Biofeedback and Locked In Syndrome -- in ALS ( Amyotrphic Lateral Sclerosis ) or Lou Gherig's Disease
Over the year's we've been repeatedly contacted by friends and family members of people in various stages of ALS. They are seeking the help of biofeedback to stay connected with their loved ones as the muscles stop working.
There have been a number of studies and reports, using different approaches to biofeedback or applied psychophysiology to enable 'locked in' patients to communicate. The basic idea is that physiological sensors can detect changes in physiology that the patient voluntarily and intentionally makes-- as means of communicating, just as giving a thumb up or down is a signal. The articles and links below are provided as a service to help pull together some of the information. We also have a DVD of a workshop presented on the use of brain biofeedback to address this problem, presented by Niels Birbaumer, to our knowledge, the inventor of this approach.
Futurehealth does offer biofeedback technology for sale. We make no promises that these technologies will enable you and your loved ones to communicate. Some people have purchased this equipment in an effort to try, to experiment with the technology. Please be clear that this is an expensive, unproven approach, though there is some research.
One thing is clear, the early a patient gets started with this, before the 'locked in' situation is reached, the better the potential results.
Oddball Science Helps "Locked In" People Communicate
Newswise — University of South Florida psychologist Emanuel Donchin and his students are perfecting ways to help people who are paralyzed yet fully conscious - with intact cognitive systems - communicate via a brain computer interface (BCI). Although the patient is unable to communicate, the electrical activity in their brains is normal. Through the BCI it becomes possible for users to “type” on a “virtual keyboard” using their brain waves.
The BCI, says Donchin, can help patients who suffer from amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease) - a rare progressive neurological disorder that ultimately leads to a complete paralysis of voluntary muscles in all parts of the body; cerebral palsy; or patients “locked in” following a brain stem stroke.
“In essence, we are trying to provide the brain with new channels for communication and control by capturing and analyzing the electrical or electroencephalographic (EEG) activity produced in the brain,” he explained. “Our goal is to restore communication functions.”
To create an assistive “mental prosthesis,” Donchin’s extensive work is focused on capturing and reporting unique brain activity that occurs upon the visual observation of a rare or “oddball” event. According to Donchin, the “oddball paradigm” relies on a response to deviant stimuli embedded in a series of standard stimuli, such as letters, symbols and commands flashing randomly on a keyboard-like screen. By analyzing the electrical activity as event-related brain potential (ERP) generated by the oddball event, the user in Donchin’s studies focuses attention on the character to be communicated as elements of the display are flashed on the screen.
“The chosen character is the one eliciting a ‘P300,’” said Donchin. “Thus, by detecting which rows and columns in the display elicit a P300 the computer can determine the character the patient is trying to ‘type.’”
In collaboration with the Wadsworth Institute at SUNY-Albany, Donchin’s group has conducted numerous studies with healthy and disabled volunteers who, wearing electrodes on their scalp attaching them to the BCI, were placed in front of an electronic screen display of 26 letters of the alphabet and other symbols and commands in a six-by-six row and columns flashing in random sequence. Test subjects were able to “operate” a virtual keyboard when their EEG reactions to oddball events in the random flashing were analyzed. Researchers found greater electrical response in the rarely presented, or oddball, stimuli and the spike in the subjects’ EEG at time of the oddball event created a means of communication.
“Ideally, the subject can spell out a message by successively choosing among the 26 letters,” explained Donchin. “We are examining the operating characteristics of this communication channel and analyzing the speed with which there was an EEG focus on the letter of interest.”
Test subjects were able to communicate their choice of a letter at the rate of about one character every 26 seconds.
“This is, of course, a slow rate of communication,” said Donchin. “But, considering there is no other channel of communication, even this slow rate is welcome.”
Since coming to USF, Donchin with his student Eric Sellers tested more than 15 ALS patients and have established that, in general, the system works although many adjustments in the procedure are required to allow the use of the BCI in patients’ homes.
- Paralyzed patients use brain waves to talk
- A German researcher Tuesday described a new technique in which paralyzed patients can use their brain waves to communicate with loved ones and caregivers. The technique, which allows patients to spell out words on a computer screen, works well, but only as long as patients learn to use it before they become completely paralyzed, University of Tubingen psychology professor Niels Birbaumer told United Press International.
