A wireless device that decodes brain waves has enabled a woman paralyzed by locked-in syndrome to communicate from the comfort of her home, researchers announced this week at the annual meeting of the Society for Neuroscience.
The 59-year-old patient, who prefers to remain anonymous but goes by the initials HB, is “trapped” inside her own body, with full mental acuity but completely paralyzed by a disease that struck in 2008 and attacked the neurons that make her muscles move. Unable to breathe on her own, a tube in her neck pumps air into her lungs and she requires round-the-clock assistance from caretakers. Thanks to the latest advance in brain–computer interfaces, however, HB has at least regained some ability to communicate.
The new wireless device enables her to select letters on a computer screen using her mind alone, spelling out words at a rate of one letter every 56 seconds, to share her thoughts. “This is a significant achievement. Other attempts on such an advanced case have failed,” says neuroscientist Andrew Schwartz of the University of Pittsburgh, who was not involved in the study, published in The New England Journal of Medicine.
HB’s mind is intact and the part of her brain that controls her bodily movements operates perfectly, but the signals from her brain no longer reach her muscles because the motor neurons that relay them have been damaged by amyotrophic lateral sclerosis (ALS), says neuroscientist Erick Aarnoutse, who designed the new device and was responsible for the technical aspects of the research. He is part of a team of physicians and scientists led by neuroscientist Nick Ramsey at Utrecht University in the Netherlands. Previously, the only way HB could communicate was via a system that uses an infrared camera to track her eye movements. But the device is awkward to set up and use for someone who cannot move, and it does not function well in many situations, such as in bright sunlight.[....]
The technology is not without controversy, however. Some experts believe that only noninvasive methods should be used to help people with locked-in syndrome communicate, for example by recording brain waves from scalp electrodes. “Implantations like the one reported here may carry an unknown risk for advanced ALS patients,” says Niels Birbaumer, an expert in brain–computer interfaces at Tübingen University in Germany who was not involved in the study.[...]
Still, some experts say the wireless new device may not justify the risks. “One to two letters per minute is not justifiable [for doing a craniotomy] unless they can improve it,” Kennedy says.
Indeed, when HB was first learning to use the device, she told Aarnoutse, “Trying to communicate like this is like tacking a sailboat.” But many patients with locked-in syndrome choose not to use ventilators to breathe when their disease reaches an advanced stage because they cannot communicate and they feel they are a burden on their loved ones, according Schwartz. Studies suggest that locked-in people can lead meaningful and productive lives if they can communicate in some way. “We need to do anything we can to help these people,” he says. “We are talking about life and death.”
Now, more than a year after the device was implanted, HB lives at home with her husband and one of her children, and she has gotten much faster at typing out her thoughts. Also, the device works outdoors in the sunshine where her eye tracker fails. “She’s happy,” Aarnoutse says. “The ability to communicate has given her more freedom and made her more independent.”
