Carnegie Mellon, Pitt Team Show That Adult Brains Compensate For Damage To Language Systems After Stroke Occurs

April 20, 1999

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, at about the same time as the patients' ability to process language was coming back to them.

In healthy brains, language functions are carried out by a network of mirror image brain areas in the left and right side of the brain, with one side, usually the left, being dominant. The subordinate side, usually the right, may spend most of its lifetime playing an understudy role, as well as developing its own specializations.

But if a stroke or some other neurological damage disables one of the network components on the dominant side, the corresponding left side component rapidly and spontaneously emerges from its understudy role, and starts to activate to a normally high level during language processing.

The rapid recovery of the ability to use language after stroke damage to the language network was previously attributed to tissue healing functions, like reduction of swelling in the brain.

Researchers say the new results show that part of the recovery is due to the brain function reorganization, a re-balancing of the network, like the cast of a play adjusting to the loss of a key actor. The adjustment can begin within a day or two after the stroke, and can continue for many months.
-end-


Carnegie Mellon University

Related Stroke Articles from Brightsurf:

Stroke alarm clock may streamline and accelerate time-sensitive acute stroke care
An interactive, digital alarm clock may speed emergency stroke care, starting at hospital arrival and through each step of the time-sensitive treatment process.

Stroke patients with COVID-19 have increased inflammation, stroke severity and death
Stroke patients who also have COVID-19 showed increased systemic inflammation, a more serious stroke severity and a much higher rate of death, compared to stroke patients who did not have COVID-19, according a retrospective, observational, cross-sectional study of 60 ischemic stroke patients admitted to UAB Hospital between late March and early May 2020.

'Time is vision' after a stroke
University of Rochester researchers studied stroke patients who experienced vision loss and found that the patients retained some visual abilities immediately after the stroke but these abilities diminished gradually and eventually disappeared permanently after approximately six months.

More stroke awareness, better eating habits may help reduce stroke risk for young adult African-Americans
Young African-Americans are experiencing higher rates of stroke because of health conditions such as high blood pressure, diabetes and obesity, yet their perception of their stroke risk is low.

How to help patients recover after a stroke
The existing approach to brain stimulation for rehabilitation after a stroke does not take into account the diversity of lesions and the individual characteristics of patients' brains.

Kids with headache after stroke might be at risk for another stroke
A new study has found a high incidence of headaches in pediatric stroke survivors and identified a possible association between post-stroke headache and stroke recurrence.

High stroke impact in low- and middle-income countries examined at 11th World Stroke Congress
Less wealthy countries struggle to meet greater need with far fewer resources.

Marijuana use might lead to higher risk of stroke, World Stroke Congress to be told
A five-year study of hospital statistics from the United States shows that the incidence of stroke has risen steadily among marijuana users even though the overall rate of stroke remained constant over the same period.

We need to talk about sexuality after stroke
Stroke survivors and their partners are not adequately supported to deal with changes to their relationships, self-identity, gender roles and intimacy following stroke, according to new research from the University of Sydney.

Standardized stroke protocol can ensure ELVO stroke patients are treated within 60 minutes
A new study shows that developing a standardized stroke protocol of having neurointerventional teams meet suspected emergent large vessel occlusion (ELVO) stroke patients upon their arrival at the hospital achieves a median door-to-recanalization time of less than 60 minutes.

Read More: Stroke News and Stroke Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.