The effect of neural pre-stimulus oscillations on post-stimulus somatosensory event-related potentials in disorders of consciousness.

Brain activity of people in a disorder of consciousness (DoC) is diffuse and different from healthy people. In order to get a better understanding of their cognitive processes and functions, electroencephalographic activity has often been examined in patients with DoC, including detection of event-related potentials (ERPs) and spectral power analysis. However, the relationship between pre-stimulus oscillations and post-stimulus ERPs has rarely been explored in DoC, although it is known from healthy participants that pre-stimulus oscillations predispose subsequent stimulus detection. Here, we examine to what extent pre-stimulus electroencephalography band power in DoC relates to post-stimulus ERPs in a similar way as previously documented in healthy people. 14 DoC patients in an unresponsive wakefulness syndrome (UWS, N = 2) or a minimally conscious state (MCS, N = 12) participated in this study. In an active oddball paradigm patients received vibrotactile stimuli. Significant post-stimulus differences between brain responses to deviant and standard stimulation could be found in six MCS patients (42.86%). Regarding relative pre-stimulus frequency bands, delta oscillations predominated in most patients, followed by theta and alpha, although two patients showed a relatively normal power spectrum. The statistical analysis of the relationship between pre-stimulus power and post-stimulus event-related brain response showed multiple significant correlations in five out of the six patients. Individual results sometimes showed similar correlation patterns as in healthy subjects primarily between the relative pre-stimulus alpha power and post-stimulus variables in later time-intervals. However, opposite effects were also found, indicating high inter-individual variability in DoC patients´ functional brain activity. Future studies should determine on an individual level to what extent the relationship between pre- and post-stimulus brain activity could relate to the course of the disorder.

[ and Riding as Well? Case Report about the Treatment of an Infant with Unresponsive Wakefulness Syndrome]. / und jetzt auch noch reiten? Fallbericht zur Behandlung eines Kleinkindes im Syndrom reaktionsloser Wachheit.

BACKGROUND: There is a growing number of children surviving birth complications with severe, multiple disabilities. Unfortunately, this is not paralleled by equal growth in knowledge about adequate therapeutic approaches. Some publications showed that Hippotherapy could, under certain circumstances, be a very useful complimentary therapy for a range of disabilities. But it remains unclear if riding could even help a quadriplegic individual with multiple brain damage and tracheal ventilation. METHOD: In this case study we examined the effect of horse riding on the mobility of joints and heart rate in a little girl with multiple disabilities. RESULTS: We found a statistically significant increase in joint mobility and a significant decrease in the heart-rate (down to a normal resting frequency). We also had a rather unexpected effect of the hippotherapy. Namely, while on horseback, the girl demonstrated a sufficient spontaneous breathing. No additional oxygen was needed. CONCLUSION: Horse-back riding helped our patient to reduce her symptoms. Therefore, it showed clear positive effects even for a girl with severe and multiple disabilities.

How to Deal With Death: An Empirical Path Analysis of a Simplified Model of Death Anxiety.

How anxious are you about dying? According to Tomer and Eliason, this depends on various personal circumstances, which they identified in their model on death anxiety. This study aims to verify various aspects of Tomer and Eliason's theoretical model. We therefore collected data from 652 German participants about demographic variables, religiosity, life satisfaction, death acceptance, and death anxiety. We then conducted a path analysis in order to verify whether the empirical data supported the theoretical model. Our results demonstrate a very good model fit, indicating that the analyzed model is valid and can be maintained. Further mediation analysis demonstrates the specific relations of variables within the model and their influence on death anxiety.

A tree of life? Multivariate logistic outcome-prediction in disorders of consciousness.

Background: Clinical outcome of patients with disorders of consciousness (DOC) is seen as generally very poor. Here, we specify individual outcome chances for patients with DOC on the basis of clinical and event-related-potentials (ERPs) data and identify subgroups, who vary substantially regarding their outcome chances.Methods: We employed data from 102 patients and used standard clinical protocol data (age, etiology, diagnosis, gender), sensory (N100, Mismatch-Negativity) and cognitive (P300, N400) ERPs to predict patients' recovery rates.Results: Two significant prediction models emerged: In both, subgroups of patients with good (51%, tree 1) to very good recovery chances (97%, tree 2) could be identified. The first model was obtained from standard clinical data. The second model included cognitive ERPs and resulted in considerably better patient classification. Moreover, when taking cognitive ERPs into account, the standard protocol data did not add further significant information, neither did sensory ERPs.Conclusion: The presented information about outcome chances of individual patients with DOC will be vital for these patients and critical for clinical professionals who have to direct specialized treatments and council relatives. Legal guardians and families, in turn, need to know what to expect in the future in order to prepare for the challenges ahead.

A problem shared is a problem halved? Comparing burdens arising for family caregivers of patients with disorders of consciousness in institutionalized versus at home care.

