Brain Implant Allows Fully Paralyzed Patient to Communicate
In 2020, Ujwal Chaudhary, a biomedical engineer then at the University of Tübingen and the Wyss Center for Bio- and Neuroengineering in Geneva, was watching his computer in amazement when an experiment he had spent years on came to light. A 34-year-old paralyzed man was lying on his back in the laboratory. A cable connected his head to a computer. A synthetic voice spoke the letters in German: “E, A, D.”
A few years earlier, the patient had been diagnosed with amyotrophic lateral sclerosis, which leads to progressive degeneration of brain cells involved in the movement. The man lost the ability to move even his eyeballs and could not communicate; medically speaking, it was in a wholly locked state.
Dr. Chaudhary’s Experiment
Or so it seemed. In Dr. Chaudhary’s experiment, a person learned to select – not with his eyes, but by imagining that his eyes were moving – individual letters from a continuous stream that the computer said aloud. He formulated words and sentences by letter by letter, one every minute or so. “Wegen essen da wird ich erst mal des curry mit kartoffeln haben und dann bologna und dann gefuellte und dann kartoffeln suppe,” he wrote at one point: “For food I want curry with potatoes, then bolognese and potato soup.”
Dr. Chaudhary and his colleagues were stunned. “I could not believe that this was possible,” recalls Dr. Chaudhary, now the managing director of ALS Voice gGmbH, a neurobiotech company based in Germany and who no longer works with a patient.
The study, published on Tuesday in Nature Communications, represents the first example of a patient in an entirely locked-down state, communicating with the outside world for extended periods, said Niels Bierbaumer, study leader and now retired neuroscientist at the University of Tübingen.
Dr. Chaudhary and Dr. Birbaumer
Dr. Chaudhary and Dr. Birbaumer conducted two similar experiments in 2017 and 2019 on patients who were completely locked in and reported that they could communicate. Both studies were withdrawn after the investigation of The German Research Foundation concluded that the researchers only partially videotaped examinations of their patients, did not correctly display the details of their tests, and made false claims. Upon discovering that Dr. Bierbaumer had committed a scientific violation. The German Research Foundation imposed the harshest sanctions on him, including a five-year ban on submitting proposals and serving as a foundation reviewer.
The agency determined that Dr. Chaudhary had also committed a breach of scientific discipline and imposed the same sanctions on him for three years. He and Dr. Bierbaumer were asked to withdraw their two articles, and they refused.
The investigation began after whistleblower researcher Martin Spühler raised concerns about the two scientists in 2018.
German Research Foundation
Dr. Birbaumer supported the findings and sued the German Research Foundation. Dr. Chaudhary says his lawyers hope to win the case. The lawsuit results are expected to be published within two weeks, said Marco Finetti, spokesman for the German Research Foundation. According to Finetti, the German Research Foundation is unaware of the publication of the current study and will investigate in the coming months. In an email, a spokesperson for Nature Communications, who asked not to be named, declined to comment on how the study was verified but expressed confidence in the process.
“We have strict policies to protect the integrity of the research we publish, including ensuring that research is conducted to high ethical standards and reported transparently,” the spokesperson said.
“I would say this is solid research,” said Natalie Mracac-Kersting, a brain-computer interface researcher in Germany at the University of Freiburg. She did not participate in the study and was aware of the previously withdrawn documents.
University of California
But Brendan Ellison, a researcher at the University of California, San Diego, expressed doubts. “This work, like Birbaumer’s other work, should be taken with a great deal of skepticism given its history,” Dr. Ellison said. He noted that in the article published in 2017his own team described being able to communicate with completely locked-in patients with simple yes or no answers.
ALS diagnosis around the world every year. This number is projected to reach 300,000 by 2040. The results are potentially promising for patients in similar unresponsive situations, including minimal consciousness and coma, and a growing number of people.
“This is a game-changer,” said Stephen Loreys, a neuroscientist and researcher who leads the coma study group at the University of Liege in Belgium and was not involved in the study. He added that the technology could have ethical implications in discussions about euthanasia for patients in confinement or a vegetative state: “It’s great to see this moving forward, giving patients a voice” in their own decisions.
Numerous methods have been used to communicate with unresponsive patients. Some of these include basic writing techniques developed by relatives of the family. In other cases, the caregiver points out or says the names of objects and looks for micro-responses – blinking, twitching fingers from the patient.
