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.

Applying the IEEE BRAIN neuroethics framework to intra-cortical brain-computer interfaces

Objective. Brain-computer interfaces (BCIs) are neuroprosthetic devices that allow for direct interaction between brains and machines. These types of neurotechnologies have recently experienced a strong drive in research and development, given, in part, that they promise to restore motor and communication abilities in individuals experiencing severe paralysis. While a rich literature analyzes the ethical, legal, and sociocultural implications (ELSCI) of these novel neurotechnologies, engineers, clinicians and BCI practitioners often do not have enough exposure to these topics.Approach. Here, we present the IEEE Neuroethics Framework, an international, multiyear, iterative initiative aimed at developing a robust, accessible set of considerations for diverse stakeholders.Main results. Using the framework, we provide practical examples of ELSCI considerations for BCI neurotechnologies. We focus on invasive technologies, and in particular, devices that are implanted intra-cortically for medical research applications.Significance. We demonstrate the utility of our framework in exposing a wide range of implications across different intra-cortical BCI technology modalities and conclude with recommendations on how to utilize this knowledge in the development and application of ethical guidelines for BCI neurotechnologies.

Limitation of life sustaining therapy in disorders of consciousness: ethics and practice

Clinical conversations surrounding the continuation or limitation of life-sustaining treatments (LLST) are both challenging and tragically necessary for patients with Disorders of Consciousness (DoC) following severe brain injury. Divergent cultural, philosophical, and religious perspectives contribute to vast heterogeneity in clinical approaches to LLST - as reflected in regional differences and inter-clinician variability. Here we provide an ethical analysis of factors that inform LLST decisions among patients with DoC. We begin by introducing the clinical and ethical challenge and clarifying the distinction between withdrawing and withholding life-sustaining therapy. We then describe relevant factors that influence LLST decision-making including diagnostic and prognostic uncertainty, perception of pain, defining a "good" outcome, and the role of clinicians. In concluding sections, we explore global variation in LLST practices as they pertain to patients with DoC and examine the impact of religious perspectives on approaches to LLST. Understanding and respecting the cultural and religious perspectives of patients and surrogates is essential for protecting patient autonomy and advancing goal-concordant care during critical moments of medical decision making.

Ethical Considerations in Endovascular Thrombectomy for Stroke

INTRODUCTION

Stroke is a leading cause of morbidity and mortality globally. Endovascular mechanical thrombectomy is considered for patients with large vessel occlusion stroke presenting up to 24 hours from onset and is being increasingly utilized across diverse clinical contexts. Proactive consideration of distinctive ethical dimensions of endovascular thrombectomy (EVT) can enable stroke care teams to deliver goal-concordant care to appropriately selected patients with stroke but have been underexplored.

METHODS

A narrative review with case examples was conducted.

RESULTS

We explain and critically evaluate the application of foundational bioethical principles and narrative ethics to the practice of EVT, highlight key ethical issues that may emerge in neuroendovascular practice and develop an ethical framework to aid in the responsible use of EVT for people with large-vessel occlusive ischemic stroke.

CONCLUSIONS

EVT for stroke introduces important ethical considerations. Salient challenges include decision-making capacity and informed consent, the telos of EVT, uncertainty, access to care, and resource allocation. An ethical framework focusing on combining patient values and preferences with the best available evidence in the context of a multidisciplinary care team is essential to ensure that the benefits of EVT are responsibly achieved and sustained.

Covert cortical processing: a diagnosis in search of a definition

Historically, clinical evaluation of unresponsive patients following brain injury has relied principally on serial behavioral examination to search for emerging signs of consciousness and track recovery. Advances in neuroimaging and electrophysiologic techniques now enable clinicians to peer into residual brain functions even in the absence of overt behavioral signs. These advances have expanded clinicians' ability to sub-stratify behaviorally unresponsive and seemingly unaware patients following brain injury by querying and classifying covert brain activity made evident through active or passive neuroimaging or electrophysiologic techniques, including functional MRI, electroencephalography (EEG), transcranial magnetic stimulation-EEG, and positron emission tomography. Clinical research has thus reciprocally influenced clinical practice, giving rise to new diagnostic categories including cognitive-motor dissociation (i.e. 'covert consciousness') and covert cortical processing (CCP). While covert consciousness has received extensive attention and study, CCP is relatively less understood. We describe that CCP is an emerging and clinically relevant state of consciousness marked by the presence of intact association cortex responses to environmental stimuli in the absence of behavioral evidence of stimulus processing. CCP is not a monotonic state but rather encapsulates a spectrum of possible association cortex responses from rudimentary to complex and to a range of possible stimuli. In constructing a roadmap for this evolving field, we emphasize that efforts to inform clinicians, philosophers, and researchers of this condition are crucial. Along with strategies to sensitize diagnostic criteria and disorders of consciousness nosology to these vital discoveries, democratizing access to the resources necessary for clinical identification of CCP is an emerging clinical and ethical imperative.

Disorders of Consciousness Rehabilitation: Ethical Dimensions and Epistemic Dilemmas

Patients with disorders of consciousness who survive to discharge following severe acute brain injury may face profoundly complex medical, ethical, and psychosocial challenges during their courses of recovery and rehabilitation. Although issues encountered in caring for such patients during acute hospitalization have received substantial attention, ethical challenges that may arise in subacute and chronic phases have been underexplored. Shedding light on these issues, this article explores the landscape of normative issues in the course of treating and facilitating access to care for persons with disorders of consciousness during rehabilitation and examines potential implications for patients, clinicians, family members, and society.

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.

