How Your Brain Heals Itself

Generation X in jeopardy

While brain injuries can come in many forms, the most common — and often the most devastating — is stroke.

Most strokes are caused by a blood clot blocking an artery. Some, like Smith’s second stroke, are the result of a blood vessel bursting and bleeding into or around the brain. Either way, a stroke interrupts the blood supply to part of the brain, causing cells in that area to die quickly from a lack of oxygen.

When we think of strokes or other brain injuries, we most often think of their physical effects — often some level of paralysis or weakness. At least half of the nearly 800,000 Americans who live through a stroke each year experience those effects. The reason physical injuries are so common is that, in many cases, the nerve fibers responsible for sending signals to move the body are densely packed into a small area of the brain, called the internal capsule, that is often damaged during a stroke. 

By contrast, strokes that affect the brain’s frontal lobes tend to mess with executive function — planning, problem-solving and the ability to sequence tasks. Some right-hemisphere strokes can produce a phenomenon called neglect, in which a patient loses awareness of the left side of their body — for instance, denying that a paralyzed arm is impaired in any way.

And about one-third of strokes affect the brain’s left hemisphere, where language is processed, resulting in aphasia. This means that more than 2 million Americans are facing stroke-related communication struggles at any given time — a number that exceeds the prevalence of Parkinson’s disease and multiple sclerosis combined. And its effects are profound: Careers collapse. Friends and colleagues don’t understand why conversations have grown strange. Family members become impatient without knowing what to call the distance they feel. “When communication is altered, life becomes hard,” says Suzanne Coyle, executive director of the Stroke Comeback Center in Vienna, Virginia.

About 30 percent of people who have a stroke develop clinical depression within six months, explains Penny Wolfe, a neuro­psychologist at MedStar National Rehabilitation Hospital in Washington, D.C.: “If your executive function pathways have been affected, that decreases your ability to reason and problem-solve, and a lot of us use reasoning and problem-solving to cope with life.”

And stroke is hitting more and more people who are still in their prime career years: Among those ages 45 to 65, the number who have had a stroke has risen 15.7 percent over the past decade, putting about 3.1 million adults in this age bracket at risk. The heightened risk is driven in part by rising rates of obesity and high blood pressure earlier in life: The longer you carry extra weight, the more profound its impact on your health at midlife. And childhood obesity is a Generation X scourge — rates started a sharp upward trajectory in the 1970s and ’80s, leaving people now in their 50s more vulnerable to stroke.

Additional studies have indicated an increase in various forms of dementia, including Alzheimer’s, in people younger than 65 — another potential consequence of higher diabetes and cardiovascular disease rates.

“Those increases among younger people are real,” says Dr. Mitchell S.V. Elkind, the American Heart Association’s chief science officer of brain health and stroke. “Approximately 40 percent of the U.S. population is obese, 50 percent hypertensive and 16 percent diabetic. Unfortunately, we may see further increases in stroke prevalence unless something changes.”

For a person in midlife, a stroke is about half as likely to be fatal as it is for an older person, but sex, race and overall health also play roles. Black men and especially Black women face stroke death rates that are at least two to three times higher than those of other races.

The doctors’ new hope

For decades, it was believed that patients who survived a stroke or other brain trauma had a limited window of time in which to work on recovery. That idea is gradually being proved wrong, as scientists learn about the power of neural plasticity to restore communication and movement.

“People thought whatever gains you make in those six months after the stroke are pretty much your upper limit,” says Dr. Peter Turkeltaub, discussing his work in aphasia. “We don’t see any kind of plateau in our patients. We see people improving continuously over years, as long as they’re still working on their communication.” Turkeltaub is a professor of neurology and rehabilitation medicine at the Georgetown University School of Medicine and director of the Aphasia Clinic at MedStar NRH.

The therapies themselves have also evolved. When Leora Cherney, a speech and language pathologist and researcher at the Shirley Ryan AbilityLab in Chicago, began her career in 1981, therapy focused almost entirely on naming objects, matching pictures to labels, filling in worksheets. The assumption was that recovery would be partial at best.

Back then, the brain’s internal architecture was largely a mystery. “We didn’t really understand how different parts of the brain could be connected to each other and to different pathways within the brain,” Cherney says.

