Encephalocele: types, causes, symptoms and treatment

The skull is a bony structure that protects our brain very effectively from blows and various injuries, in addition to allowing the brain to have a defined structure. The formation of the neural tube assembly It takes place during the first month of fetal development, closing between the third and fourth week and allowing the brain to be protected by said bone cover.

However, in some cases the neural tube does not finish closing correctly, which can cause part of the material that should be protected is visible and accessible from the outside or protrudes from what should be its protective cover. Is about problems such as spina bifida or, in the case of the brain, encephalocele.

• Related article: "Spina bifida: types, causes and treatment"

What is an encephalocele?

Encephalocele is defined as a congenital malformation in which the skull does not completely close during fetal development, which causes part of the matter and substances that generally would be inside the cranial cavity protrude through the opening, forming a bulge or sac-like protrusion that contains it in the abroad.

This means that the individual with encephalocele may have part of the brain displaced to the outside of the skull, which implies a high level of danger for their survival due to possible injuries at the neuronal level. In fact, in many cases the fetus does not survive this situation, dying during the development process.

The symptoms that this problem will cause in the baby will vary enormously depending on the type of tissue that is outside the skull and the area in which the opening in question is located.

Generally, encephaloceles present with cognitive impairment significant and developmental delay, hydrocephalus and microcephaly (since part of the neural material expands on the outside), motor incoordination in the voluntary muscles. It can also cause vision, hearing and smell problems, or even seizures.

Types of encephalocele

Encephalocele can be subdivided into different typologies according to the area in which the protrusion appears or according to the type of material that forms part of it.

Types according to the location of the protrusion

The protrusion can be located in different parts of the skull, although it is common in the three areas indicated below.

1. frontal region

In this area the opening can be found at different heights, including the nose, eye socket or forehead. Mostly the sac does not usually include brain tissue, so that it is one of the subtypes with the lowest risk of nerve damage. However, it can cause significant visual and respiratory difficulties that can endanger the life of the minor.

2. parietal region

In the parietal areas, the encephalocele tends to be linked to other malformations and neurological disorders, presenting almost half of the cases intellectual disability. In addition, speech may be affected.

3. occipital region

It is the most common type of encephalocele..

In this case, a large proportion of those affected have normal intelligence or mild disability, although it is much more likely that neuronal material will protrude than in the case of a frontal opening. Visual problems are common. It can also occur in the basal part of the skull.

Types according to the protruded material

Another classification could be made taking into account the type of material that protrudes from the skull. In this sense we can find different types, such as the following.

1. meningocele

In this subtype of encephalocele, only the meninges, so that the risk is much lower than in other cases.

2. hydroencephalocele

The protruding material is made up of the meninges and brain ventricles, which is more serious than in the previous case and often associated with the presence of hydrocephalus.

3. encephalomeningocele

In this case, in addition to the meninges also protrudes brain matter, which causes a greater risk of neuronal damage and the presence of diverse and more serious symptoms.

4. Hydroencephalomeningocele

Part of the brain including ventricles protrude out of the cranial cavity along with the meninges, in the case of an affectation that can be very severe.

What causes it?

The causes of this alteration are, as occurs with spina bifida, a poor closure or the absence of it in the neural tube during the first month of development. In fact, the encephalocele sometimes has been referred to as a "bifid skull", considering the same type of malformation as spina bifida, although at the cranial level. And as with this other disorder, the specific causes that cause the neural tube to fail to close properly during fetal development are largely unknown.

Despite this, it is considered that there is a link with low levels of folic acid during pregnancy (this being one of the factors most related to this disease), serious infections in the mother or the presence of high fever in this period or the consumption of substances. Although the possibility of genetic influence is also adduced, since families in which it has occurred previously may present a greater risk, this is not decisive.

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Treatment of encephalocele

Although the neurological consequences that the state of the baby has caused during its development are not curable, prevention and early treatment they can help improve their situation and prevent further neuronal damage.

For this, surgery is used in order to relocate the protruded matter inside the skull and seal the part that has not closed properly throughout fetal development. It is especially important to perform such surgery if there is an open lesion (that is, if there is no skin covering the sac) or if the sac makes it very difficult for the baby to breathe.

In some cases, although it depends on the type of material that is left out of the skull, the protuberances can even be amputated. In the event that there is hydrocephalus, a surgical intervention will also be necessary to solve it.

In addition to that, specific symptoms should be treated that the problem may have caused. Encephalocele is a condition that does not have to be fatal. However, in some cases this affectation can lead to the death of the minor, in which case palliative care will be provided until the minor dies.

Psychologically, it is very useful the presence of psychoeducation and counseling in the environment of the minor, since it is a condition that can generate painful sensations, fear and sometimes even feelings of guilt in the parents.

At the educational level, the special educational needs that individuals with cognitive impairments such as intellectual disabilities may present must be taken into account.

Prevention

Taking into account that the causes of this type of malformations are unknown it is advisable to adopt preventive strategies that help to avoid this and other types of malformation.

As occurs with spina bifida, the administration of folic acid during pregnancy, the maintenance of a balanced diet, and the cessation of Using substances such as alcohol, tobacco, and other drugs greatly reduces the risk of developing encephalocele in the developing fetus.

Bibliographic references:

• Siffel, C.; Wong, L.C.; Olney, R.S. & Correa, A. (2003). Survival of infants diagnosed with encephalocele in Atlanta, 1978-98. Paediatr Perinat Epidemiol.;17:40-8.

• Spacca, B.; Amasio, M.E.; Giordano, F.; Mussa, F.; Search, G.; Donati, P. & Genitori, L. (2009). Surgical management of congenital median perisellar transsphenoidal encephaloceles with an extracranial approach: a series of 6 cases. Neurosurgery ;65(6):1140-6.