Covert consciousness

Covert consciousness is a state of residual awareness following severe brain injury or neurological disorder that evades routine bedside behavioral detection. Patients with covert consciousness have preserved awareness but are incapable of self-expression through ordinary means of behavior or communication. Growing recognition of the limitations of bedside neurobehavioral examination in reliably detecting consciousness, along with advances in neurotechnologies capable of detecting brain states or subtle signs indicative of consciousness not discernible by routine examination, carry promise to transform approaches to classifying, diagnosing, prognosticating and treating disorders of consciousness. Here we describe and critically evaluate the evolving clinical category of covert consciousness, including approaches to its diagnosis through neuroimaging, electrophysiology, and novel behavioral tools, its prognostic relevance, and open questions pertaining to optimal clinical management of patients with covert consciousness recovering from severe brain injury.

Informed consent practices for acute stroke therapy: principles, challenges and emerging opportunities

IMPORTANCE

Informed consent (IC) plays a crucial yet underexplored role in acute stroke treatment, particularly in the context of intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT). This narrative review examines data on current IC practices in acute ischemic stroke management, specifically for patients treated with IVT or EVT, with the aim of identifying areas for improvement and strategies to enhance the IC process.

OBSERVATIONS

IC practices for IVT vary significantly among hospitals and physicians with the frequency of always requiring consent ranging from 21 to 37%. Factors influencing IC for IVT include patient decision-making capacity, standard of care, time sensitive nature of treatments, legal and moral obligations, risk of complications, physician age and speciality, treatment delays, and hospital size. Consent requirements tend to be stricter for patients presenting within the 3-4.5-h window. The content and style of information shared as part of the IC process revealed discrepancies in the disclosure of stroke diagnosis, IVT mechanism, benefits, and risks. Research on IC practices for EVT is scarce, highlighting a concerning gap in the available evidence base.

CONCLUSIONS AND RELEVANCE

This review underscores the significant variability and knowledge gaps in IC for EVT and IVT. Challenges related to decision-making capacity assessment and the absence of standardised guidance substantially contributes to these gaps. Future initiatives should focus on simplifying information delivery to patients, developing formal tools for assessing capacity, standardising ethical frameworks to guide physicians when patients lack capacity and harmonizing IC standards across sites. The ultimate goal is to enhance IC practices and uphold patient autonomy, while ensuring timely treatment initiation.

Ethics Along the Continuum of Research Involving Persons with Disorders of Consciousness

Interest in disorders of consciousness (DoC) has grown substantially over the past decade and has illuminated the importance of improving understanding of DoC biology; care needs (use of monitoring, performance of interventions, and provision of emotional support); treatment options to promote recovery; and outcome prediction. Exploration of these topics requires awareness of numerous ethics considerations related to rights and resources. The Curing Coma Campaign Ethics Working Group used its expertise in neurocritical care, neuropalliative care, neuroethics, neuroscience, philosophy, and research to formulate an informal review of ethics considerations along the continuum of research involving persons with DoC related to the following: (1) study design; (2) comparison of risks versus benefits; (3) selection of inclusion and exclusion criteria; (4) screening, recruitment, and enrollment; (5) consent; (6) data protection; (7) disclosure of results to surrogates and/or legally authorized representatives; (8) translation of research into practice; (9) identification and management of conflicts of interest; (10) equity and resource availability; and (11) inclusion of minors with DoC in research. Awareness of these ethics considerations when planning and performing research involving persons with DoC will ensure that the participant rights are respected while maximizing the impact and meaningfulness of the research, interpretation of outcomes, and communication of results.

Ethical Considerations in Neuroprognostication Following Acute Brain Injury

Neuroprognostication following acute brain injury (ABI) is a complex process that involves integrating vast amounts of information to predict a patient's likely trajectory of neurologic recovery. In this setting, critically evaluating salient ethical questions is imperative, and the implications often inform high-stakes conversations about the continuation, limitation, or withdrawal of life-sustaining therapy. While neuroprognostication is central to these clinical "life-or-death" decisions, the ethical underpinnings of neuroprognostication itself have been underexplored for patients with ABI. In this article, we discuss the ethical challenges of individualized neuroprognostication including parsing and communicating its inherent uncertainty to surrogate decision-makers. We also explore the population-based ethical considerations that arise in the context of heterogenous prognostication practices. Finally, we examine the emergence of artificial intelligence-aided neuroprognostication, proposing an ethical framework relevant to both modern and longstanding prognostic tools.

Modified Neuropixels probes for recording human neurophysiology in the operating room

Neuropixels are silicon-based electrophysiology-recording probes with high channel count and recording-site density. These probes offer a turnkey platform for measuring neural activity with single-cell resolution and at a scale that is beyond the capabilities of current clinically approved devices. Our team demonstrated the first-in-human use of these probes during resection surgery for epilepsy or tumors and deep brain stimulation electrode placement in patients with Parkinson's disease. Here, we provide a better understanding of the capabilities and challenges of using Neuropixels as a research tool to study human neurophysiology, with the hope that this information may inform future efforts toward regulatory approval of Neuropixels probes as research devices. In perioperative procedures, the major concerns are the initial sterility of the device, maintaining a sterile field during surgery, having multiple referencing and grounding schemes available to de-noise recordings (if necessary), protecting the silicon probe from accidental contact before insertion and obtaining high-quality action potential and local field potential recordings. The research team ensures that the device is fully operational while coordinating with the surgical team to remove sources of electrical noise that could otherwise substantially affect the signals recorded by the sensitive hardware. Prior preparation using the equipment and training in human clinical research and working in operating rooms maximize effective communication within and between the teams, ensuring high recording quality and minimizing the time added to the surgery. The perioperative procedure requires ~4 h, and the entire protocol requires multiple weeks.

