Months after concussion
symptoms such as dizziness, headaches and memory loss fade, the brain continues
to show signs of injury, a new study suggests.
Comparing 50 concussion
patients with the same number of healthy people, researchers found that the
brains of those suffering concussions showed abnormalities four months later.
This happened despite the fact that their symptoms had already eased to some
The findings may sway
conventional thinking about when it's safe to resume physical activities that
could produce another concussion, the study authors said.
"This is a very
different population than professional athletes going out and having
concussions on a fairly [frequent] basis, as well as jostling their brain
around their skull on a regular basis in practice," said study author
Andrew Mayer, an associate professor of translational neuroscience at the Mind
Research Network in Albuquerque, New Mexico.
It's hard to predict an
outcome based on these findings, he said, "but just because you feel
you're healed doesn't mean you are."
Sudden blow to the head
The study, which was funded
by the US National Institutes of Health, is published in the online edition of
the journal Neurology.
Considered a mild traumatic
brain injury that occurs from a sudden blow to the head or body, a concussion
has symptoms that range from headache and blurry vision to difficulties in
sleeping or thinking clearly. Most occur without losing consciousness,
according to the US Centres for Disease Control and Prevention.
Mayer and his team matched
50 patients with mild concussions to 50 healthy people of similar age and
education levels. They tested all participants in memory and thinking skills,
as well as other symptoms such as anxiety and depression.
Special brain scans using
technology that is not available in standard brain scans were also given. All
tests and scans were repeated two weeks after the concussion, and again four
While concussion symptoms were
reduced by up to 27% four months after injury, brain scans of those with
concussions showed abnormalities in the frontal cortex area of both sides of
These abnormalities may
have resulted from changes in location of fluid around brain cells or changes
in the shape of certain brain cells in response to damage, Mayer explained.
The findings, he noted,
suggest that the recommendation that athletes suffering concussions should
refrain from play for one to two weeks may not be sufficient.
"In one or two weeks,
most people typically report feeling better," he said. "But when we
start talking about it in an analogy of a burn or knee injury, it becomes a
little more clear when the doctor says we need to wait a bit longer [to return
to prior activities]. It makes sense that the brain would be similar to those
tissue types," added Mayer.
Kenneth Podell, co-director
of the Houston Methodist Concussion Centre, said the study strengthens the
understanding that physical changes within the brain after concussion are
separate from mental symptoms. But Podell, who was not involved in the
research, added that the study couldn't offer implications for potential
long-term concussion effects such as depression or dementia.
"Everyone seen at four
months should be followed in another four, six or eight months and then
re-scanned," he said. "One of the biggest problems we have looking at
concussions is we try to predict long-term effects from short-term findings.
This injury is very difficult to commit the
type of resources needed to do that kind of very expensive and time-consuming
The US National Library of
Medicine has more on concussions.