Craniocynostosis is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by turning into bone, thereby changing the growth pattern of the skull. Because the skull cannot expand perpendicular to the fused suture, it compensates by growing more in the direction parallel to the closed sutures.Age/sex prevalance of Craniosynostosis
Craniosynostosis is equally districuted in both boys and girls.
Neonatal period: craniosynostosis is evident at birth when associated with other craniofacial abnormalities.
Secondary or primary craniosynostosis becomes evident as the child grows.
Individuals of any race can be affected with craniosynostosis.
Types of craniosynostosis are as follows
• Sagittal synostosis also known as scaphocephaly is the most common type. It affects the main suture on the very top of the head. The early closing forces the head to grow long and narrow, instead of wide. Babies with this type of tend to have a broad forehead. It is more common in boys than in girls.
• Metopic synostosis: it is a rare from that affects the sutureclose to the forehead. The child’s head shape may be described as trigonocephaly. It may range from mild to severe.
• Frontal plagiocephaly is the next most common type. It affects the suture that runs from ear to ear on the top of the head. It is more common in girls.
Causes of premature fusion are as follows
There are many factors which can lead to premature fusion of skull bones in infants and that are as follows
• Biomechanical factors which can lead to craniosynostosis include fetal head constraint during pregnancy.
• Environmental factors include
Maternal exposure to amine- containing drugs
There is evidence that these environmental factors are responsible for an increase in the risk of craniosynostosis most likely through effects on fibroblast growth factor receptor genes.
• Hormonal factors include, hyperthyroid induced craniosynostosis is a hormone mediated premature closure. It is found that the bones mature faster if the levels of thyroid hormone are high.
• Genetic factors: Fibroblast growth factor and fibroblast growth factor receptors regulate fetal bone growth and are expressed in cranial sutures during pregnancy. The transcription factor gene TWIST is thought to decrease the function of FGFR thus also indirectly regulating fetal bone growth. Craniosynostosis is therefore likely to occur due to disturbance in the fine balance that regulates the multiplication and maturation of the precursor bone cells in the cranial sinuses.
Symptoms depend on the type of craniosynostosis and they may include
• No “soft spot” on the newborn’s skull
• Unusual head shape
• A raised hard ridge along the affected sutures
• Slow or no increase in the size of head over time as the baby grows.
First of all in investigations physical examination of the head is done
The following tests may be done
• X-rays of the skull
• CT scan of the head
• Measuring the width of the infant’s head
Surgery is done while the baby is still an infant
Surgery helps to relieve pressure on the brain of the child.
Surgery helps to improve the appearance of the child’s head.
Surgery helps to make sure there is enough room in the skull to allow the brain to properly grow.
Craniosynostosis results in head deformity in head deformity that can be severe and permanent if it is not corrected. Increased intracranial pressure, seizures and developmental delay can occur.
Wellness of child depends upon
• How many sutures are involved.
• Depends upon the overall health of child.
• Mental retardation
• Neural tube defects
• Thyroid disease
• Benign skull tumors