Signs Of Consciousness Research Articles

Magnetic resonance spectroscopy data in the prognosis of consciousness recovery in patients with vegetative state

To study the prognostic value of magnetic resonance spectroscopy (MRS) in patients with vegetative state/unresponsive wakefulness syndrome (VS/UWS). Thirty-four patients with VS/UWS underwent multi-voxel MRS (thalamus, globus pallidus, putamen, internal capsules, fornix, brainstem, temporal and frontal cortex). Subjects were grouped according to etiology: 22 patients with traumatic brain injury (TBI) (group 1) and 12 patients with a hypoxia (group 2). The groups were matched by age and duration of UWS (mean 2, 3 months). The CRS-R was used to identify the first signs of consciousness during hospitalization and 6-12 months later. Outcomes of the patients with TBI were as follows: chronic VS/UWS (n=6), minimally conscious state (MCS) plus (n=9), emergence from MCS (EMCS) (n=7). Outcomes of the patients with hypoxia were: chronic vegetative state (n=10), minimally conscious state (MCS) (n=2). The decrease in the NAA/Cr ratio in thalamus, capsula interna, temporal cortex are correlated with poor outcome in both groups. Higher rates of NAA/Cr in these structures are correlated with further recovery of consciousness. The decrease in the ratio of NAA Cr and NAA/NAA+Cho+Cr in the midbrain is correlated with poor outcome only in UWS with hypoxia. The results suggest that the MRS allows to more accurately predicting the outcome in VS/UWS patients with hypoxic brain damage, as well as in UWS patients with TBI, who have recovered consciousness to the level of EMCS.

ONE-, TWO-DIMENSIONAL MODEL OF PERSONAL IDENTITY AND PERSONAL BEING, AS AN ACCUMULATOR OF “ZOMBIES” ONTOLOGY (REGRESSIVE TENDENCY OF COMBINING A LIVING BODY AND A CORPSE WITHIN A SEMANTIC FIELD OF THE “BODY” CONCEPT IN 19 EUROPEAN LANGUAGES AND IN ALL HIE

The aim of research is revealing the correlation of one-, two-dimensional models of personal identity and the ontology of a dead body without signs of consciousness (“zombies”). Research methods are hermeneutic and systemic structural. The author pays special attention to the phenomena of “philosophical, social, soulless zombies”. It is specified that such concepts as anima (Latin), fren (Greek), 灵魂 (Chinese), 精神 (Chinese), आत्मन (atman) (Sanskrit), बुद्धि (Buddhi) (Sanskrit), رُوحٌ (ruh) (Arabic), הנשמה (Hebrew); רוח (Hebrew), ψϋχ'ή (psyche) (Greek), spirit (English), esprit” (French), gemüt (German), geist (German), Körper (German),body (English),corpus (Latin), Le corps (French), chair (French) contribute most to the deformation of personal identity. Both the transcendental form of identity (spirit, soul) and material (human body) are subject to deformation. Using the example of the substitution of the “god of the morning” (Lucifer) for the “devil” (Satan) within the Latin language, the practice of influencing the collective consciousness of people of the transformational power of letters-symbols relating to the structure of the alphabetical plan of two-dimensional dimension (as understood by A. Sviridov). It is revealed that the concepts of transformation of personal identity within 19 European languages and all hieroglyphic languages are created today by critical masses of people whose consciousness is congruent with the phenomenon of "social zombie".

Évaluation et stimulations dans un service de rééducation post-réanimation

Brain injured patients who have suffered a coma require important medical supervision with a coordinated program of rehabilitation. These patients are most likely to benefit from Post Critical Care Rehabilitation Units. An important challenge is to recognize signs of awareness and establish a diagnosis of the disorder of consciousness: unresponsive wakefulness syndrome (UWS) versus minimally conscious state (MCS). The evaluation requires clinical observations by trained caregivers, the use of specific scales such as the Coma Recovery Scale Revised (CRS-R). This clinical assessment should be completed by a neurophysiological assessment and functional imagery in order to search for brain markers of awareness. Detecting awareness requires that patients are comfortable and because of the fluctuation of awareness and wakefulness, a sufficient time of observation is essential with repeated evaluations. A favorable atmosphere to promote the emergence of awareness comprises personalized stimulations such as sensory regulation programs. Music, non-invasive brain stimulations and several drugs can also boost awareness detection. The implication of family and close people should be integrated to maximize the chance to observe emotional responses. A program combining these practices is proposed in our post critical care rehabilitation unit to patients awakening from coma or for a specific assessment before the admission in dedicated units for patients in UWS/MCS. Given the large panel of tools available and the heterogeneity of practices, guidelines should be developed with a minimal standardized expertise proposed for all patients with disorder of consciousness.