Navigating the acute to post-acute transition with patients: a first characterization of medical student knowledge gaps in rehabilitation and post-acute care

PURPOSE

Clinical rehabilitation and post-acute care (PAC) learning experiences are not uniformly required within medical school core curricula in the United States or internationally. This study aims to characterize what medical students might know/need to know to support patients in the transition from acute hospitalization to post-acute rehabilitation settings.

MATERIALS/METHODS

The medical student cohort completing required clinical rotations in a United States quaternary care hospital system was provided a voluntary survey prompting reflection on experiences discharging patients to rehabilitation/PAC and related learning needs. Data were analyzed using descriptive statistics and qualitative grounded theory.

RESULTS

Response rate was 72% (39/54). All respondents reported at least one gap in rehabilitation/PAC knowledge, falling into 8 themes: daily experience of rehabilitation/PAC; determination of eligibility/screening processes; distinctions among levels of rehabilitation/PAC; insurance coverage/equity; rehabilitation/PAC clinical practice environment; post-rehabilitation/PAC discharge support; medical capabilities within PAC settings; developing rehabilitation goals.

CONCLUSIONS

Despite caring for patients discharged to post-acute rehabilitation settings, medical students lack essential knowledge about the process of rehabilitation and recovery, including patient eligibility for and service availability across PAC settings. Explicit rehabilitation/PAC education for medical students could enhance their ability to counsel and advocate for patients with disability and rehabilitation needs through care transitions.Implications for rehabilitationMedical students lack knowledge about rehabilitation and post-acute care that is important for helping patients navigate the acute to post-acute transition.Dedicated rehabilitation/post-acute care education could prepare trainees for counseling and advocating for patients during care transitions.Knowledge gaps identified in this study could inform development of curricular interventions to address medical student learning needs.

Toward Uniform Insurer Coverage for Functional MRI Following Severe Brain Injury

Functional magnetic resonance imaging (fMRI) now promises to improve diagnostic and prognostic accuracy for patients with disorders of consciousness, and accordingly has been endorsed by professional society guidelines, including those of the American Academy of Neurology, American College of Rehabilitation Medicine, National Institute on Disability, Independent Living, and Rehabilitation Research, and the European Academy of Neurology. Despite multiple professional society endorsements of fMRI in evaluating patients with disorders of consciousness following severe brain injury, insurers have yet to issue clear guidance regarding coverage of fMRI for this indication. Lack of insurer coverage may be a rate-limiting barrier to accessing this technique, which could uncover essential diagnostic and prognostic information for patients and their families. The emerging clinical and ethical case for harmonized insurer recognition and reimbursement of fMRI for vulnerable persons following severe brain injury with disorders of consciousness is explained and critically evaluated.

Measuring Consciousness in the Intensive Care Unit

Early reemergence of consciousness predicts long-term functional recovery for patients with severe brain injury. However, tools to reliably detect consciousness in the intensive care unit are lacking. Transcranial magnetic stimulation electroencephalography has the potential to detect consciousness in the intensive care unit, predict recovery, and prevent premature withdrawal of life-sustaining therapy.

Abstract WP140: Coma As A Presentation For Large Vessel Occlusion Stroke

Introduction: Coma is an unresponsive state of disordered consciousness characterized by impaired arousal and awareness. While coma has been studied in the context of traumatic brain injury, 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 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: responds only with reflex motor or autonomic effects or totally unresponsive, flaccid, and areflexic.

Results: A total of 28/638 (4.4%) patients with large vessel occlusion stroke were identified as presenting with coma. The median age was 65 (IQR 48-78), and 57% were female. The median NIHSS was 32 (IQR 29-34). Occlusion locations included basilar (10), vertebral (2), P1 posterior cerebral (2), internal carotid (4), M1 middle cerebral (6), and M2 middle cerebral arteries (4). In all 14 patients with anterior LVO, the acute LVO was unilateral. Of these 14, 6 had evidence of acute or chronic stroke involving the contralateral hemisphere; 1 experienced seizure; 1 experienced cardiac arrest; and 1 had chronic occlusion of the contralateral ICA. Overall, 20/28 died during the admission. Of those who died, 9 presented with anterior LVO and 11 with posterior LVO. Eight patients were treated with EVT. For those not treated, reasons included established infarct with ASPECTS <6 (11), delayed presentation (2), pre-stroke disability and goals of care (3), and absence of intracranial proximal occlusion on repeat imaging (2).

Conclusions: It is not uncommon for patients with LVO stroke to present with coma, and 65% of patients not treated with EVT had delayed presentations or large established infarcts, 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. Further study of these patients may shed light on the pathophysiology of coma. Efforts to improve early diagnosis and care are crucial given their poor outcomes.

Ethics Priorities of the Curing Coma Campaign: An Empirical Survey

BACKGROUND

The Curing Coma Campaign (CCC) is a multidisciplinary global initiative focused on evaluation, diagnosis, treatment, research, and prognostication for patients who are comatose due to any etiology. To support this mission, the CCC Ethics Working Group conducted a survey of CCC collaborators to identify the ethics priorities of the CCC and the variability in priorities based on country of practice.

METHODS

An electronic survey on the ethics priorities for the CCC was developed using rank-choice questions and distributed between May and July 2021 to a listserv of the 164 collaborators of the CCC. The median rank for each topic and subtopic was determined. Comparisons were made on the basis of country of practice.

