Canadian imaging study shows injured brains work harder to perform at the
same level as healthy people
TORONTO, Sept. 8 /CNW/ - Brain imaging experts have found a distinct
"brain signature" in patients who have recovered from head injuries that shows
their brains may have to work harder than the brains of healthy people to
perform at the same level.
The patients in the study had diffuse axonal injury (DAI), the most
common consequence of head injuries resulting from motor vehicle accidents,
falls, combat-related blast injuries, and other situations where the brain is
rattled violently inside the skull causing widespread disconnection of brain
"Our imaging data revealed that the DAI patient brains showed a greater
recruitment of regions of the prefrontal cortex and posterior cortices
compared to healthy controls," said Dr. Gary Turner, who led the study at
Baycrest's Rotman Research Institute and the University of Toronto with senior
Rotman scientist Dr. Brian Levine. The study is published in the Sept.9 issue
of Neurology, the medical journal of the American Academy of Neurology.
Even though the head injury patients performed as well as the healthy
controls on a series of working memory tests that measured their ability to
organize, plan and problem solve, the fact their brains had to work harder is
an indication of "reduced cognitive efficiency", explained Dr. Turner, who is
now with the Helen Wills Neuroscience Institute at the University of
The eight patients in the Baycrest study had been in motor vehicle
accidents several years prior, sustaining significant brain injuries that left
them comatose for various lengths of time; yet all patients made good
recoveries as evidenced by a return to pre-injury employment or school. Their
fMRI scans were compared to 12 healthy adults, matched to the patients for age
The Baycrest study is the first to recruit head injury patients and
healthy controls that were evenly matched in cognitive performance from the
outset - thus yielding the strongest evidence to date of this "working harder"
effect in recovered head injury patients.
The study was funded by a grant from the NIH - National Institute of
Child Health and Human Development. Baycrest, an academic health sciences
centre affiliated with the University of Toronto, is internationally renowned
for its care of aging adults and its excellence in aging brain research,
clinical interventions, and promising cognitive rehabilitation strategies.
To read the full press release, go to www.baycrest.org and click on the
For further information:
For further information: on this release, or to interview the authors,
please contact: Kelly Connelly, Senior Media Officer, The Rotman Research
Institute, Baycrest Geriatric Health Care System, (416) 785-2432,