Behavioural improvements with thalamic stimulation after severe traumatic brain injury

Widespread loss of cerebral connectivity is assumed to underlie the failure of brain mechanisms that support communication and goal-directed behaviour following severe traumatic brain injury. Disorders of consciousness that persist for longer than 12 months after severe traumatic brain injury are generally considered to be immutable; no treatment has been shown to accelerate recovery or improve functional outcome in such cases. Recent studies have shown unexpected preservation of large-scale cerebral networks in patients in the minimally conscious state (MCS), a condition that is characterized by intermittent evidence of awareness of self or the environment. These findings indicate that there might be residual functional capacity in some patients that could be supported by therapeutic interventions. We hypothesize that further recovery in some patients in the MCS is limited by chronic underactivation of potentially recruitable large-scale networks. Here, in a 6-month double-blind alternating crossover study, we show that bilateral deep brain electrical stimulation (DBS) of the central thalamus modulates behavioural responsiveness in a patient who remained in MCS for 6 yr following traumatic brain injury before the intervention. The frequency of specific cognitively mediated behaviours (primary outcome measures) and functional limb control and oral feeding (secondary outcome measures) increased during periods in which DBS was on as compared with periods in which it was off. Logistic regression modelling shows a statistical linkage between the observed functional improvements and recent stimulation history. We interpret the DBS effects as compensating for a loss of arousal regulation that is normally controlled by the frontal lobe in the intact brain. These findings provide evidence that DBS can promote significant late functional recovery from severe traumatic brain injury. Our observations, years after the injury occurred, challenge the existing practice of early treatment discontinuation for patients with only inconsistent interactive behaviours and motivate further research to develop therapeutic interventions.

Dissociations between behavioural and functional magnetic resonance imaging-based evaluations of cognitive function after brain injury

Functional neuroimaging methods hold promise for the identification of cognitive function and communication capacity in some severely brain-injured patients who may not retain sufficient motor function to demonstrate their abilities. We studied seven severely brain-injured patients and a control group of 14 subjects using a novel hierarchical functional magnetic resonance imaging assessment utilizing mental imagery responses. Whereas the control group showed consistent and accurate (for communication) blood-oxygen-level-dependent responses without exception, the brain-injured subjects showed a wide variation in the correlation of blood-oxygen-level-dependent responses and overt behavioural responses. Specifically, the brain-injured subjects dissociated bedside and functional magnetic resonance imaging-based command following and communication capabilities. These observations reveal significant challenges in developing validated functional magnetic resonance imaging-based methods for clinical use and raise interesting questions about underlying brain function assayed using these methods in brain-injured subjects.

Residual cerebral activity and behavioural fragments can remain in the persistently vegetative brain

This report identifies evidence of partially functional cerebral regions in catastrophically injured brains. To study five patients in a persistent vegetative state (PVS) with different behavioural features, we employed [(18)F]fluorodeoxyglucose-positron emission tomography (FDG-PET), MRI and magnetoencephalographic (MEG) responses to sensory stimulation. Each patient's brain expressed a unique metabolic pattern. In three of the five patients, co-registered PET/MRI correlate islands of relatively preserved brain metabolism with isolated fragments of behaviour. Two patients had suffered anoxic injuries and demonstrated marked decreases in overall cerebral metabolism to 30-40% of normal. Two other patients with non-anoxic, multifocal brain injuries demonstrated several isolated brain regions with relatively higher metabolic rates, that ranged up to 50-80% of normal. Nevertheless, their global metabolic rates remained <50% of normal. MEG recordings from three PVS patients provide clear evidence for the absence, abnormality or reduction of evoked responses. Despite major abnormalities, however, these data also provide evidence for localized residual activity at the cortical level. Each patient partially preserved restricted sensory representations, as evidenced by slow evoked magnetic fields and gamma band activity. In two patients, these activations correlate with isolated behavioural patterns and metabolic activity. Remaining active regions identified in the three PVS patients with behavioural fragments appear to consist of segregated corticothalamic networks that retain connectivity and partial functional integrity. A single patient who suffered severe injury to the tegmental mesencephalon and paramedian thalamus showed widely preserved cortical metabolism, and a global average metabolic rate of 65% of normal. The relatively high preservation of cortical metabolism in this patient defines the first functional correlate of clinical- pathological reports associating permanent unconsciousness with structural damage to these regions. The specific patterns of preserved metabolic activity identified in these patients do not appear to represent random survivals of a few neuronal islands; rather they reflect novel evidence of the modular nature of individual functional networks that underlie conscious brain function. The variations in cerebral metabolism in chronic PVS patients indicate that some cerebral regions can retain partial function in catastrophically injured brains.

