Ethical, Palliative, and Policy Considerations in Disorders of Consciousness

Task-based EEG and fMRI paradigms in a multimodal clinical diagnostic framework for disorders of consciousness

Disorders of consciousness (DoC) are generally diagnosed by clinical assessment, which is a predominantly motor-driven process and accounts for up to 40 % of non-communication being misdiagnosed as unresponsive wakefulness syndrome (UWS) (previously known as prolonged/persistent vegetative state). Given the consequences of misdiagnosis, a more reliable and objective multimodal protocol to diagnosing DoC is needed, but has not been produced due to concerns regarding their interpretation and reliability. Of the techniques commonly used to detect consciousness in DoC, task-based paradigms (active paradigms) produce the most unequivocal result when findings are positive. It is well-established that command following (CF) reliably reflects preserved consciousness. Task-based electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) can detect motor-independent CF and reveal preserved covert consciousness in up to 14 % of UWS patients. Accordingly, to improve the diagnostic accuracy of DoC, we propose a practical multimodal clinical decision framework centered on task-based EEG and fMRI, and complemented by measures like transcranial magnetic stimulation (TMS-EEG).

Cognitive Motor Dissociation: Gap Analysis and Future Directions

BACKGROUND

Patients with disorders of consciousness who are behaviorally unresponsive may demonstrate volitional brain responses to motor imagery or motor commands detectable on functional magnetic resonance imaging or electroencephalography. This state of cognitive motor dissociation (CMD) may have prognostic significance.

METHODS

The Neurocritical Care Society's Curing Coma Campaign identified an international group of experts who convened in a series of monthly online meetings between September 2021 and April 2023 to examine the science of CMD and identify key knowledge gaps and unmet needs.

RESULTS

The group identified major knowledge gaps in CMD research: (1) lack of information about patient experiences and caregiver accounts of CMD, (2) limited epidemiological data on CMD, (3) uncertainty about underlying mechanisms of CMD, (4) methodological variability that limits testing of CMD as a biomarker for prognostication and treatment trials, (5) educational gaps for health care personnel about the incidence and potential prognostic relevance of CMD, and (6) challenges related to identification of patients with CMD who may be able to communicate using brain-computer interfaces.

CONCLUSIONS

To improve the management of patients with disorders of consciousness, research efforts should address these mechanistic, epidemiological, bioengineering, and educational gaps to enable large-scale implementation of CMD assessment in clinical practice.

Combining HD-tDCS with music stimulation for patients with prolonged disorders of consciousness: Study protocol for an RCT trial

BACKGROUND

Patients with prolonged disorders of consciousness (pDOC) pose significant challenges to healthcare workers due to their severe motor impairments and limited interaction with the environment. Non-invasive brain stimulation such as high-definition transcranial direct current stimulation (HD-tDCS) and music stimulation show promise in awakening this population.

OBJECTIVE

In this study, we present a protocol aiming at investigating the efficacy of combined HD-tDCS and music stimulation in awakening patients with pDOC through a single-blind, randomized controlled trial.

METHODS

Ninety patients with pDOC will be randomly divided into three groups: active HD-tDCS with music stimulation, active HD-tDCS, and sham HD-tDCS. All participants will receive 20 treatment sessions over a period of 10 days and the Coma Recovery Scale-Revised, Glasgow Outcome Scale and electroencephalogram will be used as assessment measures to evaluate their level of consciousness throughout the study. Adverse events and complications will be recorded during treatment. Within-group pre-post comparisons and between-group efficacy comparisons will be conducted to identify the most effective intervention approach. Statistical analysis will be performed using SPSS software with a significance level set at P < 0.05.

CONCLUSION

The pursuit of awakening therapy for patients with pDOC remains a clinical research challenge. This study protocol is designed with the aim of introducing an innovative non-pharmacological approach which combined HD-tDCS and music stimulation to facilitate the reinstatement of consciousness in patients with pDOC.

