Serum SNTF increases
in concussed professional ice hockey players and relates to the severity of
post-concussion symptoms

Siman
R., Shahim P., Tegner .Y, Blennow K., Zetterberg H., Smith DH. J Neuroscience.
2014; ahead of print

Take Home Message: Biomarkers
in the blood, such as SNTF, are elevated for up to 6 days following a
concussion compared with preseason levels. This marker may eventually be developed to determine diagnosis and
prognosis after a concussion as well as guiding return-to-play decisions.

Following
a concussion, long-lasting brain dysfunction may relate to widespread damage to
axons. Unfortunately, there is no established method to identify concussions that
may lead to long-lasting dysfunction at an early, treatable stage. One possible
candidate is an alpha II-spectrin N-terminal fragment
(SNTF), which is a fragment of a protein that is part of the axon’s
cytoskeleton. SNTF increases in blood after an injury but it has not been
studied as a marker for sports-related concussion. Therefore, the authors
evaluated whether serum SNTF is a diagnostic and prognostic biomarker for
concussion in a prospective cohort involving professional ice hockey players from
12 teams within the Swedish Hockey League (288 players). The authors collected
preseason serum from 45 players (2 teams) and 17 of these players provided
another sample 1 and 12 hours after a training game without concussion. Among
the 288 total players, 28 players had concussions and the team physicians
obtained blood samples 1 hour (25 players), 12 hours (22 players), 36 hours (20
players), 144 hours (18 players) following the concussion, as well as on the
day of return to play (10 players). At preseason, serum levels of SNTF were so
low that in 58% of the players the authors couldn’t detect any SNTF. SNTF serum
levels remained unchanged at 1 and 12 hours following a training game. Average SNTF
concentrations were up to 2-times higher at 12, 36, and 144 post-concussion
compared with preseason levels. SNTF levels at 36 hours had the best ability to
accurately diagnose a concussion and predict who would experience persistent
post-concussion symptoms that delayed the return to play for 6 or more days.

This
study is important because it demonstrates the potential to diagnose a concussion
with a blood test. This longitudinal study found that SNTF serum concentration
increases as early as 1 hour post injury and remains elevated up to return to
play. Additionally, serum SNTF levels during the subacute phase after a
concussion may enable diagnosis of a concussion and predicting who may have
prolonged symptoms.  Measuring serum at
36 hours after an injury may be easier than obtaining samples 1 hour after a
concussion, as was done in prior studies. Future research will need to verify
if SNTF could also be an objective test for making return-to-play decisions. Forty-two
percent of the preseason serum samples were above the lower limit of detection,
which suggests this marker may be elevated due to factors like a history of
concussion or smaller repetitive blows. Therefore, future research should
investigate if concussion injury from several repetitive blows would also
change the SNTF levels. While more research will be needed this study shows
that we may someday be able to use blood tests to diagnose concussions and
predict who is at risk for a prolonged recovery. Today, we can also use these
results to explain to our patient, coach, and patient’s family that there is
evidence that even though we can’t see the damage from concussions – like we
can with other sports-related injuries – there is tissue damage that we can
measure with blood tests.

Questions for
Discussion: Do you see your athletes within 36 hours after a concussed injury?
Do you think biomarkers are the next new concussion diagnosis tool?

Written by: Jane McDevitt, PhD
Reviewed
by: Jeff Driban

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Posts:


Siman R, Shahim P, Tegner Y, Blennow K, Zetterberg H, & Smith DH Dr (2014). Serum SNTF Increases in Concussed Professional Ice Hockey Players and Relates to the Severity of Post-Concussion Symptoms. Journal of Neurotrauma PMID: 25419578