- If a person cannot move, talk, or even blink, is it possible to communicate with his brain?
- Brain-Computer Communication and Slow Cortical Potentials
- Abstract— A Thought-Translation-Device (TTD) has been designed to enable direct brain-computer communication using self regulation of slow cortical potentials (SCPs). However, accuracy of SCP control reveals high inter-subject variability. To guarantee the highest possible communication speed, some important aspects of training SCPs are discussed. A baseline correction of SCPs can increase performance. Multi-channel recordings show that SCPs are of highest amplitude around the vertex electrode used for feedback but in some subjects more global distributions were observed. A new method for control of eye movement are presented. Sequential effects of trial-to-trial interaction may also cause difficulties to the user. Finally, psychophysiological factors determining SCP-communication are discussed.
- The thought translation device: a neurophysiological approach to communication in total motor paralysis.
- Self-initiation of EEG-based communication in paralyzed patients.
- Biological feedback of brain and muscle activity: basic mechanisms and clinical applications (Niels Birbaumer's facility)
- Predictors of successful self control during brain-computer communication
- A non-invasive communication device for the paralyzed.
- Timing of EEG-based cursor control.
- Mind-reading machines close communication gap
- Using human extra-cortical local field potentials to control a switch*
- EEG Signal Classification for Brain Computer Interface Applications
DVD available from Futurehealth.org $95 WZ4 Niels Birbaumer Slow Cortical Potential biofeedback-- A new form of neurofeedback, with a long history of research support
Institute of Medical Psychology and Behavioral Neurobiology University of Tuebingen
This very different approach to training the brain is not used in the US, yet it has extensive research support, mostly done in Europe. Dr. Birbaumer, awarded the honor of the most respected scientist in Europe, has developed an approach which promises to add important new tools, dimensions and applications to the armamentarium of the neurofeedback practitioner.
Slow cortical potentials indicate a state of excitation or inhibition of large cortical neuron pools. Negative slow brain potentials of several seconds duration indicate depolarization of the underlying cortical network, positivity reflects reduction of fascilitation. In several papers biofeedback of slow cortical potentials in normal populations where described (Birbaumer et al 1990, Physiological Reviews) which showed that self-produced negativity improves those behavioral and cognitive activities which utilize mobilization of cortical networks. Response speed, vigilance and concentration is increased during negativity, positivity reduces mobilization. Cholinergic inflow to the cortical mantle seems to be responsible for negativity, while positivity depends on the activation of GABAergic inhibitory synapses. Measurement of brain blood flow with functional MRI during biofeedback of slow cortical potentials (Birbaumer et al, in press) demonstrates that during self-produced negativity prefrontal thalamic and parietal structures are activated while during self-induced positivity those structures are inhibited. Therefore it can be concluded that self-regulation of slow cortical potentials involves excitation and inhibition of attentional systems in cortical and subcortical structures.
Biofeedback of slow cortical potentials was first applied to the treatment of epilepsy, particular temporal lobe epilepsy (Rockstroh et al 1989).
Several controlled studies have shown that training of positivity for more than 40 sessions improves seizure frequency and neuropsychological functions in temporal lobe epilepsy: three studies with 60 patients have demonstrated that after extended training of positivity one third of patients is seizure-free, one third shows significant improvement and one third does not respond. All patients were drug-refractory epileptic patients with more than one seizure a week. These studies will be reviewed and new data will be added.
Another successful application of slow brain potential biofeedback is a brain-computer-interface communication system for locked-in patients.
Locked-in-patients have no means to communicate because all muscles including face muscles are paralyzed. Most of the patients in our studies are patients with amyotrophic lateral sklerosis, a neurological disease which leads to complete motor paralysis while all sensory systems remain intact. Patients are artificially ventilated and have to be fed artificially. These patients learn to produce cortical negativity and positivity at different locations of the brain and use this brain response to select in a special computer program verbal communication subprograms by which a more or less fluent verbal communication through the brain with the help of the computer becomes possible. Video demonstrations and results of these studies will be presented at the conference. A new successful application of slow brain potential biofeedback is the training of left temporal negativity in aphasic patients. Already after 5 training sessions improvement in expression and processing of words can be shown.