NEW STUDY. By measuring a specific brain protein in the blood, it is possible to assess in advance how serious a case of concussion is. A new study from Sahlgrenska Academy shows that the NF-L protein can be measured in a blood test and be used as a prognostic marker for concussion, which could be of major significance for both emergency healthcare and sports medicine.
A person who has received a blow to the head and suffered concussion needs to rest. Usually, it is sufficient with a few days of rest for mild concussion to heal but it is not uncommon for the symptoms to be more prolonged. For about 15 percent of the people who suffer mild traumatic head injury, symptoms such as headache, dizziness, sleep problems, difficulty concentrating, short-term memory problems, and changes in personality can persist for a long time. Prolonged concussion is called post-concussion syndrome, or PCS, and can go on for weeks, months or more than a year.
”There is a real need for diagnostic and prognostic tests for concussion. Such tests are called biomarkers and can be used to find out whether there is a brain injury, to assess how serious the brain injury is, and to predict how prolonged the concussion will be,” says Pashtun Shahim, doctor and researcher in neuroscience and physiology.
Amateur boxers and ice-hockey players
The new study, published in the journal Neurology, shows that the neurofilament light protein, NF-L, could be just the sort of prognostic test healthcare needs. NF-L is a protein that occurs mainly in the nerve cells’ long projections, the axons. When the head receives a blow, axons are injured and NF-L is released into the blood where it can be measured.
To investigate the potential of NF-L as a biomarker for concussion, the researchers studied both amateur boxers and ice-hockey players. 14 amateur boxers took part in the study and were compared with the same number of healthy people who had not received blows to the head, and also 12 gymnasts who had not suffered any head trauma either.
”We could see that NF-L increased between seven and ten days after the amateur boxers had had a match. The boxers who had suffered many blows to the head or who had been dazed after the blows had higher levels of NF-L,” says Pashtun Shahim.
A future clinical tool
For the ice-hockey players, NF-L was measured through blood tests at a number of specific points in time after concussion, or on the date the hockey player no longer had any symptoms.
”We could see an increase in NF-L in the blood tests taken from a hockey player who had recently received a blow to the head, and the amount of NF-L could also be linked to how soon the hockey player could begin to play again,” says Pashtun Shahim.
“We hope the method will be developed into a clinical tool that can be used by both sports club doctors and in emergency healthcare generally to diagnose brain injury in conjunction with concussion, irrespective of how it was caused,” says Kaj Blennow, Professor of Clinical Neurochemistry at Sahlgrenska Academy.
It is not known why some people suffer more prolonged concussion than others. The fact that NF-L is so clearly linked to the severity of the concussion in question could also be of significance for further research on the injury mechanisms that cause prolonged problems.
