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

Clinical conversations surrounding the continuation or limitation of life-sustaining therapies (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 cultural and religious perspectives on approaches to LLST. Understanding and respecting the cultural and religious perspectives of patients and surrogates is essential to protecting patient autonomy and advancing goal-concordant care during critical moments of medical decision-making involving patients with DoC.

How well do neural signatures of resting-state EEG detect consciousness? A large-scale clinical study.

The assessment of consciousness states, especially distinguishing minimally conscious states (MCS) from unresponsive wakefulness states (UWS), constitutes a pivotal role in clinical therapies. Despite that numerous neural signatures of consciousness have been proposed, the effectiveness and reliability of such signatures for clinical consciousness assessment still remains an intense debate. Through a comprehensive review of the literature, inconsistent findings are observed about the effectiveness of diverse neural signatures. Notably, the majority of existing studies have evaluated neural signatures on a limited number of subjects (usually below 30), which may result in uncertain conclusions due to small data bias. This study presents a systematic evaluation of neural signatures with large-scale clinical resting-state electroencephalography (EEG) signals containing 99 UWS, 129 MCS, 36 emergence from the minimally conscious state, and 32 healthy subjects (296 total) collected over 3 years. A total of 380 EEG-based metrics for consciousness detection, including spectrum features, nonlinear measures, functional connectivity, and graph-based measures, are summarized and evaluated. To further mitigate the effect of data bias, the evaluation is performed with bootstrap sampling so that reliable measures can be obtained. The results of this study suggest that relative power in alpha and delta serve as dependable indicators of consciousness. With the MCS group, there is a notable increase in the phase lag index-related connectivity measures and enhanced functional connectivity between brain regions in comparison to the UWS group. A combination of features enables the development of an automatic detector of conscious states.

EEG Microstate Analysis in Patients with Disorders of Consciousness and Its Clinical Significance.

Disorders of Consciousness are divided into two major categories such as vegetative and minimally conscious states. Objective measures that allow correct identification of patients with vegetative and minimally conscious state are needed. EEG microstate analysis is a promising approach that we believe has the potential to be effective in examining the resting state activities of the brain in different stages of consciousness by allowing the proper identification of vegetative and minimally conscious patients. As a result, we try to identify clinical evaluation scales and microstate characteristics with resting state EEGs from individuals with disorders of consciousness. Our prospective observational study included 28 individuals with a disorder of consciousness. Control group included 18 healthy subjects with proper EEG data. We made clinical evaluations using patient behavior scales. We also analyzed the EEGs using microstate analysis. In our study, microstate D coverage differed substantially between vegetative and minimally conscious state patients. Also, there was a strong connection between microstate D characteristics and clinical scale scores. Consequently, we have demonstrated that the most accurate parameter for representing consciousness level is microstate D. Microstate analysis appears to be a strong option for future use in the diagnosis, follow-up, and treatment response of patients with Disorders of Consciousness.

The social and family evaluation (SAFE) scale for caregivers of individuals with disorders of consciousness: preliminary results.

BACKGROUND: Caregivers' involvement in the diagnostic and monitoring processes of the level of consciousness of patients with Disorders of Consciousness (DoC) is strongly encouraged by international guidelines, as current literature suggests a better chance to detect behavioural responses when caregivers are involved in clinical assessments. Since caregivers' involvement during clinical assessments can be difficult, the Social And Family Evaluation (SAFE) scale has been recently proposed as a standardised tool that caregivers can autonomously use to collect their opinions about the level of consciousness of patients with DoC, based on the behaviours manifested by the patients in a given time-window. OBJECTIVE: Providing preliminary results concerning SAFE adoption. METHODS: 22 patients with DoC were assessed through the Coma Recovery Scale-revised (CRS-r), while their caregivers filled-in the SAFE. RESULTS: The SAFE showed a very high internal consistency, very high test-retest reliability, and high criterion validity when correlated to the CRS-r total score. Moreover, in line with the literature, the SAFE allowed the detection of some behaviours indicative of a higher level of consciousness than those detected by clinicians through the CRS-r in more than half of the sample. CONCLUSION: Overall, these preliminary data are promising for the adoption of the SAFE to collect the opinions of the caregivers about the level of consciousness of patients with DoC, especially in those settings where it would be otherwise difficult to monitor the patients, such as long-term care structures and at home, as a tool for telemedicine allowing the monitoring of patients in remote settings.

