In American football, athletes regularly suffer minor head injuries. In fact, these blows are those that are not strong enough to cause symptoms of brain damage or even clinical symptoms. However, the repetition of these blows during a football season is associated with changes in neurophysiology and neuropsychology in athletes, and their accumulation in the long term can be the cause of severe neurological diseases such as Alzheimer''s and chronic traumatic encephalopathy (CTE). Because minor head concussions do not cause symptoms, it is very difficult to ascertain brain damage and determine when an athlete should be out of action. To conduct these experiments, Oliver and his colleagues used a simple and readily available diagnostic test to identify and monitor minor head impacts in sample athletes during a football season. They also emphasized that it is better to periodically measure the biomarkers of head injuries. A new study from the University of Eastern Finland shows that certain plasma microRNAs can serve as diagnostic biomarkers in mild concussion injury. Biomarkers have been discovered in an animal model and successfully used to diagnose mild brain injury in a subgroup of patients. This study was published in the International Journal of Molecular Sciences.