7 Key Symptoms of Craniosynostosis: Early Warning Signs to Watch For

Craniosynostosis is a birth defect in which one or more of the fibrous joints (sutures) between the bones of an infant’s skull close prematurely, before the brain is fully formed. This early fusion can affect the normal growth of the skull and brain, potentially leading to abnormal head shape and increased pressure inside the skull. Understanding the symptoms of craniosynostosis is crucial for early detection and intervention, as timely medical evaluation can significantly improve outcomes for affected children.

The condition occurs in approximately 1 in 2,000 to 2,500 live births and can range from mild to severe cases. While some symptoms are immediately visible at birth, others may develop gradually as the child grows. Parents and caregivers should be aware of these warning signs to ensure prompt medical attention when necessary.

1. Abnormal Head Shape

The most noticeable symptom of craniosynostosis is an abnormally shaped skull or head. The specific shape abnormality depends on which suture or sutures have closed prematurely. Unlike positional plagiocephaly (flat head syndrome caused by sleeping position), the head shape in craniosynostosis is typically more severe and doesn’t improve with repositioning.

Common head shape abnormalities include:

• Scaphocephaly: A long, narrow head shape when the sagittal suture (running from front to back) closes early
• Trigonocephaly: A triangular-shaped forehead with a pointed front when the metopic suture closes prematurely
• Plagiocephaly: A flattened appearance on one side of the head when one coronal suture closes early
• Brachycephaly: A flat, wide head shape when both coronal sutures close too soon
• Oxycephaly: A tall, pointed head shape when multiple sutures close prematurely

The abnormal head shape is usually present at birth or becomes noticeable within the first few months of life. As the brain continues to grow, the skull compensates by expanding in areas where the sutures remain open, which can make the shape abnormality more pronounced over time.

2. Hard Ridge Along the Affected Suture

A palpable hard ridge or raised area along the skull where the suture has prematurely fused is a characteristic physical finding in craniosynostosis. Parents or healthcare providers may feel this firm, bony ridge when gently touching the baby’s head during examination.

This ridge forms because the bones have fused together abnormally, creating a solid bony prominence rather than the normal flexible fibrous joint. The ridge is typically most noticeable along the path of the affected suture and may become more prominent as the child grows. In some cases, the ridge may be subtle and only detectable by an experienced physician, while in others it can be quite obvious to the touch.

Healthcare providers will carefully palpate the skull during well-baby checkups to assess for this finding, as it helps distinguish craniosynostosis from positional head shape abnormalities that don’t involve actual bone fusion.

3. Missing or Abnormal Fontanelle (Soft Spot)

Fontanelles are the soft spots on a baby’s skull where the bones haven’t yet fused together, allowing for brain growth and passage through the birth canal. In craniosynostosis, the fontanelle may be missing, unusually small, or may close much earlier than expected.

Normally, the anterior fontanelle (at the top front of the head) remains open until around 12 to 18 months of age, while the posterior fontanelle (at the back of the head) typically closes by 2 to 3 months. In babies with craniosynostosis, these soft spots may:

• Never be present at birth
• Be significantly smaller than normal
• Close within the first few weeks or months of life
• Feel abnormally tense or full even when the baby is calm and upright

The premature closure or absence of fontanelles can indicate that the skull sutures are not developing normally and may be a sign of craniosynostosis requiring medical evaluation.

4. Facial Asymmetry or Abnormalities

Craniosynostosis can cause noticeable facial asymmetry or abnormal facial features because the restriction in skull growth affects the underlying facial bone development. The face may appear uneven or misaligned, with one side looking different from the other.

Specific facial features that may be affected include:

• Eye position: Eyes may appear misaligned, with one positioned higher than the other, or they may appear too close together or too far apart
• Forehead: The forehead may be unusually flat, sloped, or pointed depending on which suture is affected
• Ear position: Ears may be positioned unevenly or appear asymmetric
• Nose deviation: The nose may appear deviated or off-center
• Jaw misalignment: The upper and lower jaws may not align properly, potentially affecting feeding and later dental development

These facial abnormalities often become more noticeable as the child grows, particularly if the condition is not addressed. The degree of facial asymmetry typically correlates with the severity of the craniosynostosis.

5. Increased Intracranial Pressure Signs

As the brain continues to grow within a skull that cannot expand normally due to fused sutures, increased pressure can build up inside the skull (increased intracranial pressure or ICP). This is a serious complication that requires prompt medical attention.

Signs and symptoms of increased intracranial pressure in infants and young children may include:

• Bulging fontanelle: The soft spot appears full or bulging even when the baby is upright and calm
• Irritability: Excessive fussiness, crying, or difficulty consoling the baby
• Poor feeding: Difficulty feeding, vomiting, or poor weight gain
• Sleepiness: Unusual lethargy or difficulty waking the baby
• Developmental delays: Failure to meet developmental milestones
• Headaches: In older children who can communicate, complaints of persistent headaches
• Vision problems: Swelling of the optic nerve (papilledema) visible on examination
• Seizures: In severe cases, seizure activity may occur

Not all children with craniosynostosis develop increased intracranial pressure, but it’s more likely in cases where multiple sutures are affected or when the condition goes untreated. This is why early detection and monitoring are essential.