Reliability and validation of the Japanese version of the coma recovery scale-revised (CRS-R).

PRIMARY OBJECTIVE: This study aimed to verify the reliability and validity of the Japanese version of the Coma Recovery Scale-Revised (CRS-R). METHODS: Subjects included 59 patients with disorders of consciousness (DOC) due to acquired brain injury. To validate test-retest reliability, Evaluator A assessed the CRS-R twice on the same day (A1, A2). To examine inter-rater reliability, Evaluators A (A2) and B (B) assessed the CRS-R without a time interval. To test concurrent validity, Evaluator A (A1) assessed the CRS-R, Japan Coma Scale (JCS), and the Glasgow Coma Scale (GCS) consecutively. To validate diagnostic accuracy, we evaluated the degree of agreement between A1 and A2 and between A2 and B in their diagnosis of DOC by CRS-R. RESULTS: The test-retest (ρ = 0.92) and inter- (ρ = 0.98) reliability of CRS-R were excellent" and Concurrent validity of CRS-R with JCS (ρ = -0.82) and GCS (ρ = 0.92) were high. Results of DOC diagnosis were consistent for 48/59 cases (κ = 0.82) for A1 and A2 and for 54/59 cases (κ = 0.92) for A2 and B. CONLCUSION: The Japanese version of the CRS-R may be as reliable and valid as the original English and other language versions.

Speech recovery after single-dose zolpidem in two minimally conscious patients with severe traumatic brain injuries: a case report.

BACKGROUND: In rare cases, zolpidem administration has been found to paradoxically improve cognition in patients with brain injury in disorders of consciousness. CASE PRESENTATION: Two minimally conscious plus (MCS+) patients at baseline, a 24-year-old woman 8 weeks post-traumatic brain injury (TBI) and 23-year-old man 6 weeks post-TBI, demonstrated behavioral improvements after off-label, single-dose administration of 10 mg of zolpidem. DISCUSSION/CONCLUSION: The patients demonstrated improved cognition on Coma Recovery Scale-Revised assessment after ingesting zolpidem. In particular, speech was substantially restored as one patient recovered functional communication and both demonstrated intelligible verbalizations for the first-time post-injuries following zolpidem. Overall, evidence is limited regarding the underlying mechanisms of various cognitive improvements in zolpidem response although studies incorporating neuroimaging are promising. The outcomes and similarities between these cases contribute to the current literature and highlight the need for rigorous studies in the future to guide zolpidem trials in patient care for those with DOC.

Long-term repetitive transcranial direct current stimulation in patients with disorders of consciousness: a preliminary study.

OBJECTIVES: To investigate the effects of long-term repetitive transcranial direct current stimulation on patients with DOC in the subacute phase. METHODS: In a randomized, double-blind, controlled study, 33 patients were randomly assigned to the active or sham group, and 28 patients completed the study. Patients in the active group received anodal stimulation over the DLPFC, while patients in the sham group received placebo stimulation (20 min/day, 5 days/week, for 4 weeks). The level of consciousness among patients was assessed with the Coma Recovery Scale-Revised (CRS-R) at baseline and at the end of every week from the first to the fourth week. RESULTS: The CRS-R scores of both the active and sham groups showed a consistent increasing trend over time; however, the treatment effect of the active group was better than that of the sham group. In addition, there was a statistically significant difference in the total CRS-R score between the two groups at weeks 1, 2, 3 and 4. Moreover, 10 patients (71.4%) in the active group and 3 patients (21.4%) in the sham group were regarded as responders. CONCLUSION: Long-term tDCS could improve the level of consciousness of patients with DOC in the subacute stage.

