ALS is a rare but progressive neurological disease that effects the neurons that control your voluntary muscles. It can lead to paralysis and the inabilty to do simple tasks like walk, talk, hold objects and chew.
The average life expectancy of ALS is usually 2 - 5 years after diagnosis, according to als.org.
Although there is no treatment for the diseases at the moment, this technology could potentially help patients continue to communicate with their families in some capacity and make the ordeal less lonesome and isolating.
Brain Signals and Implants
At later stages of ALS, patients are no longer able to communicate verbally or through signs, but are able to move their eyes to signal letters, or 'yes' and 'no' answers. As the disease progresses, this function is lost too.
The idea was to figure out if neural firings continue in completely locked in patients, and if they could be harnesses and interpretted to communicate the patients thoughts using a brain implant.
Similar studied to the one published in the Nature have been conducted in the past in patients with limited eye and moth movement.
This new study, conducted by researchers at the Wyss Center for Bio and Neuroengineering, in collaboration with the University of Tübingen in Germany, began in 2018 and involves a 36-year-old male participant who is completely locked in.
How did they do it?
Researchers implanted two 64 microelectrode arrays in the part of the patient's brain that controls motor movements.
The implants were able to pick up on modulations in the patient's neural firing rates, but the patient would have to find a way to control the modulation of his brain waves to be able to communicate.
After several failed attempts and techniques, the researchers decided to try out auditory neurofeedback to train the patient to control his brain firings.
With some practice, the patient was able to follow the frequency of the feedback by imagining to move his eyes and was able to control his own brain activity.
He was then able to select letters one at a time by modulating his neural firings to form words and phrases to communicate his thoughts and needs.
“That was when everything became consistent, and he could reproduce those patterns,” Onas Zimmermann, a neuroscientist at the Wyss Center and an author on the study, was quoted as saying by the New York Times.
How the Patient Responded
The patient responded well to the auditory neurofeedback from the first day itself, say the study authors
Although he first started with single letters and words, by the hundred and seventh day, he was able to form phrases in German.
A lot of the patients' communication involved instructions like where to place his hands, and how high he wanted his head raised, and the kind of food he would like to have.
He was also eventually able to have limited social interactions and request entertainment, report the study authors.
‘I would like to listen to the album by Tool (a band), loud’, he said on day 245.
By day 253, they said he was able to give feedback on the implants and suggestions on improving it as well. About the speller he said, 'boys, it works so effortlessly’.
Within a matter of months, he was able to form longer full sentences. On days 461 and 462 he reportedly, 'would you like to watch Disney’s witch and wizard with me on Amazon?' and ‘My biggest wish is a new bed and that tomorrow I come with you for barbecue’, to his 4-year-old son.
According to the study authors, although the technology can make living a lot easier for the patient, they wouldn't go as far as to base medical treatments on the speller for fear of misinterpretation.
“You certainly don’t want to misinterpret a word here or a word there. If the speller output were, ‘unplug my ventilator,’ we wouldn’t," Jonas Zimmermann, a neuroscientist at the Wyss Center for Bio and Neuroengineering, and a co-author of the study was quoted as saying by Science.
That decision would be left to the family members, he added.
According to the study authors, they are now focusing on making the technology more efficient by simplifying the technology to make it more user-friendly for relatives of patients to use.
A downside though is that three years on, the patient's ability to communicate with the speller has slowed down significantly according to Dr Zimmermann. he reportedly only responds in 'yes' and 'no', answers.
The researchers involved think it could be because of technical issues and are working to figure out alternative parts and possible noninvasive alternative techniques.
(Written with inputs from New York Times, and Science.)