Dose-response relationships of psilocybin-induced subjective experiences in humans

BACKGROUND

Psilocybin is the psychoactive component in Psilocybe mushrooms ('magic mushrooms'). Whether and how the quality of the psilocybin-induced experience might mediate beneficial health outcomes is currently under investigation, for example, in therapeutic applications. However, to date, no meta-analysis has investigated the dose-dependency of subjective experiences across available studies.

AIM

Establishing dose-response relationships of the subjective experiences induced by psilocybin in healthy study participants and a comparison of patient groups.

METHOD

We applied a linear meta-regression approach, based on the robust variance estimation framework, to obtain linear dose-response relationship estimates on questionnaire ratings after oral psilocybin administration. Data were obtained from the Altered States Database, which contains data extracted from MEDLINE-listed journal articles that used standardized and validated questionnaires: the Altered States of Consciousness Rating Scale, the Mystical Experience Questionnaire and the Hallucinogen Rating Scale.

RESULTS

Psilocybin dose positively correlated with ratings on most factors and scales, mainly those referring to perceptual alterations and positively experienced ego dissolution. Measures referring to challenging experiences exhibited small effects and were barely modulated by dose.

CONCLUSION

Psilocybin intensified almost all characteristics of altered states of consciousness assessed with the given questionnaires. Because subjective experiences are not only determined by dose, but also by individual and environmental factors, the results may only apply to controlled laboratory experiments and not to recreational use. This paper may serve as a general literature citation for the use of psilocybin in experimental and clinical research, to compare expected and observed subjective experiences.

Assessment of Visual Pursuit in Patients With Disorders of Consciousness Based on a Brain-Computer Interface

Visual pursuit assessment is extensively applied in the behavioral scale-based clinical examination of patients with disorders of consciousness (DOC). However, this assessment is challenging because it relies on behavioral markers, and these patients severely lack behavioral responses. Brain-computer interfaces (BCIs) may provide a potential solution to detect brain responses to external stimuli without requiring behavioral expressions. A BCI system was designed to simulate visual pursuit detection in the coma recovery scale-revised (CRS-R). The graphical user interface included four buttons, one that moved on the screen and three that did not. These buttons flashed in a random order. The patients were prompted to follow the moving button. Based on the collected electroencephalography data, the algorithm determined whether the patient focused on the moving target. Among the 14 DOC patients who participated in the assessments based on the BCI system and the CRS-R, four patients exhibited visual pursuit, and three were nonresponsive in both assessments. More importantly, seven patients who did not exhibit visual pursuit in CRS-R were detected to be responsive to the moving target stimuli in the BCI assessment. Furthermore, five out of seven recovered consciousness to some degree and showed visual pursuit in the second CRS-R assessment. The proposed BCI system is better able to detect visual pursuit than the behavioral scale-based assessment and thus can assist in clinically evaluating the challenging population of DOC patients.

A Brain-Computer Interface Based on Three-Dimensional Stereo Stimuli for Assisting Clinical Object Recognition Assessment in Patients With Disorders of Consciousness

The coma recovery scale-revised (CRS-R) behavioral scale is commonly used for the clinical evaluation of patients with disorders of consciousness (DOC). However, since DOC patients generally cannot supply stable and efficient behavioral responses to external stimulation, evaluation results based on behavioral scales are not sufficiently accurate. In this paper, we proposed a novel brain-computer interface (BCI) based on 3D stereo audiovisual stimuli to supplement object recognition evaluation in the CRS-R. During the experiment, subjects needed to follow the instructions and to focus on the target object on the screen, whereas EEG data were recorded and analyzed in real time to determine the object of focus, and the detection result was output as feedback. Thirteen DOC patients participated in the object recognition assessments using the 3D audiovisual BCI and CRS-R. None of the patients showed object recognition function in the CRS-R assessment before the BCI experiment. However, six of these DOC patients achieved accuracies that were significantly higher than the chance level in the BCI-based assessment, indicating the successful detection of object recognition function in these six patients using our 3D audiovisual BCI system. These results suggest that the BCI method may provide a more sensitive object recognition evaluation compared with CRS-R and may be used to assist clinical CRS-R for DOC patients.

Clinical Features of Disorders of Consciousness in Young Children

OBJECTIVES

To investigate behavioral and demographic features of levels of consciousness in young children with brain injury, including the classifications of consciousness: conscious state (CS), minimally conscious state (MCS), and vegetative state (VS), and to investigate the course of recovery in children with disorders of consciousness (DOC).

DESIGN

Retrospective chart review and post hoc analysis.

SETTING

Pediatric inpatient rehabilitation unit.

PARTICIPANTS

Children aged 6 months to 5 years (N=54) admitted for inpatient rehabilitation directly from an acute care hospital following new neurologic injury from 2011 to 2016.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Clinically abstracted behavioral features of DOC and levels of consciousness at admission and discharge, based on established guidelines from the Aspen Neurobehavioral Conference Workgroup.

RESULTS

Children in MCS were younger than children in CS. Commonly observed behaviors in children in VS were mouth movements or vocalizations, flexion withdrawal or motor posturing, visual or auditory startle, and localization to sound. Common features of MCS were contingent affect, visual fixation or pursuit, automatic motor behavior, and contingent communicative intent. No children in MCS showed command following or intelligible verbalizations. All children in CS showed functional object use, while functional communication was observed in a subset. By discharge, more than half of children in VS emerged to MCS, and a third emerged from MCS to CS. No child emerged from VS to CS.

