A man who was left in a completely locked-in state by an amyotrophic lateral sclerosis (ALS) has now been able to communicate with his family and caregivers through an implant. The device was useful to the patient, who was unable to move any muscles or even open his eyes, and helped him contact the outside world by employing his brain activity.
People with severe brain injuries or neurodegeneration have been able to resume communicating through combination of brain implants and brain-computer interfaces (BCI). The new study, published by an international research team, is the first to be successful in a patient with severe neurodegeneration.
In August 2015, a stranger was diagnosed with progressive muscle atrophy, a form of ALS, which he avoided walking or talking, but by the end of 2015, he used an eye-tracking system to communicate. However, their limited ability is dependent on neurons that control eye movements remaining functioning. Dr. Ujwal Chaudhary and Niels Birbaumer, researchers at the University of Tubingen, have reached out.
What is ALS?
The Amyotrophic lateral sclerosis (ALS) is a progressive disease of the nervous system, which is detrimental to nerve cells that stimulate movement. Despite the progressive illness, patients lose control of muscles that are used for walking and talking. There is currently no cure for the disease, and only ten percent of patients have lived for ten years after diagnosis.
Is the motionless body still holding a lot of movement in the brain?
On the resulting study, Chaudhary and Birbaumer have written about the results of a long-running research on the possibility of people with complete locked-in syndrome (CLIS) who have lost all voluntary muscle control, including the movement of the eyes or mouth, and losing the ability to communicate.
In June 2018, the team moved the patient to a hospital near his home, where his motor cortex was implanted with two microelectrode arrays. For the patient, the brain surgery provided only the first ordeal in a horrifying journey toward recovering his communication.
During the study, intracortical data was recorded. Credit: Wyss Center
It was unclear if he will ever be able to complete that journey. Several previous studies have examined the ability of patients with locked-in syndrome (LIS) to communicate with BCI interfaces. However, no patient had previously achieved communication once they entered a CLIS stage with the loss of control of eye movements. Consequently, brain-based communication was also eliminated.
One day after his implant, the patient began his attempts to prove that theory was incorrect.
The team of scientists asked the patient to mentally adopt his previously used eye-based movement strategy, hoping that even without movement, they would be able to decode the brain signals that his motor cortex would have sent to his eyes. Likewise, when the researchers asked the patient to imagine hand or foot movement, the BCI was unable to detect a reliable signal.
The patient could not see the firing rate but was impressed by the audio-based approach. According to Birbaumer, the technique slowed the ice. He now has the capacity to control the BCI.
The patient was given the ability to select letters read out by the BCI to describe their firing rate. When the cells increased their firing rate, the tone increased in pitch, while his lower activity produced a decreased tone. After 12 more days, the patient was able to reliably increase or decrease his neural activity to hit one of two targets tones. This enabled him to express painstakingly select letters read out by the BCI.
Over the next 360 days, researchers have repeatedly visited the patients'' homes, conducting multi-hour recording sessions. The COVID-19 epidemic forced some sessions to be carried remotely, with the patient wife controlling the BCIs hardware. In total, 135 experimental sessions were recorded.
After months of silence, the patient became more aware of the audio-based system; it was slow because when the patient communicated a single character, but the patient remained silent with his messages. When his visit is to Germany, the head position always very high and personal messages for his son, asking if he wanted to watch Disneys Robin Hood.
The system failed to work properly, and there are a few limitations to the study to consider. Each day, a patient had to demonstrate the ability to match his brain activity to target tones before going to a speller session. Additionally, the researchers found that modifications to the protocol may have stifled their communication lines.
Third, the output from the system was unintentionally intelligible, generating intact and understandable phrases on 44 out of 107 days. However, the patient managed to process 5747 characters that the authors might decode, thus restoring communication that would have otherwise been impossible for the patient.
In those with paralysis, successful communication has previously been demonstrated with BCIs. But ours is the first study to have achieved communication by someone who has no additional voluntary movement, and hence the BCI is now the sole communication tool, according to Zimmerman.
Despite the fact that the system is not currently available outside of clinical research, the investigators have altered it so that the family may be able to use it without technical assistance. Unlike ALS patients, the quality of life is excellent. Patients report that no communication is torture. [The] patient standard of care should improve dramatically if you can ask about pain, symptoms, etc.,
The most important decision from the trial is that of the patient, who disclosed his views about the system. Jungs es funktioniert gerade so muehelos, he wrote in his native German, translating to: Boys, it works so well.