Craniosynostosis
The normal skull of an infant consists of several plates of bone that are separated by sutures, or fibrous joints. When a child is born, the sutures are soft, which aids in the birthing process and allows room for growth. Over time, as an infant grows and develops, the sutures close, forming a solid piece of bone—the skull. Craniosynostosis is a condition in which one or more sutures close too early, causing cranial and facial deformities as other sutures expand more to accommodate brain growth. In rare cases, premature closure of multiple sutures may cause the pressure inside the skull to increase and restrict normal brain development.
Causes
Craniosynostosis is a congenital birth defect that occurs in one out of 2000 live births. The condition is a feature of many different genetic syndromes with a variety of inheritance patterns and chances for reoccurrence, depending on the specific syndrome present. Most often, craniosynostosis occurs as the result of a chance mutation, but in some families it may be passed from parent to child. Depending on the nature of the genetic defect, a child with one parent with craniosynostosis may have a 25 - 50 percent chance of having the defect.
There are numerous types of craniosynostosis.- Plagiocephaly involves fusion of either the right or left side of the suture that runs from ear to ear across the top of the head. This is called coronal synostosis and it causes the normal forehead and the brow to stop growing, resulting in a flattened forehead and brow on the affected side and an excessively prominent forehead on the opposite side. The eyes also may also have different shapes.
- Positional molding, a flattening of the back of the skull or one side of the skull caused by sleeping in one position, must be distinguished from plagiocephaly. Often little or no intervention is necessary for positional molding.
- Trigonocephaly is a fusion of the suture that runs from the top of the head down the middle of the forehead toward the nose. Early closure of this suture may result in a prominent ridge running down the forehead. Sometimes, the forehead looks pointed like a triangle, with closely spaced eyes (hypotelorism).
- Scaphocephaly is an early closure of the suture that runs front to back, down the middle of the top of the head. This fusion causes a skull that is long from front to back and narrow from ear to ear.
Symptoms
In infants with this condition, changes in the shape of the head and face may be noticeable. In particular, one side of the face may appear different from the other. Other clinical findings may include a full or bulging soft spot, sleepiness, prominent scalp veins, irritability, high-pitched crying, poor feeding, increasing head circumference, and bulging eyes. When the closure of the sutures affects brain development or increases pressure in the skull, it may cause headaches, vomiting, visual loss, seizures, developmental delays, and mental retardation.
Diagnosis
Diagnosis of craniosynostosis is made with a thorough
- Physical examination
- Complete prenatal and birth history
- Family history
- An assessment of developmental milestones because craniosynostosis can be associated with other neuromuscular disorders
During the examination, a measurement of the circumference of the infant's head is taken and plotted on a graph to identify normal and abnormal ranges.
Diagnostic tests that may be performed to confirm the diagnosis and assess the extent of the problem include x-rays and computed tomography (CT) scans.
Treatment
Specific treatment for craniosynostosis will be determined by the extent of the problem and which sutures are involved.
Surgery usually is the recommended treatment. The goal of surgery is to reduce the pressure in the head, release the closed suture, and correct the deformities of the face and skull bones. In some cases these deformities will become less noticeable over time without surgery. If surgery is desired or deemed necessary, it usually is recommended that the procedure be done as early as possible while an infant's bones are soft and before significant deformity occurs. After surgery, the child typically will be transferred to the intensive care unit (ICU) for close monitoring.Potential Complications
Problems after surgery may occur suddenly or over a period of time and may include
- Fever
- Vomiting
- Headache
- Irritability
- Redness and swelling along the incision areas
- Decreased alertness
- Fatigue