CONCLUSIONS

Visual and motor skills may be most applicable, and language-based skills may be least applicable for the assessment of DOC in very young children. Accurate classifications of consciousness may have important prognostic implications, and additional research is needed to develop clear guidelines for assessment of DOC in this population.

Outcomes of patients with altered level of consciousness and abnormal electroencephalogram: A retrospective cohort study

INTRODUCTION

Nonconvulsive seizures (NCS) are frequent in hospitalized patients and may further aggravate injury in the already damaged brain, potentially worsening outcomes in encephalopathic patients. Therefore, both early seizure recognition and treatment have been advocated to prevent further neurological damage.

OBJECTIVE

Evaluate the main EEG patterns seen in patients with impaired consciousness and address the effect of treatment with antiepileptic drugs (AEDs), continuous intravenous anesthetic drugs (IVADs), or the combination of both, on outcomes.

METHODS

This was a single center retrospective cohort study conducted in a private, tertiary care hospital. Consecutive adult patients with altered consciousness submitted to a routine EEG between January 2008 and February 2011 were included in this study. Based on EEG pattern, patients were assigned to one of three groups: Group Interictal Patterns (IP; EEG showing only interictal epileptiform discharges or triphasic waves), Group Rhythmic and Periodic Patterns (RPP; at least one EEG with rhythmic or periodic patterns), and Group Ictal (Ictal; at least one EEG showing ictal pattern). Groups were compared in terms of administered antiepileptic treatment and frequency of unfavorable outcomes (modified Rankin scale ≥3 and in-hospital mortality).

RESULTS

Two hundred and six patients (475 EEGs) were included in this analysis. Interictal pattern was observed in 35.4% (73/206) of patients, RPP in 53.4% (110/206) and ictal in 11.2% (23/206) of patients. Treatment with AEDs, IVADs or a combination of both was administered in half of the patients. While all Ictal group patients received treatment (AEDs or IVADs), only 24/73 (32.9%) IP group patients and 55/108 (50.9%) RPP group patients were treated (p<0.001). Hospital length of stay (LOS) and frequency of unfavorable outcomes did not differ among the groups. In-hospital mortality was higher in IVADs treated RPP patients compared to AEDs treated RPP patients [11/19 (57.9%) vs. 11/36 (30.6%) patients, respectively, p = 0.049]. Hospital LOS, in-hospital mortality and frequency of unfavorable outcomes did not differ between Ictal patients treated exclusively with AEDs or IVADs.

CONCLUSION

In patients with acute altered consciousness and abnormal routine EEG, antiepileptic treatment did not improve outcomes regardless of the presence of periodic, rhythmic or ictal EEG patterns.

The role of the psychologist with disorders of consciousness in inpatient pediatric neurorehabilitation: A case series

PURPOSE/OBJECTIVE

The psychologist in an inpatient pediatric neurorehabilitation setting provides a vital role in the assessment, treatment, and management of pediatric patients with disorders of consciousness (DoC). Competencies are drawn from several specialty areas of professional psychology, including rehabilitation psychology, pediatric neuropsychology, and pediatric psychology. This specialized knowledge forms the basis for tailoring assessment and treatment plans specific to the individual brain injury profile, with the goals of enhancing diagnosis, prognosis, and care transition decision.

AIM

To describe the role of the psychologist in the differential diagnosis and treatment of pediatric patients with severe brain injury and DoC during inpatient rehabilitation. Research Method/Design: Three pediatric cases admitted to inpatient rehabilitation with suspected DoC illustrate the psychologist's role in diagnostics, case conceptualization, assessment design, and data collection based on patient-specific brain injury profiles. Customized data collection informs diagnostic decisions and treatment planning, with the goal of improved of care and resource utilization. The psychologist also provides ongoing psychoeducation, psychotherapy, and supportive interventions to the patient's family and caregivers to facilitate family adjustment to disability and promote long-term adaptation and adjustment.

CONCLUSIONS/IMPLICATIONS

This case series illustrates the role of the psychologist in the use of individual brain injury profiles to coordinate assessment, diagnosis, and care for children with severe brain injury. Implications include the need for focused research to demonstrate the value-added role of the psychologist on the interdisciplinary team working in the neurorehabilitation of this complex patient population. (PsycINFO Database Record

Modulatory effect of the 5-HT1A agonist buspirone and the mixed non-hallucinogenic 5-HT1A/2A agonist ergotamine on psilocybin-induced psychedelic experience

The mixed serotonin (5-HT) 1A/2A/2B/2C/6/7 receptor agonist psilocybin dose-dependently induces an altered state of consciousness (ASC) that is characterized by changes in sensory perception, mood, thought, and the sense of self. The psychological effects of psilocybin are primarily mediated by 5-HT2A receptor activation. However, accumulating evidence suggests that 5-HT1A or an interaction between 5-HT1A and 5-HT2A receptors may contribute to the overall effects of psilocybin. Therefore, we used a double-blind, counterbalanced, within-subject design to investigate the modulatory effects of the partial 5-HT1A agonist buspirone (20mg p.o.) and the non-hallucinogenic 5-HT2A/1A agonist ergotamine (3mg p.o.) on psilocybin-induced (170 µg/kg p.o.) psychological effects in two groups (n=19, n=17) of healthy human subjects. Psychological effects were assessed using the Altered State of Consciousness (5D-ASC) rating scale. Buspirone significantly reduced the 5D-ASC main scale score for Visionary Restructuralization (VR) (p<0.001), which was mostly driven by a reduction of the VR item cluster scores for elementary and complex visual hallucinations. Further, buspirone also reduced the main scale score for Oceanic Boundlessness (OB) including derealisation and depersonalisation phenomena at a trend level (p=0.062), whereas ergotamine did not show any effects on the psilocybin-induced 5D-ASC main scale scores. The present finding demonstrates that buspirone exerts inhibitory effects on psilocybin-induced effects, presumably via 5-HT1A receptor activation, an interaction between 5-HT1A and 5-HT2A receptors, or both. The data suggest that the modulation of 5-HT1A receptor activity may be a useful target in the treatment of visual hallucinations in different psychiatric and neurological diseases.

