The Craniosynostosis Is a rare problem of the skull that causes the baby to develop or present at birth deformations in the head. "Craniosynostosis"comes from skull + without (Together) + Ostosis (Related to bones).
More specifically, it is the early fusion of the different parts of the skull so that it can not grow properly, disrupting the normal development of both the brain and the skull.
In the newborn, the skull is composed of several bones that are not yet attached, this is so that brain Has enough space for it to continue to develop. In fact, the skull bones will double in size during the first three months of life and do not fully fuse until the late teens.
In fact, the level of fusion of the bones of the skull changes with age and according to which sutures are; Closing some before others. The skull of the newborn is composed of seven bones, and are developed through two processes: bone displacement and remodeling of bones.
It seems that the skull consists of a single compact piece, however, contrary to what you may think, the skull is more like a soccer ball: it has a series of bones arranged in plates that fit together to build a sphere.
Between these plates are strong elastic tissues called sutures. These are the ones that give flexibility to the skull so that it develops as the brain grows. This flexibility also allows the baby to be born passing through the birth canal.
What happens is that when a zone of the skull that is growing merges and closes, other zones will try to compensate this, becoming more prominent and altering the normal form of the head.
It may also appear in the literature as synostosis or premature closure of the sutures.
Types of craniosynostosis
There are several types of craniosynostosis depending on the parts of the skull Which are altered and the resulting shape of the head.
Scaphocephaly
It is the most common type and affects men more often. It is the premature fusion of the sagittal suture, which lies in the midline of the upper skull and runs from the soft point (also called the fontanelle) to the posterior area of the head.
It gives rise to a long and narrow head shape. As it grows, the back of the head becomes more prominent and pointed, and the forehead protrudes. This type is the least likely problem for normal brain development and is relatively simple to diagnose.
Previous Plagiocephaly
It consists of early union one of the coronal sutures, where the forehead and the Frontal lobe of the brain Grow forward. In this type, the forehead appears flattened, and the eye sockets raised and tilted.
In addition, these protrude and the nose is also diverted to one side. A sign that the baby has this type of craniosynostosis is that he will tilt his head to one side to avoid seeing double.
Trigonocephaly
It is the union of the metopic suture, which is located in the middle of the forehead of the affected and goes from the soft point or fontanelle to the beginning of the nose.
It causes the eye sockets to come together and these are very close to each other. The forehead takes a protruding triangular shape.
Posterior plagiocephaly
It is the least common, and results from a premature closure of one of the lamboid sutures that are in the back of the head.
This results in a flattening of this area of the skull, making the bone behind the ear (mastoid bone) protruding, which manifests in one ear lower than the other. In this case the skull may also be tilted to one side.
All these correspond to unions of a single suture, but unions of more than one can also be given.
Craniosynostosis of double suture
For example:
- Anterior Brachycephaly : It is called bicoronal, because it occurs when the two coronal sutures, which goes from ear to ear, fuse prematurely, presenting the forehead area and eyebrows flat. The skull in general looks wider than normal.
- Posterior brachycephaly : The skull also widens, but due to the union of the two lamboid sutures (which, as we said, are in the back).
- Scaffolding of the satigal and metastatic suture : The head has an elongated and narrowed appearance.
Craniosynostosis of multiple sutures
For example:
- Turribraquicefalia , By the union of bicoronal, sagittal and metopic sutures: the head is pointed, and is characteristic of the Apert syndrome.
- Multisutures Which give the skull a form of"cloverleaf".
Prevalence
This disease is rare and affects approximately 1 in 1800 or 3,000 children. It is more common in males, with 3 out of 4 cases being affected by males, although this seems to vary by the type of craniosynostosis.
Between 80% and 95% of cases belong to the non-syndromic form, that is, as an isolated condition.
Although other authors have estimated that 15% to 40% of patients may be part of another syndrome (Kimonis, Gold, Hoffman, Panchal & Boyadjiev, 2007).
As for the types of craniosynostosis, it seems that the most frequent is the one involving the sagittal suture (40-60% of the cases), followed by the coronal (20-30%) and then the mettopic (10% or less). The union of the lambdoidea suture is very rare.