Four ethical priorities for neurotechnologies and AI

Artificial intelligence and brain-computer interfaces must respect and preserve people’s privacy, identity, agency and equality, say Rafael Yuste, Sara Goering and colleagues.

Incorporating palliative care into critical care education: principles, challenges, and opportunities

OBJECTIVE

To identify the goals and methods for medical education about end-of-life care in the intensive care unit (ICU).

DATA SOURCES AND STUDY SELECTION

A status report on palliative care, a summary report of recent research on palliative care education, articles in the medical literature on end-of-life care and critical care, and expert opinion were considered.

DATA EXTRACTION

A working group, including specialists in critical care, palliative care, medical ethics, consumer advocacy, and communications, was convened at the "Medical Education for Care Near the End of Life National Consensus Conference." A modified nominal group process was used to develop a consensus.

DATA SYNTHESIS

In the ICU, life and death decisions are often made in a crisis mode or in the face of uncertainty, and may necessitate the withholding and withdrawal of life-supporting technologies. Because critical illness often diminishes the capacity of patients to make decisions, clinicians must often make decisions in conjunction with surrogates, rather than with patients. Discontinuity of care can threaten trusting relationships, and cultural diversity can have a particularly powerful impact on choices for care. In the face of these realities, it is possible and appropriate to give compassionate palliative care to dying patients and their families in the ICU.

CONCLUSIONS

Teaching care of the dying in the ICU should emphasize the following: a) the goals of care should guide the use of technology; b) understanding of prognostication and treatment withholding and withdrawal is essential; c) effective communication and trusting relationships are crucial to good care; d) cultural differences should be acknowledged and respected; and e) the delivery of excellent palliative care is appropriate and necessary when patients die in the ICU.

End-of-life decision-making in the hospital: current practice and future prospects

Chart review of patients who died in the hospital was used to describe the pattern of end-of-life decision-making and care for hospitalized dying patients and to propose a structured process of assessing the suitability of patients for palliative care. The setting was a large urban academic medical center, and the sample comprised 200 of 205 consecutive adult deaths during the first 4 months of 1996. The main outcome measures were identification of the patient as dying, do-not-resuscitate (DNR) orders, and comfort care plans. Charts of 72% of the patients had evidence that they were considered dying. DNR orders were in place for 77% of all the patients, and 46% had comfort care plans. Presence of a health care proxy was significantly associated with DNR orders and comfort care plans (P < 0.001). On average, comfort care plans were put in place 15 days after admission, as compared with an overall mean length of stay of 17 days. Substantial proportions of patients with comfort care plans continued to receive antibiotics (41%) and blood draws (30%). Only 13% of the patients on mechanical ventilation and 19% of those on artificial nutrition and hydration underwent withdrawal of these interventions prior to death. These findings suggest opportunities and challenges for improving practice patterns for hospitalized dying patients. We recommend several measurable objectives for evaluating end-of-life decision-making and care and propose the development of a goals of care assessment tool to guide appropriate transitions from life-sustaining treatment to comfort care and plan palliative services.

From psychosurgery to neuromodulation and palliation: history's lessons for the ethical conduct and regulation of neuropsychiatric research

As we contemplate the emerging era of neuromodulation and imagine the utility of deep brain stimulation for disease entities in neurology and psychiatry, our enthusiasm is immediately tempered by history. Just a generation ago, other confident investigators were heralding invasive somatic therapies like prefrontal lobotomy to treat psychiatric illness. That era of psychosurgery ended with widespread condemnation, congressional calls for a ban, and avow that history should never repeat itself. Now, just 30 years later, neurologists, neurosurgeons, and psychiatrists are implanting deep brain stimulators for the treatment of Parkinson's disease and contemplating their use for severe psychiatric illnesses, such as obsessive-compulsive disorder and the modulation of consciousness in traumatic brain injury.