Longitudinal changes in functioning and disability in patients with disorders of consciousness: the importance of environmental factors

Disorders of consciousness are neurological conditions associated with low levels of functioning which pose a serious challenge to public health systems. The current study aimed to examine longitudinal changes in functioning in patients with disorders of consciousness and to identify associated biopsychosocial factors using the International Classification of Functioning, Disability, and Health. An Italian sample of 248 patients was assessed longitudinally. Differences in relative variability (an index of change that controls for baseline levels) between acute and chronic patients and predictors of relative variability in "Activities &amp; Participation" were examined. Results showed that there were subgroups of patients whose functioning improved over time. The number of problems in "Activities &amp; Participation" decreased in acute patients over time, whereas in chronic patients, an increase was found. The significant difference in relative variability for the environmental factor "support and relationships" reflects the increase in facilitators in acute patients, whereas the number of facilitators in chronic patients remained unchanged over time. Age at event, time from event, and relative variability in "Environmental Factors" were significant predictors of relative variability in "Activities &amp; Participation". It is of clinical relevance that patients with disorders of consciousness are kept in a supportive and facilitative environment, in order to prevent a decline in their functioning. Moreover, caregivers should receive tailored support in order to enhance and facilitate appropriate care of patients with disorders of consciousness.

[24-hour work: the interaction of stress and changes in the sleep-wake cycle in the police force]

Disruption in police officers. In recent years there has been a widespread growth in services, available regardless of time or day organization (24/7 service) and a diffuse increase in their use, both in work and private lives, generally ignoring the importance of a regular sleep organization. Police officers - often need to work extended shifts and long hours under highly stressful conditions, which results in reduced levels of safety and operational effectiveness. In numerous studies, perceived stress has been found to correlate with both subjective and objective disturbances in sleep. Consequently, excessive daytime sleepiness is one of the most frequent health and safety hazards that police officers have to deal with. Sleep deprivation affects performance outcomes through a wide range of cognitive domains. Sleepiness and fatigue, caused by sleep loss, extended work and wakefulness, circadian misalignment and sleep disorders are major causes of workplace human errors, incidents, and accidents. Therefore, prevention of sleep loss, high levels of stress and fatigue is a key factor to consider when assessing emergency intervention. In order to combat fatigue and sleepiness, a 30-90 minutes nap before night shift could be a viable option.

Impaired consciousness in partial seizures is bimodally distributed

OBJECTIVE

To investigate whether impaired consciousness in partial seizures can usually be attributed to specific deficits in the content of consciousness or to a more general decrease in the overall level of consciousness.

METHODS

Prospective testing during partial seizures was performed in patients with epilepsy using the Responsiveness in Epilepsy Scale (n = 83 partial seizures, 30 patients). Results were compared with responsiveness scores in a cohort of patients with severe traumatic brain injury evaluated with the JFK Coma Recovery Scale-Revised (n = 552 test administrations, 184 patients).

RESULTS

Standardized testing during partial seizures reveals a bimodal scoring distribution, such that most patients were either fully impaired or relatively spared in their ability to respond on multiple cognitive tests. Seizures with impaired performance on initial test items remained consistently impaired on subsequent items, while other seizures showed spared performance throughout. In the comparison group, we found that scores of patients with brain injury were more evenly distributed across the full range in severity of impairment.

CONCLUSIONS

Partial seizures can often be cleanly separated into those with vs without overall impaired responsiveness. Results from similar testing in a comparison group of patients with brain injury suggest that the bimodal nature of Responsiveness in Epilepsy Scale scores is not a result of scale bias but may be a finding unique to partial seizures. These findings support a model in which seizures either propagate or do not propagate to key structures that regulate overall arousal and thalamocortical function. Future investigations are needed to relate these behavioral findings to the physiology underlying impaired consciousness in partial seizures.

Making every word count for nonresponsive patients

IMPORTANCE

Despite the apparent absence of external signs of consciousness, a significant small proportion of patients with disorders of consciousness can respond to commands by willfully modulating their brain activity, even respond to yes or no questions, by performing mental imagery tasks. However, little is known about the mental life of such responsive patients, for example, with regard to whether they can have coherent thoughts or selectively maintain attention to specific events in their environment. The ability to selectively pay attention would provide evidence of a patient's preserved cognition and a method for brain-based communication, thus far untested with functional magnetic resonance imaging in this patient group.

OBJECTIVE

To test whether selective auditory attention can be used to detect conscious awareness and communicate with behaviorally nonresponsive patients.

DESIGN, SETTING, AND PARTICIPANTS

Case study performed in 3 patients with severe brain injury, 2 diagnosed as being in a minimally conscious state and 1 as being in a vegetative state. The patients constituted a convenience sample.

MAIN OUTCOMES AND MEASURES

Functional magnetic resonance imaging data were acquired as the patients were asked to selectively attend to auditory stimuli, thereby conveying their ability to follow commands and communicate.

RESULTS

All patients demonstrated command following according to instructions. Two patients (1 in a minimally conscious state and 1 in a vegetative state) were also able to guide their attention to repeatedly communicate correct answers to binary (yes or no) questions.