Common Data Element for Disorders of Consciousness: Recommendations from the Working Group on Therapeutic Interventions.

BACKGROUND: Over the past 30 years, there have been significant advances in the understanding of the mechanisms associated with loss and recovery of consciousness following severe brain injury. This work has provided a strong grounding for the development of novel restorative therapeutic interventions. Although all interventions are aimed at modulating and thereby restoring brain function, the landscape of existing interventions encompasses a very wide scope of techniques and protocols. Despite vigorous research efforts, few approaches have been assessed with rigorous, high-quality randomized controlled trials. As a growing number of exploratory interventions emerge, it is paramount to develop standardized approaches to reporting results. The successful evaluation of novel interventions depends on implementation of shared nomenclature and infrastructure. To address this gap, the Neurocritical Care Society's Curing Coma Campaign convened nine working groups and charged them with developing common data elements (CDEs). Here, we report the work of the Therapeutic Interventions Working Group. METHODS: The working group reviewed existing CDEs relevant to therapeutic interventions within the National Institutes of Health National Institute of Neurological Disorders and Stroke database and reviewed the literature for assessing key areas of research in the intervention space. CDEs were then proposed, iteratively discussed and reviewed, classified, and organized in a case report form (CRF). RESULTS: We developed a unified CRF, including CDEs and key design elements (i.e., methodological or protocol parameters), divided into five sections: (1) patient information, (2) general study information, (3) behavioral interventions, (4) pharmacological interventions, and (5) device interventions. CONCLUSIONS: The newly created CRF enhances systematization of future work by proposing a portfolio of measures that should be collected in the development and implementation of studies assessing novel interventions intended to increase the level of consciousness or rate of recovery of consciousness in patients with disorders of consciousness.

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.

EEG complexity correlates with residual consciousness level of disorders of consciousness.

BACKGROUND AND OBJECTIVE: Electroencephalography (EEG) and neuroimaging measurements have been highly encouraged to be applied in clinics of disorders of consciousness (DOC) to improve consciousness detection. We tested the relationships between neural complexity measured on EEG and residual consciousness levels in DOC patients. METHODS: Resting-state EEG was recorded from twenty-five patients with DOC. Lempel-Ziv complexity (LZC) and permutation Lempel-Ziv complexity (PLZC) were measured on the EEG, and their relationships were analyzed with the consciousness levels of the patients. RESULTS: PLZC and LZC values significantly distinguished patients with a minimally conscious state (MCS), vegetative state/unresponsive wakefulness syndrome (VS/UWS), and healthy controls. PLZC was significantly correlated with the Coma Recovery Scale-Revised (CRS-R) scores of DOC patients in the global brain, particularly in electrodes locating in the anterior and posterior brain regions. Patients with higher CRS-R scores showed higher PLZC values. The significant difference in PLZC values between MCS and VS/UWS was mainly located in the bilateral frontal and right hemisphere regions. CONCLUSION: Neural complexity measured on EEG correlates with residual consciousness levels of DOC patients. PLZC showed higher sensitivity than LZC in the classification of consciousness levels.

Behavioral scales variability in patients with prolonged disorders of consciousness.

BACKGROUND: The principal conditions differentiating disorders of consciousness (DOC) patients are the unresponsive wakefulness syndrome/vegetative state (UWS/VS) and the minimally conscious state (MCS). Many individuals who suffer from sudden-onset severe brain injury move through stages of UWS/VS and MCS before regaining full awareness. In some patients, the DOC condition is protracted for years (PDOC). In this study, we observed PDOC patients for 6 months to assess possible changes in their level of consciousness. METHODS: We enrolled 40 PDOC patients, 23 UWS/VS and 17 MCS hosted in a dedicated unit for long-term brain injury care. The time from injury was 472 ± 533 days for UWS/VS and 1090 ± 1079 days for MCS. The Wessex Head Injury Matrix (WHIM), Coma Recovery Scale-R (CRS-R), and Nociception Coma Scale were administered monthly for 6 months. RESULTS: During the period of assessment, the percentage of UWS/VS shifted from 58 to 45%, while for the MCS, from 42 to 55%. A positive correlation was found for the UWS/VS patients between the months of observation with the CRS-R total score and WHIM total numbers of behaviors (TNB). In the UWS/VS group, the CRS-R auditive and visual subscales correlated positively with the observation time. During the whole period of observation, 8 patients had constant CRS-R total scores while the WHIM TNB changed in 7 of them. CONCLUSION: Our findings demonstrated that the monthly assessment of PDOC by means of the CRS-R and WHIM was able to detect also subtle changes in consciousness level.

