal choice that can be discussed with a doctor.