CONCLUSIONS AND RELEVANCE

To our knowledge, we show for the first time with functional magnetic resonance imaging that behaviorally nonresponsive patients can use selective auditory attention to convey their ability to follow commands and communicate. One patient in a minimally conscious state was able to use attention to establish functional communication in the scanner, despite his inability to produce any communication responses in repeated bedside examinations. More important, 1 patient, who had been in a vegetative state for 12 years before the scanning and subsequent to it, was able to use attention to correctly communicate answers to several binary questions. The technique may be useful in establishing basic communication with patients who appear unresponsive to bedside examinations and cannot respond with existing neuroimaging methods.

Disorders of consciousness and communication. Ethical motivations and communication-enabling attributes of consciousness

Envisaged extensions of a functional magnetic resonance imaging (fMRI) technique allowing communication with patients affected by disorders of consciousness are here examined in connection with subjective symptom reporting, informed consent, and continued medical care decision-making. The principles of medical beneficence, personal autonomy protection, and the right to participate in social life are isolated as appropriate sources of ethical motivations for the use of fMRI-enabled communication. Consciousness requirements for each communication context are identified on the basis of qualitative distinctions between the access, phenomenal, and narrative varieties of consciousness. Ethically motivated uses of fMRI-enabled communication are hierarchically organized in terms of progressively more demanding consciousness requirements for successful communication. The outcomes of this analysis can be used to curb unrealistic expectations of these new scientific developments, and to promote mutual trust between medical doctors, patient surrogates and families.

[Neurological aspects related to altered consciousness states associated with spirituality]

INTRODUCTION

Religiosity in the human being constitutes a universal and present phenomenon in all their evolution, extending times and cultures. The spirituality, like a base of the human religious dimension, and not strictly identified with this one, implies, among others manifestations, intense subjective experiences that, sometimes, can derive in altered consciousness states.

AIM

To review some of the most outstanding phenomena that constitute consciousness alteration related to experiences of spiritual nature, trying to explain the neurological framework that justifies them.

DEVELOPMENT

We analyze the connection that takes place between peculiar expressions of religious and mystical exacerbation with respect to some forms of epilepsy, distinguishing between distinct manifestations from those based on its appearance moment within the epileptic moment (ictal, postictal and interictal periods). Later on, we present the most important psychoactive substances, also used in ritual contexts, with capacity to bring about ecstasies experiences.

CONCLUSIONS

Affirming the possibility of including the religious fact and their manifestations within the scientific argument, we tentatively propose the neurological foundations that underlie to these exceptional consciousness states to associate to the spirituality. They are involved in many occasions in the clinical practice requiring of being known and considered as a deeper investigation, which continues clarifying all these aims.

[Effect of strong stimulation of acupuncture at twelve Jing-well points as main for neurosurgery patients with disorder of consciousness]

OBJECTIVE

To observe the promoting consciousness effect of acupuncture for neurosurgery patients with disorder of consciousness.

METHODS

Ninety-two neurosurgery patients with medium or severe disorder of consciousness were randomly divided into an acupuncture plus medicine group and a western medicine group, 46 cases in each group. The acupuncture plus medicine group was treated with the routine western medicine and acupuncture with strong stimulation at twelve Jing points and Shuigou (GV 26) combined with electroacupuncture at Baihui (GV 20), Sishencong (EX-HN 1), Shenting (GV 24) and Benshen (GB 13). The western medicine group was treated by routine western medicine. Two courses later, the therapeutic effects were compared between the two groups.

RESULTS

After treatment, the total effective rate was 100.0% in the acupuncture plus medicine group and 91.3% in the western medicine group, with a significant difference between the two groups (P<0.01).

CONCLUSION

Strong stimulation of acupuncture at twelve Jing points and Shuigou (GV 26) combined with electroacupuncture at the head acupoints have an obvious promotion of consciousness recovery for neurosurgery patients with disturbance of consciousness, and acupuncture involved in the treatment can significantly shorten the healing time.

Theories of impaired consciousness in epilepsy

Although the precise mechanisms for control of consciousness are not fully understood, emerging data show that conscious information processing depends on the activation of certain networks in the brain and that the impairment of consciousness is related to abnormal activity in these systems. Epilepsy can lead to transient impairment of consciousness, providing a window into the mechanisms necessary for normal consciousness. Thus, despite differences in behavioral manifestations, cause, and electrophysiology, generalized tonic-clonic, absence, and partial seizures engage similar anatomical structures and pathways. We review prior concepts of impaired consciousness in epilepsy, focusing especially on temporal lobe complex partial seizures, which are a common and debilitating form of epileptic unconsciousness. We discuss a "network inhibition hypothesis" in which focal temporal lobe seizure activity disrupts normal cortical-subcortical interactions, leading to depressed neocortical function and impaired consciousness. This review of the major prior theories of impaired consciousness in epilepsy allows us to put more recent data into context and to reach a better understanding of the mechanisms important for normal consciousness.

