The development of maturing brain is a complex and delicate process. Although humans are born with a very large head compared to the body (especially compared to other animals), throughout the first decades of our lives our nervous system will still have to grow and develop so that we can achieve healthy adult life.
However, during this process there are a lot of things that could go wrong and which although they are rare, if they do appear, they greatly influence our lives. Macrocephaly is an example.
What is macrocephaly?
Macrocephaly is a biological alteration in which the head circumference is larger than expected for gender and age of a boy or a girl. Simply put, the identification of macrocephaly is done by taking measurements of the perimeter of the skull and checking if the skull arch is larger than normal in healthy people. Therefore, macrocephaly is included in cranial growth disorders, a category to which microcephaly also belongs.
In addition, it is considered that for a correct study of each case of macrocephaly it does not depend only on a measurement, but it is necessary to make a follow-up to see how it evolves. the size of the head in relation to the rest of the body and if the situation worsens over time.
Indeed, this proportion changes very quickly during the first months of life and in fact between birth and 6 years the size of the body under the neck increases at a rapid rate.
On the other hand, the concept of macrocephaly is not in itself a disorder but a term used to superficially describe an impairment.
How often does it appear?
There are currently no statistics on the prevalence of macrocephaly from related research, but it is believed to be a rare malformation present in less than 5% of people.
However, as is always the case in these cases, it is possible that some poorly studied populations are more likely to suffer from such complications in the first months of life, possibly due to genetic issues or pollution. After all, during pregnancy you are very sensitive to external conditions and small changes can in some cases promote the onset of disease in the fetus.
Additionally, macrocephaly is thought to be more common in men and usually occurs during pregnancy or the first few months of life, so most cases are examples of infantile macrocephaly.
Macrocephaly can be caused by a wide variety of disorders. It is often a hereditary root, While in others, it is caused by injuries or complications during pregnancy or childbirth.
For example, many 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 it can contain inside the skull. This means that in the first months of life, the walls of the skull become more “dilated” than normal to accommodate so much fluid, because at this vital stage the head is much less hard than in adulthood.
Macrocephaly it can also be due to abnormal growth of the bones in the skull or brain, Which is compressed against the meninges and through it presses the bones of the cranial vault.
Also there are other disorders in which macrocephaly may also appear, Such as neurofibromatosis, alterations in bone growth, intracranial bleeding, Hurler’s syndrome or dwarfism.
Types of macrocephaly
There is a brief classification that serves to distinguish the different types of macrocephaly based on their causes. However, it should be noted that even within each type there are different variations which will depend on each individual case, such as which area the skull is pumped through the most or which areas of the brain are most damaged.
In any case, the types of macrocephaly are as follows:
This type of macrocephaly is characterized by being caused by an increase in the size and weight of the brain. For example, this happens due to an abnormal multiplication of stem cells. It has genetic causes and is also known as macroencephaly.
In this class of macrocephaly, the increase in the skull is due to biological processes that are not due to an increase in the brain itself, But other related substances that occupy free space. For example, hydrocephalus produces this variant.
Macrocephaly due to a 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, which produces pumping caused by abnormal development of the nervous system produced by the chain reaction, which means that there is no room to seize. dilate at some point.
Diagnosis and associated symptoms
In many cases, macrocephaly can be detected during the gestation phase through the use of ultrasound. However, in non-congenital macrocephaly, it may appear a little later, with the manifestation of certain disorders, and is diagnosed during pediatric consultations.
Macrocephaly can have a wide variety of associated symptoms, depending on its causes and the severity of the disorder. These include the following:
- cognitive impairments
- Delay in general development
- endocranial hypertension
some these symptoms may go away over time and depending on the procedure performed, although they may also become more intense, depending on the case.
The development of macrocephaly and its associated symptoms depend on the type of disorder that occurs.
In some cases, such as those with hydrocephalus, the life of the person may be at risk if no surgery is performed (Which will consist in releasing an excess of cerebrospinal fluid). In others, neither the child’s life nor his cognitive abilities will be compromised. In fact, the cases in which macrocephaly is not associated with the onset of mental retardation are very common.
There is no specific treatment targeting the disappearance of macrocephaly. However, some aim to treat the symptoms associated with the disorder causing this disorder.
Many of them are pharmacological and psychiatric, while others are psychological in nature and focus on cognitive stimulation of the child.
- Adams, HH; Hibar, DP; Chouraki, V .; Stein, JL; Nyquist, PA; Rentería, ME; Trumpet, S .; Arias-Vasquez, A. et al. New genetic loci underlying human intracranial volume identified by association throughout the genome. Nature Neuroscience, 19 (12): pages 1569-1582.
- Portellano, JA (2005). Introduction to neuropsychology. Madrid: McGraw Hill.
- Williams, C, A .; Dagli, A .; Battaglia, A. (2008). Genetic disorders associated with macrocephaly. American Journal of Medical Genetics, 146A (16): pp. 2023-2037.