The maturative development of the
brain is a complex and delicate process. Although humans are born with a very large head in relation to the body (especially compared to other animals), throughout the first decades of our lives our nervous system will still need to grow and develop in order for us to reach a healthy adulthood.

However, during this process there are many things that could go wrong and that, although they are rare, if they appear they influence our lives a lot.
Macrocephaly is an example of this .

What is macrocephaly?

Macrocephaly is
a biological alteration by which the circumference of the head is larger than expected for the sex and age of a child. In other words, the identification of macrocephaly is done by taking measurements of the perimeter of the skull and checking whether the cranial vault is larger than normal in healthy people.For this reason, macrocephaly is included among the disorders of cranial growth, a category to which microcephaly also belongs.

Furthermore, it is considered that for a correct study of each case of macrocephaly, it is not only necessary to measure, but also to follow up to see how it evolves
the size of the head in relation to the rest of the body and whether the situation is getting worse over time.

This is because this proportion changes very quickly during the first months of life and, in fact, between birth and 6 years of age the size of the body below the neck increases at great speed.

On the other hand, the concept of macrocephaly is not a disorder per se but a term used to describe a disturbance in a superficial way.

How often does it appear?

Currently there are no statistics on the prevalence of macrocephaly that have been extracted from related research, but it is estimated that it is a rare malformation present in
less than 5% of people .

However, as is always the case in such cases, certain poorly studied populations may be more prone to this type of complication during the first few months of life, perhaps because of genetic issues or contamination. After all, during pregnancy one is very sensitive to external conditions, and small alterations may, in some cases, favour the appearance of illnesses in the foetus .

Furthermore, it is believed that macrocephaly is more frequent in males and that it usually appears during pregnancy or in the first months of life, which is why most cases are examples of infantile macrocephaly .

Causes

Macrocephaly can be produced by a wide variety of alterations.
Many times it is of hereditary root , while in others it is produced by injuries or complications during pregnancy or delivery.

For example, many of the cases of macrocephaly are due to
a disorder known as hydrocephalus , in which more cerebrospinal fluid (a substance that surrounds the brain and spinal cord) is produced than can fit inside the skull. In the first few months of life, the walls of the skull become more “stretched” than normal to accommodate this amount of fluid because the head is much less hard than in adulthood.

Macrocephaly
may also be due to abnormal growth of the bones of the skull or brain , which is compressed against the meninges and through it presses on the bones of the skull dome.

In addition, there are
other disorders in which macrocephaly may also appear, such as neurofibromatosis, bone growth disorders, intracranial bleeding, Hurler syndrome, or dwarfism.

Types of macrocephaly

There is a rough classification that serves to
distinguish between different types of macrocephaly according to their causes . However, it must be taken into account that even within each type there are different variants that will depend on each individual case, such as the area where the skull is most convex or the areas of the brain that are most damaged.

In any case, the types of macrocephaly are as follows:

Primary macrocephaly

This type of macrocephaly is characterized by
caused by an increase in the volume and weight of the brain . For example, it occurs due to an abnormal multiplication of stem cells.It has genetic causes and is also known as macroencephaly.

Secondary macrocephaly

In this type of macrocephaly, the increase in the skull is due to
biological processes that are not due to an increase in the brain itself , but to other related substances that occupy the head space. For example, hydrocephalus produces this variant.

Macrocephaly due to bone malformation

Some cases of macrocephaly are explained by abnormal bone development. For example, they may be due to early closure of the cranial sutures, resulting in a bulge caused by abnormal development of the nervous system due to the chain reaction that means that there is no room for expansion at any given time.

Diagnosis and associated symptoms

In many cases macrocephaly
can be detected during the gestation stage thanks to the use of ultrasound scans.However, in non-congenital macrocephalias this can appear somewhat later, with the manifestation of certain disorders, and is diagnosed in paediatric consultations .

Macrocephaly can present a great variety of associated symptoms, depending on its causes and the intensity of this alteration. Among them, the following stand out:

  • Cognitive disorders
  • Vomiting
  • Seizures
  • Overall developmental delay
  • Headaches
  • Endocranial hypertension
  • Irritability

Some of
these symptoms may remit over time and depending on the intervention performed, although they may also become more intense, depending on the case.

Prognosis

The way in which macrocephaly and its associated symptoms develop depends on the kind of alteration that this phenomenon is producing.

In some cases, such as those involving hydrocephalus, the life of
the person may be in danger if a surgical intervention is not performed (which will consist of releasing the excess spinal fluid). In others, neither the life nor the cognitive abilities of the child will be compromised. In fact, the cases in which macrocephaly is not associated with the appearance of mental retardation are very frequent .

Treatment

There is no specific treatment that targets the disappearance of macrocephaly . However, there are those that aim to intervene on the symptoms associated with the disorder that is producing this alteration.

Many of these are pharmacological and psychiatric in nature, while others are psychological in nature and focus on cognitive stimulation of the child.