RESULTS

The survey was completed by 93 respondents (57% response rate); 67% practiced in the United States. On the basis of respondent ranking of each topic, the prioritization of ethics topics across respondents was as follows: (1) clinical care, (2) diagnostic definitions, (3) clinical research, (4) implementation/innovation, (5) family, (6) data management, (7) public engagement/perceptions, and (8) equity. Respondents who practiced in the United States were particularly concerned about public engagement, the distinction between clinical care and research, disclosure of results from clinical research to families, the definition of "personhood," and the distinction between the self-fulfilling prophecy/nihilism and medical futility. Respondents who practiced in other countries were particularly concerned about diagnostic modalities for clinical care, investigational drugs/devices for clinical research, translation of research into practice, and the definition of "minimally conscious state."

CONCLUSIONS

Collaborators of the CCC considered clinical care, diagnostic definitions, and clinical research the top ethics priorities of the CCC. These priorities should be considered as the CCC explores ways to improve evaluation, diagnosis, treatment, research, and prognostication of patients with coma and associated disorders of consciousness. There is some variability in ethics priorities based on country of practice.

Comparative optimization of combinatorial CRISPR screens

Combinatorial CRISPR technologies have emerged as a transformative approach to systematically probe genetic interactions and dependencies of redundant gene pairs. However, the performance of different functional genomic tools for multiplexing sgRNAs vary widely. Here, we generate and benchmark ten distinct pooled combinatorial CRISPR libraries targeting paralog pairs to optimize digenic knockout screens. Libraries composed of dual Streptococcus pyogenes Cas9 (spCas9), orthogonal spCas9 and Staphylococcus aureus (saCas9), and enhanced Cas12a from Acidaminococcus were evaluated. We demonstrate a combination of alternative tracrRNA sequences from spCas9 consistently show superior effect size and positional balance between the sgRNAs as a robust combinatorial approach to profile genetic interactions of multiple genes.

Emerging Subspecialties in Neurology: Neuroethics: An Emerging Career Path in Neurology

Essential to responsible practice and progress in neurology and neuroscience research is robust engagement with associated ethical dimensions and challenges. By virtue of the privileged relationship between personhood and the brain, and the importance of properties of the nervous system to what for most makes life worth living, conditions that affect neurologic function introduce a growing host of novel ethical and philosophical issues. Rather than serving a reactionary role, it is important for neurologists to anticipate such issues and develop familiarity with ethical analysis to inform quality medical practice and to safeguard neuroscience research. The field of neuroethics is an emerging career path devoted to identifying and evaluating such issues with the aim of informing optimal clinical practice and responsible neuroscience research. This article describes the past, present, and future of neuroethics, informed by an interview with one of the field's key founders and luminaries, Dr. James Bernat, with specific focus on training and career opportunities for neurologists in training.

Ethics and the 2018 Practice Guideline on Disorders of Consciousness: A Framework for Responsible Implementation

The 2018 practice guideline on disorders of consciousness marks an important turning point in the care of patients with severe brain injury. As clinicians and health systems implement the guideline in practice, several ethical challenges will arise in assessing the benefits, harms, feasibility, and cost of recommended interventions. We provide guidance for clinicians when interpreting these recommendations and call on professional societies to develop an ethical framework to complement the guideline as it is implemented in clinical practice.

Ethical Considerations in Clinical Trials for Disorders of Consciousness

As the clinical trial landscape for patients with disorders of consciousness (DoC) expands, consideration of associated ethical challenges and opportunities is of ever-increasing importance. Responsible conduct of research in the vulnerable population of persons with DoC, including those with coma, vegetative state/unresponsive wakefulness syndrome (VS/UWS), minimally conscious state (MCS), covert cortical processing (CCP), and cognitive motor dissociation (CMD), demands proactive deliberation of unique ethical issues that may arise and the adoption of robust protections to safeguard patients, surrogates, and other key stakeholders. Here we identify and critically evaluate four central categories of ethical considerations in clinical trials involving participants with DoC: (1) autonomy, respect for persons and informed consent of individuals with liminal consciousness; (2) balancing unknown benefits and risks, especially considering the epistemological gap between behavior and consciousness that complicates ordinary ascription of subjective states; (3) disclosure to surrogates and clinical teams of investigational results pertaining to consciousness; and (4) justice considerations, including equitable access to clinical trial enrollment across communities and geographies. We outline guiding principles and research opportunities for clinicians, neuroethicists, and researchers engaged in DoC clinical trials to advance ethical study design and deployment in this complex yet crucial area of investigation.

Return to Work Within Four Months of Grade 3 Diffuse Axonal Injury

Neuroprognostication following diffuse axonal injury (DAI) has historically relied on neuroimaging techniques with lower spatial resolution and contrast than techniques currently available in clinical practice. Since the initial studies of DAI classification and prognosis in the 1980s and 1990s, advances in neuroimaging have improved detection of brainstem microbleeds, a hallmark feature of Grade 3 DAI that has traditionally been associated with poor neurologic outcome. Here, we report clinical and radiologic data from two patients with severe traumatic brain injury and grade 3 DAI who recovered functional independence and returned to work within 4 months of injury. Importantly, both patients were scanned using 3 Tesla MRI protocols that included susceptibility-weighted imaging (SWI), a technique that provides enhanced sensitivity for detecting brainstem microbleeds. These observations highlight the importance of developing approaches to DAI classification and prognosis that better align with contemporary neuroimaging capabilities.

Neuroethics in the Era of Teleneurology

The accelerating integration of telehealth technologies in neurology practice has transformed traditional interactions between neurologists and patients, allied clinicians and society. Despite the immense promise of these technologies to improve systems of neurological care, the infusion of telehealth technologies into neurology practice introduces a host of unique ethical challenges. Proactive consideration of the ethical dimensions of teleneurology and of the impact of these innovations on the field of neurology more generally can help to ensure responsible development and deployment across stages of implementation. Toward these ends, this article explores key ethical dimensions of teleneurology practice and policy, presents a normative framework for their consideration, and calls attention to underexplored questions ripe for further study at this evolving nexus of teleneurology and neuroethics. To promote successful and ethically resilient development of teleneurology across diverse contexts, clinicians, organizational leaders, and information technology specialists should work closely with neuroethicists with the common goal of identifying and rigorously assessing the trajectories and potential limits of teleneurology systems.

