Craniosynostosis

Craniosynostosis - premature overgrowing of one or more seams of the skull, leading to the formation of a characteristic deformation.

Craniostenosis is a nonspecific brain damage that occurs as a result of insufficient expansion of the cranial cavity during the most active growth of the brain.

Despite the fact that premature synostosis leads to characteristic deformations of the skull and facial skeleton and it is easy to suspect the disease even in a newborn, in our country this developmental defect is diagnosed rather rarely. And most importantly - in the vast majority of cases, the diagnosis is made after 1 year, which is significantly reflected both in the development of the child and the final result of treatment. The modern achievements of reconstructive surgery and the changing attitude of doctors towards deformities of the skull as to inoperable conditions that occurred in recent years allow us to hope for more frequent and, most importantly, early detection of craniofacial deformities associated with premature synostosis of the sutures.

ICD-10 code

In the International Classification of Diseases, craniosynostosis is listed in several headings.

Class XVII.

• (Q00-Q99). Congenital anomalies [malformations], deformities and chromosomal abnormalities.
• (Q65-79). Congenital anomalies [malformations] and deformations of the musculoskeletal system.
• Q67. Congenital musculoskeletal deformities of the head, face, spine and thorax.
• Q75. Other congenital malformations of the bones of the skull and face.
• Q80-89. Other congenital anomalies [malformations] and deformations of the musculoskeletal system.
• Q87.0. Syndromes of congenital anomalies, affecting mainly the appearance of the face.

Epidemiology

According to international statistics, premature closure of one of the cranial suture on average occurs in 1 per 1,000 newborns (from 0.02 to 4%). Syndromic craniostenosis occurs at a frequency of 1: 100,000-300,000.

[1], [2], [3], [4], [5], [6], [7]

What causes craniostenosis?

At present, little is known about the nature of premature synostosis of sutures. Many explanations are offered why craniostenosis occurs. The most popular of them are theories about intrauterine, hormonal, hereditary disorders, mechanical theory (compression of the fetal head in the uterus), etc. Deficiency in the fibroblast growth factor receptor gene (FGFR) 1,2,3 is currently recognized as one of the major pathogenetic factors.

The main seams of the cranial vault are sagittal, coronary, lambdoid and metopic. When the bone seam is affected, compensatory growth of the bones is perpendicular to its axis (Virchow's law). The result is a characteristic deformation - its own for each of the closed seams.

Thus, sagittal craniostenosis leads to scaphocephaly, synostosis of the entire coronary suture to brachycephaly, synostosis of the half of the coronary suture causes plagiocephaly, and synostosis of the metoplastic suture trigonometheal. Synostozirovanie entire lambdovidnogo seam or its half leads to deformation of the occipital region. Its degree directly depends not only on the degree of synostosis and the number of sutures included in the deformation, but also on the state of the brain itself. So, in the presence of concomitant hydrocephalus, its severity increases. In the presence of microcephaly due to impaired brain growth, they are barely noticeable.

How is craniosynostosis manifested?

The most famous indicator of premature synostosis of the seam of the skull is the early closure of the large fontanel. In some cases of syndromic synostosis, when several pathways are involved in the pathological process, and especially with the concomitant expansion of the ventricles of the brain, a large fontanel may not close until the age of 2-3 years.

The presence of finger impressions on the survey radiographs of the skull is characteristic of patients with premature synostosis of the cranial sutures. Strengthening the finger pressure pattern occurs when other compensatory mechanisms fail to cope with intracranial hypertension. Sometimes finger impressions are already visible in newborns. In such cases, a combination of "lesion of several seams of the skull."

Another pathognomonic sign of increased intracranial pressure is venous congestion on the fundus and edema of the nipple of the optic nerve. In cases of isolated monosynostosis, such findings are not so frequent. With polysynostosis, long-term intracranial hypertension often leads to the formation of partial atrophy of the optic nerves.

How is craniosynostosis classified?