6. Developmental Delays

Some children with craniosynostosis may experience developmental delays, particularly if the condition is severe or involves multiple sutures. The restricted skull growth can potentially limit brain development and function, though many children with single-suture craniosynostosis have normal cognitive development.

Developmental concerns may include:

• Motor delays: Delayed reaching of motor milestones such as rolling over, sitting up, crawling, or walking
• Speech and language delays: Slower development of verbal communication skills
• Cognitive delays: Difficulties with learning, memory, or problem-solving skills
• Social-emotional delays: Challenges with social interaction or emotional regulation

It’s important to note that developmental delays are more commonly associated with syndromic craniosynostosis (when craniosynostosis occurs as part of a genetic syndrome) or cases with multiple suture involvement. Children with simple, single-suture craniosynostosis who receive appropriate early intervention typically have excellent developmental outcomes.

Regular developmental screening and monitoring by healthcare providers can help identify any delays early so that appropriate support and interventions can be provided.

7. Eye Problems and Vision Changes

Eye-related symptoms can occur in craniosynostosis, particularly in cases affecting the coronal sutures or when multiple sutures are involved. These problems arise from the abnormal skull and facial bone development affecting the eye sockets (orbits) and surrounding structures.

Common eye-related symptoms include:

• Proptosis: Bulging or protruding eyes due to shallow eye sockets
• Strabismus: Crossed eyes or eye misalignment affecting eye coordination
• Refractive errors: Need for corrective lenses due to abnormal eye shape or position
• Exposure keratopathy: Dry, irritated eyes due to incomplete eyelid closure from eye prominence
• Vision impairment: Reduced visual acuity from structural abnormalities or increased intracranial pressure affecting the optic nerve
• Amblyopia: “Lazy eye” developing from uncorrected strabismus or refractive errors

These eye problems may not be immediately apparent at birth but can develop or become more noticeable as the child grows. Regular ophthalmologic examination is often recommended for children with craniosynostosis to monitor for these complications and provide appropriate interventions to preserve and optimize vision.

In cases with increased intracranial pressure, swelling of the optic nerve (papilledema) can occur, which if left untreated may lead to permanent vision loss. This underscores the importance of comprehensive medical evaluation and monitoring for children diagnosed with craniosynostosis.

Main Causes of Craniosynostosis

Understanding the causes of craniosynostosis can help parents and healthcare providers identify risk factors and potentially related conditions. While the exact cause isn’t always clear, research has identified several contributing factors:

Genetic Factors: Mutations in certain genes (including FGFR2, FGFR3, TWIST1, and others) can cause craniosynostosis. These may occur spontaneously or be inherited from a parent. Genetic factors are more commonly involved in syndromic craniosynostosis, where the condition occurs as part of a recognized genetic syndrome such as Crouzon syndrome, Apert syndrome, or Pfeiffer syndrome.

Syndromic Causes: Approximately 15-40% of craniosynostosis cases occur as part of a genetic syndrome that affects multiple body systems. These syndromic cases often involve multiple suture fusion and may be associated with other physical abnormalities, including limb differences, hearing loss, or organ problems.

Non-Syndromic (Isolated) Causes: The majority of craniosynostosis cases (60-85%) are non-syndromic, meaning they occur in isolation without other associated abnormalities. The cause of these cases is often unknown, though both genetic and environmental factors may play a role.

Environmental Factors: Some research suggests that certain environmental exposures during pregnancy may increase the risk of craniosynostosis, including:

• Maternal thyroid disease or thyroid medication use during pregnancy
• Certain medications taken during pregnancy, particularly some seizure medications
• Maternal smoking during pregnancy
• Advanced parental age
• Multiple births (twins, triplets)
• Assisted reproductive technology

Intrauterine Constraint: In some cases, mechanical forces in the womb, such as constraint from multiple fetuses or unusual positioning, may contribute to craniosynostosis development, though this is less common.

Metabolic Disorders: Rarely, certain metabolic conditions such as hyperthyroidism or rickets may be associated with craniosynostosis.

In many cases, craniosynostosis occurs sporadically without a clear identifiable cause, and most affected families have no family history of the condition. Genetic counseling may be recommended for families with craniosynostosis to better understand recurrence risks and to identify any underlying genetic syndromes.

Prevention Strategies

While most cases of craniosynostosis cannot be prevented because they result from genetic factors or unknown causes, there are some general strategies that may help reduce the risk or support overall fetal development:

Prenatal Care: Regular prenatal checkups and appropriate prenatal testing can help identify potential issues early and ensure optimal maternal and fetal health throughout pregnancy.