Sex-specific differences in presentations and determinants of outcomes after endovascular thrombectomy for large vessel occlusion stroke

INTRODUCTION

Sex-specific differences in ischemic stroke outcomes are prevalent. We sought to investigate sex differences in the determinants of reperfusion and functional outcomes after endovascular thrombectomy (EVT) for emergent large vessel occlusion ischemic stroke (ELVO).

METHODS

Patients presenting to a single referral center with an anterior circulation ELVO that underwent EVT from 2011 to 2019 were included in this retrospective analysis. Sex differences in history, presentation, adequate reperfusion (TICI 2b-3), and 90-day good outcome [delta modified Rankin Scale (mRS) ≤ 2 from pre-stroke] were examined. Multivariable logistic regression analyses were performed to assess sex-specific associations with outcomes.

RESULTS

Three hundred and eighty-one consecutive ELVO patients were identified. Women (N = 193) were older (75 vs 64 years, p < 0.0001), had more pre-stroke disability (17% vs 9%, p = 0.032), more atrial fibrillation (41% vs 30%, p = 0.033), but less carotid atherosclerosis (8% vs 16%, p = 0.027). Rates of TICI 2b-3 and good outcome were similar between sexes. Carotid atherosclerosis (OR 0.315, 95% CI 0.130, 0.762) and dissection (OR 0.124, 95% CI 0.027, 0.569) independently decreased the odds of TICI 2b-3 among men but not women. Older age, more severe stroke, and not achieving TICI 2b-3 independently decreased the odds of good outcome among both sexes, while prior stroke (OR 0.258, 95% CI 0.083, 0.797) and hemorrhagic transformation (OR 0.111, 0.021, 0.592) were determinants exclusive to men.

CONCLUSION

In a real-world analysis of ELVO stroke patients treated with EVT, we found that despite advanced age and more pre-stroke disability, women have comparable reperfusion rates and functional outcomes compared to men. Sex-specific determinants of reperfusion and functional outcome were identified that require further study.

When Should Neuroendovascular Care for Patients With Acute Stroke Be Palliative?

Noncurative surgeries intended to relieve suffering during serious illness or near end of life have been analyzed across palliative settings. Yet sparse guidance is available to inform clinical management decisions about whether, when, and which interventions should be offered when ischemic stroke and other neurological complications occur in patients whose survival is extended by other novel disease-modifying interventions. This case commentary examines key ethical and clinical considerations in palliative neuroendovascular care of patients with acute stroke.

The neuroethics of disorders of consciousness: a brief history of evolving ideas

Neuroethical questions raised by recent advances in the diagnosis and treatment of disorders of consciousness are rapidly expanding, increasingly relevant, and yet underexplored. The aim of this thematic review is to provide a clinically applicable framework for understanding the current taxonomy of disorders of consciousness and to propose an approach to identifying and critically evaluating actionable neuroethical issues that are frequently encountered in research and clinical care for this vulnerable population. Increased awareness of these issues and clarity about opportunities for optimizing ethically-responsible care in this domain are especially timely given recent surges in critically ill patients with unusually prolonged disorders of consciousness associated with coronavirus disease 2019 (COVID-19) around the world. We begin with an overview of the field of neuroethics: what it is, its history and evolution in the context of biomedical ethics at large. We then explore nomenclature used in disorders of consciousness, covering categories proposed by the American Academy of Neurology, the American Congress of Rehabilitation Medicine, and the National Institute on Disability, Independent Living, and Rehabilitation Research, including definitions of terms such as coma, the vegetative state, unresponsive wakefulness syndrome, minimally conscious state, covert consciousness, and the confusional state. We discuss why these definitions matter, and why there has been such evolution in this nosology over the years, from Jennett and Plum in 1972 to the Multi-Society Task Force in 1994, the Aspen Working Group in 2002 and up until the 2018 American and 2020 European Disorders of Consciousness guidelines. We then move to a discussion of clinical aspects of disorders of consciousness, the natural history of recovery, and ethical issues that arise within the context of caring for persons with disorders of consciousness. We conclude with a discussion of key challenges associated with assessing residual consciousness in disorders of consciousness, potential solutions and future directions, including integration of crucial disability rights perspectives.

Molecular basis for substrate recruitment to the PRMT5 methylosome

PRMT5 is an essential arginine methyltransferase and a therapeutic target in MTAP-null cancers. PRMT5 uses adaptor proteins for substrate recruitment through a previously undefined mechanism. Here, we identify an evolutionarily conserved peptide sequence shared among the three known substrate adaptors (CLNS1A, RIOK1, and COPR5) and show that it is necessary and sufficient for interaction with PRMT5. We demonstrate that PRMT5 uses modular adaptor proteins containing a common binding motif for substrate recruitment, comparable with other enzyme classes such as kinases and E3 ligases. We structurally resolve the interface with PRMT5 and show via genetic perturbation that it is required for methylation of adaptor-recruited substrates including the spliceosome, histones, and ribosomal complexes. Furthermore, disruption of this site affects Sm spliceosome activity, leading to intron retention. Genetic disruption of the PRMT5-substrate adaptor interface impairs growth of MTAP-null tumor cells and is thus a site for development of therapeutic inhibitors of PRMT5.

