Tech & Science

Brain Imaging Scans Show Some Vegetative Patients Are Living on the Edge of Consciousness

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05/06/16
In the Magazine
Given the right stimuli, brain activity in patients in persistent vegetative states can bear similarity to non-injured people. Don Heupel/AP

Maggie Worthen was a week away from graduating from Smith College in May 2006 when she suffered a massive stroke. Her classmates found her unconscious on the floor of her dorm room, unable to speak or move.

A CT scan revealed that the stroke in the otherwise healthy 22-year-old was brought on by a blood clot in the basilar artery, a critical blood vessel in the back of her head that supplies oxygen-rich blood to the brainstem, the part of the brain that controls the body’s basic life support system. It took 12 hours before neurosurgeons at the closest trauma center were able to remove the clot and restore blood flow to Maggie’s brain. She was in a deep coma, kept alive by the ventilator that told her lungs to breathe because her brain could not.

“They told me most people don’t survive these kinds of strokes. If she made it through the next couple days, it was almost certain she would have no meaningful recovery,” says Maggie’s mother, Nancy Worthen. As Nancy grappled with Maggie’s prognosis, she felt pressured to make some harrowing choices. One doctor advised removing Maggie from the ventilator and letting her die. Another suggested foregoing the insertion of a feeding tube and tracheotomy that would help Maggie breathe. A representative from an organ procurement organization approached her for consent to transplant Maggie’s organs. But Nancy resisted them all, believing in the resilience that had always defined her daughter.

About two weeks after the stroke, Maggie regained the ability to breathe on her own. And after another two weeks, she was strong enough to be transferred to a brain rehabilitation facility. With a tracheostomy helping to keep her airway clear and a feeding tube in place, Maggie received intensive physical, speech and occupational therapy each day. Nurses were able to help her sit up in a wheelchair. But when she remained unresponsive and failed to show any outward signs of progress two months later, she was labeled “vegetative,” a diagnosis that disqualified her from insurance coverage for future rehabilitation.

Maggie was transferred to a local nursing home, where, over time, Nancy began to notice Maggie do things that made her believe there was more going on in her mind than doctors claimed: laughing at her boyfriend’s jokes, crying when a moving poem was read aloud. “Her reactions made sense to what was happening in the moment,” Nancy says. The problem was that these behaviors weren’t consistent and no one outside of the immediate family had witnessed them. “She did nothing on command,” says Nancy, so most of the medical staff overseeing Maggie’s care “thought I was in denial.”

But one doctor questioned Maggie’s diagnosis and arranged for her to be transported to Weill Cornell Medical College in New York City. There, she was enrolled in a clinical trial aimed at understanding how the severely injured brain recovers. While using high-tech imaging to assess brain activity, doctors asked Maggie a series of simple questions. The responses showed, without a doubt, that Maggie was still conscious. During that same visit, one of the doctors got Maggie to respond to a question using eye movement. “They told her to look down for ‘yes’ and look up for ‘no.’ When they asked her if I was in the room, there was no mistaking it, she very clearly look down,” says Nancy.

No longer labeled vegetative, but “minimally conscious,” Maggie again qualified for rehabilitation that would help her learn to communicate through an assistive device that let her use eye movements to control a computer cursor to select words and predetermined questions. Though Maggie succumbed to pneumonia in August 2015 at the age of 31, the last years of her life included regular communication. “She was fighting her way back to us when she left us,” Nancy says.

Dr. Joseph Fins, chief of the division of medical ethics at Weill, says Maggie’s experience and that of others like her raise troubling questions about how people with serious brain injuries are diagnosed and cared for. “Patients like Maggie are routinely misdiagnosed and placed in what we euphemistically call ‘custodial care’ where they have no access to any treatments that might help them recover or give them a chance of engaging with others,” says Fins, even as research suggests that 68 percent of severely brain-injured patients who receive rehabilitation eventually regain consciousness and that 21 percent of those are able to one day live on their own.