Drawing from research on learning disabilities, Cherney developed a treatment that came to be called ORLA (Oral Reading for Language in Aphasia). The therapy built intensive repetition into a structured sequence: The patient saw a sentence on an index card, heard it read aloud by the therapist, heard it again while pointing along, then spoke the sentence with the therapist in what Cherney calls “choral reading.” Eventually, the patient was able to produce the sentence independently.

“Even though we didn’t know a lot about neural plasticity at that time, repetition and a lot of practice was really, really important,” Cherney says.

A computerized ORLA — and other treatments like it — is now widely used for aphasia rehabilitation. While not all stroke injuries will ever fully heal, these therapies have yielded results beyond what doctors could have imagined years ago. Cherney has had patients who arrived unable to speak, read or write, she notes.

“Years later,” she says, “they’re able to speak in sentences, read a book, and text their family members and friends.”

Even simple steps like picking up a paintbrush or a pencil — or any kind of artistic expression — can help the brain rewire itself, according to the American Heart Association.

Kim Dyer was a physiologist at the National Institutes of Health when an aneurysm led to a stroke 11 years ago at age 49. She lost her career as well as her sense of identity. In the first year after her stroke, she was consumed by depression. “I was crying all the time,” she says. What finally made a difference was an art class. Dyer started painting — mountains, snowmen, landscapes — and found that the canvas gave her something the therapist’s office couldn’t. “Painting is freeing for me,” she says. Research has shown that art can boost cognitive functioning, strengthen fine motor skills and improve hand-eye coordination.

And researchers are beginning to understand how these therapies impact the brain. “All the parts of the brain are connected to each other in different ways, and so a stroke in one place will affect the entire network that it’s connected to,” Turkeltaub says.

For a lost capacity to return, the brain must reconfigure that network — making certain connections stronger, rebuilding the synapses where signals cross between nerve cells, pressing neighboring tissue into service.

At the Shirley Ryan AbilityLab, postdoctoral researcher Evan Houldin observes brain activity during therapy using a portable brain imaging technology called functional near-infrared spectroscopy.

Patients sit at a table and go through the steps of therapy as they normally would but wear snug caps studded with small sensors that press gently against the head.

The sensors emit pulses of near-infrared light that pass through the skull and into the cortex, or outer gray matter, beneath. When a region of the brain becomes active, blood flow increases there. The sensors detect that shift in real time.

To explain what’s going on inside the brain during this recovery process, Houldin uses a Chicago traffic analogy.

The nerve tissue connecting the brain’s major language networks functions like a highway, he says; when it is damaged by a stroke, some of the neural traffic is forced to find alternate routes.

“So if you damage, you know, Lake Shore Drive, all the cars have to take side streets, right?” Houldin says. The damage experienced by these patients “forces a dramatic redirection of traffic in the brain.” The alternate routes may be slower and less efficient, but they can create real improvements in brain function.

Finding the words

David Smith of San Diego (no relation to Derek Smith), 57, tapped his fingers on his armrest, trying to come up with a number. Finally, he found it.

“Fifteen years,” he said, after completing the math. That’s how long he had been living with the effects of a stroke he had in his early 40s.

Smith was among about a dozen survivors from across the United States who met over Zoom once a week to talk about their lives and the progress they were making, a gathering facilitated by a moderator from the Shirley Ryan AbilityLab. I joined them one day this summer.

The men and women on the screen were from different backgrounds and had different personalities, some more extroverted than others. But they each had one experience in common: A stroke had changed their lives in significant ways.

A few of them were wheelchair users; others relied on a cane or a walker. All of them spoke with some degree of difficulty. Some took long pauses to search for the right word. Others provided minimal responses, shying away from elaborating because of the struggle involved in getting the words out.

Smith had been a sales rep for software companies before the stroke left him with severe aphasia, making it impossible to continue in that line of work. For the next six years, he didn’t have a job. Then he found work as a dishwasher at a Whole Foods and stayed there for several years. Throughout, he worked on recovering his language. His speech now is broken and ungrammatical at times, but he can convey what he’s trying to say.

“I remember when I first started, no words, nothing,” he told the Zoom group. “But every year, a little more. Syllables and bigger words. Now I’m 15 years since I have a stroke and now easier to talk, more sentences, bigger words, and it’s just practice.”

Smith acknowledged the social isolation that the rest of the group knew all too well. Many friends and former colleagues had drifted away. But, he added, some friends never changed how they treated him.

“The people that are still friends from college are still the same,” he said. “It doesn’t matter to them that this is now me.”