P53. Optimizing ERP detection in disorders of consciousness by taking into account pre-stimulus brain states

Objective Two conditions can be summarized as disorders of consciousness (DOC) - the unresponsive wakefulness syndrome (UWS) and the minimal consciousness state (MCS). The first is defined by the total absence of awareness while in the latter, patients show some marginal signs of awareness but in a somewhat inconsistent way. At present, the extent to which a patients is capable of processing environmental information is still unclear. To address this questions, many researchers have used event related potentials (ERPs), as means to assess cognitive capabilities in the absence of overt behaviour. However, the extent to which studies find ERPs in DOC patients varies greatly. For example, the P300 has been demonstrated in 100% of DOC patients in a study by Schnakers et al. (2009; 22 DOC patients) but only in 18% in a study of Witzke et al. (1996; 12 of 66 DOC patients). This wide range might be a result of the fact, that there is no gold-standard in analyzing DOC patients ERPs. However, most DOC ERP studies are based on classical averaging methods which need several artifact-free epochs to average, but do not take into account the pre-stimuli brain state. This makes a great many repetitions of stimuli a necessity. However, reports from recovered DOC patients indicate, that patients rapidly drift in an out of awareness. So, it is possible, that in typical averaging methods, the few actual P300 responses get averaged away because of lots of ‘missed stimuli’ that the brain did not register. At the same time, results from basic research indicate that the likelihood of stimulus registration is related to pre-stimulus brain activity, in particular to alpha band power. We therefore use a method that help to predict that a stimuli might be missed, so this trials could be excluded from further analysis. Method In the undamaged brain, activity in the alpha band is related to inattentiveness or inhibition of external stimuli. Therefore, we reanalyzed ERP date of 17 DOC patients in such a way that we first determined pre-stimulus alpha power and then sorted trials accordingly, excluding those with dominant alpha activity from further analysis. We tested the patients’ data for a significant P300 reaction by means of standard averaging methods (every artifact free trial) in comparison with the analysis of only those trials with the least amount of alpha band power. Results With the standard averaging methods we found a significant P300 in only a few patients. However, using the alpha sorted trials, we were able to demonstrate significant P300 reactions in patients, where the standard method did not detect an ERP. Implication With standard averaging methods the amount of patients able to respond with cognitive ERPs might be underestimated. Further research assessing the cognitive abilities of DOC patients should aim to deliver stimuli either at the optimal moment, or try to separate post hoc optimal phases from those, where patients were unable to respond.

Electrodermal reactivity to emotional stimuli in healthy subjects and patients with disorders of consciousness.

After a coma, one major challenge is the detection of awareness in patients with disorders of consciousness. In some patients, the only manifestation indicative of awareness is an appropriate emotional response. Preferred music is a powerful medium to elicit emotions and autobiographical memory. Furthermore, music has been shown to improve cognitive functions both in healthy subjects and patients with neurological impairment. We hypothesized that signs of awareness could be enhanced in some patients with disorders of consciousness under appropriate emotional stimulation such as preferred music and also probably preferred odors. To investigate an objective, easily recordable marker of emotions at the patients' bedside, electrodermal activity (skin conductance level, SCL) was assessed with stimulations in auditory and olfactory modalities, notably with preferred music, neutral sound, preferred odors, and neutral odors. The study was conducted in 11 patients with disorders of consciousness (DOC) and 7 healthy participants. In healthy subjects, the mean amplitude of the SCL was increased during exposure to preferred music as compared to neutral sounds (respectively: 0.00037±0.0004 vs. - 0.00004±0.00019μS). No significant difference between conditions was detected in patients. The results of this study suggest that electrodermal activity could be a useful marker of emotions induced by music in healthy controls. However, it failed to show any significant difference between conditions in patients with DOC.

