Communication in Late-Stage Amyotrophic Lateral Sclerosis Made Possible
Amyotrophic lateral sclerosis is a fast-progressing and unusual neurological disease. It leads to the steady degeneration and then the demise of motor neurons—that are nerve cells situated in the brain stem, spinal cord, and brain.
As the disease advances, the activities, including swallowing, walking, gripping, breathing, and speaking become more and more hard. As time passes, the ability of nerves to activate definite muscles is lost, making them frail, and ultimately results in paralysis. The disease leaves the individual immobile and rigorously impacts their capability to interact in its last stage. Individuals that go through absolute paralysis, but uphold blinking, eye movements, awareness, and cognition are said to have locked-in syndrome.
These patients have an alternate way of communicating via dedicated devices that depend on nonverbal signals, including eye fixation and finger movement after losing the verbal communication ability. Nevertheless, as the disease progresses further and the eye muscle movements are also ceased, interaction thus becomes impossible. This state of the patient is known as the completely locked-in syndrome.
But now, a research team at the Wyss Center for Bio and Neuroengineering, guided by Professor Niels Birbaumer, in Geneva, Switzerland, performed a trial to investigate whether a brain–computer interface dependent on functional near infrared spectroscopy can make communication possible in completely locked-in syndrome.
The research team included 4 people in the study with advanced amyotrophic lateral sclerosis in an abiding condition of a completely locked-in syndrome and 2 going to the completely locked-in syndrome state. The study volunteers were left with no dependable way of communicating.
The method includes patients bearing a cap that utilizes the infrared light to estimate the blood flow in the diverse regions of the brain as they deem about reacting “no” or “yes” to a question. The team skilled the patients by quizzing them with the control test questions to ensure the device could correctly trace their answers.
Brain–computer interfaces with implantable electrodes were successfully utilized before in individuals with less severe types of locked-in paralysis. But, these techniques consisted of directly implanting the electrodes into the brain. The present technique is non-invasive and is the first of its kinds to work reliably in patients who are completely locked-in.