Fins interviewed Worthen and more than 50 others who had family members with profound disorders of consciousness brought on by lack of oxygen or through trauma to the brain. Almost all, he says, were “written off” immediately and asked to make what he calls “premature” decisions about their loved one—such as whether to withhold or withdraw care or to consent to organ donation. Research backs up Fins’s claims, including one recent study that found one-third of patients brought to Canadian trauma centers for severe brain injury died within 72 hours following the injury—and nearly two-thirds of those deaths were caused by life support being withdrawn, and not because the trauma progressed to brain death. “Far too many cases are based on a rush to judgment that assumes that loss of consciousness signals the end of life when it can also be the first sign of recovery,” says Fins.

Mild brain injuries cause relatively minor changes, such as confusion or disorientation, while severe brain injuries, like the one Maggie suffered, can cause profound disorders of consciousness or brain death. People who survive a severe brain injury usually pass through different states of consciousness as they recover, beginning with a coma, a brief period of complete unconsciousness. From there, some of those patients will die, others will regain consciousness, typically within a few days or weeks, and still others will remain in a different kind of unconsciousness known as a vegetative state. Fins says patients who move on to a vegetative state are awake but unaware. “Their eyes are often open and roving, but they have no ability to relate to or interact with the world around them,” he says. For some, the vegetative state is a temporary condition. In others, it becomes a permanent condition that offers “no chance” of recovery.

Brain imaging scans have confirmed what neurologists have long suspected: Some seemingly vegetative patients are actually teetering between consciousness and unconsciousness. People in this penumbra, called the minimally conscious state, “may respond to questions or speak spontaneously, gesture or reach for objects, or track people’s movement across the room with their gaze but then not do so again for days, or weeks, or months,” Fins says.

What’s more, some of these people, widely assumed to have zero shot of improvement, are actually capable of recovery to varying degrees. In fact, a rare few have staged stunning recoveries, even after a decade or more. Almost 20 years after a traumatic brain injury sustained in a car accident left him paralyzed and minimally conscious, 39-year-old Terry Wallis said “mom.” In the days that followed, Wallis regained the ability to move and converse with his family. Donald Herbert, a firefighter who suffered brain damage after a burning roof collapsed, spoke his first words in more than nine years after being given a cocktail of medications used to treat depression, Parkinson’s and attention deficit disorder. He spent the next 14 hours in animated conversation with family and friends before retreating back into silence. Two years after a car crash, an Italian man emerged from a minimally conscious state after being given a mild sedative and retained the ability to speak. He was also able to read and understand simple sentences and calculate basic math problems until the effect of the drug wore off.

05_06_Brain_Consciousness_02 Buffalo Fire Department firefighter Donald Herbert is remembered during funeral services at in Lackawanna, New York, on February 25, 2006. Herbert was a brain-injured firefighter who emerged from a near-vegetative state to learn that nearly a decade had passed while he lay unconscious. He died February 21, 2006. Max Rossi/Reuters

Though the how and the why behind these patients’ awakenings are not understood, Fins says that “they show that the potential for recovery from the minimally conscious state seems to have no expiration date.” And identifying whether a patient has the potential to recover is difficult—as many as 40 percent of patients in nursing homes or chronic care facilities are misdiagnosed as being permanently vegetative when they are minimally conscious. “They are awake and aware—at least part of the time—whether or not we see it,” says Fins.

Dr. Nicholas Schiff, a neurologist at Weill Cornell Medical College, says even one person wrongly diagnosed when they have intact mental life is one too many. “Imagine being conscious in a body in which you have no control. It’s difficult to imagine anything more terrifying.” He attributes misdiagnosis to a number of factors, chiefly neglect. “Society as a whole has given up on these people. When somebody is not waking up, it gives people an uncomfortable feeling. It’s easier to say, ‘Nope, they’re not there.’”

A lack of diagnostic tools can also make it difficult to determine consciousness. “While MRIs and CT scans can help doctors visualize the extent of brain damage, they cannot detect signs of consciousness,” says Schiff. Instead, diagnosis is based on bedside evaluations that gauge a patient’s response to stimuli and neurological testing that involves asking for physical cues, such as looking up or down or blinking twice—tasks patients may not be able to perform even if they are conscious.

