Last summer Dr. Joseph Slate, a professor in the Department of English for more than 45 years, was preparing to start teaching a summer class when he suffered a massive stroke. Slate’s physical recovery was fairly rapid, but he soon discovered something amiss.
Slate, an eloquent speaker who estimates he’s read a book a day since he was a boy, couldn’t read even the simplest word. The letters on the page were unintelligible to him.
Dr. Swathi Kiran develops new therapies to help stroke survivors overcome aphasia and learn to communicate again.
Slate suffered aphasia, an impairment of the ability to communicate affecting about one in four stroke survivors. Some aphasic patients lose their ability to read, others their ability to name familiar objects and others their ability to write or talk or spell. Often in aphasia, multiple aspects of communication are impaired.
Slate’s aphasia was mostly limited to his ability to read.
“The most startling thing was that because he was so articulate, the doctors couldn’t believe he never lost his ability to converse,” says Patricia Bauer-Slate, Slate’s wife. “He could compare books or compare books to movies, but he couldn’t read a single letter and put the sound to it.”
Slate was fortunate to be referred to the lab of Dr. Swathi Kiran, assistant professor in the Department of Communication Sciences and Disorders in the College of Communication and director of the Aphasia Lab. Kiran and her colleagues are working with aphasic patients to identify new, more effective therapies and ultimately to try to better understand what happens in the brain when people suffer aphasia and, ultimately, recover from it.
In most cases, aphasia occurs when a person suffers damage to the left hemisphere of the brain because of a stroke or accident. The extent of the aphasia depends on which part of the brain was damaged.
“If the damage is confined to one part of the brain, then it’s more specific,” Kiran explains. “A person with damage to the temporal lobe would have problems with understanding, whereas a person would have more problems with speaking if the damage is in the frontal lobe.”
When Kiran started working with Slate, whose damage was in parts of the left occipital, parietal and posterior temporal lobes, he couldn’t read any of the 50 basic words she presented to him. At the end of three months of work, he could read them all.
“What she gave him in addition to the ability to connect a sound to a letter was the hope that he will read again, somewhat normally,” says Bauer-Slate. “We’re doing more and more with him all the time.”
Slate entered therapy within the first three months after his stroke, a time when the brain is most rapidly repairing itself. But Kiran more often works with patients nine or more months after their strokes, when traditionally fewer options have been available. She’s realized great progress with those patients as well.
At the core of Kiran’s research and the therapies she develops is the realization that although aphasic patients may have to relearn things they learned as young children, they are not young children. Kiran’s approach recognizes what aphasics already bring to the table.
“We say, let’s not train every patient as if they’re a blank slate, because they’re not,” she says. “They come with a lot of experience in their life. The idea is let’s use what we know their brains could do before they had their stroke.”
example of generalization for the category of birds. When
aphasic patients learn to name less typical birds like ostriches
and penguins, they can then name more typical birds like
owls, cardinals and robins.
In traditional teaching, ideas are presented from the simple to the complex. However, aphasics will already understand complex ideas, just not be able to communicate them. So Kiran begins with more complex ideas.
For example, when training a patient to read or name vegetables, it would seem obvious to begin with the names of typical vegetables like carrots and cucumbers and move to less typical vegetables over time. Kiran has actually found the opposite to be true.
Aphasic patients already know what a carrot is, as well as a cucumber, a cauliflower, an onion or garlic That is, they can identify them as part of the overall category of vegetable. What they can’t do is name them or read their names.
Kiran found that if you train aphasic patients on just carrots and cucumbers, they can only identify carrots and cucumbers. However, if you train them on less typical vegetables such as garlic and artichokes, they not only learn garlic and artichokes. They learn carrots and cucumbers, too.
In other words, if you teach the complex, you don’t have to teach the simple.
“The idea is not unlike if I knew you knew something about calculus, and you had problems with math, I wouldn’t start by teaching you addition,” she says. “Let me start with calculus, and maybe addition will come as part of that.”
The same has proven true of all kinds of categories. When training for birds, if patients can be taught to name an ostrich and a penguin, they’ll also be able to name a robin and a cardinal without being trained on them. When training for furniture, if patients can name hammocks and mirrors, they can then name tables and sofas.
MRI images of strokes in the brain, seen from below. The areas with lesions show up as a lighter contrast. The image on the left shows a fatal stroke to the middle cerebral artery. On the right, a posterior stroke in the left lobe causes the patient to have aphasia.
This approach, which Kiran calls “generalization,” has proven to be effective across the breadth of patients with whom she has worked. Like the other therapies she’s developing, including new ways of working with bilingual aphasic patients, it makes therapy more efficient.
Faster progress is important, particularly because aphasic patients often suffer a blow to their self-esteem. Kiran sees a number of patients who suffered strokes between the ages of 40 and 60 and were at the peak of their careers as doctors or attorneys or other professionals. To lose the ability to communicate is devastating, and the better the therapy, the better the chance a patient has of returning to his or her previous life.
“Aphasia is one of the worst things that can happen to a person because their mind is intact, they know everything,” she says. “They have perfectly good ideas of what happened to them, but they have problems communicating.”
Kiran has had tremendous success with therapy, but she recognizes that therapy is only half the story. The other half is what’s happening in the brain itself.
To better understand that, Kiran is using functional magnetic resonance imaging (fMRI) to look at the brains of aphasic patients before and after therapy.
fMRI allows practitioners to interpret brain function by detecting the changes in blood oxygen level that accompanies neural activity in the brain. They can watch the brain do its work in real time. In the case of Kiran’s research, she can determine what parts of the brain are working when a patient who couldn’t read now reads, for example.
Over time, this may start to answer the question of how the brain changes or repairs itself.
Imaging brain plasticity as a result of therapy in aphasic patients is an emerging area of research, and Kiran admits the work meets her personal interest in both the function of the brain and the rewards of working one-on-one with patients. She also thinks the work offers the best chance of really improving the therapies available to aphasic patients.
“Ultimately, my aim is to find out how the brain is capable of change,” she says. “I know how therapy works, but maybe there’s a better way of doing this. If I knew how the brain can reorganize itself, I could then go back and see what kind of therapies we could design to get people back to 100 percent.”
Getting back to 100 percent is the hope of every person who suffers aphasia. Kiran’s research has shown that even more than a decade after a stroke, improvement is possible. But the going is often slow.
Recalling the therapy she did with English professor Slate, Kiran says his improvement was phenomenal. But his work continues.
Slate can read through the headlines of the New York Times and thinks
with just a bit more progress, he can read the paper as well. While he
works his way to that place, his head is filled with the Hemingway stories
and classic films he taught his students for decades.