fMRI reveals large-scale network activation in minimally conscious patients - this abstract is taken from the Journal of Neurology
|Brain Scans Show Increased Activity During Story-Telling In Patients With Severe Brain Injuries - a brief editorial|
|New Signs of Awareness Seen in Some Brain-Injured Patients A bit more in depth|
Those who has a family member with a brain injury, who have also been following Terri Schiavo, and the husband who wants her dead by starvation and dehydration, will be interested in this report. CHN
© 2005 American Academy of Neurology
From the Department of Neurology and Neuroscience (Drs. Schiff, Kamal, and Plum) and Graduate School of Medical Sciences (D. Rodriguez-Moreno), Weill College of Medicine, Cornell University, and Departments of Radiology and Psychology, fMRI Research Center (Dr. Hirsch), Center for Neurobiology and Behavior, Columbia University, New York, Center for Functional and Molecular Imaging, Division of Clinical Pharmacology (Dr. Kim), Georgetown University Medical Center, Washington, DC, and JFK Johnson Rehabilitation Institute (Dr. Giacino), Edison, NJ.
Address correspondence and reprint requests to Dr. J. Hirsch, Functional MRI Research Center, Neurological Institute, Columbia University, 710 W. 168 St., Box 108, New York, NY 10032; e-mail: firstname.lastname@example.org
Background: The minimally conscious state (MCS) resulting from severe brain damage refers to a subset of patients who demonstrate unequivocal, but intermittent, behavioral evidence of awareness of self or their environment. Although clinical examination may suggest residual cognitive function, neurobiological correlates of putative cognition in MCS have not been demonstrated.
Objective: To test the hypothesis that MCS patients retain active cerebral networks that underlie cognitive function even though command following and communication abilities are inconsistent.
Methods: fMRI was employed to investigate cortical responses to passive language and tactile stimulation in two male adults with severe brain injuries leading to MCS and in seven healthy volunteers.
Results: In the case of the patient language-related tasks, auditory stimulation with personalized narratives elicited cortical activity in the superior and middle temporal gyrus. The healthy volunteers imaged during comparable passive language stimulation demonstrated responses similar to the patientsí responses. However, when the narratives were presented as a time-reversed signal, and therefore without linguistic content, the MCS patients demonstrated markedly reduced responses as compared with volunteer subjects, suggesting reduced engagement for "linguistically" meaningless stimuli.
Conclusions: The first fMRI maps of cortical activity associated with language processing and tactile stimulation of patients in the minimally conscious state (MCS) are presented. These findings of active cortical networks that serve language functions suggest that some MCS patients may retain widely distributed cortical systems with potential for cognitive and sensory function despite their inability to follow simple instructions or communicate reliably.
|Brain Scans Show Increased Activity During Story-Telling In Patients With Severe Brain Injuries|
By Dave Reynolds, Inclusion Daily Express
February 9, 2005
NEW YORK, NEW YORK--New technology may be revealing what many advocates already knew: People who have severe brain injuries are not necessarily "brain dead".
In an important study published in this week's edition of the journal Neurology, researchers used functional magnetic resonance imaging (fMRI) to look at the brain activity of two men considered to be in "minimally conscious state" (MCS) as a result of brain injuries, along with seven volunteers who had no brain injuries.
The scientists noted that, while the resting brain activity for the two men was almost non-existent, when researchers played audio tapes of loved ones telling familiar stories and talking about shared experiences from the past, the brain activity of the two men jumped up to the same level as that of the subjects that had no brain injuries.
"We assumed we would get some minimal response in these patients, but nothing like this," said the study's lead author Dr. Nicholas Schiff, an assistant professor of neurology and neuroscience at Weill Cornell Medical College.
The researchers also noticed that when the sequences of the stories were reversed, and therefore had no particular meaning to the men, their brain activity dropped again.
The study suggests that people with such disabilities are aware of their surroundings and can hear what is going on around them -- even though they may not be able to respond.
The authors noted that, because the sample group was so small, more research needs to be done to determine whether the results can be duplicated with other similar patients. Still, this study could have serious implications for the estimated 100,000 to 300,000 Americans diagnosed with MCS.
"This study gave me goose bumps, because it shows this possibility of this profound isolation, that these people are there, that they've been there all along, even though we've been treating them as if they're not," Dr. Joseph Fins, chief of the medical ethics division of New York Presbyterian Hospital-Weill Cornell Medical Center, told the New York Times.
"Signs of Awareness Seen in Brain-Injured Patients" (New York Times)
Abstract of study "MRI reveals large-scale network activation in minimally conscious patients" (Neurology)
|New Signs of Awareness Seen in Some Brain-Injured Patients By BENEDICT CAREY|
The findings, if repeated in follow-up experiments, could have sweeping implications for how to care best for these patients. Some experts said the study, which appeared yesterday in the journal Neurology, could also have consequences for legal cases in which parties dispute the mental state of an unresponsive patient.