Causes
- Craniosynostosis can be syndromic, that is, it is linked to other rare syndromes. A syndrome is a series of associated symptoms that arise for the same cause and which in most cases is usually genetic.
- On the other hand, it may also be non-syndromic; Being the causes variable and not totally known.
It is known that there are factors that can facilitate craniosynostosis as:
- Little space inside the uterus or abnormal form of it, mainly provoking coronal synostosis.
- Disorders that impinge on bone metabolism: Hypercalcemia or rickets .
- It can also occur what is called as secondary craniosinostosis, which is more common, and has its origin in a failure in brain development. That is, as the growth of the brain is the one that drives the bony plates so that they acquire their normal form; If the brain grows properly, the fusion of the cranial sutures will occur. Normally it will lead to Microcephaly Or reduced cranial size.
Therefore, here the craniosynostosis will appear united to other problems of development of the encephalon like Holoprosencephaly or Encephalocele .
- May be due in some cases to haematological (blood) disorders, such as congenital haemolytic jaundice, sickle cell anemia or Thalassemia .
- In some cases, craniosynostosis is a consequence of iatrogenic problems (ie, caused by the error of a doctor or health professional)
- It can also be caused by teratogenic agents, this means any chemical substance, deficiency state or some harmful physical agent that produces morphological alterations in the fetal stage. Some examples are substances such as aminopterin, valproate, fluconazole or cyclophosphamide, among others.
symptom
In some cases, craniosynostosis may not be noticeable until a few months after birth. Specifically, when it is associated with other craniofacial problems it can be seen from birth, but if it is milder or has other causes, it will be observed as the child grows.
In addition, some symptoms described here usually appear in childhood.
- The fundamental is the irregular skull shape, which is determined by the type of craniosynostosis that it possesses.
- A hard ridge can be perceived by touch in the joint area of the sutures.
- The soft part of the skull (fontanelle) is not perceived or different from normal.
- The baby's head does not seem to grow in proportion to the rest of the body.
- Increased intracranial pressure may occur in any type of craniosynostosis. It is obviously due to the malformations of the skull, and the more sutures that are attached the more common will be this increase and more serious. For example, in the type of multiple sutures, intracranial pressure increases in about 60% of cases, whereas in cases of a single suture the percentage decreases to 15%.
As a consequence of the previous point, the following symptoms will also occur in craniosynostosis:
- Persistent headache, mainly in the morning and at night.
- Difficulties in vision such as seeing double or blurred.
- In somewhat older children, lower academic performance.
- Delayed neurological development.
- If the intracranial pressure increase is not treated, vomiting, irritability, slow reaction, swelling of the eyes, difficulty in following an object, hearing and respiratory problems can occur.
Diagnosis
It is important to note that not all skull deformities are craniosynostosis. For example, an abnormal head shape may occur if the baby remains in the same position for a long time, such as lying on his back.
However, it is necessary to consult a doctor if it is observed that the baby's head is not developing properly or has irregularities. However, diagnosis is favored since routine pediatric examinations are done for all babies in whom the specialist examines the growth of the skull.
If it is a milder form, it may not be detected until the child grows and increases in intracranial pressure. So we should not ignore the symptoms mentioned above, which in this case would occur between 4 and 8 years of age.
The diagnosis should include:
- A physical exam : Palpating the head of the affected to check if there are ridges in the sutures or observe if there are facial deformities.
- Imaging studies , as the Computed tomography (CT), which will allow you to see the sutures that have been attached. You can identify it will observe that where there should be a suture there is not, or else, that the line protrudes into ridge.
- X-rays : To obtain accurate measurements of the skull (through cephalometry).
- Genetic testing : If it is suspected that it can be hereditary type linked to some syndrome, with the aim of detecting what the syndrome would be and treating it as soon as possible. They usually require a blood test, although samples of other tissues such as skin, inner cheek cells or hair can also sometimes be tested.
Associated syndromes
There are more than 180 different syndromes that can cause craniosynostosis, although they are all very rare (Kimonis, Gold, Hoffman, Panchal & Boyadjiev, 2007).