Complicating this, says Schiff, is that behaviors that may indicate consciousness—tracking an item across a room, for example, or, as Maggie did, showing emotions in the correct context—are often “sporadic and not reproducible.” Minimally conscious patients may appear indistinguishable from vegetative patients to the untrained eye, especially in an isolated single examination. “If only family sees a behavior, it’s not unusual for doctors to chalk that up to wishful thinking,” he says.

And because there is no standardized protocol for re-examination of brain-injured patients following their diagnosis, patients may leave the hospital with a vegetative diagnosis and then over time migrate into a minimally conscious state.

That may be changing as advances in neuroimaging allow doctors to detect cognitive processes that are imperceptible through traditional bedside tests. Adrian Owen, a neurologist at Western University in Ontario, Canada, demonstrated that neuroimaging technologies could help facilitate recovery during a research study in which a 23-year-old woman thought to be vegetative was asked to picture herself playing tennis and walking through her home while resting inside a functional magnetic resonance imaging (fMRI) scanner, which allows mapping of brain activity. When healthy adults imagine playing tennis, the premotor cortex, the part of the brain that controls movement, becomes active. When they imagine walking through a house, the parahippocampal gyrus, which is needed for spatial navigation, activates.

Researchers were stunned when the fMRI showed that the young woman, who had been unresponsive for five months after being struck by two cars while crossing the street, had brain activity, Owen says, that was “almost indistinguishable from healthy people” performing the same tasks.

Several research teams have since used fMRI, as well as other imaging technologies, with similar success. Among the most promising is electroencephalogram, which uses electrodes attached to the scalp to directly measure activity of the brain. EEG tests have shown that they can demonstrate consciousness undetectable in a bedside test. And because the technology is portable, cheap and doesn’t require a patient’s active participation, Owen sees it becoming a broad screening tool—and a way to make sure patients get the help they need to recover. While neuroimaging can’t prove a lack of consciousness, it can prove consciousness, which can be life-changing.

05_06_Brain_Consciousness_03 Sandra Wallis talks with family members about her husband Terry Wallis's recovery from a 19 year semicomatose state during a visit to her mother's home in Round Mountain, Arkansas on July 10, 2003. Sandra looks through a family scrapbook turned to a page with a wedding photo of her and Terry and their marriage license from March 26, 1984, just four months before Terry's accident. Benjamin Krain/Getty

Owen has already used fMRI to communicate with a small number of patients. The first, a Belgian man injured in a traffic accident with seemingly no consciousness, was able to correctly answer a series of questions by thinking about different actions that caused different part of his brain to light up on the fMRI scan. To answer “yes,” he visualized himself playing tennis, and to answer “no,” he imagined walking through his home. These findings have laid the groundwork for developing computerized devices powered completely by the mind, called brain computer interfaces, that could someday allow for constant communication. “In the meantime,” says Owen, “there are questions we need to ask right away, such as, ‘Are you in any pain?’”

Schiff is at the forefront of another frontier in communicating with patients who are otherwise unreachable: deep brain stimulation, a common treatment for Parkinson’s disease that involves implanting electrodes into the thalamus, the part of the brain that regulates consciousness and sleep, to jolt the brain into responsiveness. He used the technique to restore consciousness in a 38-year-old man who’d been in a minimally conscious state for six years. Following the treatment, the man regained the ability to speak and eat on his own. “Despite his brain being badly damaged, some neural circuits were still intact. We were able to target electrical impulses to these circuits to kick-start them again,” says Schiff.

Schiff is also investigating the potential of zolpidem (the common sleep medicine sold under the brand name Ambien) to restore consciousness. In some brain-injured patients the sedative has a paradoxical effect—“it creates a buzz that switches brain circuits from off to on.” Schiff notes that amantadine, a treatment for tremor in Parkinson's disease, has had a similar effect on certain patients.

But before anyone can benefit from these new treatments, they must first be correctly diagnosed as having the potential to recover. “There are a lot of people out there who could be helped but aren’t,” says Schiff. “All patients should be treated as if they too have that same potential for recovery.”