The research showed that the brain-imaging technology, magnetic resonance imaging, can be a powerful tool to help doctors and family members determine whether a person has lost all awareness or is still somewhat mentally engaged, experts said.
"This study gave me goose bumps, because it shows this
possibility of this profound isolation, that these
people are there, that they've been there all along,
even though we've been treating them as if they're
not," said Dr. Joseph Fins, chief of the medical
ethics division of New York Presbyterian Hospital-Weill Cornell Medical Center. Dr. Fins was
not involved in the study but collaborates with its
authors on other projects.
Other experts warned that the new research was more suggestive than conclusive, and that it did not mean that unresponsive people with brain damage were more likely to recover or that treatment was yet possible.
But they said the study did open a window on a world that has been neglected by medical inquiry. "This is an extremely important work, for that reason alone," said Dr. James Bernat, a professor of neurology at Dartmouth.
Dr. Bernat said findings from studies like these would be relevant to cases like that of Terri Schiavo, a Florida woman with brain damage who has been kept alive for years against her husband's wishes. In that case, which drew the attention of Gov. Jeb Bush and the Legislature, relatives of Ms. Schiavo disagreed about her condition, and a brain-imaging test - once it has been standardized - could help determine whether brain damage has extinguished awareness.
The patients in question have significant brain damage. Three million to six million Americans live with the consequences of serious brain injuries, neurologists said. An estimated 100,000 to 300,000 of them are in what is called a minimally conscious state: they are bedridden, cannot communicate and are unable to feed or care for themselves, but they typically breathe on their own.
They may occasionally react to instructions to blink their eyes or even reach for a glass, although such responses are unpredictable. By observing behavior in a bedside examination, neurologists can determine whether a person is minimally conscious or in a "persistent vegetative state" - without awareness, and almost certain not to recover.
In the study, a team of neuroscientists in New York, New Jersey and Washington, D.C., used imaging technology to compare brain activity in two young men determined to be minimally conscious with that of seven healthy men and women. In a measure of overall brain activity, the two groups were vastly different: the two minimally conscious men showed less than half the activity of the others.
But the researchers also recorded an audiotape for each of the nine subjects in which a relative or loved one reminisced, telling familiar stories and recalling shared experiences. In each of the brain-damaged patients, the sound of the voice prompted a pattern of brain activity similar to that of the healthy participants.
"We assumed we would get some minimal response in these patients, but nothing like this," said Dr. Nicholas Schiff, an assistant professor of neurology and neuroscience at Weill Cornell Medical College in Manhattan and the study's lead author. The two men showed near-normal patterns in the language-processing areas of their brains, Dr. Schiff said, suggesting that some neural networks "could be perfectly preserved under some conditions."
Although the number of patients studied was very small, the specificity and intricacy of the patterns made it all but impossible that the results were a fluke, said Dr. Joy Hirsch, director of the Functional MRI Research Center at Columbia University Medical Center and the study's senior author.
One of the two minimally conscious men lay still in a brain-imaging machine while his sister recounted his toast at her wedding and recalled times playing together as children. Although his eyes were closed, the researchers found that visual areas of his brain were active, suggesting that he might have been producing images, Dr. Hirsch said.
"We do not know for sure what is happening in this man's head, but if he were imagining things at the sound of his sister's voice, that would suggest some connection to emotion," Dr. Hirsch said.
Since the study was completed, Dr. Hirsch said, the team has run the same kinds of tests on seven similar brain-injury patients, with similar results: the language processing networks in their brains display seemingly normal patterns upon their hearing the voice of a loved one. The government has provided financing for the team to conduct a larger study of mental activity in minimally conscious people.
A better understanding of brain patterns in minimally conscious patients should also help cut down on misdiagnosis by doctors, Dr. Fins said. He said one study had found that as many as 30 percent of patients identified as being unaware, in a persistently vegetative state, were not. They were minimally conscious.
Moreover, mental states can change over time, and some patients have almost completely recovered function after being thought vegetative. Brain imaging would be one way to track these changes, and even link them to efforts at treatment. Doctors have no cure for either a minimally conscious or persistently vegetative state.
"The most consequential thing about this is that we
have opened a door, we have found an objective voice
for these patients, which tells us they have some
cognitive ability in a way they cannot tell us
themselves," Dr. Hirsch said. The patients are, she
added, "more human than we imagined in the past, and
it is unconscionable not to aggressively pursue
research efforts to evaluate them and develop
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