The most convenient etiological classification of craniosynostosis was suggested by M. Cohen (1986).

The following craniosynostosis is known:

• Nonsindromal craniostenosis (isolated).
• Syndromic craniostenosis:
  • monogenic craniosynostosis:
  • with autosomal dominant type of inheritance:
  • with an autosomal recessive type of inheritance:
  • X-linked craniosynostosis;
  • with an unspecified type of inheritance:
  • chromosomal craniosynostosis;
  • incomplete syndromal (from two to four signs):
  • syndromes caused by environmental factors.

According to the anatomical sign, craniosynostosis can be divided as follows.

• Monosynostosis:
  • isolated sagittal craniosynostosis;
  • isolated metopic craniosynostosis;
  • isolated coronary unilateral craniosynostosis;
  • isolated coronary bilateral craniosynostosis;
  • isolated lambdoid one-sided craniosynostosis;
  • isolated lambdoid bilateral craniosynostosis.
• Polysynostosis.
• Pansinostoz.

In most cases, premature closure of one of the seams of the skull - monosynostosis. Sometimes two sutures and more can be included in the process - polysynostosis. In the most severe cases, there is synostosis of all cranial sutures - this condition is called pansinostosis.

Very often premature synostosis is not accompanied by other malformations. In such cases, they speak of isolated craniosynostosis. There is another group, which is characterized by the presence of a set of developmental anomalies accompanying synostosis of a certain suture or in which there is a synostosis of a separate group of cranial sutures that lead to a characteristic deformation of the face and skull. In such cases, as a rule, the type of inheritance can be established, and sometimes genetic disorders are also revealed - then they speak of syndromic craniosynostosis.

Sagittal craniosynostosis

Among the total number of isolated synostosis, scaphocephaly is the most frequent disease that occurs with a frequency of 50-60%.

Symptoms

Sagittal craniosynostosis is characterized by an increase in the anterior-posterior size of the skull and a decrease in its width. The head of the child is sharply elongated in the longitudinal direction with overhanging frontal and occipital areas and impressed temporal areas. These changes in the skull lead to the formation of a narrow oval face. This kind of deformation is called scaphocephaly, or a scaphoid cranium.

Diagnosis, examination and physical examination

The characteristic shape of the skull is visible from birth. When examining the head from above, there is a noticeable retraction of the parietal areas, which gives a sensation of a circular constriction of the cranial vault at or slightly posterior to the auricles. A characteristic feature is the presence of a bone crest, palpable in the projection of the sagittal suture. The shape of the head changes insignificantly with age. By the end of the growth of the cerebral cranium (5-6 years), the deformation of the face becomes more obvious as an oval elongated along the vertical axis, narrowed in the temporal areas.

In infancy, children may have an easy delay in psychomotor development. But, as a rule, in the absence of concomitant pathology the child normally develops up to 3-4 years. From this age, visual impairments due to optic nerve damage, and neurological symptoms in the form of headaches, rapid fatigue, irritability, etc., may appear. Often, these complaints are regarded as a character for a long time, reaction to weather changes, vitamin deficiency, attention deficit, etc.

[8], [9], [10], [11], [12]

Laboratory and instrumental research

Computed tomography (CT) scan for sagittal synostosis is considered to be specific for the detection of enlarged anteroposterior diameter in sections and practically the same length of the bi-temporal and biparietal diameters. When carrying out a three-dimensional remodeling image, there is a lack of clearance in the projection of the sagittal seam.

Treatment

Operative treatment is best for children from the age of 4-6 months. In this period, with a minimal amount of intervention, a fairly stable result can be obtained. At this age, the l-plastic technique is usually used. The meaning of the operation is to create bone defects in the parietal bones to facilitate the growth of the brain in width.

Children older than a year often have to perform remodeling of the entire cranial vault, which increases the time of operation three times and is accompanied by a greater risk of postoperative complications. Usually one operation is enough to allow the brain to grow without hindrance, and the proportions of the face become normal.