International survey on the implementation of the European and American guidelines on disorders of consciousness

Diagnostic, prognostic, and therapeutic procedures for patients with prolonged disorders of consciousness (pDoCs) vary significantly across countries and clinical settings, likely due to organizational factors (e.g., research vs. non-academic hospitals), expertise and availability of resources (e.g., financial and human). Two international guidelines, one from the European Academy of Neurology (EAN) and one from the American Academy of Neurology (AAN) in collaboration with the American Congress of Rehabilitation Medicine (ACRM) and the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR), were developed to facilitate consistent practice among professionals working with this challenging patient population. While the recommendations of both guidelines agree in principle, it remains an open issue how to implement them into clinical practice in the care pathway for patients with pDoCs. We conducted an online survey to explore health professional clinical practices related to the management of patients with pDoCs, and compare said practices with selected recommendations from both the guidelines. The survey revealed that while some recommendations are being followed, others are not and/or may require more honing/specificity to enhance their clinical utility. Particular attention should be given to the implementation of a multimodal assessment of residual consciousness, to the detection and treatment of pain, and to the impact of restrictions imposed by COVID-19 pandemics on the involvement of patients' families/representatives.

Multimodal prediction of residual consciousness in the intensive care unit: the CONNECT-ME study

Functional MRI (fMRI) and EEG may reveal residual consciousness in patients with disorders of consciousness (DoC), as reflected by a rapidly expanding literature on chronic DoC. However, acute DoC is rarely investigated, although identifying residual consciousness is key to clinical decision-making in the intensive care unit (ICU). Therefore, the objective of the prospective, observational, tertiary centre cohort, diagnostic phase IIb study 'Consciousness in neurocritical care cohort study using EEG and fMRI' (CONNECT-ME, NCT02644265) was to assess the accuracy of fMRI and EEG to identify residual consciousness in acute DoC in the ICU. Between April 2016 and November 2020, 87 acute DoC patients with traumatic or non-traumatic brain injury were examined with repeated clinical assessments, fMRI and EEG. Resting-state EEG and EEG with external stimulations were evaluated by visual analysis, spectral band analysis and a Support Vector Machine (SVM) consciousness classifier. In addition, within- and between-network resting-state connectivity for canonical resting-state fMRI networks was assessed. Next, we used EEG and fMRI data at study enrolment in two different machine-learning algorithms (Random Forest and SVM with a linear kernel) to distinguish patients in a minimally conscious state or better (≥MCS) from those in coma or unresponsive wakefulness state (≤UWS) at time of study enrolment and at ICU discharge (or before death). Prediction performances were assessed with area under the curve (AUC). Of 87 DoC patients (mean age, 50.0 ± 18 years, 43% female), 51 (59%) were ≤UWS and 36 (41%) were ≥ MCS at study enrolment. Thirty-one (36%) patients died in the ICU, including 28 who had life-sustaining therapy withdrawn. EEG and fMRI predicted consciousness levels at study enrolment and ICU discharge, with maximum AUCs of 0.79 (95% CI 0.77-0.80) and 0.71 (95% CI 0.77-0.80), respectively. Models based on combined EEG and fMRI features predicted consciousness levels at study enrolment and ICU discharge with maximum AUCs of 0.78 (95% CI 0.71-0.86) and 0.83 (95% CI 0.75-0.89), respectively, with improved positive predictive value and sensitivity. Overall, both machine-learning algorithms (SVM and Random Forest) performed equally well. In conclusion, we suggest that acute DoC prediction models in the ICU be based on a combination of fMRI and EEG features, regardless of the machine-learning algorithm used.

Effects of Acupuncture on Cortical Activation in Patients with Disorders of Consciousness: A Functional Near-Infrared Spectroscopy Study

