Craniosynostosis

Craniosynostosis Definition

This is a congenital defect in which one or more joints in between the bones in the skull of a newborn close even before the brain has fully developed [¹]. This changes the pattern of growth of the infantile skull.

It is also known as “Premature closure of sutures”.

Craniosynostosis Epidemiology

It affects one out of 2,000 to 2,500 live births around the world.

Craniosynostosis Types

It is classified into the following forms:

• Sagittal synostosis (Scaphocephaly) – It affects the main suture at the apex of head (sagittal suture) and results in a broad forehead. The head grows long and narrow, rather than wide. The most common form of Craniosynostosis, it affects boys more than girls.
• Frontal plagiocephaly – The second-most common form, it affects girls more, and impacts the suture which runs from one ear to another.
• Coronal synostosis – It involves premature fusion of one of the coronal sutures, structures running from ears to the sagittal suture at the apex of the head. It may cause flattening of affected head section, slanted skull, deviated nose and elevated eye socket.
• Metopic synostosis – This is rarer, but may vary from mild to acute in intensity. It affects the metopic suture located near the forehead and leads to an abnormal head shape (Trigonocephaly).

Lamboid synostosis is a rare form that involves the lamboid suture, which runs across the skull, and is characterized by flattening of the affected head section.

Craniosynostosis Causes

It is not known what exactly causes this disease. However, it is believed to be hereditary in nature. No family history of the disorder is generally observed [²]. However, a hereditary form exists that occurs along with other problems like blindness, reduced intelligence and seizures.

Some genetic disorders commonly related with Craniosynostosis include:

• Apert
• Carpenter
• Crouzon
• Chotzen
• Pfeiffer syndromes

Most affected children have normal intelligence and are healthy otherwise.

Craniosynostosis Risk Factors

Individuals with a family history of the condition are at a high risk of suffering from it. This is true in case of the type of Craniosynostosis that affects members of the same family.

Craniosynostosis Symptoms

The signs and symptoms depend on the form of the disease that one suffers from, and typically include:

• Abnormal shape of head [³]
• Elevated hard ridge along the sutures that are impacted
• Reduced or non-enlargement of head size over time
• Absence of fontanelle (soft spot) on the skull of newborns

Some types of the disorder can be related with strabismus, a disorder in which the eyes fail to move in tandem.

Craniosynostosis Testing and Diagnosis

It initially involves a physical examination, in which the skull is felt. The following tests may be performed:

• X-ray exam of the skull
• CT scan of the head
• MRI scans (in isolated cases)
• Measurement of head width
• Ultrasound, that helps rule out Craniosynostosis in clinically suspected cases

Genetic Testing

It may help detect the disease if an underlying hereditary disorder is suspected as the cause. Although a blood sample is usually required, a sample of skin, hair or other tissue may be needed depending on the type of suspected abnormality. The sample may be sent for lab tests.

Craniosynostosis Treatment

While mild cases may require no surgery or medical intervention other than a cranial helmet (for reshaping the head), more severe cases need surgery as primary mode of cure. The timing and type of surgery depends on the type of the disease as well as the possible presence or absence of an underlying disorder.

Operative options include:

• Traditional surgery – An incision is made into the cranial bones and scalp to re-shape the affected skull section. Post-surgery, infants need at 3 days of hospital stay.
• Endoscopic surgery – It is a less invasive form of surgery, involving the insertion of a lighted tube (endoscope) through incisions made over the affected suture. It generally includes less bleeding, inflammation and hospital stay.

Craniosynostosis – Post-Operative Management

Following operation, the head of affected children are commonly wrapped with turban. Typically, they are shifted to an ICU setting for close monitoring after surgery. Possible complications like vomiting, headaches, fever and fatigue should be promptly evaluated.

Craniosynostosis Prognosis

The outcomes depend on the overall health of infants as well as the number of sutures (immovable joints) involved. Affected children operated on generally show good recovery. Quality of life especially improves when no genetic syndrome is associated.

The disease also has a risk of recurrence, which can range from 2-50%, and can only be determined after complete genetic assessment.

Craniosynostosis Complications

Patients may suffer from head deformity that can be acute and permanent if left untreated [⁴]. Other possible problems (which can involve long term effects) include:

• Seizures
• Developmental delays
• Learning disabilities and vision problems, in later years
• Raised intracranial pressure, causing irritability, vomiting , headaches, breathing difficulties etc.

Differing appearance may also result in psychological problems in adulthood. Possible risks involved with surgical repair include:

• Brain infection
• Brain inflammation
• Damage to brain tissue
• Fusion of bones again, requiring further operations

Craniosynostosis Pictures

The images here show how affected infants and adults look like.

Picture 1 – Craniosynostosis

Picture 2 – Craniosynostosis Image

Craniosynostosis ICD9 Code

The ICD9 Code for this disorder is 756.0.

References:

1. Craniosynostosis (nlm.nih.gov)
2. Craniosynostosis (Mayoclinic)
3. Craniosynostosis (Wikipedia)
4. Craniosynostosis (nhs.uk)