For the first time, a group of researchers has shown that people who experience continuing symptoms from a concussion have abnormal levels of specific proteins in the brain and spinal column compared to those who have not experienced concussions. According to the results of the small study published in JAMA Neurology this week, these proteins could potentially be used as biomarkers to objectively diagnose traumatic brain injuries in the future.
While past studies have found several potent biomarkers for TBI, none have been conclusively proven to be useful for assessing the severity of a brain injury. This study is the first to identify biomarkers in the cerebrospinal fluid of athletes with post-concussion symptoms.
For the study, the researchers evaluated 31 people, including 16 Swedish professional hockey players with post-concussion syndrome. Post-concussion syndrome is characterized by long-lasting symptoms related to a concussion, including headaches, mood changes, and attention problems following a concussion. The injured players were then compared with the 15 neurologically healthy control participants.
By measuring the levels of proteins in samples of cerebrospinal fluid, the researchers were able to see that those who had experience concussion symptoms lasting more than a year had higher levels of specific proteins called Neurofilament Light (NF-L) proteins found in the white matter of the brain.
The researchers say the abnormal levels of this unique protein suggest the players experienced damage to areas of the brain containing nerve fibers essential for connecting various brain structures.
The proteins were also abnormally high in players who reported experiencing more concussions than others. Players with a high number of severe post-concussion symptoms had particularly high levels of NF-L proteins.
The team also observed that those with post-concussion syndrome showed lower levels of amyloid-beta proteins in the samples of their cerebrospinal fluid. These proteins have been associated with cognitive deficiencies and are most associated with Alzheimer’s disease. The low levels of the Amyloid-beta proteins suggest they are clumping together into plaques which are being deposited in the brain, as occurs in patients with Alzheimer’s disease.
“These findings could inform decisions about whether to continue to play or not,” Dr. Michael DiGeorgia, director of the Neurocritical Care Center at University Hospitals Cleveland Medical Center, told ABC News. DiGeorgia was not involved in this study.
“It could affect decisions around post-concussion syndrome management. If you have higher levels of NF-L proteins or low levels of amyloid, you may be on a trajectory toward more serious neurologic illness. The second or third concussion should be taken even more seriously,” DiGeorgia said.
While the study suggests these proteins could be used as effective biomarkers for diagnosing more severe concussions, it is unlikely to be widely used for the most common cases of concussions. The method used in this study requires a lumbar puncture to obtain a sample of spinal fluid, which can be painful.
“On the other hand, if you are a professional football or hockey player at high risk, I would think it may be worth an occasional lumbar puncture to see how levels of these proteins are being affected by head trauma,” he suggested.