Enhanced migration of engrafted retinal progenitor cells into the host retina via disruption of glial barriers

Purpose

Migration and integration remain critical challenges for stem cell replacement therapy. Glial barriers play an important role in preventing cell migration and integration. The purpose of this study was to investigate the effect and mechanisms of chondroitinase ABC on the migration of murine retinal progenitor cells (mRPCs) transplanted into the subretinal space of B6 mice.

Methods

mRPCs were harvested from the neural retinas of P1 enhanced green fluorescent protein (GFP) B6 mice. Two μl containing 2 × 10⁵ expanded RPCs alone or combined with chondroitinase ABC in suspension were injected into the subretinal space of the recipient B6 mice. Immunohistochemistry was performed on the recipient B6 retinas to evaluate the glial barrier formation and migration of the mRPCs. Western blotting was also used to check the expression of the glial barriers.

Results

Glial fibrillary acidic protein (GFAP) and vimentin could be seen around the transplanted mRPCs in the B6 mice. Formation of glial barriers prevented the migration of donor cells into the retinal layers. Chondroitinase ABC promoted the migration and survival rates of the engrafted retinal progenitor cells in the retinal layers of recipient B6 mice. Injection induced upregulation of GFAP, chondroitin, and CD44 expression. Chondroitinase ABC disrupted the glial barriers. The CD44 around the mRPCs was much lower in the chondroitinase group. However, the CD44 in the retinal layers was considerably higher in the chondroitinase group. With the employment of chondroitinase ABC, more cells migrated into the outer nuclear layer or inner nuclear layer. The chondroitin and CD44 expression decreased 3 weeks after transplantation in the chondroitinase ABC group.

Conclusions

Chondroitinase ABC degraded glial barriers and enhanced the migration of transplanted mouse retinal progenitor cells. Chondroitinase ABC may also have induced activation of the CD44 signaling pathway to exert the effect.

Brain-Computer Interfaces in Neurorecovery and Neurorehabilitation

Recent advances in brain-computer interface technology to restore and rehabilitate neurologic function aim to enable persons with disabling neurologic conditions to communicate, interact with the environment, and achieve other key activities of daily living and personal goals. Here we evaluate the principles, benefits, challenges, and future directions of brain-computer interfaces in the context of neurorehabilitation. We then explore the clinical translation of these technologies and propose an approach to facilitate implementation of brain-computer interfaces for persons with neurologic disease.

A Safe GDNF and GDNF/BDNF Controlled Delivery System Improves Migration in Human Retinal Pigment Epithelial Cells and Survival in Retinal Ganglion Cells: Potential Usefulness in Degenerative Retinal Pathologies

We assessed the sustained delivery effect of poly (lactic-co-glycolic) acid (PLGA)/vitamin E (VitE) microspheres (MSs) loaded with glial cell-derived neurotrophic factor (GDNF) alone (GDNF-MSs) or combined with brain-derived neurotrophic factor (BDNF; GDNF/BDNF-MSs) on migration of the human adult retinal pigment epithelial cell-line-19 (ARPE-19) cells, primate choroidal endothelial (RF/6A) cells, and the survival of isolated mouse retinal ganglion cells (RGCs). The morphology of the MSs, particle size, and encapsulation efficiencies of the active substances were evaluated. In vitro release, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability, terminal deoxynucleotidyl transferase (TdT) deoxyuridine dUTP nick-end labelling (TUNEL) apoptosis, functional wound healing migration (ARPE-19; migration), and (RF/6A; angiogenesis) assays were conducted. The safety of MS intravitreal injection was assessed using hematoxylin and eosin, neuronal nuclei (NeuN) immunolabeling, and TUNEL assays, and RGC in vitro survival was analyzed. MSs delivered GDNF and co-delivered GDNF/BDNF in a sustained manner over 77 days. The BDNF/GDNF combination increased RPE cell migration, whereas no effect was observed on RF/6A. MSs did not alter cell viability, apoptosis was absent in vitro, and RGCs survived in vitro for seven weeks. In mice, retinal toxicity and apoptosis was absent in histologic sections. This delivery strategy could be useful as a potential co-therapy in retinal degenerations and glaucoma, in line with future personalized long-term intravitreal treatment as different amounts (doses) of microparticles can be administered according to patients’ needs.

Toward a more inclusive paradigm: thrombectomy for stroke patients with pre-existing disabilities

BACKGROUND

Persons with pre-existing disabilities represent over one-third of acute stroke presentations, but account for a far smaller proportion of those receiving endovascular thrombectomy (EVT) and thrombolysis. This is despite existing ethical, economic, legal, and social directives to maximize equity for this vulnerable population. We sought to determine associations between baseline modified Rankin Scale (mRS) and outcomes after EVT.

METHODS

Individuals who underwent EVT were identified from a prospectively maintained database. Demographics, medical history, presentations, treatments, and outcomes were recorded. Baseline disability was defined as baseline mRS≥2. Accumulated disability was defined as the delta between baseline mRS and absolute 90-day mRS.

RESULTS

Of 381 individuals, 49 had baseline disability (five with mRS=4, 23 mRS=3, 21 mRS=2). Those with baseline disability were older (81 vs 68 years, P<0.0001), more likely female (65% vs 49%, P=0.032), had more coronary disease (39% vs 20%, P=0.006), stroke/TIA history (35% vs 15%, P=0.002), and higher NIH Stroke Scale (19 vs 16, P=0.001). Baseline mRS was associated with absolute 90-day mRS ≤2 (OR=0.509, 95%CI=0.370-0.700). However, baseline mRS bore no association with accumulated disability by delta mRS ≤0 (ie, return to baseline, OR=1.247, 95%CI=0.943-1.648), delta mRS ≤1 (OR=1.149, 95%CI=0.906-1.458), delta mRS ≤2 (OR 1.097, 95% CI 0.869-1.386), TICI 2b-3 reperfusion (OR=0.914, 95%CI=0.712-1.173), final infarct size (P=0.853, β=-0.014), or intracerebral hemorrhage (OR=0.521, 95%CI=0.244-1.112).