[Functional pathophysiology of consciousness]

Consciousness (Latin conscientia "moral conscience"), according to the English philosopher John Locke (1632-1704) [103], is the awareness of all that occurs in the mind of a person, whereas the American philosopher John Searle (2000) defined it as "inner qualitative, subjective states and processes of awareness". In modern science it is defined as a continuous state of full awareness of the Self and one's relationship to the external and internal environment, describing the degree of wakefulness in which an organism recognizes stimuli. This widely discussed biological term for complex neuronal processes that allow an individuum to recognize itself and its environment and to act accordingly, has been and still is the subject of much research in philosophy and natural/neuroscience. Its definition is often used for awareness and recognition, too. While the Egyptians in the papyrus Edwin Smith already recognized the brain as the seat of consciousness, René Descartes (1644 [36]) believed its special structure should be "a small gland in the middle", but the anatomical structures and physiological processes involved in consciousness were elucidated only in the middle of the 20th century. Neuronal substrates include several functional networks that are hierarchically organized and cooperate functionally. The lowest level is the mesencephalic formatio reticularis and its projections to the thalamus that were identified als ascending reticular system (ARAS) by the classical experiments of Moruzzi and Magoun, whereas later analyses of patients with impaired consciousness provided further insights. The mesencephalic ARAS as motor of the function of higher structures projects 1. via the reticular thalamus diffusely to the cortex, 2. via hypothalamus to the basal forebrain and limbic system, and 3. to the medial raphe of the brainstem and locus coeruleus and their diffuse cortical projections. The reticular system is stimulated directly and indirectly via numerous collaterals from important somatic and sensory pathways and acts as a control system of neuronal activities of the cerebral cortex. The principal function of the ARAS is to focus our alertness on specific stimuli or internal processes, which run via complex neuronal cell groups and numerous neurotransmitters that influence various aspects of consciousness and wakefulness. Stimulation of the ARAS produces an arousal reaction as the electric correlate of consciousness; its destruction causes coma and related states. The highest level are cortical (prefrontal and association) networks for recognition, motor activity, longterm memory and attention, the left hemisphere being considered as the dominant one. Different levels of consciousness are distinguished: 1. hyperalertness, 2. alertness (normal state of wakefulness), 3. somnolence or lethargy, 4. obtundation with tendency to fall asleep, 5. stupor, 6. coma and its subtypes, like akinetic mutism, apallic syndrome or persistent vegative state, locked-in syndrome, delirium, and catatonia. They are caused by damages in various functional levels of the brain, by psychogenic factors or experimentally, and are accompanied by characteristic neurological and psychiatric disorders. The relevant morphological lesions can be detected by electrophysiological and imaging studies. The bases of functional anatomy and pathophysiology of consciousness, its cognitive aspects and its major disorders, their causes and functional substrates with reference to sleep and both spontaneous and iatrogenic disorders of consciousness are critically summarized.

Using the Human Response to Illness Model to assess altered level of consciousness in patients with subdural hematomas

Head injuries are the leading cause of trauma mortality and account for nearly half of all deaths related to trauma injuries. Patients who present with subdural hematomas are at risk for initial damage to the brain, as well as for subsequent brain damage related to re-bleed, ischemia or cerebral edema. These injuries can be acute or chronic in nature, and may be manifested in the patient as an altered level of consciousness. Skilled nursing assessment of altered level of consciousness leads to early nursing and medical intervention, which, in turn, can improve patient outcomes. In this paper, a critical review of the literature will focus on altered level of consciousness in patients presenting with a subdural hematoma. The Human Response to Illness Model will be utilized as a framework for this review. Accordingly, the physiological, pathophysiological, behavioural, and experiential perspectives of altered level of consciousness will be examined. Thus, a comprehensive understanding of this human response and rationale for evidence-based interventions will be established.

Behavioral assessment in patients with disorders of consciousness: gold standard or fool's gold?

In the absence of "hard" neurophysiologic markers, the burden of proof for establishing conscious awareness in individuals who sustain severe brain injury lies in behavioral assessment. Because behavior represents indirect evidence of consciousness, reliance on behavioral markers presents significant challenges and may lead to misdiagnosis. Detection of conscious awareness is confounded by numerous factors including fluctuations in arousal level, difficulty differentiating reflexive or involuntary movement from intentional behavior, underlying sensory and motor impairments, and medication side effects. When an ambiguous behavior is observed, the onus falls to the clinician to determine where along the continuum of unconsciousness to consciousness, it lies. This paper (1) summarizes the current diagnostic criteria for coma, the vegetative state, and the minimally conscious state, (2) describes current behavioral assessment methods, (3) discusses the limitations of behavioral assessment techniques, (4) reviews recent applications of functional neuroimaging in the assessment of patients with disorders of consciousness, and (5) concludes with a case study that illustrates the disparity between behavioral and functional neuroimaging findings that may be encountered in this population.

[Neurobiology of consciousness]

Disorders of consciousness have captivated neurologists, neuroscientists, and philosophers for decades, but few consistent studies have been conducted on these conditions due to their difficult experimental approach. In recent years, an increasing number of cognitive neuroscience research groups have examined the physiology of consciousness from an experimental perspective, despite the methodological and epistemological complexities of the field. While describing consciousness can be challenging, a close definition must acknowledge a combination of wakefulness and awareness. Form a neurobiological standpoint, it has been argued that the ascending reticular system and its thalamic projections are critical in modulating awareness and wakefulness sleep cycles. Awareness may be a function of the neural networks within the cortex, the thalamus, and the cortico-cortical system. Different models have been employed to tackle this difficult problem, including non-invasive in vivo studies, examination of conscious patients with brain lesions, and studies on both animals and patients with disorders of consciousness. This article reviews the scientific evidence for the neural basis of conscious and unconscious processes in different states of consciousness, focusing on patients in the vegetative and minimally conscious state.

