Reports that a blood test approved by the US Food and Drug Administration is being characterized as a way to detect concussion are misleading, warns a concussion expert based at the University at Buffalo (UB).
“Calling this blood test a concussion blood test is a misnomer,” says John Leddy, MD, clinical professor in the Department of Orthopaedics in the Jacobs School of Medicine and Biomedical Sciences at UB, medical director of the UB Concussion Management Clinic and a physician with UBMD Orthopaedics and Sports Medicine.
“This blood test does not provide a way to confirm or rule out a concussion,” he adds, explaining in a news story that the purpose of the blood test is to determine who should and should not receive a CT scan after a head injury.
“This test will help the ER doctor to decide whether or not they should order a CT scan,” which is worthwhile, he says, because CT scans expose patients to relatively high levels of radiation.
The test’s value may even be limited in these cases too, he adds, because the blood test provides results within 3 to 4 hours, longer than it would take to simply order a CT scan.
Emergency room physicians currently have very good, validated clinical rules about which patients would benefit from a CT scan after a head injury, he adds.
“And if a patient doesn’t have signs of a brain bleed, such as lethargy, seizures, worsening headache, or vomiting, then they may not need this test.”
Leddy shares caution regarding the potential for future diagnostic tests to detect whether someone has experienced a concussion.
“After a concussion, there are multiple proteins that appear in the blood at different times,” he explains. “One protein may be present 6 hours after the concussion, but will disappear within 48 hours, while another may not be present 6 hours afterward, but will start to emerge within 48 hours.
“There will probably never be one single biomarker that can reveal if someone has had a concussion,” he concludes, “but rather a group of biomarkers will be required that have clinically useful appearance times in the circulation and specificity for concussion.”
[Source: University at Buffalo]