Misuse of the FDA's humanitarian device exemption in deep brain stimulation for obsessive-compulsive disorder

Deep brain stimulation-a novel surgical procedure-is emerging as a treatment of last resort for people diagnosed with neuropsychiatric disorders such as severe obsessive-compulsive disorder. The US Food and Drug Administration granted a so-called humanitarian device exemption to allow patients to access this intervention, thereby removing the requirement for a clinical trial of the appropriate size and statistical power. Bypassing the rigors of such trials puts patients at risk, limits opportunities for scientific discovery, and gives device manufacturers unique marketing opportunities. We argue that Congress and federal regulators should revisit the humanitarian device exemption to ensure that it is not used to sidestep careful research that can offer valuable data with appropriate patient safeguards.

Viewpoint: power and communication: why simulation training ought to be complemented by experiential and humanist learning

The authors present an analysis of communication training for medical students using simulation patients, and its possible influence on later doctor-patient relationships. Many empirical studies have shown the various benefits of using simulation patients to teach communication skills, but theoretical sociology and humanistic reflection shed light on some fundamental differences between the student-doctor/actor-patient interactions practiced in simulation encounters and real doctor-patient relationships. In contrast to the usual power dynamics of a doctor-patient relation, those of simulation encounters are inverted and overwritten by an entirely different set of power relations, namely, those of the evaluator-student relationship. Since the power dynamics of real doctor-patient relations are generally overlooked, the altered dynamics of the simulation encounter are not readily perceived, and simulation encounters are thus often mistaken as accurate representations of clinical reality. Exclusive reliance on this pedagogic approach of simulation training may be encouraging students to become "simulation doctors" who act out a good relationship to their patients but have no authentic connection with them. The authors propose that liberal-arts learning and encounters with real patients should be used to cultivate students' abilities to create good doctor-patient relationships, as a compliment to the pedagogic benefits of simulation encounters.

Central thalamic deep brain stimulation to promote recovery from chronic posttraumatic minimally conscious state: challenges and opportunities

BACKGROUND

Central thalamic deep brain stimulation (CT-DBS) may have therapeutic potential to improve behavioral functioning in patients with severe traumatic brain injury (TBI), but its use remains experimental. Current research suggests that the central thalamus plays a critical role in modulating arousal during tasks requiring sustained attention, working memory, and motor function. The aim of the current article is to review the methodology used in the CT-DBS protocol developed by our group, outline the challenges we encountered and offer suggestions for future DBS trials in this population. RATIONAL FOR CT-DBS IN TBI:  CT-DBS may therefore be able to stimulate these functions by eliciting action potentials that excite thalamocortical and thalamostriatal pathways. Because patients in chronic minimally conscious state (MCS) have a very low probability of regaining functional independence, yet often have significant sparing of cortical connectivity, they may represent a particularly appropriate target group for CT-DBS. PIlOT STUDY RESULTS:  We have conducted a series of single-subject studies of CT-DBS in patients with chronic posttraumatic MCS, with 24-month follow-up. Outcomes were measured using the Coma Recovery Scale-Revised as well as a battery of secondary outcome measures to capture more granular changes. Findings from our index case suggest that CT-DBS can significantly increase functional communication, motor performance, feeding, and object naming in the DBS on state, with performance in some domains remaining above baseline even after DBS was turned off.

CONCLUSIONS

The use of CT-DBS in patients in MCS, however, presents challenges at almost every step, including during surgical planning, outcome measurement, and postoperative care. Additionally, given the difficulties of obtaining informed consent from patients in MCS and the experimental nature of the treatment, a robust, scientifically rooted ethical framework is resented for pursuing this line of work.

Implantable cardioverter-defibrillator deactivation at the end of life: a physician survey

BACKGROUND

Among older adults, implantable cardioverter-defibrillator (ICD) use is increasing. ICD shocks can occur at end of life (EOL) and cause substantial distress, warranting consideration of ICD deactivation discussions. This nationwide physician survey sought to (1) determine if physicians discuss ICD deactivation at the EOL, (2) identify predictors of those discussions, and (3) ascertain physicians' knowledge/attitudes about ICD use.