S29. rTMS application in disorders of consciousness

Introduction There is an unmet need in effective neurorehabilitation methods in chronic disorders of consciousness (DOC). Non-invasive brain stimulation, such as navigated rTMS, is a perspective tool for modulation of the cerebral networks activity in such patients, and resting FMRI, that allows estimating the neural networks activation and interactions, may indicate the target for precise stimulation. Patients with severe brain damage after anoxia or trauma who survived coma, show selective activation of the default mode network (DMN), particularly, gyrus angularis, as the level of consciousness increases. Here, we studied effects of high-frequency navigated rTMS on gyrus angularis as a new approach for the chronic DOC rehabilitation. Methods We included 10 patients with post-anoxic VS (median age 39.3, mean CRS-R score 5.1); 8 patients with post-anoxic MCS (median age 45.8, mean CRS-R score 14.4); 4 patients with traumatic VS (median age 22.3, mean CRS-R 5.8), and 5 traumatic MCS patients (median age 45.8, mean CRS-R 14.4). EEG revealed no seizure-like electric activity. Individual activation assessed by resting fMRI represented DMN activation including left gyrus angularis area in MCS patients, with no activation of DMN in VS patients. Against the background of standard rehabilitation program (motomed letto II-assisted mechanical therapy, massage, passive joints movements) we provided high-frequency rTMS on the gyrus angularis (10 sessions of stimulation with 20 Hz, 2400 stimulus 90% MT). Consciousness level was assessed with CRS-R scale by the same independent rater before and after stimulation course. Results CRS-R score increased in the patients with the residual signs of consciousness behavior (MCS). Median increase in CRS-R score after neurorehabilitation course was 2 points. However, we found no change in clinical assessment in the VS cases. No side effects of the rTMS were observed. Correlation of CRS-r score in permanent disorders of consciousness before and after rTMS course on gyrus angularis. Conclusion The course of the high-frequency TMS with navigation on gyrus angularis is a potentially effective method of rehabilitation in permanent disorders of consciousness. We obtained clinical effect in states of the minimal signs of consciousness, but not in VS. These results are advisable to continue researches in studies of this new protocol’s effectiveness. The study is supported by Russian Science Foundation grant No. 16-15-00274 .

T114. Predicting coma outcome using resting-state fMRI and machine learning

Introduction Early prediction of neurological outcome of post-anoxic comatose patients after cardiac arrest(CA) is challenging. Prognosis of comatose patient relies on multimodal testing: clinical examination, electrophysiological testing and structural neuroimaging (mainly diffusion MRI DWI). This multimodal prognostication is accurate for predicting poor outcome(i.e.death) but not sensitive for identifying patients with good outcome (i.e. consciousness recovery). Resting state functional MRI (rs-fMRI) is a powerful tool for mapping functional connectivity, especially in patients with low collaboration. Several studies showed that rs-fMRI can differentiate states of consciousness in chronically brain damaged patients. A recent study also showed that fMRI can detect early signs of consciousness in patient with acute traumatic brain injury. However, rs-fMRI has not been systematically assessed for the early prognositcation of post-anoxic comatose patient. Methods We assessed whole brain functional connectivity (FC) of 17 post-anoxic comatose patients early after CA using rs-fMRI. Nine patients recovered consciousness(good outcome) while eight died(poor outcome). We estimated FC for each patient following a standard procedure described by Leonardi and Richiardi et al. We statistically compared whole brain FC between good and poor outcome group, to assess which brain connections differed between them. Then, we trained a machine learning classifier(a Support Vector Machine classifier, SVM) using a Leave-One-Out Cross-Validation method, to automatically predict coma outcome (good/poor) based on whole-brain FC of comatose patients. Finally, we compared this outcome-prognostication based on fMRI to those using standard structural DWI. Results Good and poor coma outcome groups were similar in terms of demographics, except for time to ROSC. Good outcome group showed significant increase in whole-brain FC between most cortical brain regions, with the strongest changes occuring within and between occipital and parietal, temporal and frontal regions. Using whole-brain FC and a SVM classifier to predict coma outcome yielded to an overall prediction accuracy of 94.4% (AUC 0.94). Interestingly, automatic outcome prognostication using functional neuroimaging achieved better results that state-of the-art structural neuroimaging methods like DWI (accuracy 70.6%). Conclusion We used rs-fMRI to predict coma outcome in a cohort of post-anoxic comatose patients early after CA. We deliberately chose to include only patients with indeterminate prognosis after standard multimodal testing, in order to assess the contribution of rs-fMRI in the early prognostication of coma outcome. We found that automatic prediction based on fMRI yielded much better results than current diffusion neuroimaging methods, notably for identifying patients who recovered consciousness.

