MedicalResearch.com Interview with:
Mariska Van Steensel PhD
Nick F. Ramsey, Ph.D.
Department of Neurology and Neurosurgery
Brain Center Rudolf Magnus
University Medical Center Utrecht
Utrecht, the Netherlands
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Patients who are severely paralyzed due to for example ALS or brain stem stroke are often unable to speak (also called ‘ Locked-in State’), and therefore need assistive devices, such as an eye tracker, for their communication. When these devices fail (e.g. due to environmental lighting or eye movement problems), people may indicate yes or no with eye blinks in response to closed questions. This leaves patients in a highly dependent position, since questions asked may or may not represent their actual wish or comment.
In the current study, we used a technology called brain-computer interfacing (BCI), to allow a patient with late-stage amyotrophic lateral sclerosis (ALS) to control a communication device using her brain signals. The patient was implanted with subdural electrodes that covered the brain area that is normally responsible for hand movement. The electrodes were connected with wires, subcutaneously, to an amplifier/transmitter device that was placed subcutaneously under the clavicle. The patient was able to generate a signal equivalent to a mouse-click with this brain-computer interface by attempting to move her hand, and used it to make selections of letters or words on her communication device, with high accuracy and a speed of 2 letters per minute. She used the brain-computer interface system to communicate whenever she was outside, as her eye-tracker device does not function well in that situation.
MedicalResearch.com: What should readers take away from your report?
Response: Our study shows that it is possible for severely paralyzed patients with an inability to speak, to control an assistive communication device using brain signals recorded from the surface of the brain. The brain-computer interface system we report on is invisible on the patient except for a small antenna that has to be clipped to the clothing. Moreover, it is mobile, allowing patients to use it outside, and does not require any specialized skills from caretakers to be used. Perhaps the most important achievement is that the patient uses the BCI system at home, without any involvement of experts or researchers. She can still use an eye-tracker in her home, but depends on the BCI implant for going outside and traveling (where the eye trackers becomes unreliable) since it is the only way that she can be sure she can draw the caregivers attention when necessary
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Response: Our results indicate that communication using brain signals is a viable alternative when muscle-based communication fails. Since adequate communication (meaning: the ability to self-initiate a conversation by, for example, asking questions) is a determining factor for the quality of life of severely paralyzed patients, we believe research and society should invest in making implantable brain-computer interfaces accessible for those who need them. We aim to include two more patients in the current study to demonstrate the reproducibility of our findings also in other patients and to increase the speed of communication. Subsequently, we aim to start an international clinical trial, in order to lay the grounds for actual clinical application of our brain-computer interface system. We also hope that our research encourages the translation of research on decoding limb movements (eg Braingate project, www.braingate.org) to systems for home use in amputees or quadriplegic patients
MedicalResearch.com: Is there anything else you would like to add?
Response: We think that this case study constitutes the first proof that BCI implants can really enhance the lives of people with Locked-in State. From here, we expect to be able to make it possible for patients worldwide to have access to this BCI system through standard medical channels (and commercial delivery of the implant). We plan the clinical trial for this reason. We and others are already working on the next generation BCI implant that will contain tens of electrodes and can translate attempted hand sign language or perhaps even attempted speech, into speech via a voice-generating computer. Such systems will potentially benefit also less paralyzed people such as those with loss of speech capability after stroke
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Fully Implanted Brain–Computer Interface in a Locked-In Patient with ALS
Mariska J. Vansteensel, Ph.D., Elmar G.M. Pels, M.Sc., Martin G. Bleichner, Ph.D., Mariana P. Branco, M.Sc., Timothy Denison, Ph.D., Zachary V. Freudenburg, Ph.D., Peter Gosselaar, M.D., Sacha Leinders, M.Sc., Thomas H. Ottens, M.D., Max A. Van Den Boom, M.Sc., Peter C. Van Rijen, M.D., Erik J. Aarnoutse, Ph.D., and Nick F. Ramsey, Ph.D.
November 12, 2016DOI: 10.1056/NEJMoa1608085
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