New brain-computer interface gives unresponsive patients a voice

Clinical takeaway: In patients with acute severe brain injury who appear unable to respond, EEG-based testing may identify covert consciousness and help refine prognostication; patients able to control a bedside brain-computer interface (BCI) were substantially more likely to recover consciousness and functional independence.

Research over the past decade has shown that a meaningful minority of seemingly comatose patients retain awareness despite an inability to move or communicate, a phenomenon known as cognitive motor dissociation (CMD). However, clinicians currently lack practical tools to establish communication with these patients at the bedside.

In this prospective single-center study, investigators evaluated a noninvasive EEG-based BCI in 41 clinically unresponsive patients with acute brain injury. Patients were instructed to mentally attempt hand movements to make a series of beeps sound faster or slower, while real-time EEG signals were translated into auditory feedback.

Overall, 32% of patients successfully controlled the BCI despite showing no clinical signs of command-following. Notably, nearly half of those who achieved BCI control did so within the first week after injury, and all patients with EEG evidence of CMD were able to control the interface. The findings suggest that covert consciousness may be more common than bedside examination alone indicates.

BCI control was strongly associated with recovery. By hospital discharge, 31% of patients with BCI control recovered consciousness compared with 4% of those without control. At 12 months, 46% of patients with BCI control regained functional independence versus 7% of those who could not control the system. Importantly, no patient who was both CMD-negative and unable to control the BCI achieved functional independence.

The authors noted that responses from unresponsive patients were often delayed by nearly 50 seconds, far slower than those seen in conscious patients or healthy volunteers, highlighting the need to allow extra processing time when assessing severely brain-injured patients. They also emphasized that the technology remains an early proof of concept and is not yet capable of meaningful bidirectional communication.

“Our brain-computer interface is only a first step, but it shows that, in principle, we could hopefully in the future give some of these patients a voice,” said senior author Dr. Jan Claassen. Family members overwhelmingly supported further development of the technology, particularly features that could help patients communicate pain, hunger, comfort, or awareness.

Source: Shen Q, et al. (2026 Oct 22) Brain. Clinically unresponsive patients with acute brain injury activate a brain-computer interface