[Consciousness in psychiatry]

This article takes a look at the different meanings given to the notion of consciousness and shows how abandoning psychopathological controversies in view of an alleged a-theoricism can only lead to shallowness in the understanding of psychiatric pathology. It also highlights how different philosophical doctrines and psychological theories, which have attempted to explain the constitution of the human subject and of its mental phenomena, can be traced in every point of view which approaches the phenomenon of consciousness.

[The hard problem of conciousness and the clinical psychiatry]

The present paper reviews what in the specialized literature has been called the "easy problem" and the "hard problem" of consciousness. Taking David Chalmers' original paper as a starting point, first person perspective and subjective point of view are discussed. Literature and Philosophy are mentioned as having a role in these debates as a way of ending the privilege that clinics used to have.

The cognitive consequences of critical illness: practical recommendations for screening and assessment

Critically ill patients are at risk for several secondary complications, including delirium and long-term cognitive impairment. The exact mechanisms of delirium and ICU-related cognitive decline are not fully understood; however, the authors review several recent investigations that have proposed plausible explanations. This article also includes several practical guidelines for the identification and management of delirium to aid in the development and implementation of clinical procedures that will lower the risk for ICU delirium and cognitive decline.

Delirium as a disorder of consciousness

Delirium is a common clinical phenomenon, often described as a disorder of consciousness. Delirium is commonly under recognised. The usual response to under recognition is to exhort practitioners to do a better job, but perhaps under recognition should instead be seen as a daily pragmatic challenge to how delirium is conceptualised. Here we retain the view that delirium is a disorder of consciousness, but propose a more multidimensional approach to this key feature. We argue that delirium can be recognised through evaluating arousal, attention and temporal orientation. We suggest that this approach can be validated by testing whether it leads to better delirium identification, accounts for the characteristic clinical disturbances, explains why delirium is common in the extreme age groups and why in later life its boundaries often blend with dementia.

The anarchic hand syndrome and utilization behavior: a window onto agentive self-awareness

Two main approaches can be discerned in the literature on agentive self-awareness: a top-down approach, according to which agentive self-awareness is fundamentally holistic in nature and involves the operations of a central-systems narrator, and a bottom-up approach that sees agentive self-awareness as produced by lowlevel processes grounded in the very machinery responsible for motor production and control. Neither approach is entirely satisfactory if taken in isolation; however, the question of whether their combination would yield a full account of agentive self-awareness remains very much open. In this paper, I contrast two disorders affecting the control of voluntary action: the anarchic hand syndrome and utilization behavior. Although in both conditions patients fail to inhibit actions that are elicited by objects in the environment but inappropriate with respect to the wider context, these actions are experienced in radically different ways by the two groups of patients. I discuss how top-down and bottom-up processes involved in the generation of agentive self-awareness would have to be related in order to account for these differences.

Depersonalization, mindfulness, and childhood trauma

Depersonalization (DP), i.e., feelings of being detached from one's own mental processes or body, can be considered as a form of mental escape from the full experience of reality. This mental escape is thought to be etiologically linked with maltreatment during childhood. The detached state of consciousness in DP contrasts with certain aspects of mindfulness, a state of consciousness characterized by being in touch with the present moment. Against this background, the present article investigates potential connections between DP severity, mindfulness, and childhood trauma in a mixed sample of nonpatients and chronic nonmalignant pain patients. We found a strong inverse correlation between DP severity and mindfulness in both samples, which persisted after partialing out general psychological distress. In the nonpatient sample, we additionally found significant correlations between emotional maltreatment on the one hand and DP severity (positive) and mindfulness (negative) on the other. We conclude that the results first argue for an antithetical relationship between DP and certain aspects of mindfulness and thus encourage future studies on mindfulness-based interventions for DP and second throw light on potential developmental factors contributing to mindfulness.

Self-consciousness in non-communicative patients

The clinical and para-clinical examination of residual self-consciousness in non-communicative severely brain damaged patients (i.e., coma, vegetative state and minimally conscious state) remains exceptionally challenging. Passive presentation of the patient's own name and own face are known to be effective attention-grabbing stimuli when clinically assessing consciousness at the patient's bedside. Event-related potential and functional neuroimaging studies using such self-referential stimuli are currently being used to disentangle the cognitive hierarchy of self-processing. We here review neuropsychological, neuropathological, electrophysiological and neuroimaging studies using the own name and own face paradigm obtained in conscious waking, sleep, pharmacological coma, pathological coma and related disorders of consciousness. Based on these results we discuss what we currently do and do not know about the functional significance of the neural network involved in "automatic" and "conscious" self-referential processing.

Thalamic D2 receptors in dementia with Lewy bodies, Parkinson's disease, and Parkinson's disease dementia

Dementia with Lewy bodies (DLB) is characterized by progressive dementia with two of three core symptoms; Parkinsonism, visual hallucinations or disturbances of consciousness/fluctuating attention. Dementia in Parkinson's disease (PDD) has similar neuropsychiatric characteristics. Reduced nigrothalamic dopamine and altered thalamic D2 receptors may mediate some of the non-motor symptoms of DLB and PDD. The study aims were to ascertain whether thalamic D2 density was altered in Parkinson's disease (PD), PDD and DLB, and whether D2 density was related to core symptoms. Thalamic D2 receptor binding was measured by post-mortem autoradiography in 18 cases of DLB, 13 PDD, 6 PD and 14 normal elderly controls. Highest D2 density in control cases was in the intralaminar, midline, anterior and mediodorsal nuclei. In PD without dementia D2 binding was elevated above controls in all thalamic regions, significantly in reticular, laterodorsal, centromedian, ventral centromedian, parafascicular, paraventricular, ventroposterior, ventrolateral posterior, and ventrointermedius nuclei. Compared to controls, DLB cases with Parkinsonism (DLB+EPS) had significantly elevated D2 receptor density in laterodorsal and ventrointermedius nuclei; PDD cases had significantly raised density in the ventrointermedius, and DLB cases without Parkinsonism (DLB-EPS) did not show increased D2 density in any areas. In DLB and PDD cases with disturbances of consciousness, cases treated with neuroleptics had higher D2 binding in all thalamic regions, significantly in the mediodorsal and ventrolateral posterior nuclei. D2 receptor binding did not vary with cognitive decline (MMSE) or visual hallucinations, but was significantly higher with increased extrapyramidal symptoms.