METHODS

We surveyed 4,876 physicians stratified by specialty (cardiologists, electrophysiologists, general internists, and geriatricians). The mailed survey presented 5 vignettes (eg, end-stage chronic obstructive pulmonary disease, advanced dementia) wherein ICD deactivation might be considered and 17 Likert-scaled items.

RESULTS

Five hundred fifty-eight (12%) physicians returned surveys. Respondents were largely men (77%) and white (69%). Most physicians (56%-83%) said they would initiate deactivation discussions in all 5 vignettes, whereas significantly more (82%-94%) would discuss advance directives and do not resuscitate status. In logistic regression analyses, a history of prior deactivation discussions was an independent predictor of willingness to discuss deactivation (adjusted OR range, 2.8-8.8) in 4 of the 5 vignettes. General internists and geriatricians were less likely than electrophysiologists to agree that ICD shocks are painful and to distinguish between the ICD's pacing and defibrillator functions. Finally, most physicians believed that informed consent for ICD implantation should include information about deactivation (77%) and endorsed the need for expert guidance in this area (58%).

CONCLUSIONS

Most physicians would discuss ICD deactivation at EOL. The strongest predictor of this was a history of prior discussions. Knowledge about ICDs varies by specialty, and most expressed a desire for more expert guidance about ICD management at EOL.

Ethical, palliative, and policy considerations in disorders of consciousness

This essay complements the scientific and practice scope of the American Academy of Neurology Guideline on Disorders of Consciousness by providing a discussion of the ethical, palliative, and policy aspects of the management of this group of patients. We endorse the renaming of "permanent" vegetative state to "chronic" vegetative state given the increased frequency of reports of late improvements but suggest that further refinement of this class of patients is necessary to distinguish late recoveries from patients who were misdiagnosed or in cognitive-motor dissociation. Additional nosologic clarity and prognostic refinement is necessary to preclude overestimation of low probability events. We argue that the new descriptor "unaware wakefulness syndrome" is no clearer than "vegetative state" in expressing the mismatch between apparent behavioral unawareness when patients have covert consciousness or cognitive motor dissociation. We advocate routine universal pain precautions as an important element of neuropalliative care for these patients given the risk of covert consciousness. In medical decision-making, we endorse the use of advance directives and the importance of clear and understandable communication with surrogates. We show the value of incorporating a learning health care system so as to promote therapeutic innovation. We support the Guideline's high standard for rehabilitation for these patients but note that those systems of care are neither widely available nor affordable. Finally, we applaud the Guideline authors for this outstanding exemplar of engaged scholarship in the service of a frequently neglected group of brain-injured patients.

Late recovery from the minimally conscious state: ethical and policy implications

We consider the ethical and public policy implications of late recovery from the minimally conscious state in light of an Institute of Medicine exploratory meeting convened to discuss current knowledge about disorders of consciousness as well as a recently published study demonstrating axonal regrowth in a patient two decades after traumatic injury. Participants at the meeting (which included the authors) described a lack of research initiatives for basic investigations of patients in these states, the frequent warehousing of patients following a diagnosis of persistent vegetative state that limits their access to appropriate neurologic and diagnostic tests, and the breadth of public confusion about disorders of consciousness. Meeting participants encouraged the Institute to pursue a more formal study to outline both the need for research and the unique opportunities to study consciousness, now available through the use of neuroimaging and related technologies. Areas of initial focus would be to define the epidemiology of the minimally conscious state, elucidate mechanisms of recovery, and identify clinically useful diagnostic and prognostic markers that will aid decision making at the bedside.