Resistance to eye opening in patients with disorders of consciousness.

Resistance to eye opening (REO) is a commonly encountered phenomenon in clinical practice. We aim to investigate whether REO is a sign of consciousness or a reflex in severely brain-injured patients. We recorded REO in chronic patients with disorders of consciousness during a multimodal diagnostic assessment. REO evaluations were performed daily in each patient and clinical diagnosis of unresponsive wakefulness syndrome (UWS), minimally conscious state with (MCS+) or without (MCS-) preserved language processing was made using the Coma Recovery Scale-Revised (CRS-R). Out of 150 consecutive patients, 79 patients fit inclusion criteria. REO was seen in 19 patients (24.1%). At the group level, there was a significant relationship between the presence of REO and the level of consciousness. We also observed a difference in the repeatability of REO between patients in UWS, MCS- and MCS+. Out of 23 patients in UWS, six showed REO, in whom five showed atypical brain patterns activation. Our findings suggest a voluntary basis for REO and stress the need for multiple serial assessments of REO in these patients, especially since most patients show fluctuating levels of consciousness.

Is oral feeding compatible with an unresponsive wakefulness syndrome?

The aim of the study is to explore the possibility of oral feeding in unresponsive wakefulness syndrome/vegetative state (UWS/VS) patients. We reviewed the clinical information of 68 UWS/VS patients (mean age 45±11; range 16-79years) searching for mention of oral feeding. UWS/VS diagnosis was made after repeated behavioural assessments using the Coma Recovery Scale-Revised. Patients also had complementary neuroimaging evaluations (positron emission tomography, functional magnetic resonance imaging and electroencephalography and diffusion tensor imaging). Out of the 68 UWS/VS patients, only two could resume oral feeding (3%). The first patient had oral feeding (only liquid and semi liquid) in addition to gastrostomy feeding and the second one could achieve full oral feeding (liquid and mixed solid food). Clinical assessments concluded that they fulfilled the criteria for a diagnosis of UWS/VS. Results from neuroimaging and neurophysiology were typical for the first patient with regard to the diagnosis of UWS/VS but atypical for the second patient. Oral feeding that implies a full and complex oral phase could probably be considered as a sign of consciousness. However, we actually do not know which components are necessary to consider the swallowing conscious as compared to reflex. We also discussed the importance of swallowing assessment and management in all patients with altered state of consciousness.

Preference Modeling to Support Stakeholder Outreach toward the Common Fishery Policy Objectives in the North Mediterranean Sea

Participatory management is a working method of paramount importance based on the principles of knowledge sharing and accountability for addressing the sustainable management of the fishery sector. To approach this multidimensional problem we applied two Multi Criteria Decision Analysis (MCDA) methods, the Analytic Hierarchy Process (AHP) and the Non-Structural Fuzzy Decision Support System (NSFDSS), which were applied incorporating uncertainty to generate probabilistic rankings. The NSFDSS technique was applied for the first time to address a fishery problem. Two surveys were carried out among Mediterranean Advisory Council (MEDAC) stakeholders with different backgrounds. By the two surveys we: i) made an AHP test for exploring stakeholders’ perception of the objectives and indicators used in the monitoring of the stocks, ecosystem, and fisheries, and ii) introduced the NSFDSS technique, gathering feedback on stakeholders’ preferences on management options for improving fishery sustainability (e.g., reducing discards, improving ecosystem state and economic yield in the long term). In the AHP the respondents were asked to evaluate the importance of one objective against another according to a scale of semantic scores from 1 to 5, whereas a simpler scoring scale, with only 3 possible options, was used in the NSFDSS. The two MCDA methods were proven to be useful to elicit stakeholders’ view on the potential effects of key issues on economic and environmental fishery sustainability. The results showed stakeholders’ awareness of the fact that the reproductive potential should be secured by checking mortality and/or fishing intensity. Consistently, among the ecological indicators that are tracking the fisheries policy objectives, a higher rank was attributed to “mean size of the spawners,” while cost efficiency was considered to be essential for improving profits. Regarding the economic indicators, stakeholders gave higher priority to “revenue” in comparison to “production (catches),” which is a sign of awareness that increasing fish production does not necessarily turn into increased revenue. Among the different management strategies, “fleet withdrawal” (scraping) was considered as the worst option, while the “combination of measures” was considered to be the best alternative for achieving a sustainable fishery in the long term.