CONCLUSIONS

While baseline mRS was associated with absolute 90-day disability, there was no association with accumulated disability or other outcomes. Patients with baseline disability should not be routinely excluded from EVT based on baseline mRS alone.

Creutzfeldt-Jakob disease in a man with COVID-19: SARS-CoV-2-accelerated neurodegeneration?

We describe a man whose first manifestations of Creutzfeldt-Jakob disease occurred in tandem with symptomatic onset of coronavirus disease 2019 (COVID-19). Drawing from recent data on prion disease pathogenesis and immune responses to SARS-CoV-2, we hypothesize that the cascade of systemic inflammatory mediators in response to the virus accelerated the pathogenesis of our patient's prion disease. This hypothesis introduces the potential relationship between immune responses to the novel coronavirus and the hastening of preclinical or manifest neurodegenerative disorders. The global prevalence of both COVID-19 and neurodegenerative disorders adds urgency to the study of this potential relationship.

Goal-Concordant Care in the Era of Advanced Stroke Therapies

Stroke is a leading cause of disability and mortality worldwide. Recent advances in stroke care now enable patients with severe ischemic stroke owing to large vessel occlusion to safely undergo endovascular thrombectomy (EVT) up to 24 hours since their time of last known well, with the goal of improving functional outcomes by recanalization of the occluded vessel and reperfusion of downstream ischemic brain tissue. The objective of this analysis is to highlight clinical and ethical challenges related to ensuring goal-concordant care in this era of unprecedented advances in acute stroke care. Specifically, there is a salient challenge of whether advanced therapies such as EVT may be justifiably considered comfort focused, given their potential to preempt accumulated neurologic disability and suffering at the end of life. Through the lens of a patient case, we discuss key challenges, lessons learned, and suggestions for future care and research endeavors at the intersection of acute stroke care and palliative care principles. Although therapies such as thrombolysis and EVT may be considered aggressive prima facie, their potential to ameliorate additional disability and potential suffering at the end of life prompt close consideration of the proper role of these therapies on a case-by-case basis in the context of comfort-focused care. Modification to the workflow for EVT evaluations may facilitate goal-concordant care and timely resource allocation, especially for cases that involve hospital-to-hospital transfers for advanced stroke care.

Disabling stroke in persons already with a disability: Ethical dimensions and directives

Stroke is the second leading cause of death worldwide and a leading cause of adult disability worldwide. More than a third of individuals presenting with strokes are estimated to have a preexisting disability. Despite unprecedented advances in stroke research and clinical practice over the past decade, approaches to acute stroke care for persons with preexisting disability have received scant attention. Current standards of research and clinical practice are influenced by an underexplored range of biases that may hinder acute stroke care for persons with disability. These trends may exacerbate unequal health outcomes by rendering novel stroke therapies inaccessible to many persons with disabilities. Here, we explore the underpinnings and implications of biases involving persons with disability in stroke research and practice. Recent insights from bioethics, disability rights, and health law are explained and critically evaluated in the context of prevailing research and clinical practices. Allowing disability to drive decisions to withhold acute stroke interventions may perpetuate disparate health outcomes and undermine ethically resilient stroke care. Advocacy for inclusion of persons with disability in future stroke trials can improve equity in stroke care delivery.

In Situ Cross-linking Hydrogel as a Vehicle for Retinal Progenitor Cell Transplantation

One of the current limitations of retinal transplantation of stem cells as well as other cell types is the dispersion of cells from the injection site (including loss of cells into the vitreous chamber) and low survival after transplantation. Gelatin-hydroxyphenyl propionic acid (Gtn-HPA) conjugate is a biodegradable polymer that can undergo covalent cross-linking in situ, allowing for injection of incorporated cells through a small caliber needle followed by gel formation in vivo. We tested the hypothesis that Gtn-HPA hydrogel supports survival and integration of retinal progenitor cells (RPCs) post-transplantation. In vitro compatibility and in vivo graft survival were assessed by mixing an equal volume of Gtn-HPA conjugate and RPC suspension and triggering enzyme-mediated gelation, using minute amounts of horseradish peroxidase and peroxide. Immunocytochemistry showed >80% survival of cells and minimal apoptosis for cells incorporated into Gtn-HPA, equivalent to controls grown on fibronectin-coated flasks. RPCs undergoing mitosis were seen within the three-dimensional Gtn-HPA hydrogel, but the percentage of Ki-67-positive cells was lower compared with the monolayer controls. For in vivo studies, gel-cell mixture or cell suspension in saline was trans-sclerally injected into the left eye of female Long Evans rats immunosuppressed with cyclosporine A. Grafts survived at the 1 week time point of the study, with Gtn-HPA-delivered grafts showing less inflammatory response demonstrated by anti-leukocyte staining. More eyes in the gel-cell mixture group showed surviving cells in the subretinal space compared with saline-delivered controls, while the number of cells surviving per graft was not significantly different between the two groups. This work demonstrates an injectable in situ cross-linking hydrogel as a potential vehicle for stem cell delivery in the retina.