Spinal cord stimulation and deep brain stimulation for disorders of consciousness: a systematic review and individual patient data analysis of 608 cases.

The application of spinal cord stimulation (SCS) and deep brain stimulation (DBS) for disorders of consciousness (DoC) has been increasingly reported. However, there is no sufficient evidence to determine how effective and safe SCS and DBS are for DoC owing to various methodological limitations. We conducted a systematic review to elucidate the safety and efficacy of SCS and DBS for DoC by systematically reviewing related literature by searching PubMed, EMBASE, Medline, and Cochrane Library. Twenty eligible studies with 608 patients were included in this study. Ten studies with 508 patients reported the efficacy of SCS for DoC, and the estimated overall effectiveness rate was 37%. Five studies with 343 patients reported the efficacy of SCS for VS, and the estimated effectiveness rate was 30%. Three studies with 53 patients reported the efficacy of SCS for MCS, and the estimated effectiveness rate was 63%. Five studies with 92 patients reported the efficacy of DBS for DoC, and the estimated overall effectiveness rate was 40%. Four studies with 63 patients reported the efficacy of DBS for VS, and the estimated effectiveness rate was 26%. Three studies with 19 patients reported the efficacy of DBS for MCS, and the estimated effectiveness rate was 74%. The adverse event rate of DoC was 8.1% and 18.2% after SCS and DBS, respectively. These results suggest that SCS and DBS can be considered reasonable treatments for DoC with considerable efficacy and safety.

Citizen attitudes to non-treatment decision making: a Norwegian survey.

BACKGROUND: Decisions about appropriate treatment at the end of life are common in modern healthcare. Non-treatment decisions (NTDs), comprising both withdrawal and withholding of (potentially) life-prolonging treatment are in principle accepted in Norway. However, in practice they may give rise to significant moral problems for health professionals, patients and next of kin. Here, patient values must be considered. It is relevant to study the moral views and intuitions of the general population on NTDs and special areas of contention such as the role of next of kin in decision-making. METHODS: Electronic survey to members of a nationally representative panel of Norwegian adults. Respondents were presented with vignettes describing patients with disorders of consciousness, dementia, and cancer where patient preferences varied. Respondents answered ten questions about the acceptability of non-treatment decision making and the role of next of kin. RESULTS: We received 1035 complete responses (response rate 40.7%). A large majority, 88%, supported the right of competent patients to refuse treatment in general. When an NTD was in line with the patient's previously expressed preferences, more respondents tended to find NTDs acceptable. More respondents would accept NTDs for themselves than for the vignette patients. In a scenario with an incompetent patient, clear majorities wanted the views of next of kin to be given some but not decisive weight, and more weight if concordant with the patient's wishes. There were, however, large variations in the respondents' views. CONCLUSION: This survey of a representative sample of the Norwegian adult population indicates that attitudes to NTDs are often in line with national laws and guidelines. However, the high variance among the respondents and relatively large weight given to next of kin's views, indicate a need for appropriate dialogue among all stakeholders to prevent conflicts and extra burdens. Furthermore, the emphasis given to previously expressed opinions indicates that advance care planning may increase the legitimacy of NTDs and prevent challenging decision-making processes.

Comparison of veterans affairs and NIDILRR traumatic brain injury model systems participants with disorders of consciousness.

