Translating the Discovery of Covert Consciousness Into Clinical Practice

Abstract

In conditions of prognostic uncertainty, neurointensivists and families often struggle to make decisions for unresponsive patients with brain injuries. However, a new study demonstrates that after brain injury electrophysiological assessment (electroencephalography [EEG]) has potential prognostic value. 1 This could have profound implications for clinically and ethically consequential decisions, such as withdrawing life-sustaining treatment or managing potentially life-threatening events such as sepsis. Here, we outline 2 interrelated ethical considerations for neurointensivists who use these methods when communicating prognostic information to patients' families. Discovering Covert Consciousness in the Intensive Care UnitA 2019 study of 104 seemingly unconscious patients with brain injuries cared for in a neuro-intensive care unit (ICU) demonstrated that 16 patients responded to the command to open and close their hand. 1 Researchers did not observe this hand movement at the bedside. Instead, they witnessed EEG evidence of motor cortex activation.A machine learning algorithm identified latent evidence of brain responsiveness from multiple EEG test results. Six days after injury, half of the 16 patients with responsive brain activity recovered the ability to behaviorally follow commands, and follow-up showed that 7 patients recovered functional independence. Compared with patients who showed no evidence of motor cortex activation and recovered (12 of 84 [14%]), those with brain responsiveness recovered faster and with greater odds of a positive outcome.These results are similar to those of previous studies reporting brain activity in unresponsive patients with brain injuries. 2 Indeed, a significant proportion of unresponsive patients, estimated to be at least 15%, are able to modulate their brain activity to command. 3 These patients are correctly regarded as unconscious according to clinical criteria, yet their brain activity shows that they are aware. Such patients are variously described as having cognitive-motor dissociation or as being covertly conscious. Their consciousness is hidden until we discover it by measuring their brain activity.These findings have important implications for neurocritical care. The novel combination of machine learning with EEG can improve prognostic accuracy. The feasibility of these methods also suggests that they are likely to be used. In the days following brain injury, EEG is more practical for ICU patients compared with other costly and complex neuroimaging methods. 4 Despite the promise of these methods, little is known about how families will use test results to make VIEWPOINT

Caregiver reactions to neuroimaging evidence of covert consciousness in patients with severe brain injury: a qualitative interview study

“…Second, disclosure of neuroimaging results to caregivers should be standardized, involve professionals who are trained in communication, and allow sufficient time for questions and discussion [10,34,35]. These mechanisms are intended to mitigate disagreement, improve caregiver comprehension of the results, and potentially optimize decision making.…”

Brain–Computer Interfaces for Awareness Detection, Auxiliary Diagnosis, Prognosis, and Rehabilitation in Patients with Disorders of Consciousness

“…37 An accurate prediction of rehabilitation in patients with DoC is significant for the patient, the family, the clinicians, and caregivers. 38 39 Importantly, patients with DoC with minimal signs of consciousness are more likely to recover than patients without signs of consciousness. According to several previous studies, 40 the prognosis of VS/UWS and MCS patients could be evaluated by behavioral scales and neuroimaging techniques.…”

Medical AI, inductive risk and the communication of uncertainty: the case of disorders of consciousness

“…A diagnosis of CMD is likely to influence life-or-death decisions about the patient's best interests. [3][4][5] In the first two weeks after a serious brain injury, the patient's surrogate decision makers, in discussion with clinicians, will typically face the terrible decision of whether or not to withdraw life-sustaining treatment. [6] The surrogate decision makers are usually family members, with some exceptions, [7] so I will say "family" in what follows.…”