P 135 Using a BCI approach to record ERPs for detecting signs of awareness in patients with severe disorders of consciousness

Objective In the clinical setting mainly behavioral methods are used for differentiating between patients with unresponsive wakefulness syndrome (UWS) and minimally consciousness syndrome (MCS). These may result in a high rate of false negative classifications, as some patients cannot produce clear behavioral responses, although they are conscious. To increase diagnostic objectivity additional methods to assess patients” states of consciousness are needed. FMRI methods have proven useful, but are costly and rarely available. Building up on previous ERP (event related potential ) studies in patients with severe disorders of consciousness ( Neumann and Kotchoubey, 2004 ) we tested an ERP measurement system based on brain-computer interface (BCI) technology (mindbeagle, g.tec, Schiedlberg) as patient bedside instrument to detect consciousness under exclusion of behavioral response requirements. Methods Recordings were performed in 13 patients with severe disorders of consciousness(5MCS, 8UWS), as diagnosed by the Coma Recovery Scale revised (CRSr). The BCI testing consisted of two subtests, an auditory and vibro-tactile paradigm. For both subtests patients were instructed to react to a rare target stimulus and to neglect an often occurring non-target stimulus. Accordingly the subtests combine the passive (Oddball structure) and the active (instruction to react to target stimulus) paradigm. In the auditory subtest two distinct pure tones (500 Hz and 1000 Hz) were presented on both ears. In the vibro-tactile subtest vibration via vibro-tactile trajectories was either transported to the patients left (target) or right (non-target) wrist. The accuracy level at which a non-target and target could be differentiated by the system classifier, trained on the patient’s P300 response, was used as an outcome measure. Results With exception of two patients (one in UWS and one in MCS ) all participants showed an accuracy level above chance (12.5%) in at least one of the subtests. In the auditory subtest this was true for two patients with MCS (20%, 30%) and three with UWS (100%, 30%, 80%). In the vibro-tactile subtest for three patients with MCS (40%, 20%, 20%) and four patients with UWS (50%, 20%, 60%, 60%) the target vs. non-target discrimination could be made. Conclusion Although there are still improvements necessary to use the applied system as a diagnostic instrument in the clinical setting (e.g. adaptations to the clinical population, precise manual for standardized testing), we were able to detected signs of awareness in patients that were not accessible by behavioral measurements. Additional research is needed to determine validity and significance of that finding.

Court ruling on ending life support is right

Wilson talks about legal issues for life support. A judgment from the Court of Protection of England and Wales may make it easier for the families of people in such conditions to stop artificial feeding and let their loved one die without having to go through a lengthy and distressing legal process. It might seem like this could allow significant decisions to be made too easily, or even that the court is legalizing a form of euthanasia. In fact, this change is long overdue, and is in line with other Western countries, such as the US and Australia. The ruling concerns people who are left in a permanent vegetative or minimally conscious state, usually after they have received a brain injury and emerged from a coma into a state where they can breathe unaided but have almost no sign of awareness.

Prevalence of coma-recovery scale-revised signs of consciousness in patients in minimally conscious state

ABSTRACTDifferent behavioural signs of consciousness can distinguish patients with an unresponsive wakefulness syndrome from patients in minimally conscious state (MCS). The Coma Recovery Scale-Revised (CRS-R) is the most sensitive scale to differentiate the different altered states of consciousness and eleven items detect the MCS. The aim of this study is to document the prevalence of these items. We analysed behavioural assessments of 282 patients diagnosed in MCS based on the CRS-R. Results showed that some items are particularly frequent among patients in MCS, namely fixation, visual pursuit, and reproducible movement to command, which were observed in more than 50% of patients. These responses were also the most probably observed items when the patients only showed one sign of consciousness. On the other hand, some items were rarely or never observed alone, e.g., object localisation (reaching), object manipulation, intelligible verbalisation, and object recognition. The results also showed that limiting the CRS-R assessment to the five most frequently observed items (i.e., fixation, visual pursuit, reproducible movement to command, automatic motor response and localisation to noxious stimulation) detected 99% of the patients in MCS. If clinicians have only limited time to assess patients with disorders of consciousness, we suggest to evaluate at least these five items of the CRS-R.