Folic Acid Supplementation: Taking folic acid before conception and during early pregnancy (at least 400 mcg daily) is recommended for all women of childbearing age to reduce the risk of neural tube defects and potentially other birth defects.

Medication Review: Women who are pregnant or planning to become pregnant should discuss all medications with their healthcare provider to ensure they are safe during pregnancy. Some medications, particularly certain anti-seizure drugs, may need to be adjusted or changed.

Avoid Harmful Substances: Avoiding smoking, alcohol, and illicit drugs during pregnancy is essential for overall fetal health and may reduce the risk of various birth defects.

Thyroid Management: Women with thyroid disorders should work closely with their healthcare provider to ensure proper thyroid function during pregnancy, as both hyperthyroidism and hypothyroidism can affect fetal development.

Genetic Counseling: Families with a history of craniosynostosis or related genetic syndromes may benefit from genetic counseling before conception to understand their risks and options.

Positional Care After Birth: While this doesn’t prevent craniosynostosis, practicing proper positioning for infants (including “tummy time” when awake and supervised, and varying head position during sleep) can help prevent positional plagiocephaly, which is sometimes confused with craniosynostosis.

It’s important to understand that even with all recommended precautions, craniosynostosis may still occur, as many cases result from spontaneous genetic changes that cannot be predicted or prevented. Parents should not blame themselves if their child is diagnosed with this condition.

Frequently Asked Questions

What is the difference between craniosynostosis and a flat head from positioning?

Craniosynostosis involves actual premature fusion of skull bones and typically presents with a hard ridge along the affected suture, abnormal head shape that doesn’t improve with repositioning, and potentially other symptoms like facial asymmetry. Positional plagiocephaly (flat head syndrome) is caused by external pressure on the soft skull from lying in one position and improves with repositioning therapy. A healthcare provider can distinguish between these conditions through physical examination and imaging if needed.

Can craniosynostosis be detected during pregnancy?

In some cases, severe craniosynostosis may be detected on prenatal ultrasound during the second or third trimester, though it’s often difficult to diagnose before birth. Most cases are identified after birth through physical examination or within the first few months of life as the abnormal head shape becomes more apparent.

Is craniosynostosis painful for babies?

Craniosynostosis itself is not typically painful. However, if increased intracranial pressure develops, it can cause discomfort, irritability, and headaches in older children. Babies with increased pressure may show signs of fussiness, poor feeding, and excessive crying.

Will my child’s head shape improve on its own?

Unlike positional plagiocephaly, craniosynostosis will not improve on its own and typically becomes more pronounced as the child grows if left untreated. Medical evaluation and intervention are necessary to address the fused suture and allow for normal brain growth and skull development.

How is craniosynostosis diagnosed?

Diagnosis is made through physical examination by a healthcare provider, including careful assessment of head shape, palpation of the skull for ridges, and measurement of head circumference. Imaging studies such as CT scan or X-rays may be ordered to confirm the diagnosis, identify which sutures are affected, and assess for increased intracranial pressure. In some cases, genetic testing may be recommended.

Are there different types of craniosynostosis?

Yes, craniosynostosis is classified based on which suture(s) are affected. Single-suture craniosynostosis involves only one suture and is most common, while complex or multi-suture craniosynostosis involves two or more sutures. It’s also categorized as either non-syndromic (isolated) or syndromic (occurring with other abnormalities as part of a genetic syndrome).

What specialists treat craniosynostosis?

Craniosynostosis is typically managed by a multidisciplinary team including pediatric neurosurgeons, craniofacial surgeons, pediatricians, geneticists, ophthalmologists, and other specialists as needed. This team approach ensures comprehensive care addressing all aspects of the condition.

If craniosynostosis runs in my family, what are the chances my child will have it?

The recurrence risk depends on whether the craniosynostosis is part of a genetic syndrome and the specific genetic cause. For non-syndromic, single-suture craniosynostosis without an identified genetic cause, the recurrence risk is generally low (around 2-5%). For syndromic cases or those with identified genetic mutations, the risk may be higher, and genetic counseling is recommended to provide specific risk assessment.

Can craniosynostosis affect my child’s brain development?

Most children with single-suture craniosynostosis who receive appropriate early care have normal cognitive development. However, if left untreated, particularly in cases with multiple suture involvement or increased intracranial pressure, there is a risk of developmental delays and cognitive impairment. Early detection and appropriate intervention are key to optimizing developmental outcomes.

How soon after birth can craniosynostosis be detected?

Some cases are noticeable immediately at birth, particularly those with severe skull shape abnormalities. Others may not become apparent until the first few weeks or months of life as the abnormal head shape becomes more pronounced with growth. This is why regular well-baby checkups that include head shape and size assessment are important for early detection.

References:

• Mayo Clinic – Craniosynostosis
• Centers for Disease Control and Prevention – Craniosynostosis
• National Institute of Neurological Disorders and Stroke – Cephalic Disorders
• Boston Children’s Hospital – Craniosynostosis
• Johns Hopkins Medicine – Craniosynostosis