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Computer recordings of the ALS patient's brain waves: data from sensors in the brain are converted into letters
Photo: Wyss Center
According to an international team of researchers, even if a person can no longer move a muscle and therefore cannot indicate what they want by hand signals, nodding or eye movements, it is still possible to communicate with the person concerned.
At least that was successful in the case of a man with amyotrophic lateral sclerosis (ALS), the scientists working with the Tübingen brain researcher Niels Birbaumer report in the journal Nature Communications.
The affected patient is said to be a man born in 1985 who was diagnosed with ALS at the age of 30.
It is a progressive and incurable disease of the nervous system in which the motor nerve cells die.
The result is that the muscles can be controlled less and less, making movements impossible.
The man was initially able to communicate using an eye tracking system, but he lost that ability as early as 2017.
Coma, vegetative state, locked-in syndrome
areacomaopen
A
coma
can be caused by traumatic brain injury or a stroke, lack of oxygen after a cardiac arrest, encephalitis or brain tumors, among other things.
The patients have to be artificially fed and ventilated.
Anyone who is in a coma cannot regain consciousness even through strong external stimuli.
There are four degrees of coma depth.
In the first degree, there is still a targeted reaction to pain, movements of the pupils are detectable, stimulation of the vestibular system can trigger eye movements.
In the fourth degree there is no longer any reaction to be observed.
Expand areaVibrant coma
The
vegetative
state , also called
apallic syndrome
or
persistent vegetative state
(PVS), is often the result of some recovery in comatose patients: brain functions stabilize so that artificial ventilation and nutrition are no longer necessary.
However, the cerebrum is still completely or largely absent.
Diencephalon, brainstem and spinal cord keep breathing, circulation and digestion intact.
Patients are often awake during the day with their eyes open.
However, they do not consciously perceive their environment.
ExpandareaLocked-In Syndrome
In
locked-in syndrome
, also known as being trapped, people are almost completely paralyzed but fully conscious and hearing.
Often they can only move their eyes vertically, which allows at least rudimentary communication with the outside world.
Otherwise, the use of a brain-computer interface is possible, which translates the brain waves directly into control commands for a computer.
Locked-in syndrome is often caused by brain trauma or a stroke.
Another path to lockdown is Amyotrophic Lateral Sclerosis, in which sufferers gradually lose their motor skills until they are completely paralyzed and need artificial life support.
His family therefore contacted Birbaumer from the Institute for Medical Psychology at the University of Tübingen and his colleague Uwal Chaudhary from ALS Voice GmbH in Mössingen, Baden-Württemberg.
Birbaumer and Chaudhary have collaborated and published on several occasions.
In 2017 and 2019 they had published articles about communication systems for ALS patients, which they later had to retract.
The reason: The German Research Foundation (DFG) accused them of scientific misconduct, data had been falsified.
Birbaumer and Chaudhary were excluded from the DFG, the SPIEGEL reported.
In the current study, the scientists presented a lot of data and evaluations of the experiment with their patient, which two independent researchers critically examined and questioned.
After the authors provided additional explanations and details, the renowned journal »Nature Communications« accepted the work and has now published it.
»would you like to watch disneys robin hood with me soon«
The special feature of the new system is that the patient can communicate using acoustic signals.
He chooses between "yes" and "no" in his answers, which results in different activities in his nerve cells.
These are read from electrodes in his brain that were implanted in the man in 2019.
According to the information, he learned which activity »yes« and which »no« means in numerous sessions using an acoustic feedback system: if he chooses »yes«, the tone rises, when »no« it drops.
In this way, the patient has learned to spell whole words and to formulate sentences such as "guys, it's working so effortlessly right now" or "my biggest wish is a new bed and that I can come to the barbecue tomorrow".
So he asked his son:
This acoustic neurofeedback system is unusual and it is unclear to what extent it could be used by other locked-in patients.
It also requires brain surgery for the implants, which can lead to complications such as bleeding or infection.
For the man from Tübingen, however, it is obviously an opportunity to still communicate with his son, his wife, his mother, the nurses and doctors and researchers - even if he needs several minutes for each individual word.
As time goes on, however, the statements made in this way also become significantly slower and less reliable, said Jonas Zimmermann from the Wyss Center for Bio- and Neuroengineering in Geneva, who is currently taking care of the patient, to the "New York Times".
The cause is probably technical problems, because the implanted electrodes only have a limited lifespan.
However, replacing them is too risky due to the risk of infection.
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