This alteration in babies occurs when the skull or brain does not grow enough.
The nervous system is one of the first systems in our body to begin to develop during pregnancy. Throughout the entire pregnancy and even throughout the individual’s life, this system is going to be modified and developed, especially from gestation to the beginning of adulthood.
However, in some cases the brain does not grow as it should or with the usual speed already from pregnancy, causing the birth of children with heads of a much lower perimeter than the average, this is often linked to the presence of different alterations and a some degree of intellectual disability. It is what is known as microcephaly.
Microcephaly: concept and symptoms
We understand as microcephaly the situation, condition or neonatal affectation in which the skull and brain of the boy or girl presents an absence or evident delay of development at birth or during the first years, compared to other individuals of the same age. It is a rare disorder that can come from different causes. The head circumference of a child with microcephaly is generally considered to be two to three standard deviations below the mean.
Although in some cases children with microcephaly may have a normative level of intelligence, as a general rule this affectation course with a variable degree of intellectual disability. Various alterations such as vision loss, feeding difficulties, generalized slowing of development and seizures can also occur.
With the passage of time and as the child grows, the face and the rest of the body develop, but the skull still does not grow. For this reason, these types of infants usually have a sunken forehead and a long face.
Generally, this situation is detected throughout pregnancy, or after the first hours after delivery. However, sometimes years may pass before an atypical development is identified, not being evident in the first months of life.
Origin of this type of medical condition
There is no single cause that can generate microcephaly, but we can find different disorders and conditions that can generate it. Most of these are conditions and diseases that occur or are transmitted throughout the development of the fetus or during childbirth.
Some genetic disorders, mutations, and alterations can cause microcephaly. Among them, trisomies 18 (Edwards syndrome) and 21 (Down syndrome) stand out.
Another of the most common causes of microcephaly has to do with the transmission of various viruses from the mother to the fetus. Toxoplasmosis, cytomegalovirus, rubella or the well-known Zika virus have been shown to cause alterations in the fetus that can lead to microcephaly.
In addition, pregnant women should take care of their health and treat diseases such as phenylketonuria or diabetes (which if not controlled can also alter the development of the fetus due to the absence of certain nutrients). Some drugs and the abusive use of alcohol can cause this alteration. Malnutrition also makes it difficult for the future child to develop normally.
Complications during delivery
Even if fetal development is completed properly, complications such as anoxia can develop during delivery that can impair the function and developmental capacity of the brain.
Likewise, although in general the size of the skull increases throughout development thanks to the growth of the brain, being the size of the second what causes the first to be smaller in cases of microcephaly, there are cases in which a suture occurs premature bone of the skull that does not allow the brain to grow, a medical condition known as craniosynostosis.
Microcephaly does not have a treatment that reverses this condition. The treatments that are carried out are based on occupational therapy, stimulation and educational practice. It is necessary and very useful to offer therapies focused on speech and motor skills so that these children improve their basic skills, as well as work on the child’s emotional sphere. It is about ensuring that they can lead the best possible standard of living by optimizing their skills and exploiting their potential.
Likewise, psychoeducation and counseling to the family and the close environment is essential in order for it to help the minor to function in the most adaptive way possible, at the same time as it allows providing information and allowing the expression of doubts and fears to the family.
One of the conditions that can cause microcephaly is premature hardening of the bony plates of the skull or craniosynostosis, which prevents the growth and normative development of the brain by physically limiting it. This specific condition, if it is detected in time, can be reversed by surgery, so that harmful effects on the brain would be avoided.
Prevention is also essential. The use of drugs and certain substances by the mother, malnutrition, the lack of treatment for medical conditions such as phenylketonuria or the transmission of certain viruses such as toxoplasmosis (which can be spread through the feces of cats or consumption of uncooked, spoiled or contaminated food) can be possible causes of microcephaly, and in some cases can be avoided.
- Kinsman, SL & Johnston, MV (2016). Congenital anomalies of the central nervous system. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier.