Thanks to the efforts of Dr. Niels Birbaumer, a former neuroscientist at the University of Tübingen in Germany, and Dr. Ujwal Chaundhary, a former biomedical engineer at the same university and the current managing director at ALS Voice gGmbH, a German-based neurobiotechnology company, a totally locked-in patient was able to type out words and short sentences to his family via a brain implant.
The findings of this study are not only emotionally charged for the patient but give valuable insight into the experience of a “locked-in” person and invalidates the previous theories about the communicative abilities of individuals who have lost their voluntary muscle control entirely. This includes the movement of their eyes or mouth.
What is locked-in syndrome?
Locked-in syndrome (or pseudocoma) is a rare condition that makes it impossible for the patient to move or speak due to the total paralysis of their voluntary muscles, but are still conscious and can see, hear, and smell. The condition could be the result of a progressive neurodegenerative disease like amyotrophic lateral sclerosis (ALS).
Some people with this disease are still able to communicate through blinking or moving their eyes. Those with completely locked-in syndrome (CLIS), however, cannot do that.
Previous research has led severely paralyzed individuals to speak via brain signals or text their thoughts through a brain-computer interface (BCI). However, according to Dr. Jonas Zimmerman, a senior neuroscientist at the Wyss Center in Geneva, Switzerland, and one of the co-authors of this most recent study, to their knowledge, theirs “is the first study to achieve communication by someone who has no remaining voluntary movement and hence for home the BCI is now the sole means of communication.”
As reported by The Guardian, the 36-year-old patient received two square 3.2 mm microelectrode arrays into the part of his brain involved in planning and controlling voluntary movements. The man still had some control of his eye movements, so was able to consent to the procedure, but his condition worsened to being completely locked down in late 2018.
The researchers helped the man learn how to generate brain activity that could alter the frequency of a sound wave through a computer program. The man was then able to apply this strategy to control a spelling program that allowed him to select letters one at a time to form words and phrases. Though the process is slow (an average rate of about one character per minute), Dr. Chaundhary points out “if you have a choice of no communication, and a communication of one character per minute, the choice is very obvious.”
What does this mean for CLIS patients?
The German man has since used his new, cutting-edge method of communication to ask for goulash soup and beer (even though he’s fed through a tube that bypasses his mouth and tastebuds), requested a head massage from this mom, and asked his four-year-old son if he wanted to watch a movie together. On one occasion he even told his family: “My biggest wish is a new bed and that tomorrow I come with you for barbecue.”
Dr. Chaundhary also shared an emotional moment when the patient communicated with his sister, who helps care for him, saying: “thank you for everything, sister.”
These sentences, though short and slowly communicated, offer insight into the patient’s quality of life. “If someone is forming sentences like this, I would say it is positive,” says Dr. Chaundhary. “Even if it is not positive, it is not negative.”
The hope is for this technology to be further developed so that patients with CLIS can express themselves faster, perhaps through a dictionary of common words or sentences for patients to choose from.
Source study: Nature Communications—Spelling interface using intracortical signals in a completely locked-in patient enabled via auditory neurofeedback training