Saliva Liquid Biopsy Predicts Concussion Symptoms in Children

Child Psychology
New findings show that measuring a biomarker for brain injuries is more accurate than standard concussion survey questions to gauge how long symptoms will last. [wildpixel/Getty Images]

Over the past several years, athletic organizations from little league to the NFL have begun to address issues surrounding concussions. However, the initial diagnosis of concussions can be subjective as they are often based on gauging physical symptoms and answers to concussion surveys. Moreover, most of the 3 million concussions diagnosed in the U.S. each year occur in children, yet the bulk of clinical guidelines are based on adults. Because of this, pediatricians are limited in how accurately they can advise families about how long a child may suffer symptoms such as headaches, fatigue, and trouble concentrating—which can interfere with school and other activities.

Now, investigators Penn State College of Medicine have developed a simple saliva test that they believe will yield more diagnostic answers for both families and physicians. Findings from the new study are set to be presented on Saturday, May 6 in San Francisco at the 2017 Pediatric Academic Societies Meeting in a presentation entitled “Peripheral MicroRNA Patterns Predict Prolonged Concussion Symptoms in Pediatric Patients.”

In the current study, the investigators studied 50 children between the ages of 7 and 18 years with mild traumatic brain injury. Spit samples were collected and tested for microRNA (miRNA) levels. miRNAs are genetic molecules, typically found within cells, that help regulate protein production. Previous studies have found altered miRNA levels in the saliva of children with mild concussions. This mirrored similar miRNA changes in cerebrospinal fluid, which cushions the brain and spinal cord, of patients with severe brain injury.

Additionally, concussion symptoms were evaluated through parent and child Sport Concussion Assessment Tool (SCAT-3) surveys, a standardized tool commonly used to evaluate injured children for a concussion and to guide clinical decision-making. The surveys were taken within 14 days of injury and again 4 weeks post-concussion. The 29 children with prolonged concussion symptoms had higher scores for headaches, fatigue, and difficulties concentrating.

The researchers noted that the salivary miRNA levels were significantly more effective than evaluations using the SCAT-3 survey in predicting which children would continue to experience headaches, fatigue, concentration difficulties, and other concussion symptoms that lasted longer than 4 weeks. Moreover, the findings showed the standard survey to be less than 70% accurate in identifying children who would have prolonged concussion symptoms. In comparison, miRNA in saliva correctly predicted whether concussion symptoms would remain present for at least a month nearly 90% of the time.

“We believe that saliva-based RNA testing holds great promise as an accurate and noninvasive method for evaluating pediatric concussions and giving patients and families a more solid prognosis,” concluded lead study investigator Steven Hicks, M.D., Ph.D., assistant professor in the department of pediatrics at Penn State College of Medicine.