Can a Blood Test Diagnose Concussions?

Ann McKee at Boston University School of Medicine examines the donated brains of former professional athletes to understand how repeated head injuries affect the brain. Her findings about pro-athletes—like Tom McHale, who died at age 45 due to chronic traumatic encephalopathy, caused by multiple concussions—has influenced the new NFL ruling on concussions. Until 2009, players could play after sustaining a head injury as long as they didn’t lose consciousness. Since then, players cannot play if they show signs such as dizziness, headaches, memory lapses, and an inability to recall plays.

But physicians know that these signs—and diagnostic imagining—don’t always indicate concussions and athletes (and others) might continue normal activities with mild concussions. A new blood test might make it easier for physicians to detect head injuries.

U.S. Army researchers, with partners at Banyan Biomarkers, have devised a simple blood test to determine a concussion. The test looks for proteins, SBDP145 and BSDP120, which flood the bloodstream after axons (the neuron’s tails, which aid in transmitting electrical messages) break. The test also detects UcH-L1, which indicates cell damage, and MAP-2, which oozes out following dendrite injuries (dendrites are branch-like projections, aiding in electrochemical stimulation).

Army Col. Dallas Hack, MD, managed the research of this biomarker test, which accurately diagnosed 34 people with concussions. After the researchers finished the blood test, the preformed traditional imagining tests, confirming the mild brain injury. Doctors sometimes miss mild concussion because signs don’t appear on X-rays and patients frequently minimize symptoms (consider the professional athletes who don’t want to sit out games).

Experts warn that the excitement surrounding such a discovery might be premature. This initial study looked at a small sample and there is little agreement about what actually constitutes a mild concussion. The Army plans to conduct more pilot and feasibility studies as well as a larger study of 1,200 patients, slated for completion in 2013.