What is macrocephaly?

It is defined as the abnormal growth of the above 3 standard deviations for the mean according to age and sex. When macrocephaly is associated with neurological alterations, it becomes a relevant clinical sign that must be considered in order to reach a diagnosis.

Baby head growth

The growth of the brain goes at a different rate and occurs mainly in the first two or three years of life.

Yes we compare ourselves with the rest of the mammals, the human being is born very immature with superior brain functions pending to make millions of connections. To the extent that baby interacts with the environment Neural networks are being consolidated that will allow acquiring and perfecting the skills that will forge an autonomous individual.

Between birth and 3 years of life, the formation of new brain circuits is maximum, and that is why the growth rate of the cranial perimeter is much more accelerated than later.

The skull is the bone structure that contains inside the brain and cerebellum and that it has to grow after birth. The bones of the skull have a planar growth, as if they were the islands of an archipelago that try to touch each other growing by their shores. So that the brain can grow properly, the bones of the cranial shell do not have to be welded, so that they leave space for the brain and that it grows normally. If the brain grows too large or does not grow enoughFor different reasons, we can easily detect it by periodically measuring the baby's head.

Head circumference (CP)

The normal head circumference is different between boys and girls and between different ethnicities. To know if a PC value is correct, it must be compared with those for the same age, ethnicity and sex.

A value of head circumference is normal when it is between the values ​​of the population mean plus 2 standard deviations (SD) or minus 2 deviations standard. It should be noted that knowing that 4% of the normal population may have a cranial growth below or above that detailed in the standard graphs.

We cannot forget that the PC is a isolated value that must be put in context. We have to, even their genetics.

FOR EXAMPLE: A 9-month-old child who has always followed a CP curve at the 25th percentile should call our attention if in one month it has risen to a 95th percentile, both percentiles being normal if we assess them "out of context".

Types of macrocephaly

Non-evolutionary macrocephaly

 It is called non-evolutionary macrocephaly when macrocephaly is a variant of normal and it is not associated with neurological or neurodevelopmental disorders.

In these cases, parents also tend to have a larger head than usual. In this circumstance, the child's development is monitored and an imaging test is not requested unless some alteration in neurological functions or a deterioration in neurodevelopment is observed.

In all cases of benign macrocephaly there is normal neurodevelopment and there are no symptoms of increased intracranial pressure (vomiting, alteration in the position of the eyes, irritability, drowsiness ...), only an increase in CP is evident.

Evolutionary macrocephaly

Pediatricians are concerned about the macrocephaly that is associated with accelerated growth rate, which could be the reflection of some intracranial structure that is growing too much: a brain tumor, a hemorrhage or a hydrocephalus (excess cerebrospinal fluid). These suspicions by themselves already warrant an urgent neuroimaging test (a cranial CT or MRI).

Despite the concern about encountering evolutionary macrocephaly, most cases are benign and they correspond to an external hydrocephalus that generates an accelerated growth of the cranial perimeter in the first six months of life, stabilizing without causing any neurodevelopmental problems.

Most common causes of macrocephaly

1. Macrocephaly secondary to bone disease. 2. Macrocephaly due to pathology of the central nervous system or cerebrospinal fluid:

• Benign macrocephaly of infancy.
• Benign external hydrocephalus.
• Benign enlargement of the subarachnoid spaces.
• Brain tumors.
• Deposit diseases.
• Genetic metabolic syndromes.

What to do if my child is diagnosed with macrocephaly

If the pediatrician observes an accelerated growth of the cranial perimeter, the baby is He was referred to the pediatric neurologist and an urgent neuroimaging test was performed. The urgency is greater if there are signs of increased intracranial pressure in the infant:

• Irritability
• Drowsiness
• Vomiting (in the oldest child).
• Seizures
• Squint
• Refusal of feeding.
• Headache (in the oldest child).
• Gait disturbance.
• Papilledema.
• Motor and / or visual deficits.
• Psychomotor retardation.

Treatment for macrocephaly

Each case must be evaluated individually and the therapeutic option must be chosen according to the diagnosis within a multidisciplinary team of pediatric neurologists, neuro-oncologists and neurosurgeons.

• It is defined as abnormal head circumference growth above three standard deviations for the mean according to age and sex.
• If the pediatrician observes an accelerated growth of the cranial perimeter, the baby is referred to the pediatric neurologist and an urgent neuroimaging test is performed.
• Each case must be evaluated individually and the therapeutic option must be chosen according to the diagnosis within a multidisciplinary team of

Pediatric specialist