Harnessing AI for health equity in oncology research and practice

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Background: Recent advances in artificial intelligence (AI) carry underexplored practical and ethical implications for the practice of clinical oncology. As oncologic applications of AI proliferate, a framework for guiding their ethical implementations and equitable distribution will be crucial. Methods: We reviewed the current landscape of AI applications in oncology research and clinical practice by reviewing the current body of evidence in PubMed and Medline. Key ethical challenges and opportunities to address health equity are critically evaluated and highlighted. Ethical implications for patients, clinicians and society at large are delineated, with particular focus on the impact and ramifications of AI with respect to healthcare disparities and equity of oncology care delivery. Results: Growing concerns that AI may widen disparities in oncologic care by virtue of lack of affordability, inconsistent accessibility and biased machine-learning models are addressed. Although there is potential for AI to widen disparities in oncology care, using foresight in application, AI has the potential to (1) democratize access to specialized clinical knowledge, (2) improve the accuracy of predicting cancer susceptibility, recurrence and mortality, (3) prevent diagnostic errors in under-resourced settings, (4) minimize unintended bias and (5) enable access to tailored therapeutic options including clinical trials if appropriately deployed. Separately, AI can be harnessed to identify areas of underserved needs and optimize systems of health-information sharing and reimbursements as blockchain technology converges with AI. As AI advances it will have a larger presence in oncology research and clinical practice. Conclusions: A strategic framework integrating ethical standards and emphasizing equitable implementation can help ensure that the potential of AI to address disparities in oncology are maximally captured and its perils averted. Further work is being done on exploring these challenges and will be submitted as a manuscript.

The changing practice of transurethral resection of the prostate

Introduction Transurethral resection of the prostate (TURP) is considered the gold standard surgical treatment for lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia. The number of TURPs performed has declined significantly over the last three decades owing to pharmaceutical therapy. TURP data from a single institution for the years 1990, 2000 and 2010 were compared to assess the difference in performance. Methods A retrospective analysis was undertaken of all patients who underwent TURP between January and December 2010. These findings were compared with historical data for the years 1990 and 2000: 100 sets of case notes were selected randomly from each of these years. Results The number of TURPs performed fell from 326 in 1990 to 113 in 2010. The mean age of patients increased from 70.6 years to 74.0 years. There was also a significant increase in the mean ASA grade from 1.9 to 2.3. The most common indication for TURP shifted from LUTS to acute urinary retention. No significant change in operating time was observed. The mean resection weight remained constant (22.95g in 1990, 22.55g in 2000, 20.76g in 2010). A reduction in transfusion rates was observed but there were higher rates of secondary haematuria and bladder neck stenosis. There was an increase from 2% to 11.5% of patients with long-term failure to void following TURP. Conclusions The number of TURPs performed continues to decline, which could lead to potential training issues. Urinary retention is still by far the most common indication. However, there has been a significant rise in the percentage of men presenting for TURP with high pressure chronic retention. The number of patients with bladder dysfunction who either have persistent storage LUTS or eventually require long-term catheterisation or intermittent self-catheterisation has increased markedly, which raises the question of what the long-term real life impact of medical therapy is on men with LUTS secondary to benign prostatic hyperplasia who eventually require surgery.

SMV1, an extremely stable thermophilic virus platform for nanoparticle trafficking in the mammalian GI tract

AIMS

Analysis of the stability and safety of Sulfolobus monocaudavirus 1 (SMV1) during passage through the mammalian GI tract.

METHODS AND RESULTS

A major challenge of using nano-vectors to target gut microbiome is their survival during passage through the extremely acidic and proteolytic environment of the mammalian GI tract. Here, we investigated the thermo-acidophilic archaeal virus SMV1 as a candidate therapeutic nano-vector for the distal mammalian GI tract microbiome. We investigated the anatomical distribution, vector stability and immunogenicity of this virus following oral ingestion in mice and compared these traits to the more classically used Inovirus vector M13KE. We found that SMV1 particles were highly stable under both simulated GI tract conditions (in vitro) and in mice (in vivo). Moreover, SMV1 could not be detected in tissues outside the GI tract and it elicited a nearly undetectable inflammatory response. Finally, we used human intestinal organoids (HIOs) to show that labelled SMV1 did not invade or otherwise perturb the human GI tract epithelium.

CONCLUSION

Sulfolobus monocaudavirus 1 appeared stable and safe during passage though the mammalian GI tract.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study evaluating an archaeal virus as a potential therapeutic nanoparticle delivery system and it opens new possibilities for future development of novel nanoplatforms.

Interphotoreceptor matrix based biomaterial: Impact on human retinal progenitor cell attachment and differentiation

While cell transplantation therapies show great promise as treatments for retinal degeneration, the challenge of low cell survival upon transplantation motivates exploration of materials that may serve as cell delivery vehicles and promote survival and differentiation. In this study, we explored the native matrix that surrounds the outer segments of photoreceptors and promotes their homeostasis, interphotoreceptor matrix (IPM), as a substrate for human retinal progenitor cells (hRPCs). Bovine IPM was characterized to determine its structure and biochemical composition, and processed to develop substrates for cells. Cell viability, morphology, proliferation and expression of photoreceptors marker genes were studied on IPM-based substrates in vitro. We explored different preparations of IPM as a scaffold. Lectin staining revealed that a distinct honeycomb structure of native IPM is lost during centrifugation to prepare a more concentrated suspension of matrix. Biochemical analysis of bovine IPM indicated presence of glycosaminoglycans and proteins. IPM mediated hRPC attachment and spreading with no signs of cytotoxicity. Cells proliferated more on native IPM substrates compared to IPM that was centrifuged to create a concentrated suspension. Cells cultured on IPM substrates expressed markers of photoreceptors: rhodopsin, NRL and ROM1. Together this data supports further exploration of IPM as a tool for retinal tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 891-899, 2018.