Awakening from coma: Assessment and stimulation in a Post-Critical Care Rehabilitation Units (PCCRU)

Brain injured patients who have suffered a coma require important medical supervision with a coordinated program of rehabilitation and are most likely to benefit from Post-Critical Care Rehabilitation Units (PCCRU). For these patients, an important challenge is to recognize signs of awareness beyond wakefulness. This evaluation is necessary to establish a diagnosis of the disorder of consciousness: vegetative state (VS) or unresponsive wakefulness syndrome versus minimally conscious state (MCS). Daily clinical observations of patients by trained caregivers confer to these particular environments an expertise in this field. The use of specific scales such as the Coma Recovery Scale Revised (CRS-R) allows the standardization of practices and provides quantitative data that are useful to follow patients, to assess the beneficial effect of a treatment or to compare patients. Neurophysiology and functional imagery can be used to search for markers of high-level brain activity. These tools are mostly used in research areas but can provide information complementary to the clinical evaluation, which involves a degree of subjectivity. Detecting awareness requires that patients are comfortable and because of the fluctuation of awareness, a sufficient time of observation is essential. A favorable atmosphere to promote the emergence of awareness comprises personalized stimulations such as sensory regulation programs. Music, noninvasive brain stimulations and several drugs can also boost awareness detection. A program integrating these practices is proposed to patients awakening from coma or for a specific assessment before the admission in dedicated units for patients in VS/MCS.

En oversikt over vurderings­metoder for bevissthets­tilstander etter ervervet hjerneskade

It can be problematic to distinguish between the altered states of consciousness that may occur following acquired brain injury. To inform non-specialist clinicians and next-of-kin, this article introduces the relevant methods for assessing consciousness. The current clinical standard is to monitor for behavioral signs of consciousness using the checklist scale CRS-R. In addition, neurophysiological methods have shown promise, but most of this work has not yet been validated for clinical use. The current operational definition of awareness may be biased toward classifying behaviour rather than the phenomenological experience. Studies have suggested that behavioural assessment underestimates the level of consciousness, and patients failing to show behavioural signs of awareness could benefit from a more thorough multicentre and multi-method examination.

Evaluación de la eficacia del método de insensibilización por electronarcosis en porcinos

SUMMARY National and international sanitary legislation state the guidelines that regulate the slaughter of animals for human consumption purposes due to its implications in animal welfare and meat quality. The aim of this study was to evaluate the slaughter in the swine population of a commercial slaughter plant using behavioural and management indicators. A total of 1,341 pigs were monitored. The electrical stunning method was assessed using behavioural indicators in the stunning box (jumps, falls, vocalizations, slips); the signs of consciousness (blink reflex, righting reflex, vocalizations, pain response) and organizational variables (stunning to bleed interval, collapse of the animal, position of the electrodes, application time of the tongs and effectiveness of the stunning procedure). Vocalizations (26.8%) were the behavioural response most commonly found and they were associated to the presence of falls and slips (P < 0.01), making evident certain problems related to the handling of the animals and the infrastructure design. Effective stunning was accomplished in 20.6% of the cases. The righting reflex was positively associated to the presence of all the other signs of consciousness (P < 0.01). The duration of the application of the tongs, the stunning to bleed interval and the electrical specifications were not adequate, evidencing several failures in the standardization of the process. It is strongly recommended to incorporate the behavioral and management indicators to audit routinely the efficiency and animal welfare standards during pig slaughter, as well as promoting training of the staff to guarantee a humane procedure.

Assessing learning as a possible sign of consciousness in post-coma persons with minimal responsiveness

A learning test procedure based on operant principles may be useful in the diagnosis (and eventually rehabilitation) of post-coma persons with minimal responsiveness. This study was aimed at extending the evaluation of such a procedure with seven participants who presented with very limited behavior and apparently severe disorders of consciousness. The procedure was evaluated through an ABACB design, in which A represented baseline phases without stimulation, B intervention phases with brief stimulation periods contingent on specific responses of the participants, and C a control phase in which stimulation was available all the time. Increased responding during the B phases, as opposed to the A and C phases, was taken to indicate learning and possibly a non-reflective expression of phenomenal consciousness. All participants were also evaluated with the coma recovery scale-revised (CRS-R) prior to the start of the learning test procedure and at the end of it. The results of the learning test showed that all participants had significantly higher responding levels during the B phases. The CRS-R scores suggested minimally conscious state for four of them prior to the learning test and for five of them after the completion of the learning test. The implications of the findings are discussed in terms of potential and time cost of the learning test.