Beurteilung der tiefgreifenden Bewusstseinsstörung

The difficulties of experts to judge and evaluate so-called affect crimes are due to theoretical and conceptual shortcomings on the one hand and problems of reproducibility on the other. This study describes an attempt to set up diagnostic guidelines for such cases. A vulnerability/stress model was developed which integrates features from different areas: predisposition (including social perception, thinking, and problem solving), triggering conditions (mainly derived from stress theories and concepts), and the established Sass criteria (1983). The characteristics of these respective diagnostic features were collected from a sample of 31 criminal responsibility examinations. Finally, implementing multivariate analysis, 13 criteria were established that could be useful in evaluating criminal responsibility with regard to consciousness disturbances in that they enable testimony based on the prognostic and discriminant validity of the individual criteria.

[Cognitive aging considered from the point of view of cognitive neurosciences of consciousness]

Linking together cognitive neurosciences of aging with the study of psychological and neurophysiological properties of consciousness opens rich fundamental and clinical perspectives. Indeed, several aspects of cognitive aging seem to deal with modifications of processes directly involved in conscious processing. In the light of this relation between consciousness and aging, three tracks of experimental research are proposed and discussed.

Preserved subliminal processing and impaired conscious access in schizophrenia

BACKGROUND

Studies of visual backward masking have frequently revealed an elevated masking threshold in schizophrenia. This finding has frequently been interpreted as indicating a low-level visual deficit. However, more recent models suggest that masking may also involve late and higher-level integrative processes, while leaving intact early bottom-up visual processing.

OBJECTIVE

To test the hypothesis that the backward-masking deficit in schizophrenia corresponds to a deficit in the late stages of conscious perception, whereas the subliminal processing of masked stimuli is fully preserved.

DESIGN

Twenty-eight patients with schizophrenia and 28 normal control subjects performed 2 backward-masking experiments. We used Arabic digits as stimuli and varied quasi-continuously the interval with a subsequent mask, thus allowing us to progressively unmask the stimuli. We finely quantified their degree of visibility using objective and subjective measures to evaluate the threshold duration for access to consciousness. We also studied the priming effect caused by the variably masked numbers in a comparison task performed on a subsequently presented and highly visible target number.

RESULTS

The threshold delay between the digit and mask necessary for the conscious perception of the masked stimulus was longer in patients compared with controls. This higher consciousness threshold in patients was confirmed by an objective and a subjective measure, and both measures were highly correlated for the patients and controls. However, subliminal priming of masked numbers was effective and identical in patients and controls.

CONCLUSIONS

Access to conscious report of masked stimuli is impaired in schizophrenia, whereas fast bottom-up processing of the same stimuli, as assessed by subliminal priming, is preserved. These findings suggest a high-level origin of the masking deficit in schizophrenia, although they leave open for further research its exact relation to previously identified bottom-up visual processing abnormalities.

A single case report of recurrent surgery for chronic back pain and its implications concerning a diagnosis of Münchausen syndrome

While undergoing treatment in the psychiatric department, A.C., a 40-year-old white male, who had arrived in the casualty department complaining of an uncontrollable anxiety attack and in a state of fluctuating consciousness, was found to be suffering from a psychopathological condition characterized by pathological lying, gambling, compulsive restlessness, a long clinical history of chronic back pain, with multiple invasive diagnostic investigations and repeated surgery for disc hernia with relative complications, culminating in the fitment of a fixed neurostimulator, a slow-discharge morphine pump and the patient being granted a full disability pension. The continual increases in the doses of morphine suggested a tendency towards drug addiction. After providing a brief overview of the historical background and current concepts relating to the relationship between factitious disorders, malingering and hysteria, the authors discuss the differential diagnosis of the case, suggesting a diagnosis of Münchausen syndrome (the hypothesis best supported by the clinical evidence). This diagnosis, although the subject of much academic debate, is, unfortunately, still not frequently encountered in the medical literature, with the result that even today it has a strong clinical, relational and social impact.

Cough-induced hemiplegic migraine with impaired consciousness in cystic fibrosis

The coughing paroxysms of patients with cystic fibrosis may occasion neurological symptoms. Although cough syncope is well-known, and is associated with headache and paralysis, a migrainous mechanism has not been reported. We reviewed the medical records, autonomic testing results, and responses to treatment in two cystic fibrosis patients with similar presentations of cough-induced impairment of consciousness followed by headache and paralysis. A 24-year-old woman and an unrelated 38-year-old man, both with cystic fibrosis, developed post-tussive neurologic deficits. Both patients reported infrequent dramatic spells, always preceded by major hemoptysis, and associated with left-sided paralysis, transient blindness, nausea, and severe pulsating headaches. Autonomic testing demonstrated only postural tachycardia and a near-vasodepressor episode in the woman, and mild, generalized sympathetic dysfunction in the man. Treatment for presumptive migraine with aura with verapamil nearly eradicated symptoms in both patients. Discontinuation of verapamil in the woman was associated with symptom recurrence and a stroke, with significant persistent residual left hemiparesis. In conclusion, cough-induced neurologic deficits were previously reported with cystic fibrosis, without clear understanding of the mechanism of impairment of consciousness. Based on the hemiparesis, nausea, and throbbing headache, which repeatedly followed the events in both patients, and based on the response to verapamil, we hypothesize a migrainous mechanism in both of our patients. The pathophysiology that links the hemoptysis to the spells deserves further investigation.

