From Washington University in St. Louis Newsroom:
Damage to brain ‘hubs’ causes extensive impairment
Injuries to six brain areas are much more devastating to patients’ abilities to think and adapt to everyday challenges than damage to other parts of the brain, scientists at Washington University School of Medicine in St. Louis have learned.
Brain mapping highlighted the regions, which are “hubs” where multiple brain networks come together. The networks make it possible for parts of the brain to work with each other to complete cognitive tasks.
The findings offer a new perspective on how injury impairs brain function. This may help better predict the effects of strokes, trauma and other brain damage and one day could lead to reassessment of the risks of some brain surgeries.
The findings are available online from the Proceedings of the National Academy of Sciences.
Petersen and his colleagues at Washington University School of Medicine identified the sites by mapping brain networks, which make it possible for parts of the brain to work with each other to complete cognitive tasks.
Their maps highlighted hubs, regions where the boundaries of multiple networks come together in one spot. Scientists had not previously identified the regions as areas that made important contributions to brain function.
“We wondered, though, if the hubs were sites where all the different networks talk to each other,” Petersen said. “If that’s true, damage in these areas could disrupt several networks, impairing multiple mental functions.”
To test their theory, the researchers collaborated with colleagues at the University of Iowa, including Daniel Tranel, PhD, and David Warren, PhD. Tranel heads the Iowa Neurological Patient Registry, a database of patients who suffered strokes and other brain injuries.
The scientists identified 19 patients with brain injuries centered on one of six hubs. The researchers compared them to 11 patients with similarly sized injuries in one of two areas of the brain far from any hubs.
“The patients with injuries to a hub had considerably more impairment,” Petersen said. “For example, 18 of the 19 patients with harm to a hub experienced ‘real-world’ problems, while less than half of the group with injuries far from hubs had such difficulties.”
According to Petersen, the findings may help explain anecdotal reports of patients who suffered relatively small brain injuries yet experienced surprisingly significant disabilities and impairments.