New Insights on Craniosynostosis

Seattle Children’s researchers found that the mild to moderate developmental delays that can accompany the most common type of craniosynostosis can be overcome.

In 2015, Dr. Matthew Speltz’s team published results indicating that school-age children with the most common form of craniosynostosis are more likely to suffer developmental delays and learning problems than children who don’t have the disorder. But the good news outweighs the bad – the delays tend to be mild to moderate and most children in the study were doing as well as their peers in school.

The condition, called single-suture craniosynostosis (SSC), occurs when one seam in an infant’s skull fuses prematurely, stopping it from expanding as the brain grows. Researchers have linked multi-suture forms of craniosynostosis to serious developmental problems – such as not being able to read – that can require intensive special education. The research, along with anecdotes that many children with SSC have learning disabilities, created an assumption that kids with SSC have considerably higher rates of significant developmental issues.

Speltz’s study was the first to track neurodevelopment in a large group of children with SSC from infancy until they started elementary school. The study found that children with SSC had higher rates of learning problems than similar children without SSC. Still, less than half of children with SSC had learning issues, and those issues were usually mild enough that they could be treated with standard interventions like tutoring and special education.

Speltz, a psychologist who sees patients in Seattle Children’s Craniofacial Clinic, hopes the results spur craniofacial programs to make developmental screening part of standard SSC care.

“If we can intervene early – ideally when these children are in preschool – we should be able to help them manage their learning issues and keep them on track to be successful in school,” Speltz says.

Young children suffer delays

In 2002, Speltz and his colleagues enrolled 270 infants with SSC in their study and started comparing their developmental progress to typical children. They initially found that, on average, children with SSC suffered mild developmental delays as infants and at age 3. But the researchers, who included Seattle Children’s Drs. Michael Cunningham and Brent Collett, didn’t know if those problems would persist.

“In typical children, developmental delays will often go away or sort themselves out by the time a child starts school,” Speltz says.

Slightly lower scores

When the study participants reached an average age of 7.5 years old, the children with SSC scored lower, on average, on standardized tests of intelligence, reading, spelling and math.

The biggest differences came in IQ and math computation, where the scores of children with SSC were about one-third of a standard deviation lower than the kids who didn’t have craniosynostosis. But children with SSC scored only slightly lower on reading and spelling tests. While 40% of them had learning disabilities, it is a relatively small step above the 30% rate among children who didn’t have the disorder.

“We were really encouraged to see that the majority of kids with SSC will be able to have a normal childhood and function well in school,” Speltz says.

Higher risks for a small group

Children with metopic, unicoronal or lambdoid synostosis – which affect particular skull seams – did have significantly lower test scores, suggesting they are more likely than children with sagittal synostosis to need a special education program. And six children with SSC had extremely low test scores that suggest they might be intellectually disabled, compared to just one of the children who didn’t have craniosynostosis.

How surgery affects development

The research is part of Speltz’s push to both pinpoint developmental delays among children with craniofacial disorders and find ways to minimize them. He’s getting set to investigate whether the two surgeries that repair SSC – typically performed before a child’s first birthday – have different effects on development and skull shape.

Most infants with SSC have undergone lengthy surgeries that reconstruct their skulls and give the brain room to grow. But there is growing interest in an endoscopic procedure that is less invasive and uses less anesthesia than total reconstruction, but requires patients to spend months wearing a helmet that remolds the skull after surgery.

“If one of these surgeries is shown to have better outcomes, it could make a big difference in which procedure surgeons recommend and parents choose for their children,” Speltz says.

Speltz hopes the results spur craniofacial programs to make developmental screening part of standard single-suture craniosynostosis care.