Nonotopic craniosynostosis (trigoncephalus)

The rarest representative of the group of isolated craniosynostosis is the hetopic craniosynostosis, which is 5-10% of the total.

Symptoms

Despite the low frequency, this disease, perhaps, is most often recognized because of the characteristic clinical picture.

With the early closure of the metoplastic suture, a triangular deformation of the forehead is formed with the formation of a bone keel, going from the nadperium to the large fontanel. When viewed from above, a clear triangular deformation is seen with a vertex in the region of the peri-transference. In this case, the upper and lateral margins of the orbits move posteriorly, which gives a sensation of turning the orbital plane outward in the reduction of the orbital distance-hypo-hologorism. This pathology of the forehead is so unusual that children with trigonecephaly often consult genetics and are seen as carriers of hereditary syndromes, accompanied by a decrease in intelligence. Indeed, trigonecephaly is considered as an integral part of such syndromes as Opitz, Oro-facio-digital and some others.

With age, there is a slight correction of deformity of the forehead due to smoothing of the crest top and development of the frontal sinuses, but the pronounced curvature of the frontal bone, hypo-hallorrhizm and the turn of the supraorbital margin outwards remain. To predict the extent of damage to the brain is impossible.

In this group of patients, with almost equal frequency, both good compensation and pronounced disturbances from the visual organs are noted, with a noticeable intellectual delay.

Treatment

It is treated such craniosynostosis can already from 6-month old age. The traditional scheme of the operation consists in remodeling the upper orbital complex with the elimination of the orbits turning backwards and correcting the curvature of the frontal bone. In most cases, by one operation performed on time, it is possible not only to achieve improvement in the functions of the central nervous system, but also to achieve a good cosmetic result.

One-sided coronary craniosynostosis

With this pathology, the coronary suture is perpendicular to the median axis and consists of two equivalent halves. In the premature infestation of one of its halves, a typical asymmetric deformation, called plagiocephaly, is formed. The type of child with plagiocephaly is characterized by a flattening of the upper orbital margin of the orbit and the frontal bone on the side of the lesion with compensatory overhang of the opposite half of the forehead (Figure 6-14, see color insert). With age, the flattening of the zygomatic area and the curvature of the nose to the healthy side are more clearly manifested. At school age, deformity of the occlusion is associated with an increase in the height of the upper jaw and, as a consequence, displacement of the lower jaw on the side of the prematurely closed suture.

Disturbances on the part of the organs of vision are most often represented by strabismus. Plagiocephaly is more often regarded as a peculiarity of the postnatal configuration of the head. But unlike the latter, it does not disappear in the first weeks of life.

Treatment

This craniosynostosis is the only one of monosynostosis, in which the cosmetic significance of the operation is equal, and sometimes even higher than the functional one. Operative treatment, as with other craniosynostosis, can be performed from the first months of life. An operation performed at 6 months of age, if not completely eliminates the deformity presented, will significantly soften its manifestation. Correction of residual cosmetic deformities of the face can be undertaken at an older age. The procedure of the operation consists in the craniotomy of the frontal bone and the supraorbital margin from one or both sides with subsequent symmetrical remodeling of the upper margin of the orbits and elimination of deformation of the frontal bone. Sometimes, to obtain a more persistent cosmetic effect, it is necessary to remodel the parietal region from the side of the lesion.

Bilateral coronary craniosynostosis

Isolated bilateral coronary craniosynostosis is encountered with the same frequency as its one-sided lesions, approximately 15-20% of the total number of synostoses.

Double-sided coronary craniosynostosis leads to the formation of a wide flattened anteroposterior direction with a flat high forehead and flattened upper orbital margins. This form is called brachycephaly. In severe cases, the head acquires a tower shape, tapering upward. This deformation is called acrocephaly.

Neurological picture, as for most cases of isolated synostosis, is non-specific, but the severity of neurological and ophthalmic phenomena is usually stronger and manifests itself at earlier times. It is connected, most likely, with a long length of the seam.

