PITTSBURGH-- A team of brain scientists at Carnegie Mellon University and the University of Pittsburgh has found spontaneous reorganization of cognitive function immediately following brain damage caused by stroke.
The findings, which appear in the journal Stroke this month, are based on functional magnetic resonance imaging (fMRI) scans showing that brain function associated with language shifted away from the stroke-damaged area of the adult brain to the corresponding area on the undamaged side of the brain. The findings show the "healing" that happens after a stroke occurs at a high level of organization, demonstrating the plasticity of the human brain long into adulthood. Such plasticity was routinely credited to the brain in the first few years of life.
The research team consists of Dr. Keith Thulborn of the University of Pittsburgh Medical Center, and Marcel Just and Patricia Carpenter, co-directors of the Carnegie Mellon's Center for Cognitive Brain Imaging and professors of psychology.
"The new findings demonstrate extremely rapid adaptation in adult patients," said Just. "While no one looks forward to a stroke, there is some comfort in knowing that we all carry around a set of thinking spare parts that know how to install themselves if the need arises."
The results also indicate the organizational flexibility of the cortical systems that underlie higher level thinking processes. The researchers say this knowledge may be useful in designing future rehabilitation strategies that can exploit the flexibility.
Using non-invasive fMRI, the team looked at the brains of two stroke
patients, 34 and 45 years old, as they read and indicated their comprehension of
normal English sentences. Very soon after stroke, the cortical areas on the
right sides of their brains, the right-hand homologues of Broca's area or of
Wernick's area, showed increasing activation during the sentence comprehension,
Contact: Marcel Just
Carnegie Mellon University