Nov 14, 2012
Does Playing Soccer Harm the Brain?
observe alterations in white matter integrity in a study of 12 soccer players even
in the absence of symptomatic concussion
is one of the world's most popular sports and it is also the only sport where
the head, unprotected, is a primary point of contact for the ball when playing.
In other contact sports, the negative effects of repetitive traumatic brain
injury are well recognized; however, the effects of frequent subconcussive
(below the threshold of concussion) blows to the head, as seen in soccer
players, remains controversial.
the first study to show alterations in white matter in professional soccer
players, researchers from Brigham and Women's Hospital (BWH) in Boston, MA and Ludwig-Maximilians-University
in Munich, Germany investigated the brains of 12 soccer players using
high-resolution diffusion tensor imaging to investigate structural changes in
the brain, specifically white matter architecture. White matter is the
communication network responsible for communicating messages between neurons
(gray matter) in the brain.
research is published in a letter in the Journal
of the American Medical Association on November 14, 2012.
"Our study found differences in integrity of
the white matter of the brains of soccer players compared with swimmers," said
Inga Katharina Koerte, M.D, lead author and a physician-researcher in the
Psychiatry Neuroimaging Laboratory at BWH. "Although only participants without
previous symptomatic self reported concussion or physician diagnosed concussion
were included, we found changes in the brain that are consistent with findings
observed in patients with mild traumatic brain injury."
evaluated 12 right-handed male soccer players from elite soccer clubs in
Germany compared to eight swimmers, a sport with low exposure to repetitive
brain trauma, from competitive clubs.
Aside from their professional sport, the groups were otherwise similar
in age, handedness and gender.
this study, conventional magnetic resonance images used routinely in clinical
settings showed no abnormalities when read by a neuroradiologist, suggesting
the importance of using more sensitive measures to detect subtle changes in the
brain. Researchers then employed
high-resolution diffusion tensor imaging, and observed widespread differences
between the twelve soccer players and the eight swimmers.
diffusion tensor imaging non-invasively provides information about the
diffusion of water molecules in biological tissue and can therefore reveal
microscopic details about tissue architecture. In the brain's white matter,
diffusion of water molecules reflects coherence, organization, and density of
fibers which makes it highly sensitive to changes in white matter architecture.
alterations were observed in the white matter of the frontal lobe, temporal and
occipital lobes in the soccer players when compared to the swimmers. These regions of the brain are known to be
responsible for attention, visual processing, higher
order thinking and memory.
origin of these results is not clear. One explanation may be the effect of
frequent subconcussive brain trauma, although differences in head injury rates,
sudden accelerations, or even lifestyle could contribute," said Martha Shenton,
PhD, senior author and a researcher at the VA Boston Healthcare System and
Brigham and Women's Hospital. "Additional research is needed to confirm these
results we observed in this small sample of soccer players and to help clarify
the effects that alterations of white matter have on behavior and health."
Co-authors, including Ross Zafonte, DO, Vice President
of Medical Affairs at the Spaulding Rehabilitation Network, and
Birgit Ertl-Wagner, MD and Maximilian Reiser, MD from Ludwig-Maximilians-University,
agree that following up on this important finding will be key to understanding
the meaning of the changes observed in this group of athletes.
research was funded by the Else Kröner-Fresenius-Stiftung, Germany (IKK) and
the Deutsche Akademischer Austauschdienst (IKK). This work was also supported
in part by the INTRuST Posttraumatic Stress Disorder and Traumatic Brain Injury
Clinical Consortium funded by the Department of Defense Psychological
Health/Traumatic Brain Injury Research Program (X81XWH-07-CC-CS-DoD; RZ, MES),
and by an NIH NINDS funded R01 (R01 NS 078337 MES). The sponsors had no role in
the design and conduct of the study; in the collection, analysis, and
interpretation of the data; or in the preparation, review, or approval of the