Noninvasive brain-computer interface enables communication after brainstem stroke
Published Oct 8, 2014 · E. Sellers, D. Ryan, C. K. Hauser
Science Translational Medicine
123
Citations
5
Influential Citations
Abstract
An individual “locked-in” by a brainstem stroke was able to communicate using noninvasive brain-computer interface technology. Communicating with a Locked-in Patient “Locked-in” syndrome describes a patient who is awake, or conscious, but can’t communicate verbally; some patients even lack the ability to convey thoughts and emotions by movement, whether it be with a hand, a headshake, or the eyes. To help these patients communicate, Sellers et al. used a brain-computer interface (BCI) that relies on spelling. Over the course of a year, the authors tested their BCI in one patient locked-in as a result of a brainstem stroke. The patient would focus on a computer screen with either different choices—Yes, No, Pass, and End—or letters to spell out a desired word. When his desired choice would flash, a concurrent deflection in the brain signal, called the P300 event-related potential, would occur and be recognized by the computer. After calibration of the BCI, the patient was able to freely spell words and relay messages to his wife, such as “Thank you for all of your hard work.” Although this message took 45 min to complete, without such technology communication between the patient and his family would be nearly impossible. The case study by Sellers et al. was in one locked-in patient, and future studies will be needed to determine accuracy and broad applicability. Brain-computer interfaces (BCIs) provide communication that is independent of muscle control, and can be especially important for individuals with severe neuromuscular disease who cannot use standard communication pathways or other assistive technology. It has previously been shown that people with amyotrophic lateral sclerosis (ALS) can successfully use BCI after all other means of independent communication have failed. The BCI literature has asserted that brainstem stroke survivors can also benefit from BCI use. This study used a P300-based event-related potential spelling system. This case study demonstrates that an individual locked-in owing to brainstem stroke was able to use a noninvasive BCI to communicate volitional messages. Over a period of 13 months, the participant was able to successfully operate the system during 40 of 62 recording sessions. He was able to accurately spell words provided by the experimenter and to initiate dialogues with his family. The results broadly suggest that, regardless of the precipitating event, BCI use may be of benefit to those with locked-in syndrome.