Treatment

Operative treatment is aimed at increasing the anterior-posterior size. For this, bifrontal craniotomy and osteotomy of the supraorbital complex are carried out. Then the supraorbital complex is fixed with anterior forward 1-2 cm. The frontal bone is rigidly fixed on the supraorbital complex and left without fixation in the area of the formed defect in the projection and overgrown coronary suture, thus allowing further growth of the brain. Such a technique is widespread in the world and is called the "floating forehead".

The prognosis of surgical treatment of isolated coronary craniosynostosis is quite favorable, usually in one operation they eliminate deformations and ensure the subsequent growth of the brain.

[13], [14], [15], [16], [17]

Lambdoid craniosynostosis

Lambdovidy suture, as well as coronary suture, is divided into two halves at the point of contact with the sagittal suture, therefore, possibly both one-sided and bilateral damage.

The frequency of premature closure of the joint is approximately 10% and in the overwhelming majority of cases is unilateral.

With one-sided synostosis, a flattening of the occipital part occurs with the formation of occipital plagiocephaly. This synostosis seems to be the most difficult for diagnosis due to the fact that one-sided occlusion of the nape is almost always regarded by doctors as "positional" caused by the forced position of the child's head on its side. Such a forced situation is often observed in children with a unilateral increase in muscle tone or in the case of torticollis. Distinctive signs of synostosis: sinostotic deformation is determined from birth, with age it does not change significantly, regardless of the measures taken to change the position of the baby's head in the crib.

Positional plagiocephaly occurs after birth, is aggravated in the first years of life and has a tendency to significant regress after the start of physiotherapy.

Since the deformation is almost invisible under the hair, there are no obvious neurological manifestations, the lambdoid synostosis is the most undiagnosed in this group of diseases. Despite this, the risk of neurological disorders dictates the need for early recognition and treatment of the disease.

Treatment

Surgical treatment is usually performed at the age of 6-9 months. When the child begins to spend more time in a state of wakefulness, as the probability of relapse of pressure from the pressure to the remodeled region decreases. The meaning of the operation is a craniotomy of the parietal-occipital flap from the side of the lesion and its remodeling to create an acceptable curvature.

Almost always the treatment is one-stage and one-stage, since small residual deformations reliably hide the scalp and do not require repeated interventions.

Syndromic Kraksiosynystosis

Syndromal craniosynostosis is the rarest and at the same time the most complex group of congenital craniofacial diseases, both from the point of view of surgical correction of the presented deformities, and from the point of view of the prognosis of neurological and mental development.

Clinical picture and diagnosis

In the overwhelming majority of cases, along with craniosynostosis in children, a violation of the growth of the bones of the facial skull is revealed, leading to disturbances in breathing, eating, visual impairment, and severe cosmetic deformation.

Usually, the leading clinical sign is brachycephaly with a premature synostosis of the coronary suture. Deformation is exacerbated by maldevelopment of the upper jaw, which leads to a characteristic depressed facial deformity with exophthalmos and orbital hypertlerioriem. As a result of such a combined defeat in the newborn, breathing and the process of feeding are severely disrupted, which determines the severity of the condition in the first days and months of life and requires intensive monitoring. Often in cases of syndromic craniosynostoenes, not only coronary, but also other seams are overgrown, which causes craniostenosis. Thus, respiratory distress and nutritional difficulties are aggravated by neurologic disorders, which dictates the need for early surgical treatment. It is important to remember that most patients with syndromic craniosynostosis have a sharp increase in the large fontanel and even widening the sagittal suture along the entire length. This often confuses clinicians who do not imagine the possibility of coexisting of an extended fontanel with premature overgrowth of the joints.

As a rule, in the absence of skilled care, children with syndromic synostosis die in the first year of life against severe and frequent respiratory diseases complicated by pneumonia. In the absence of competent timely surgical treatment, most such patients have severe mental and neurological abnormalities.