OBJECTIVE: To characterize demographic, pre-injury, and outcome data within the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) and Veterans Affairs (VA) Traumatic Brain Injury Model Systems (TBIMS) cohorts with severe traumatic brain injury (TBI) with no command-following ability at time of admission to acute rehabilitation. DESIGN: Retrospective cohort. SETTING: NIDILRR and VA TBI Model Systems (TBIMS) centers. PARTICIPANTS: 396 NIDILRR and 72 VA participants without command-following ability who experienced TBI with subsequent Disorder of Consciousness (DoC). MAIN OUTCOME MEASURE: Pre-injury and injury characteristics, rehabilitation outcomes, and 1-year self-reported outcomes. RESULTS: VA TBIMS cohort included individuals who were active duty or had military service before their injury. The VA cohort were more likely to be re-hospitalized at 1-year follow-up or residing in a long-term care or rehab setting. The NIDILRR TBIMS cohort had higher FIM and DRS scores at rehabilitation discharge, while the VA participants saw longer lengths of stay and higher numbers of "violent" injury types. CONCLUSIONS: This study allows for a better understanding of the comparability between VA and NIDILRR DoC cohorts providing guidance on how veteran and civilian samples might be merged in future TBIMS studies to explore predictors of recovery from a DoC.

Contemplating on the Nature of Selfhood in DoC Patients: Neurophenomenological Perspective.

Medical well-regarded policy recommendations for patients with disorders of consciousness (DoC) are almost exclusively relied on behavioural examination and evaluation of higher-order cognition, and largely disregard the patients' self. This is so because practically establishing the presence of self-awareness or Selfhood is even more challenging than evaluating the presence of consciousness. At the same time, establishing the potential (actual physical possibility) of Selfhood in DoC patients is crucialy important from clinical, ethical, and moral standpoints because Selfhood is the most central and private evidence of being an independent and free agent that unites intention, embodiment, executive functions, attention, general intelligence, emotions and other components within the intra-subjective frame (first-person givenness). The importance of Selfhood is supported further by the observation that rebooting of self-awareness is the first step to recovery after brain damage. It seems that complex experiential Selfhood can be plausibly conceptualized within the Operational Architectonics (OA) of brain-mind functioning and reliably measured by quantitative electroencephalogram (qEEG) operational synchrony.

LOCCATE: A tool to identify the diagnostic spectrum profile of motor function and functional communication responses for the individual with a prolonged disorder of consciousness.

Standardized neurobehavioural assessment tools (SNBATs) form a key aspect of diagnostic assessment for individuals with prolonged disorders of consciousness (PDOCs). Each SNBAT has different psychometric properties, operational definitions of behaviours, scoring systems and methods of administration. Selection and implementation of SNBATs varies within and between healthcare settings. Defining diagnostic and prognostic parameters requires collating multiple SNBAT results over time, which is problematic if several assessors and professions are involved. The Levels of Consciousness Calibration of Assessment Tools Evaluations (LOCCATE) is the first tool designed to calibrate the results of any recognized PDOC SNBAT. It also categorizes the diagnostic spectrum profile of both motor and communication responses into eight criteria of behaviours. Each criterion has up to three levels of reproducibility, ultimately producing a LOCCATE calibration score ranging from 1 to 27. A case study is presented to illustrate changes in LOCCATE scores over time, while an audit explores the tool's clinical utility. With current directives placing less emphasis on a PDOC diagnosis, there is now a greater need for a calibration tool such as LOCCATE to identify exactly what the individual can do and create an accurate trajectory as an evidence base to support clinical and best-interest decision-making.

Who gets to decide?: Substitute decision making following severe brain injury with communication impairment.