Brain-Computer Interface Technologies
In recent years, a new method has taken center stage: brain-computer interface technologies, which aim to translate human brain signals into commands. Research institutions, private companies, and entrepreneurial billionaires like Elon Musk have invested heavily in this technology. The results have been mixed but compelling: Patients moving prostheses using only their thoughts, and people with stroke, multiple sclerosis, and other illnesses reconnect with loved ones.
However, scientists have not been able to communicate extensively with people like the man in the new study, who didn’t move.
In 2017, before becoming completely withdrawn, the patient used eye movements to communicate with his family. Anticipating that he would soon lose even that ability, the family asked for an alternative communication system and turned to Dr. Chaudhary and Dr. Birbaumer, pioneers in brain-computer interface technology, both of whom worked nearby.
With the man’s approval, Dr. Jens Lemberg, a neurosurgeon and author of the study, implanted two tiny electrodes in areas of the man’s brain that control movement. The man was then asked to imagine moving his hands, arms, and tongue over two months to see if they would generate a clear brain signal. But the efforts did not give anything reliable.
Then Dr. Birbaumer suggested using auditory neurofeedback, an unusual method by which patients are taught to manipulate their brain activity actively. First, the man was presented with a note – high or low, corresponding to yes or no. This was his “target tone” – the message he had to match. He was then played a second note, which displayed the brain activity detected by the implanted electrodes. By concentrating and imagining moving his eyes to increase or decrease brain activity, he changed the pitch of the two tones to match the first. He received real-time feedback on how the note changed, allowing him to raise the pitch when he wanted to say yes, or lower it when he didn’t.
This approach gave immediate results. On the first day of trying, the man was able to change the two tones. Twelve days later, he managed to match the second with the first.
“That’s when things became consistent, and he could replicate those patterns,” said Jonas Zimmermann, a neuroscientist at the Wyss Center and author. When the patient was asked what he imagined to change his brain activity, he replied: “Eye movement.”
Over the next year, the man used this skill to create words and sentences. The scientists borrowed a communication strategy that the patient used with his family when he could still move his eyes.
They grouped the letters into sets of five colors. The computerized voice-first listed the colors, and the person answered “yes” or “no” depending on whether the letter they wanted to choose was in that set. The voice then listed each note, which it had selected differently. He repeated these steps set by the group, letter by letter, to formulate complete sentences.
On the second day of his spelling, he wrote: “First, I would like to thank Niels and his bierbaumer.”
Some of his suggestions included instructions like “massage mom’s head” and “everyone should use eye gel more often.” Others described the craving: “Goulash soup and sweet pea soup.”
Of the 107 days the man spent spelling, 44 ended in coherent sentences. And although the speed varied greatly, he wrote at a rate of about one character per minute.
“Wow, that blew my mind,” Dr. Mracac-Kersting said. She suggested that locked-in patients who can stimulate their minds could live longer, healthier lives.
However, Dr. Mracac-Kersting stressed that the study was based on one patient and needed to be tested on many others.
Other researchers have also expressed caution about their results.
Head Of Mission For The ALS Association
Neil Thakur, head of mission for the ALS Association, said: “This is an experimental approach, so we still have a lot to learn.” The technology is also too complex for patients and their families at this stage. According to Dr. Chaudhary, it is essential to make it user-friendly and increase communication speed. He said that the patient’s relatives are likely, please. “You have two options: no communication or one character per minute,” he said. “What do you choose?”
Perhaps the biggest problem is time. It has been three years since implants were first inserted into a patient’s brain. Since then, his responses have become much slower, less reliable, and often indistinguishable, said Dr. Zimmermann, who now cares for the patient at the Wyss Center.
This decline is unclear, but Dr. Zimmermann suggested that it was probably due to technical issues. For example, the service life of the electrodes is approaching the end. However, replacing them now would be unwise. “This is a risky procedure,” he said. “Suddenly, I told you about new types of bacteria in the hospital.”
Dr. Zimmermann and others at the Wyss Center are developing wireless microelectrodes which are safer to use. The team is also exploring other non-invasive methods that have proven fruitful. In previous studies on patients who are not blocked. “As much as we want to help people, I think creating false hope is also hazardous,” said Dr. Zimmermann.
At the same time, Dr. Loreys of the Coma Science Group said it is useless to foster a sense of “false desperation” when viable innovations appear on the horizon.
“I am very excited as a caregiver and clinician,” he said. “I think it’s great that we’re offering these new scientific ideas and technologies in a very vulnerable and dramatic environment.”