Treatment

Treatment of children with syndromic synostosis should begin already in the maternity hospital. It is necessary to ensure optimal breathing and feeding of such patients. Because of hypoplasia of the maxilla in children, it is often falsely assumed atresia of the khoan, about which the chanotomy is carried out. Sometimes such treatment is effective, since postoperative wearing of nasal liners improves nasal breathing. You can also use an oral air duct, which facilitates breathing during sleep. In some cases, the child may need tracheostomy.

The baby should be fed as soon as possible. Naturally, during the first days of life, it can sometimes be justifiably probed feeding, but the baby should be transferred from the nipple, spoon or drinker as soon as possible. Expansion of the ventricular system of the brain is sometimes misunderstood as hydrocephalus and prescribed large doses of diuretics. However, with close observation of the growth of the head circumference, it is important to note that there are practically no deviations from normal growth rates. Expressive exorbitism in children with syndromic synostosis should be the object of close attention of oculists. Children should be given specific therapy aimed at preventing the drying of the cornea. In severe cases of exorbitism, blepharophrenia may be required for several weeks to prevent severe damage to the cornea and dislocation of the eyeball. Surgical treatment of children with syndromic craniosynostosis traditionally consists of three stages.

• In the first year of life, cranioplasty is performed using the "floating forehead" technique. Eliminate brachycephaly and increase the volume of the skull, creating conditions for normal growth of the brain. In cases where a large fontanel is closed or small, treatment can be started from 6 months.
• At the next stage, the middle zone of the face is advanced to improve nasal breathing, eliminate hypertellorism and exorbitism. At this stage, a significant cosmetic correction is performed and normal occlusion. This stage is carried out for children aged 5-6 years.
• At the last stage, the final cosmetic interventions aimed at normalizing the occlusion, correcting deformations of the nose, orbits and periorbital area are performed.

At present, a compression-distraction method has been developed for the movement of the bones of the skull and face. With the help of distraction apparatus, it is possible to combine the first and second stages into one, which both greatly simplifies the treatment itself and provides early improvement of the respiratory function. Craniosynostosis is treated with distraction apparatus at the age of 9 months.

Despite all attempts to accelerate the restoration of normal proportions of the skull and normalize respiration in cases of syndromic disorders, the prognosis of treatment of such children is worse than in the treatment of isolated synostosis. This is due to the fact that about 90% of children have concomitant malformations of the brain and other organs. Despite qualified and timely treatment, about 30% of patients have a delay in neuropsychological development.

But if we consider a group of untreated children, then the percentage of their intellectual full value reaches 80%, in spite of the fact that exactly half of the children can be rehabilitated. Thus, craniosynostosis, with all the severity of external and functional manifestations, with the help of modern achievements of reconstructive surgery is successfully treated, and allows us to hope for significant progress in the aesthetic, functional and social rehabilitation of such patients in the near future.

[18], [19], [20], [21], [22], [23], [24]

How to recognize craniosynostosis?

From the instrumental methods of diagnosis, the best is computed tomography with three-dimensional remodeling of the image of the bones of the cranial vault and the face. The study allows to identify intracranial signs of hypertension, confirm the presence of a synostosis in the case of an isolated lesion, and establish all interested stitches in the case of polysynostosis.

The easiest way to diagnose premature synostosis of the cranial suture is to examine. Even a newborn can assume craniosynostosis only on the basis of the shape of the head. The non-standard form of the skull, especially in combination with deformity of the facial skeleton, should prompt any doctor to think about this disease.

In children with synostosis of several sutures, there is a clear tendency to increase the degree of neurological deficit in proportion to the number of interested sutures. In cases of damage to two joints or more, one can already speak of craniostenosis. If in children with an isolated synostosis of one of the cranial sutures the transition from the stage of subcompensation to the stage of decompensation occurs in about 10% of cases, then in polysynostosis such a transition occurs in more than half of the children. Usually neurological signs appear at the age of 2-3 years, but by this time the brain is already damaged.

