A new study finds that small molecules in saliva may help diagnose and predict the length of concussions in children. The findings, published in JAMA Pediatrics, could help pave the way toward more accurate concussion diagnoses and treatment plans.
Researchers at Penn State College of Medicine measured the levels of microRNAs — tiny snippets of noncoding RNA — in the saliva of pediatric concussion patients. They discovered that the presence of certain microRNAs in saliva was better able to identify concussions and more accurately predict the length of concussion symptoms compared to relying on patient surveys alone.
“There’s been a big push recently to find more objective markers that a concussion has occurred, instead of relying simply on patient surveys,” said Dr. Steven Hicks, an assistant professor of pediatrics.
“Previous research has focused on proteins, but this approach is limited because proteins have a hard time crossing the blood-brain barrier. What’s novel about this study is we looked at microRNAs instead of proteins, and we decided to look in saliva rather than blood.”
Concussions symptoms may involve headaches, nausea, confusion, amnesia, or lack of consciousness. While most concussions clear up within two weeks, about one-third of patients will experience symptoms for a longer period of time.
Patients are typically told to rest and to not engage in any physical activity such as sports or gym class until their symptoms subside. Hicks said that while it is important to give the brain enough time to heal, it is difficult to accurately predict how long patients should rest.
“As a general pediatrician, I often see children with concussions,” Hicks said. “The tools we use to diagnose and manage concussions are subjective — we do a physical exam and then have them answer a survey about their symptoms. Then we make an educated guess about how long that child might continue to have a headache or feel nauseous. But those guesses aren’t evidence-based and aren’t always accurate.”
MicroRNAs are present throughout the body and can impact how genes are expressed depending on different conditions, like disease or injury. The researchers suspected these biomarkers might be able to identify concussions and even predict their duration.
For the study, the research team looked at 52 concussion patients aged seven to 21. Each participant was evaluated with the Sport Concussion Assessment Tool (SCAT-3), a common tool that doctors use to inventory concussion symptoms and severity, within two weeks of their injury. The researchers also asked the parents to report their children’s symptoms. This assessment was repeated four weeks after the injury occurred.
Saliva was collected from each participant and analyzed for levels of different microRNAs. The researchers then compared the microRNA profiles to the patient’s symptoms at both the initial and follow-up assessments.
The researchers then isolated five microRNAs that could correctly identify which patients would go on to experience longer symptoms. This method correctly identified 42 of the 50 patients who would experience prolonged symptoms.
“The microRNAs were able to predict whether symptoms would last beyond four weeks with about 85 percent accuracy,” Hicks said. “In comparison, using the SCAT-3 report of symptoms alone is about 64 percent accurate. If you just go off the parent’s report of symptoms, it goes down to the mid-50s. In this pilot study, these molecular signatures are outperforming survey tools.”
While more studies are needed, Hicks said he is hopeful that measuring microRNAs in saliva could one day be an accurate, quick way to diagnose and manage concussions.
“The ultimate goal is to be able to objectively identify that a concussion has happened and then predict how long the symptoms will go on for,” Hicks said. “Then we can use that knowledge to improve the care that we provide for children who have concussions, either by starting medicine earlier or holding them out of activities for longer.”
Source: Penn State College of Medicine