Background. Disorder of consciousness (DoC) is a clinical condition caused by severe brain damage. Some studies have reported that acupuncture, a traditional Chinese treatment, could facilitate the recovery of the patient’s consciousness. The therapeutic effects of acupuncture may be due to its modulation of facilitating cortex (PFC) activity, but it has not been greatly demonstrated. Objectives. We intended to observe the effects of acupuncture on prefrontal cortical activity, explore the potential correlation between cortical activation and the severity of DoC, and analyze the functional brain network connectivity to provide a theoretical basis for its application in clinical practice. Methods. Participants diagnosed with DoC were included in the study. Before the intervention, we assessed the patient’s state of consciousness using relevant scales, such as the Glasgow coma scale (GCS) and the coma recovery scale-revised (CRS-R). All patients received acupuncture manipulation with the functional near-infrared spectroscopy (fNIRS) system monitored. Result. A total of 16 subjects participated in our study. We observed that the concentration of oxygenated hemoglobin (HbO) in the PFC was increased during the acupuncture manipulation and declined during the resting state. Then, the connection strength of the left cerebral cortex was generally higher than that of the right. Finally, we observed only a weak difference in hemodynamic responses of PFC between the vegetative state (VS) and minimally conscious state (MCS) groups. However, the difference was not statistically significant. Conclusion. Our results indicated that acupuncture can increase the concentration of HbO in the PFC and strengthen the connection strength of the left cerebral cortex. However, our present study did not find a significant correlation between the cortical hemodynamic response and the severity of DoC.

What Does Coma Mean? Implications for Shared Decision Making in Acute Brain Injury

BACKGROUND

Insufficient attention has been devoted to shared decision-making (SDM) in the setting of acute brain injury (ABI). Communication occupies a central role that has been highlighted in recent research on SDM with brain injured patients, with respect to "the impact of specific clinician words and expressions". In this investigation, we seek to understand lay public understandings of the term "coma."

METHODS

Qualitative analysis of lay interpretations of the term "cComa" using modified open coding of a free-text response question at the end of a survey exploring public attitudes in the context of hypothetical ABI. Respondents (n = 511) were drawn from a convenience sample using Amazon Mechanical Turk. This analysis focuses on respondents' free-text responses to the question: "When doctors say a patient is in a coma, what does that mean?"

RESULTS

We analyzed 206 unique responses in order to derive emergent lay conceptualizations of coma. The following 4 themes emerged in how respondents understood coma: (1) State descriptive. (2) Marker of injury severity. (3) As in distinction (or lack thereof) from brain death or sleep. (4) Covert consciousness. For each concept, we discuss its salient elements and offer representative quotes.

CONCLUSIONS

This study provides preliminary qualitative evidence of lay public understandings of the neurologic term "coma". These findings can have implications for surrogate/family-clinician communications. While a physician may intend "coma" to convey a technical description, a family member or surrogate may interpret it as a very different activity (e.g., prognostication, emotional signaling), setting the stage for miscommunication.

Intensive neurorehabilitation for patients with prolonged disorders of consciousness: protocol of a mixed-methods study focusing on outcomes, ethics and impact

BACKGROUND

Prolonged disorders of consciousness (PDOC) are amongst the severest sequelae of acquired brain injury. Evidence regarding epidemiology and rehabilitation outcomes is scarce. These knowledge gaps and psychological distress in families of PDOC patients may complicate clinical decision-making. The complex PDOC care and associated moral dilemmas result in high workload in healthcare professionals. Since 2019, all PDOC patients in the Netherlands have access to intensive neurorehabilitation up to 2 years post-injury provided by one rehabilitation center and four specialized nursing homes. Systematic monitoring of quantitative rehabilitation data within this novel chain of care is done in a study called DOCTOR. The optimization of tailored PDOC care, however, demands a better understanding of the impact of PDOC on patients, their families and healthcare professionals and their views on rehabilitation outcomes, end-of-life decisions and quality of dying. The True Outcomes of PDOC (TOPDOC) study aims to gain insight in the qualitative outcomes of PDOC rehabilitation and impact of PDOC on patients, their families and healthcare professionals.

METHODS

Nationwide multicenter prospective cohort study in the settings of early and prolonged intensive neurorehabilitation with a two-year follow-up period, involving three study populations: PDOC patients > 16 years, patients' family members and healthcare professionals involved in PDOC care. Families' and healthcare professionals' views on quality of rehabilitation outcomes, end-of-life decisions and dying will be qualitatively assessed using comprehensive questionnaires and in-depth interviews. Ethical dilemmas will be explored by studying moral deliberations. The impact of providing care to PDOC patients on healthcare professionals will be studied in focus groups.