Differential diagnostics

Skull deformities may not be associated with premature synostosis of the joints. Or, on the contrary, craniosynostosis may be the result of any brain damage causing a stop of its growth. In such cases, operative treatment can be considered only for cosmetic reasons, since it is impossible to obtain a functional improvement from such interference.

The most frequent example of non-sinostotic deformation of the skull is positional plagiocephaly. In this condition, the change in the shape of the head occurs during the period of the newborn on the background of the limitation of the spontaneous motor activity of the child with the involuntary rotation of the head in any direction. The cause is often torticollis and dystonic disorders that result from perinatal encephalopathy. The positional deformation of the skull differs from the true craniosynostosis in that it manifests itself from the first weeks of life, whereas synostoses exist from the moment of birth. Further, with proper care of the child and carrying out physiotherapy and physiotherapy exercises, massage and normalization of the baby's head in the crib with the help of various devices, the deformation can significantly decrease or even completely disappear. When carrying out radiographic examination of the skull, all cranial sutures are always clearly traced.

The bulging or twisting of certain areas of the head may be the result of an intrapartum trauma (fracture of the skull bones, cephalohematoma, etc.). In such cases, an anamnesis always indicates an abnormality in the normal course of labor or the early postnatal period. The same deformations can be a consequence of the underlying cerebral cysts, vascular malformations, etc.

Previously, brachycephaly was often observed in children with craniotubies against a background of vitamin D deficiency. Nowadays, the widespread prevention of rickets has reduced the number of such pathologies to a minimum.

In some cases, craniosynostosis is mistaken for microcephaly. As for synostosis, early closure of ferns and seams of the skull is characteristic of microcephaly. And in some cases, a true synostosis of individual cranial sutures may occur in a time that is not characteristic of their physiological closure. It must be remembered that with microcephaly the delay in the growth rate of the brain leads to a decrease in osteogenic activity, so synostosis of the joints occurs gradually. In the case of craniosynostosis, the reduction of osteogenic activity is primary, therefore, from birth it is always possible to reveal a characteristic radiographic picture. The lag of psychomotor development in children with microcephaly occurs earlier and is always much heavier than that with craniostenosis.

And, finally, the most important difference between microcephaly and craniosynostosis is the signs of brain damage without signs of an increase in intracranial pressure, detected by neuroimaging methods, such as magnetic resonance imaging and computed tomography. Correct differential diagnosis is very important from the point of view of the forecast, since in the case of early detection of synostosis, mental retardation can be successfully prevented, and with microcephaly surgical treatment is practically ineffective.

[25], [26], [27]

How to treat craniosynostosis?

As for the treatment of craniosynostosis, now surgical techniques have been thoroughly worked out and in the conditions of a specialized clinic they are practically not accompanied by complications. And most importantly - the less the patient's age, the less the risk of complications and the better the functional and cosmetic results.

The most active period of brain growth is the age of up to 2 years. By this age, the brain reaches 90% of the adult's volume. Thus, from the functional point of view, craniostenosis can be prevented by early surgical treatment. According to the literature, the optimal age of treatment of craniosynostosis can be considered the period from 6 to 9 months. The following facts are recognized as the advantages of treatment at this age:

• ease of manipulating the persistent and soft bones of the skull:
• facilitating the final remodeling of the shape of the skull by a rapidly growing brain:
• the younger the child, the fuller and faster heal residual bone defects.

If treatment is performed after 3 years is doubtful that it will lead to a significant improvement in the functions of the brain and the organ of vision. To a greater extent, the operation will be aimed at eliminating the presented deformation, i. E. Will have a cosmetic character.

The main feature of modern surgical treatment is not only an increase in the volume of the skull, but also a correction of its shape.

Currently, the most successful treatment is where the maxillofacial surgeon and the neurosurgeon work together. Operative treatment consists in remodeling the bones of the cranial vault. For this, the bones of deformed areas are removed and rearranged to the correct anatomical position, with the cranial cavity increasing.