Psychological needs of patients in low awareness states, their families, and health professionals

Patients who have emerged from low awareness states may present with psychological needs that can be addressed via adapted formal clinical psychological interventions, or by behavioural techniques. Families of these patients may experience similar psychological reactions to relatives of any patients with severe brain injury, but there are also additional factors that are unique to patients in low awareness states. These sources of psychological distress for relatives are discussed. The needs of clinicians working with these clients are also discussed. It is important that services attending to the needs of clients in low awareness states also have adequate support for both relatives and clinicians.

Using a coma scale to assess patient consciousness levels

The Glasgow coma scale is the most widely used method for assessing a patient's level of consciousness. This article outlines the Leeds Teaching Hospitals NHS Trust's guidelines to assist practitioners with the practical aspects of carrying out and interpreting the scale.

[Disorders of executive consciousness]

Executive function is a higher order cognitive capacity that involves memory, perception and performance of complex tasks. Disorders of the executive functions are sign of lesions in the prefrontal cortex, involving the prefrontal-striatal-thalamic networks and the parietal association areas. According to signs and localization, five basic prefrontal syndromes are recognised. 1. Damage in posterior dorsolateral prefrontal cortex and subcortical nuclei causes the dorsolateral syndrome with impaired decision making, working memory and planning. 2. The ventromedial-orbitofrontal syndrome: if lesion spares the basal forebrain, memory can be preserved, but poor social decision making develops. 3. The dorsomedial syndrome consists of attention disorder, akinesia, mutism and apathy. 4. The bilateral ventrolateral prefrontal regions serve perception of self and environment. 5. The ventral lateral (verbalizer) area of the dominant hemisphere coordinates language. Executive impairments can be found in cerebrovascular, Parkinson's and other diseases of basal ganglia, and in frontotemporal lobar degeneration. The dorsolateral syndrome can be examined by the use of Wisconsin card sorting test, self ordered pointing task and the delayed response task. Prefrontal-basal function can be assessed by Gambling-, Faux Pas-, and Emotion identification tasks.

CONCLUSIONS

1. A dysexecutive syndrome does not fulfil the criteria of dementia. 2. A "frontal syndrome" is an indefinite eponym. Focal lesions in prefrontal systems lead to localization-specific symptoms, which can be defined by psychometric tests. 3. In neurological diseases associated with multifocal damage of the brain neuropsychologic tests may help to determine strategic lesions, which are responsible for the actual syndromes.

Do people with schizophrenia display theory of mind deficits in clinical interactions?

BACKGROUND

Having a 'theory of mind' (ToM) means that one appreciates one's own and others' mental states, and that this appreciation guides interactions with others. It has been proposed that ToM is impaired in schizophrenia and experimental studies show that patients with schizophrenia have problems with ToM, particularly during acute episodes. The model predicts that communicative problems will result from ToM deficits.

METHOD

We analysed 35 encounters (> 80 h of recordings) between mental health professionals and people with chronic schizophrenia (out-patient consultations and cognitive behaviour therapy sessions) using conversation analysis in order to identify how the participants used or failed to use ToM relevant skills in social interaction.

RESULTS

Schizophrenics with ongoing positive and negative symptoms appropriately reported first and second order mental states of others and designed their contributions to conversations on the basis of what they thought their communicative partners knew and intended. Patients recognized that others do not share their delusions and attempted to reconcile others' beliefs with their own but problems arose when they try to warrant their delusional claims. They did not make the justification for their claim understandable for their interlocutor. Nevertheless, they did not fail to recognize that the justification for their claim is unconvincing. However, the ensuing disagreement did not lead them to modify their beliefs.

CONCLUSIONS

Individuals with schizophrenia demonstrated intact ToM skills in conversational interactions. Psychotic beliefs persisted despite the realization they are not shared but not because patients cannot reflect on them and compare them with what others believe.

Schizophrenia and theory of mind

We suspect that people have an everyday theory of mind because they explain and frequently talk about the behaviour of others and themselves in terms of beliefs and desires. Having a theory of mind means that we believe that other people have minds like ours and that we understand the behaviour of these others in terms of the contents of their minds: their knowledge, beliefs and desires. But how can we demonstrate experimentally that people are using their theory of mind to predict the behaviour of others. This problem is particularly acute in the case of animals or young human children when they do not have language. Dennett (1978) discussing Premack & Woodruff's (1978) seminal paper ‘Does the chimpanzee have a theory of mind?’, suggested that the use of false beliefs to explain behaviour would provide convincing evidence. When their belief is true (i.e. corresponds to the actual state of the world) we can explain peoples' behaviour on the basis of the state of the world without needing to know about their beliefs. This ambiguity does not arise when the belief is false. The first experiment to use this approach was published by Wimmer & Perner (1983). They showed that at around 4 years of age a child knows that Maxi will look for his chocolates where Maxi believes them to be, even though the child knows that this belief is false because he has seen Maxi's mother moving the chocolates. In the English-speaking world the task involving Maxi and the chocolates has become the Sally-Anne task (see this issue, Lee et al. 2004).