The auditory P300-based single-switch brain–computer interface: Paradigm transition from healthy subjects to minimally conscious patients

Within this work an auditory P300 brain-computer interface based on tone stream segregation, which allows for binary decisions, was developed and evaluated. Two tone streams consisting of short beep tones with infrequently appearing deviant tones at random positions were used as stimuli. This paradigm was evaluated in 10 healthy subjects and applied to 12 patients in a minimally conscious state (MCS) at clinics in Graz, Würzburg, Rome, and Liège. A stepwise linear discriminant analysis classifier with 10×10 cross-validation was used to detect the presence of any P300 and to investigate attentional modulation of the P300 amplitude. The results for healthy subjects were promising and most classification results were better than random. In 8 of the 10 subjects, focused attention on at least one of the tone streams could be detected on a single-trial basis. By averaging 10 data segments, classification accuracies up to 90.6% could be reached. However, for MCS patients only a small number of classification results were above chance level and none of the results were sufficient for communication purposes. Nevertheless, signs of consciousness were detected in 9 of the 12 patients, not on a single-trial basis, but after averaging of all corresponding data segments and computing significant differences. These significant results, however, strongly varied across sessions and conditions. This work shows the transition of a paradigm from healthy subjects to MCS patients. Promising results with healthy subjects are, however, no guarantee of good results with patients. Therefore, more investigations are required before any definite conclusions about the usability of this paradigm for MCS patients can be drawn. Nevertheless, this paradigm might offer an opportunity to support bedside clinical assessment of MCS patients and eventually, to provide them with a means of communication.

‘It's in the eyes’: how family members and care staff understand awareness in people with severe dementia

Objectives: In this study, we explored how family members and care staff understand awareness in people with severe dementia and what this awareness means to them.Method: We conducted four focus groups between 2007 and 2009 in the UK with 11 family members and 12 care staff. Transcripts of the focus groups were analysed using thematic analysis.Results: A model of awareness emerged in which the perceived level of awareness in the person with dementia was influenced by an interaction between attributes of the person with dementia and the environment, with expressions of awareness being hindered by environmental factors and facilitated through appropriate stimulation. Awareness did fluctuate, and differences in interpretations of awareness were linked to the meaning assigned to particular kinds of responses. For family members, awareness was intrinsically linked to their emotional connection with the person with dementia. For care staff, identifying signs of awareness helped them to do their job and enabled them to feel that they had connected with the person with dementia.Conclusion: The findings of this study suggest that care staff would benefit from training both on identifying awareness and on providing suitable activities for people with severe dementia. Care staff and family members would also benefit from greater sharing of information about the person with dementia. This could help to enhance quality of life for person with dementia and improve quality of care.

N400 predicts recovery from disorders of consciousness

Patients with the unresponsive wakefulness syndrome (UWS; formerly vegetative state) or in a minimally conscious state (MCS) open their eyes spontaneously but show no (UWS) or only marginal (MCS) signs of awareness. Because these states can become permanent, residual information processing capacities need to be determined, and reliable outcome predictors need to be found. We assessed higher-order cortical information processing in UWS or MCS in a large group of patients using electroencephalographic event-related potentials (ERPs) and determined their long-term prognostic value for recovery. Cognitive ERPs elicited by sound (P300) and speech (N400) were used to assess information processing in 92 behaviorally unresponsive patients diagnosed as in the state of either UWS (n=53) or MCS (n=39). ERPs were assessed with a clinical standard evaluation method and a computerized method, the t-continuous wavelet transform. The patients' clinical outcome was followed up between 2 and 14 years after discharge from the rehabilitation center. Within the first year of the disease, many patients showed an intact P300 and several also an N400, indicating considerable residual information processing. At clinical follow-up, about 25% of the patients recovered and regained communicative capabilities. A highly significant relationship between N400, but not P300, presence and subsequent recovery was found. Results specify cognitive capabilities in disorders of consciousness, and determine their prognostic value. Specifically the N400 ERP is suggested as an important tool to assess information-processing capacities that can predict the likelihood of recovery of patients in UWS or MCS.