Some of the most distinctive are:
- Crouzon Syndrome This is the most common and is associated with bilateral coronal craniosynostosis, anomalies of the middle third facial and protruding eyes. It appears to be due to a mutation in the FGFR2 gene, although some cases arise spontaneously.
- Apert Syndrome It also presents bilateral coronal craniosynostosis, although other forms of synostosis can be observed. There are fusions in the base of the skull, in addition to deformities in the hands, elbows, hips and knees. Its origin is hereditary and gives rise to characteristic facial features.
- Carpenter's Syndrome This syndrome is usually linked to posterior plagiocephaly or union of lamboid sutures, although scaphocephaly also occurs. It is differentiated by deformations also in the extremities and by an extra digit in the feet, among other things.
- Pfeiffer's Syndrome Unicoronal craniosynostosis is common in this condition, as well as facial deformities, which cause him to have auditory problems, and in the extremities. It is also associated with hydrocephalus.
- Saethre-Chotzen Syndrome Usually have unilateral coronal craniosynostosis, with very limited development of the anterior cranial base, very low hair growth, facial asymmetry and developmental delay. It is also congenital.
Treatment
Try to develop an early treatment, as many of the problems can be managed by the rapid growth of the brain and the flexibility of the baby's skull to adapt to the changes.
If we are in the situation where other deformations have occurred in the skull such as positional plagiocephaly, or one side of the head flattened by being in the same position for a long time, by pressure of the uterus or complications in childbirth; You can re-acquire the normal head shape with a Casting helmet Personalized for baby.
Another option is the Repositioning , Which has been effective in 80% of cases. It consists of placing the baby on the unaffected side, and working the muscles of the neck positioning it face down, over his abdomen. This technique is effective if the baby is less than 3 or 4 months old.
Even in cases that are very mild, no specific treatment may be recommended, but it is expected that its aesthetic effects will not be as serious as the affected person develops and grows his hair.
If the cases are not very severe, non-surgical methods should be used. Usually, these treatments will prevent disease progression or improve, but it is common for there to continue to be some degree of disfigurement that can be solved with simple surgery.
The surgical intervention Developed by a craniofacial surgeon and a neurosurgeon, is indicated in cases of severe craniofacial problems, such as lamboid or coronal craniosynostosis, or if there is an increase in intracranial pressure. Surgery is the treatment that is usually chosen for most craniofacial malformations, especially those that are associated with a main syndrome.
The surgery aims to decrease the pressure the skull is making on the brain and provide enough room for the brain to grow, in addition to improving physical appearance.
After surgery, the affected person may need a second intervention later if they tend to develop craniosynostosis as they grow. The same happens if they also present facial deformities.
Another type of Surgery is the endoscopic , Which is much less invasive; As it involves the introduction of an illuminated tube (endoscope) through small incisions in the scalp, to detect the exact location of the fused suture to open later. This type of surgery can be done in just one hour, the swelling is not so severe, there is less blood loss and recovery is faster.
In the case where there are other underlying syndromes, periodic monitoring of skull growth is necessary to monitor the occurrence of increased intracranial pressure.
If your baby has an underlying syndrome, your doctor may recommend regular follow-up visits after surgery to control head growth and check for increased intracranial pressure.
References
- Craniosynostosis . (February 2015). Retrieved from Cincinnati Children's.
- Craniosynostosis . (March 11, 2016). Obtained from NHS.
- Diseases and Conditions: Craniosynostosis . (September 30, 2013). Obtained from Mayo Clinic.
- Kimonis, V., Gold, J., Hoffman, T.L., Panchal, J., & Boyadjiev, S.A. (2007). Genetics of Craniosynostosis. Seminars In Pediatric Neurology, 14 (Advances in Clinical Genetics (Part II), 150-161.
- Sheth, R. (September 17, 2015). Pediatric Craniosynostosis . Obtained from Medscape.
- Types of Craniosynostosis . (S.f.). Retrieved on June 28, 2016, from Center for Endoscopic Craniosynostosis Surgery.
- Villarreal Reyna, G. (s.f.). Craniosynostosis . Recovered on June 28, 2016, of endovascular neurosurgery.
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