Nerve protein in blood shows extent of brain damage following
1 April 2014
Elevated blood levels of tau, a nerve cell protein, indicates the
extent of brain damage from concussion, according to research at
Sahlgrenska Academy in Sweden.
The researchers have now developed a method that can show just an
hour after the injury how severe the concussion is, if there is a
risk of long-term symptoms and when the player can return to the
They monitored and examined all of the players in Sweden's top
hockey league in cooperation with Luleå University of Technology.
Between September and December of the 2012/2013 season alone, 35 of
288 players in the Swedish Hockey League (SHL) had had a concussion
— in three cases, it was so severe that the player was knocked
The goal of the unique study was to find safer methods of
diagnosing sports-related brain injuries, and to obtain a better
basis for decisions about when the player can return to the game.
In the study, the players who had a concussion were asked to
provide repeated blood samples, directly after the concussion and
during the ensuing days. The results were compared with the
pre-season samples from two full teams.
Professor Henrik Zetterberg and his colleagues identified the
nerve cell protein, called tau, was at elevated levels in the blood
following concussion. By measuring the tau levels in a regular blood
test, the researchers could say how severe the concussion was just
one hour after the injury, and with a high level of certainty could
predict which players would have long-term symptoms and thereby
needed to rest longer.
"In ice hockey and other contact sports, repeated concussions are
common, where the brain has not finished healing after the first
blow. This kind of injury is particularly dangerous, but there have
not been any methods for monitoring how a concussion in an athlete
heals," says Prof Zetterberg.
"In contact sports like ice hockey, boxing and American football,
concussions are a growing international problem. The stakes for the
individual athlete are high, and the list of players forced to quit
with life-long injury is getting ever longer," says Henrik
"We hope that this method will be developed into a clinical tool
for club physicians and others in sports medicine, and is used as a
basis for the decision on how long the player should rest after a
blow to the head," says Henrik Zetterberg. “It could even be used in
general in emergency medical care to diagnose brain damage from
concussions regardless of how they happened.”
The study was conducted in cooperation with researchers at the
Luleå University of Technology, Sahlgrenska University Hospital and
the US biotech firm Quanterix Corporation.
Shahim P, et al. Blood Biomarkers for Brain Injury in Concussed
Professional Ice Hockey Players, JAMA Neurol. Published online March
13, 2014. doi:10.1001/jamaneurol.2014.367