Communicating At Last: Locked-In ALS Patients Using Blood Oxygen Levels to Communicate

Completely paralysed Amyotrophic Lateral Sclerosis (ALS) patients who were also unable to talk can now communicate. They make use of a computer interface that can detect their thoughts by monitoring their blood oxygen levels and brain activity.

According to the study done by researchers, the technology allows the patients to express their happiness despite the extremely tough condition they were suffering from. The patients ailing from complete motor paralysis, but with preserved awareness, cognition and eye movements are categorized as suffering from Locked-In Syndrome. In the event of loss of eye movements, full paralysis and inability to move the condition is then known as Completely Locked-In Syndrome.

ALS also known as Lou Gehrig’s disease affects the motor neurons that control voluntary muscle movement. It is a progressively degenerative condition which as it progresses, it destroys nerve cells in the brain and spinal cord and consequently patients lose their ability to walk, talk, move limbs, swallow or even breathe. They eventually become fully paralyzed and locked-in such that they can no longer communicate by word of mouth to those around them. Patients who are completely locked-in remain conscious but are unable to move even their eyes. If the patients accept being on artificial ventilation, they stay alive at the expense of being completely cut off from communicating with the world surrounding them. Researchers have been trying to figure out ways to get back in touch with them over a long period of time. Finally, there is hope for these patients as new technology has made it possible for them to communicate with the outside world.

One of the techniques employed allows patients to communicate is known as a Brain Computer Interface (BCI). The BCI utilizes near-infrared spectroscopy (fNIRS) that measures brain hemodynamic responses associated with neuronal activity in combination with electroencephalography (EEG) that would overcome the barrier of communication. However, EEG changes in the frequency band correlates with inferior communication performance, probably as a result of reduced vigilance and attention span.
Nearly two decades ago researchers found that BCI helped ALS patients who still had eye movement to communicate. Down the line, other researchers developed methods to translate blood flow and electrical waves from the brains of locked-in patients who also still had some movement.

However, the techniques had not been able to engage the minds of those with no movement left. It was noted with concern that ALS patients in a completely locked-in state were unable to make use of the existing BCIs since these systems were dependent on processes in the brain that were damaged in the advanced stages of ALS. This situation held until fNIRS was introduced. It has been established that fNIRS is so far, the only successful approach in the restoration of communication for patients of Completely Locked-In Syndrome. It deciphers the thoughts of people who are unable to communicate as they are suffering from Completely Locked-In Syndrome.

The non-invasive device measures brain waves and blood flow to determine a ‘Yes’ or ‘No’ answer to simple questions. The BCI is responsible for measurement of blood oxygen levels and the electrical activity in the human brain. Researchers observed four patients with ALS and Completely Locked-In Syndrome. The participants had advanced forms of ALS which resulted in the brain being unable to control muscles, eventually trapping them in their own bodies where they were incapacitated in movement or talking but were able to think.

The researchers used their BCI to decipher what a ‘Yes’ response looked like and what a ‘No’ response looked like for each patient. To train and test the technique, the researchers asked questions. In the case study, patients were to think the answers ‘Yes’ or ‘No’ to simple spoken questions such as: “Is your wife’s name is Clara?”, “Are you excited?” or “Are you happy?”. When asked if they were happy, the four patients responded with ‘Yes’ time and again over the period of study.

The activity of the brain cells led to change in oxygen levels in the blood which in turn changed the colour of the blood. Consequently, the researchers were able to observe the inside of the brain using light to detect the blood’s colour through the technique called fNIRS. In the measurement of resultant blood oxygen levels, researchers discovered that in approximately 70 percent of the clinical trials, the patients provided accurate responses to the questions posed. There was a consistent pattern observed in the responses which ascertained that the technique was exhibiting remarkable results.

With time, the researchers advanced to open-ended questions that included “I have back pain”, “I barely feel sad” and “I love to live”. In replying to these questions, three of the patients answered in the affirmative that they were happy and loved to live. The remaining patient was excluded from this part of the study as she was relatively young and had undergone rapid onset of ALS symptoms thus her mental condition was deemed vulnerable by her family members. The fact that the patients answered geographical centred questions appropriately, correctly identified family members’ names, and even said they were happy and glad to be alive was reassuring and gave hope in the continued research in management and treatment of ALS.

The findings from the technique employed in this study indicated that in can aid these patients to pass information back and forth effectively. It was a crucial step towards the elimination of completely locked-in conditions, at least for ALS patients with complete motor paralysis but intact cognitive and emotional processing. The researchers noted that, there was need to verify these results in more ALS patients who are in a completely locked-in state. However, this recent development in technology will facilitate the monitoring locked-in patients, providing treatment and enable them regain their quality of life.

It had earlier on been assumed that individuals with Completely Locked-In Syndrome were lacking in goal directed thinking that was essential in using a BCI and were therefore incapable of communicating. Speaking at a press release, Niels Birbaumer, part of the team of researchers mentioned that opposite to common belief that patients with completely Locked-In Syndrome could not communicate, the results from the study proved otherwise. It was discovered that the four patients who were under testing were in a position to respond to all the personal questions directed at them through independent thinking. If the study could be replicated in more ALS patients, there would be restoration of effective communication in completely locked-in conditions for patients with neurodegenerative diseases.

Researchers were at the very beginning surprised by the positive responses when the four locked-in patients had inquiry made regarding the quality of their life. The four candidates had willingly agreed to artificial ventilation in order to sustain their life when breathing difficulties occurred, therefore it was concluded in part that they had already chosen to live. They found the quality of their life acceptable as long as they continued to receive adequate care, meet their needs and dwell in a conducive environment.

There is need to widely avail this method in clinics as its impact would be phenomenal. It can positively influence the day-in day-out life of a patient with completely Locked-In Syndrome. On a rather interesting note, one of the family members asked one of the four patients participating if he would approve of his daughter marrying the man she was dating. The patient to the surprise of many responded with ‘No’ 90 percent of the time. Being able to say ‘Yes’ or ‘No’ makes a huge difference considering that prior to discovery of this technology patients of Locked-In Syndrome were unable to communicate entirely.

Using it in practicality in their daily lives, patients are able to express what they are feeling and their wants. To be able to communicate while in a completely locked-in state is liberating to the mind of the patient to engage with the world surrounding them. The patients who have eventually recovered from Locked-In Syndrome emphasize on the fact that ability to communicate makes a huge difference. Occasionally, patients in this fatal state have resulted to blinking once for ‘Yes’ and twice for ‘No’.

The restoration of communication for completely locked-in patients will be a critical initial step in the difficulty at re-establishing muscle movement. This was mentioned by John Donoghue, director of the Wyss Centre, a neurotechnology research foundation. He further added that the foundation sought to add to the findings from the above study in order to facilitate the development of clinically significant technology that will be availed to individuals with paralysis arising from ALS, Stroke or injury to the spinal cord. He concluded that it was a great relief for the families of the ALS patients experiencing the positive responses.

The technology that has been employed in this study has exhibited use in others spheres that could be developed further in order to closely monitor and treat patients suffering from a wide range of neurological disorders. It is anticipated that it could revolutionize the quality of life of those living with the Locked-In Syndrome.