|A Friday Story|
We have all heard stories about people awakening from comas and recounting conversations they heard while they were "under." Yet, much of the information we have about the brain functions of comatose people is anecdotal; much of the medical knowledge is based on subjective assessments and - until recently - there have not been any objective clinical measurements.
Last year Dr. Netta Levin, a Senior Physician in the Department of Neurology who also holds a PhD in Neurosciences, began using a Functional MRI to try and find out what is going on in the brain of a person in a coma. Unlike an ordinary MRI, which produces the equivalent of a still picture, the Functional MRI provides a sophisticated dynamic picture of the brain in action - a video, you might say, of the brain areas involved in a task, process or emotion.
Clinically, Hadassah's Functional MRI Unit is used mainly for pre-surgical evaluation. Neurosurgeons use the results of Functional MRI scans to precisely determine important areas of the brain. The information from the Functional MRI is transmitted directly to the operating room navigation system and helps surgeons avoid damaging motor and language centers, for example, when removing a tumor.
Dr. Levin has new use for the Functional MRI - as an important tool to assess brain activity in comatose patients. It is non-invasive, allows investigation of the entire brain and can identify neural activity even when a patient appears unresponsive.
Emboldened by a European study that used Functional MRI to examine 54 comatose people, she fine-tuned the protocol and began her own study. The Europeans found that only five of their patients showed brain activity.
Using a control group and comatose patients, Dr. Levin began at the lowest level of brain function - measuring a sound against silence and seeing if the patients responded. Then she moved up the functional ladder, measuring the patients' response to garbled words, then to actual words, then recognizing their own name - and finally, the patients' ability to differentiate between a familiar voice and an unknown one.
Auditory Language Mapping
"The Functional MRI shows how much blood is arriving to an area of the brain. From that we can identify where the activity is," she says. "There is a difference between recognizing sound and recognizing language; each is processed in a different part of the brain."
The better the signs of brain activity, the better the chances are that the patient will emerge from the coma, she believes. Yet, Dr. Levin cautions, a lack of response may not be a definitive indicator. While not outwardly noticeable, people in this condition fluctuate between being asleep and being awake, just as we do.
One of her patients, a 20-year-old man who was completely comatose and appeared to be totally unresponsive, responded well when tested with the Functional MRI. He differentiated between his own name and others and responded to a familiar voice. And so she moved on to more complicated functions - those that involve voluntary interaction. She asked him to imagine different activities - viewing objects, going home, playing tennis and humming a song. Each involves a different area of the brain - imaging objects, the visual cortex; going home, a navigational activity, the hippocampus; playing tennis, the motor cortex; and humming a song, the auditory cortex.
Again he responded, indicating he understood language and was able to perform tasks on command.
Remember that all this time, the young man was lying in a hospital bed apparently totally removed from the world around him.
Dr. Levin plans to use these results to try and create interactive communication with the patient. She will follow the paradigm developed by the European group, who asked their patient a question and told him to respond by thinking of something specific for 'yes' and something else for 'no.' For example, they asked: "Is your father's name Carl?" and told him to think of a motor activity if his answer was 'yes' and a spatial image if his answer was 'no.'
Of course the young man's parents are thrilled to know that his brain functions even though his body does not - and that he has the ability to communicate, albeit with the Functional MRI.
Now it is up to us, the medical world, to decide how to use these recent - and very exciting - findings, and what exactly they mean. For instance, "What are the implications if you can create communication?" Dr. Levin wonders.
She and her team of post doctoral students plan to broaden their investigation and continue to analyze the results.
She believes the future holds great promise. "Remember," she says, "this information is only a year old. Who knows? By next year, there may be another even more sophisticated tool that will expand our knowledge of the brain and how it functions."
Dr. Levin's specialty is trying to break through the communication barrier that comas cause patients, to reading their minds, if you will. She is just one of Hadassah's many physician-scientists who are marrying their academic knowledge with practical clinical application. They are constantly challenging conventional wisdom and presenting previously unconsidered concepts, tenaciously determined to unravel medical mysteries - to make the world a better place for their patients, for people everywhere.
This week, we were saddened by the death of Madlyn Barnett, a lovely lady with a beguiling smile and a heart that embraced all who knew her. She, too, was determined to make the world a better place, devoting her life to her family, to Hadassah in the United States and to us here at Hadassah in Jerusalem.
A role model for all of us, her memory serves as a blessing.
Prof. Shlomo Mor-Yosef
Hadassah Medical Organization