Covert cortical processing: a diagnosis in search of a definition

Equity in Clinical Care and Research Involving Persons with Disorders of Consciousness

People with disorders of consciousness (DoC) are characteristically unable to synchronously participate in decision-making about clinical care or research. The inability to self-advocate exacerbates preexisting socioeconomic and geographic disparities, which include the wide variability observed across individuals, hospitals, and countries in access to acute care, expertise, and sophisticated diagnostic, prognostic, and therapeutic interventions. Concerns about equity for people with DoC are particularly notable when they lack a surrogate decision-maker (legally referred to as "unrepresented" or "unbefriended"). Decisions about both short-term and long-term life-sustaining treatment typically rely on neuroprognostication and individual patient preferences that carry additional ethical considerations for people with DoC, as even individuals with well thought out advance directives cannot anticipate every possible situation to guide such decisions. Further challenges exist with the inclusion of people with DoC in research because consent must be completed (in most circumstances) through a surrogate, which excludes those who are unrepresented and may discourage investigators from exploring questions related to this population. In this article, the Curing Coma Campaign Ethics Working Group reviews equity considerations in clinical care and research involving persons with DoC in the following domains: (1) access to acute care and expertise, (2) access to diagnostics and therapeutics, (3) neuroprognostication, (4) medical decision-making for unrepresented people, (5) end-of-life decision-making, (6) access to postacute rehabilitative care, (7) access to research, (8) inclusion of unrepresented people in research, and (9) remuneration and reciprocity for research participation. The goal of this discussion is to advance equitable, harmonized, guideline-directed, and goal-concordant care for people with DoC of all backgrounds worldwide, prioritizing the ethical standards of respect for autonomy, beneficence, and justice. Although the focus of this evaluation is on people with DoC, much of the discussion can be extrapolated to other critically ill persons worldwide.

Disclosing Results of Tests for Covert Consciousness: A Framework for Ethical Translation

The advent of neurotechnologies including advanced functional magnetic resonance imaging and electroencephalography to detect states of awareness not detectable by traditional bedside neurobehavioral techniques (i.e., covert consciousness) promises to transform neuroscience research and clinical practice for patients with brain injury. As these interventions progress from research tools into actionable, guideline-endorsed clinical tests, ethical guidance for clinicians on how to responsibly communicate the sensitive results they yield is crucial yet remains underdeveloped. Drawing on insights from empirical and theoretical neuroethics research and our clinical experience with advanced neurotechnologies to detect consciousness in behaviorally unresponsive patients, we critically evaluate ethical promises and perils associated with disclosing the results of clinical covert consciousness assessments and describe a semistructured approach to responsible data sharing to mitigate potential risks.

Characterizing coma in large vessel occlusion stroke

BACKGROUND

Coma is an unresponsive state of disordered consciousness characterized by impaired arousal and awareness. The epidemiology and pathophysiology of coma in ischemic stroke has been underexplored. We sought to characterize the incidence and clinical features of coma as a presentation of large vessel occlusion (LVO) stroke.

METHODS

Individuals who presented with LVO were retrospectively identified from July 2018 to December 2020. Coma was defined as an unresponsive state of impaired arousal and awareness, operationalized as a score of 3 on NIHSS item 1a.

RESULTS

28/637 (4.4%) patients with LVO stroke were identified as presenting with coma. The median NIHSS was 32 (IQR 29-34) for those with coma versus 11 (5-18) for those without (p < 0.0001). In coma, occlusion locations included basilar (13), vertebral (2), internal carotid (5), and middle cerebral (9) arteries. 8/28 were treated with endovascular thrombectomy (EVT), and 20/28 died during the admission. 65% of patients not treated with EVT had delayed presentations or large established infarcts. In models accounting for pre-stroke mRS, basilar occlusion location, intravenous thrombolysis, and EVT, coma independently increased the odds of transitioning to comfort care during admission (aOR 6.75; 95% CI 2.87,15.84; p < 0.001) and decreased the odds of 90-day mRS 0-2 (aOR 0.12; 95% CI 0.03,0.55; p = 0.007).

CONCLUSIONS

It is not uncommon for patients with LVO to present with coma, and delayed recognition of LVO can lead to poor outcomes, emphasizing the need for maintaining a high index of suspicion. While more commonly thought to result from posterior LVO, coma in our cohort was similarly likely to result from anterior LVO. Efforts to improve early diagnosis and care of patients with LVO presenting with coma are crucial.