Reflective practice and palliative care education: a clerkship responds to the informal and hidden curricula

The authors discuss the damaging influence of informal and hidden curricula on medical students and describe a two-week clerkship in palliative care and clinical ethics at their school (Weill Medical College of Cornell University). This required clerkship, begun in 1999, uses reflective practice and a special pedagogic technique, participant observation, to counteract the influences of the informal and hidden curricula. This technique seeks to immerse the participant observer in the context of care. In their role as participant observers, students are relieved of any direct clinical responsibilities for two weeks so they have time for the careful observation and reflection required and also can consider the humanistic dimensions of practice, which are often displaced by the need to master diagnostic and therapeutic skills. Course objectives include identifying psychosocial and contextual factors that influence care, principles of pain and symptom management, and ethical and legal issues at the end of life. Students are expected to learn how to apply ethical norms to patient care, describe methods of pain and symptom management, communicate in an effective and humanistic manner, and articulate models of patient-centered advocacy. The clerkship fosters professionalism in patient care, appreciation of cultural diversity, and the student's ability to assume responsibility for developing competency in these areas. Although it is too early to know whether this clerkship will ultimately affect the practice patterns of students who experience it, short-term evaluation has been very favorable.

Communication in intensive care settings: the challenge of futility disputes

In intensive care settings, suboptimal communication can erode family trust and fuel so-called "futility" disputes. Presenting a teaching case used by >225 hospitals participating in the Decisions Near the End-of-Life program, we identify critical communication challenges and opportunities. We emphasize that good communication requires not only clear and sensitive language but also clinician self-awareness, psychological insight, and an institutional culture that promotes good communication with families. The article concludes with two examples of steps institutions can take to foster good communication between families and healthcare professionals.

Ethical Challenges of Risk, Informed Consent, and Posttrial Responsibilities in Human Research With Neural Devices: A Review

Importance

Developing more and better diagnostic and therapeutic tools for central nervous system disorders is an ethical imperative. Human research with neural devices is important to this effort and a critical focus of the National Institutes of Health Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Despite regulations and standard practices for conducting ethical research, researchers and others seek more guidance on how to ethically conduct neural device studies. This article draws on, reviews, specifies, and interprets existing ethical frameworks, literature, and subject matter expertise to address 3 specific ethical challenges in neural devices research: analysis of risk, informed consent, and posttrial responsibilities to research participants.

Observations

Research with humans proceeds after careful assessment of the risks and benefits. In assessing whether risks are justified by potential benefits in both invasive and noninvasive neural device research, the following categories of potential risks should be considered: those related to surgery, hardware, stimulation, research itself, privacy and security, and financial burdens. All 3 of the standard pillars of informed consent-disclosure, capacity, and voluntariness-raise challenges in neural device research. Among these challenges are the need to plan for appropriate disclosure of information about atypical and emerging risks of neural devices, a structured evaluation of capacity when that is in doubt, and preventing patients from feeling unduly pressured to participate. Researchers and funders should anticipate participants' posttrial needs linked to study participation and take reasonable steps to facilitate continued access to neural devices that benefit participants. Possible mechanisms for doing so are explored here. Depending on the study, researchers and funders may have further posttrial responsibilities.

Conclusions and Relevance

This ethical analysis and points to consider may assist researchers, institutional review boards, funders, and others engaged in human neural device research.

Development of a palliative education assessment tool for medical student education

Studies assessing palliative care education in U.S. medical schools reveal that little attention is paid to this topic. Although core competencies have been defined, few schools have implemented effective means to incorporate formal palliative care education into undergraduate curricula. To promote reform, each school needs to conduct a thorough assessment to identify palliative care content throughout the four-year curriculum. The authors developed an innovative assessment instrument to facilitate curricular mapping of palliative care education. The Palliative Education Assessment Tool (PEAT) comprises seven palliative care domains: palliative medicine, pain, neuropsychologic symptoms, other symptoms, ethics and the law, patient/family/nonclinical caregiver perspectives on end-of-life care, and clinical communication skills. Each domain details specific curricular objectives of knowledge, skills, and attitudes. Designed as a flexible self-assessment tool, PEAT helps determine the existence of palliative care education, which usually is found in various formats throughout a medical school's curriculum and thus sometimes "hidden." PEAT enables educators to describe a specific, multidimensional aspect of the curriculum and use the information for strategic planning, educational reform, and evaluation. The curricular reform implications of such an instrument are broader than palliative care assessment. A modified version of PEAT can be used to assess systematically other topics that are taught in various formats in the curriculum and to develop collaborative approaches to fulfilling the educational objectives of those topics.