Intracranial hypertension — an increase in the pressure of the brain inside a baby’s cranium — can cause neurodevelopmental damage and requires immediate treatment, but detecting the condition can be an imprecise science when it develops slowly.
“Surgeons avoid using intracranial monitors — monitors you put inside the cranium to see whether there is pressure or not — or spinal taps, because these two things are very invasive, and they can cause hemorrhage and infections,” says Antonio Porras, PhD, associate professor in the Division of Plastic and Reconstructive Surgery and associate professor of biostatistics and informatics in the Colorado School of Public Health. “And because they're babies, they're never going to tell you if they have a headache.”
Other methods of detecting intracranial pressure, including evaluation of the optic disc and radiological evaluation of images, are often inconclusive in young children, Porras says, putting surgeons at a loss when it comes to diagnosing and treating the condition.
Cranial bone density as accurate measure
In research published recently in the journal Neuroradiology, Porras, along with CU surgery faculty members Brooke French, MD, and Allyson Alexander, MD, finds that cranial bone density is an accurate indicator of chronic intracranial hypertension, revealing a noninvasive way of testing for the condition.
“When the brain needs more space and starts putting pressure on the bone, it creates an imprint in the bone, and that imprint show up as a loss of bone density that happens because of the increased pressure,” Porras says.
Previously, those imprints weren’t often visible until the skull was opened during surgery, but Porras’s research used CT scans of the skulls from more than 2,000 patients — both with intracranial hypertension and without — to teach an AI tool to identify children at risk for the condition, based on their bone density.
“Bone density changes very quickly with age, so you need to have a very specific reference case for every single child you're evaluating,” he says. “Our focus has been on creating normative references of cranial development — the size of the cranium, the shape of the cranium, but also the thickness and density at every single location of the bone. And because those references are age- and sex-specific, they are a very accurate reference for every patient.”
The method is not yet in clinical use, but Porras continues to study its efficacy and make the case for using it as an early detection tool.
Detecting increased pressure in craniosynostosis
Since craniosynostosis — a condition in which the plates in a baby’s skull fuse too early, restricting cranial growth and causing deleterious effects on the brain — can cause increased intracranial pressure, it’s all the more important to detect the condition early so it can be treated immediately, Porras says.
“We know that early treatment is going to reduce morbidity in these children, and these are children who can grow up with migraines, neurodevelopmental delays, learning problems or vision issues if they are not treated timely,” he says. “Early intervention can decrease the likelihood of these effects, and also the severity.”
To operate or wait
The AI technology to evaluate CT scans of the skull also can let surgeons know how urgent it is to get a child with craniosynostosis to surgery right away.
“Craniosynostosis is usually diagnosed in the first few weeks of life, but because the babies are so little, surgeons try to delay surgery to reduce the risks of treatment,” Porras says. “Surgeons would rather do surgery when they are eight months old than when they are two weeks old, just because of the risks and the invasiveness of the surgery. The problem is that if these children develop signs of intracranial hypertension, you need to go to surgery right away, because the risks of delaying surgery are a lot higher than there is of going to surgery early.
“That determination has usually been extremely subjective,” he continues. “We can use the bone density from scans to inform the surgeons of the risks of intracranial pressure so they can decide to go immediately to surgery or they can delay it because a child still doesn't have signs of pressure. That decision is essential, because the longer you grow up with pressure, the more likely you are to have neurodevelopmental damage associated with it.”
