Brain-Computer Interfaces for Communication in Patients with Disorders of Consciousness: A Gap Analysis and Scientific Roadmap

Abstract

Background: We developed a gap analysis that examines the role of brain-computer interfaces (BCI) in patients with disorders of consciousness (DoC), focusing on their assessment, establishment of communication, and engagement with their environment.

Methods: The Curing Coma Campaign convened a Coma Science work group that included 16 clinicians and neuroscientists with expertise in DoC. The work group met online biweekly and performed a gap analysis of the primary question.

Results: We outline a roadmap for assessing BCI readiness in patients with DoC and for advancing the use of BCI devices in patients with DoC. Additionally, we discuss preliminary studies that inform development of BCI solutions for communication and assessment of readiness for use of BCIs in DoC study participants. Special emphasis is placed on the challenges posed by the complex pathophysiologies caused by heterogeneous brain injuries and their impact on neuronal signaling. The differences between one-way and two-way communication are specifically considered. Possible implanted and noninvasive BCI solutions for acute and chronic DoC in adult and pediatric populations are also addressed.

Conclusions: We identify clinical and technical gaps hindering the use of BCI in patients with DoC in each of these contexts and provide a roadmap for research aimed at improving communication for adults and children with DoC, spanning the clinical spectrum from intensive care unit to chronic care.

Keywords: Cognitive motor dissociation; Coma; Communication; Electroencephalography; Functional magnetic resonance imaging; Head injury; Neural repair.

Fig. 1

Set up for BCI systems for communication in a patient with DoC

Fig. 2.

Patients with a DoC need to be clinically assessed for their BCI readiness, as success of this approach can only be expected when certain minimal clinical prerequisites are met. Typically, a patient’s clinical assessment would comprise three elements: 1) a neurobehavioral examination through a standardized or well validated scale for consciousness, such as Coma Recovery Scale – Revised (CRS-R), complemented by Motor Behavior Tool-revised (MBT-r) or a similar tool, 2) a neurological examination, possibly including a radiological investigation through structural imaging, such as brain CT or MRI, and 3) a neurophysiological assessment with standard electroencephalography and, possibly, evoked potentials. It is important for the initial clinical assessment to be comprehensive, so that sufficient elements can be gathered by the clinical team to recommend (or not) specific sensory response assessment for BCI candidacy. AEP Auditory Evoked Potentials, CMD Cognitive Motor Dissociation, CRS-R Coma Recovery Scale – Revised (CRS-R), MBT-r Motor Behavior Tool – revised, VEP Visual Evoked Potentials, SSEP Somatosensory Evoked Potentials.