DISCUSSION

To our knowledge, this is the first nationwide study exploring quality of outcomes, end-of-life decisions and dying in PDOC patients and the impact of PDOC in a novel chain of care spanning the first 24 months post-injury in specialized rehabilitation and nursing home settings. Newly acquired knowledge in TOPDOC concerning quality of outcomes in PDOC rehabilitation, ethical aspects and the impact of PDOC will enrich quantitative epidemiological knowledge and outcomes arising from DOCTOR. Together, these projects will contribute to the optimization of centralized PDOC care providing support to PDOC patients, families and healthcare professionals.

Ethical and legal considerations related to disorders of consciousness

PURPOSE OF REVIEW

The purpose of this review is to describe ethical and legal issues that arise in the management of patients with disorders of consciousness ranging from the minimally conscious state to the coma state, as well as brain death.

RECENT FINDINGS

The recent literature highlights dilemmas created by diagnostic and prognostic uncertainties in patients with disorders of consciousness. The discussion also reveals the challenges experienced by the disability community, which includes individuals with severe brain injury who are classified as having a disorder of consciousness. We review current guidelines for management of patients with disorders of consciousness including discussions around diagnosis, prognosis, consideration of neuropalliation, and decisions around life sustaining medical treatment.

SUMMARY

In the setting of uncertainty, this review describes the utility of applying a disability rights perspective and shared decision-making process to approach medical decision-making for patients with disorders of consciousness. We outline approaches to identifying surrogate decision makers, standards for decision-making and decision-making processes, specifically addressing the concept of futility as a less useful framework for making decisions. We also highlight special considerations for research, innovative and controversial care, brain death, organ donation, and child abuse and neglect.

Disorders of Consciousness and Disability Law

In 2018, the American Academy of Neurology, the American Congress of Rehabilitation Medicine, and the National Institute on Disability, Independent Living, and Rehabilitation Research published a systematic evidence-based review and an associated practice guideline for improved assessment, treatment, and rehabilitation of patients with disorders of consciousness. Patients with disorders of consciousness include individuals in the vegetative and minimally conscious states, as well as others with covert consciousness and cognitive motor dissociation. These landmark publications (concurrently published in Neurology and Archives of Physical Medicine and Rehabilitation) supplant the 1994 New England Journal of Medicine Multi-Society Task Force report on the vegetative state and the 2002 criteria establishing minimally conscious states. The guideline re-designates the permanent vegetative state as chronic. In our article, we consider the legal and ethical implications of the practice guideline for clinical practice and explain the vulnerability of these patients who suffer from high rates of misdiagnosis, inadequate medical surveillance, undertreatment of pain, inadequate rehabilitation, and segregation in chronic care. We argue that these deficiencies in medical care are inconsistent with our growing appreciation of the dynamic nature of these brain states and an emerging standard of care as articulated by the national guideline. These deficiencies also violate domestic and international disability law. To substantiate this latter claim, we apply disability law to this population, focusing on key Americans with Disabilities Act mandates, the relevance of the 1999 Supreme Court, Olmstead v. L.C., and the utility of Olmstead enforcement actions to integrate the care of these individuals into the medical mainstream.

Assessment of Covert Consciousness in the Intensive Care Unit: Clinical and Ethical Considerations

OBJECTIVE

To propose a practical ethical framework for how task-based functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) may be used in the intensive care unit (ICU) to identify covert consciousness in patients with acute severe traumatic brain injury (TBI).

METHODS

We present 2 clinical scenarios in which investigational task-based fMRI and EEG were performed in critically ill patients with acute severe TBI who appeared unconscious on the bedside behavioral assessment. From these cases, we consider the clinical and ethical challenges that emerge and suggest how to reconcile them. We also provide recommendations regarding communication with families about ICU patients with covert consciousness.

RESULTS

Covert consciousness was detected acutely in a patient who died in the ICU due to withdrawal of life-sustaining therapy, whereas covert consciousness was not detected in a patient who subsequently recovered consciousness, communication, and functional independence. These cases raise ethical challenges about how assessment of covert consciousness in the ICU might inform treatment decisions, prognostication, and perceptions about the benefits and burdens of ongoing care.

CONCLUSIONS

Given that covert consciousness can be detected acutely in the ICU, we recommend that clinicians reconsider evaluative norms for ICU patients. As our clinical appreciation of covert consciousness evolves and its ethical import unfolds, we urge prognostic humility and transparency when clinicians communicate with families in the ICU about goals of care.