Repetitive mild head impacts in sports (sub-concussions) are becoming a major public health concern because long-term exposure to these head impacts may have the potential to cause severe brain disorder in later life.
A recent study by Dr. Keisuke Kawata at the Indiana University School of Public Health-Bloomington, published in the prestigious Journal of Neurotrauma, measured a blood biomarker in association with seemingly harmless head butting by a soccer ball as an indicator of brain injury. The biomarker, neurofilament-light protein (NF-L), is associated with Alzheimer’s disease, dementia, and different severities of brain injury.
This study relied on an innovative “soccer heading” model, which can produce head impacts safely by controlling ball traveling speed, frequency, interval, magnitude of hit, and ball placement to the head.
The study found that NF-L levels gradually increased with repeated simulated blows to the head, and the highest level was observed at 24 hours afterwards.
The data suggest that repetitive hits to the head by soccer balls can possibly cause damage in neuronal axons, and NF-L served as a messenger raveling through the blood stream telling the body that “the brain is injured.”
According to Dr. Keisuke “Since brain imaging like MRI and CT scans are not readily available and are costly, NF-L has the great potential in monitoring brain damage from repetitive mild head impacts. This work has a large implication to other sports (American football, rugby, ice-hockey) as well as military personnel, who also experience frequent head impacts. However, it is important to note that given small sample size in our study, the results are yet preliminary, and there needs to be a larger scale study to confirm our data.”