Purpose: In our prior study (Malhi et al., 2021), we demonstrated that cognitive ability may be masked by communication impairments. We used binary choice (i.e., yes/no) neuropsychological tests to assess cognitive functioning in four patients with severe brain injury and communication impairments. In this study, we aimed to better understand the decision-making process of their substitute decision makers (SDMs). Methods: We interviewed SDMs - two SDMs were supporting patients in the minimally conscious state, one SDM was supporting a patient who had locked-in syndrome and was an augmentative communication user, and the last SDM was supporting a patient who was an alternative communication user. Results: SDMs were performing various roles ranging from making all decisions to simply being the vocal advocate (for the augmentative and alternative communication users). SDMs described heuristics they used to make decisions, and all identified auditory comprehension capabilities as being an important element for decision making. Conclusion: We argue that if mode of communication is established and utilized, and binary choice neuropsychological tests are used to ascertain cognitive functioning, SDMs may more confidently make low/medium stakes decisions based on the present condition and context, rather than solely on past wishes and values before capacity was in question.

Measuring consciousness in severely damaged brains.

Significant advances have been made in the behavioral assessment and clinical management of disorders of consciousness (DOC). In addition, functional neuroimaging paradigms are now available to help assess consciousness levels in this challenging patient population. The success of these neuroimaging approaches as diagnostic markers is, however, intrinsically linked to understanding the relationships between consciousness and the brain. In this context, a combined theoretical approach to neuroimaging studies is needed. The promise of such theoretically based markers is illustrated by recent findings that used a perturbational approach to assess the levels of consciousness. Further research on the contents of consciousness in DOC is also needed.

Risk factors for 2-year mortality in patients with prolonged disorders of consciousness: An international multicentre study.

BACKGROUND AND PURPOSE: Patients with prolonged disorders of consciousness (pDoC) have a high mortality rate due to medical complications. Because an accurate prognosis is essential for decision-making on patients' management, we analysed data from an international multicentre prospective cohort study to evaluate 2-year mortality rate and bedside predictors of mortality. METHODS: We enrolled adult patients in prolonged vegetative state/unresponsive wakefulness syndrome (VS/UWS) or minimally conscious state (MCS) after traumatic and nontraumatic brain injury within 3 months postinjury. At enrolment, we collected demographic (age, sex), anamnestic (aetiology, time postinjury), clinical (Coma Recovery Scale-Revised [CRS-R], Disability Rating Scale, Nociception Coma Scale-Revised), and neurophysiologic (electroencephalogram [EEG], somatosensory evoked and event-related potentials) data. Patients were followed up to gather data on mortality up to 24 months postinjury. RESULTS: Among 143 traumatic (n = 55) and nontraumatic (n = 88) patients (VS/UWS, n = 68, 19 females; MCS, n = 75, 22 females), 41 (28.7%) died within 24 months postinjury. Mortality rate was higher in VS/UWS (42.6%) than in MCS (16%; p < 0.001). Multivariate regression in VS/UWS showed that significant predictors of mortality were older age and lower CRS-R total score, whereas in MCS female sex and absence of alpha rhythm on EEG at study entry were significant predictors. CONCLUSIONS: This study demonstrated that a feasible multimodal assessment in the postacute phase can help clinicians to identify patients with pDoC at higher risk of mortality within 24 months after brain injury. This evidence can help clinicians and patients' families to navigate the complex clinical decision-making process and promote an international standardization of prognostic procedures for patients with pDoC.

The importance of instrumental assessment in disorders of consciousness: a comparison between American, European, and UK International recommendations.

The use of instrumental tools for improving both the diagnostic accuracy and the prognostic soundness in patients with disorders of consciousness (DOC) plays an important role. However, the most recent international guidelines on DOC published by the American and the European Academies of Neurology and by the UK Royal College of Physicians contain heterogeneous recommendations on the implementation of these techniques in the clinical routine for both diagnosis and prognosis. With the present work, starting from the comparison of the DOC guidelines' recommendations, we look for possible explanations behind such discrepancies considering the adopted methodologies and the reference health systems that could have affected the guidelines' perspectives. We made a provocative argument about the need to find the most appropriate common methodology to retrieve and grade the evidence, increase the meta-analytic studies, and reduce the health policies that influence on the guidelines development that, in turn, should inform the health policies with the strongest scientific evidence.