BACKGROUND: Disorders-of-consciousness (DOC) are rare conditions leading to very severe physical and mental disabilities. Providing care for DOC patients has been described as a stressful experience, eroding the physical and psychological health of the caregiver. Different forms of care may have different impacts on the caregivers and institutionalized care has been suggested to have an unburdening effect, but this possibility has never been empirically studied. To address this issue, in this study caregiver-burden between family-caregivers who provide home care themselves and those who have placed their patients in a specialized care unit is compared. METHOD: The demographics of the caregivers, life satisfaction, coping strategies, meaning in life, and grief reactions were assessed with questionnaires in 81 long term (m = 7.9 years) caregivers (44 patients in specialized care-units, 37 patients taken care of at home). RESULTS: Caregiver groups were similar on the vast majority of demographic factors. Remarkably, there were no major differences in self-assessed burden and distress between the two caregiver groups. They both demonstrated generally reduced life satisfaction, were especially dissatisfied with their amount of spare time, and many caregivers in both groups demonstrated long lasting grief reactions, as well as a somewhat enhanced crisis of meaning. However, caregivers with patients in institutionalized care exhibited enhanced self-accusation as well as reduced satisfaction with their own health. Home care caregivers, on the other hand, report below average opportunities to care for themselves. CONCLUSION: Surprisingly, placement in institutionalized care in itself does not seem to disburden caregivers as much as expected as the amount of subjective care-giving burden and reported distress is on average similarly high, although profiles differ somewhat according to type of care. Moreover, vast inter-individual variability can be observed. Further research should address the mechanisms that foster positive adjustment and reduce negative impacts for care providers regardless of type of care, enabling the health care system, institutions and self-aid groups alike, to provide more specific support for caregivers by addressing the topics of quality-of-life, own health, self care, and grief reactions.

Frequency Band Variations Predict EEG Single-Trial Classification Performance in Disorder of Consciousness Patients.

Single-trial classification of EEG data from Disorder of Consciousness patients (DoC) has proved particularly challenging. We present an approach that establishes a measure to relate the performance of single-trial classification of DoC patient EEG data with relational frequency bands and thus with their mental state. We evaluate our approach on 31 patient data sets from two studies, showing that our measure indicates for different data sets a particular likelihood for misclassifying either target or non-target class samples.

The living dead? Perception of persons in the unresponsive wakefulness syndrome in Germany compared to the USA.

BACKGROUND: The extent to which people ascribe mind to others has been shown to predict the extent to which human rights are conferred. Therefore, in the context of disorders of consciousness (DOC), mind ascription can influence end of life decisions. A previous US-American study indicated that participants ascribed even less mind to patients with unresponsive-wakefulness-syndrome (UWS) than to the dead. Results were explained in terms of implicit dualism and religious beliefs, as highly religious people ascribed least mind to UWS. Here, we addresses mind ascription to UWS patients in Germany. METHODS: We investigate the perception of UWS patients in a large German sample (N = 910) and compare the results to the previous US data, addressing possible cultural differences. We further assess effects of medical expertise, age, gender, socio-economic status and subjective knowledge about UWS in the German sample. RESULTS: Unlike the US sample, German participants did not perceive UWS patients as "more dead than dead", ascribing either equal (on 3 of 5 items) or more (on 2 items) mental abilities to UWS patients than to the dead. Likewise, an effect of implicit dualism was not replicated and German medically trained participants ascribed more capabilities to UWS patients than did a non-medical sample. Within the German sample, age, gender, religiosity and socio-economic status explained about 15% of the variability of mind ascription. Age and religiosity were individually significant predictors, younger and more religious people ascribing more mind. Gender had no effect. CONCLUSION: Results are consistent with cross-cultural differences in the perception of UWS between Germany and the USA, Germans ascribing more mind to UWS patients. The German sample ascribed as much or more but not less mind to a UWS patient than to a deceased, although within group variance was large, calling for further research. Mind ascription is vital, because, in times of declining resources for healthcare systems, and an increasing legalization of euthanasia, public opinion will influence UWS patients' rights and whether 'the right to die' will be the only right conceded to them.

Against the odds: a case study of recovery from coma after devastating prognosis.

To demonstrate the possibility for hidden rehabilitation potential even following most severe brain injury and the uncertainty of current prognosis factors for coma and unresponsive wakefulness syndrome, we detail the rehabilitation of J. W., after coma from traumatic brain injury. Originally, with many negative prognosis factors and several medical complications, prognosis was devastating. But, with continuing treatment, J. W. improved to a high level of independence in everyday life. This shows the need for rehabilitation research to further specify the "prognostic power" of various combinations of prognosis factors, so that practitioners can come to accurate single-case recommendations when both positive and negative predictors are present.

Higher, faster, worse? An event-related potentials study of affective picture processing in migraine.

BACKGROUND: Migraine is a disorder of periodic disabling headache. Facilitated cortical responsivity has been suggested as one predisposing factor. Although the underlying mechanisms of migraine attack onsets are not fully understood, facilitated cortical responsivity has been suggested as one predisposing factor. Here, we investigate if enhanced cortical responsivity is reflected in altered event-related potentials during processing of complex pictures. METHOD: Altogether, 16 migraine patients and 16 healthy volunteers participated in this study. Each patient had a diagnosed migraine and was headache- and medication-free for the study. Participants watched positive, negative and neutral pictures from the international affective picture system. An electroencephalogram was recorded during picture presentation. Afterwards, participants were asked to rate the pictures for valence and arousal. RESULTS: Migraine patients showed significantly more negative-going early event-related potential components from 100 ms to 180 ms to all picture categories over occipital regions as well as more positive-going late potentials over central regions. Patients and controls did not differ in valence and arousal ratings for the international-affective picture system. DISCUSSION: Patients with migraine seem to react cortically more intensely to all kinds of pictorial stimuli, regardless of emotional content. This facilitated processing may be related to the high cortical responsivity shown in various other event-related potential studies and might contribute to the recurring intense headache attacks.

Perceived communicative context and emotional content amplify visual word processing in the fusiform gyrus.

The personal significance of a language statement depends on its communicative context. However, this is rarely taken into account in neuroscience studies. Here, we investigate how the implied source of single word statements alters their cortical processing. Participants' brain event-related potentials were recorded in response to identical word streams consisting of positive, negative, and neutral trait adjectives stated to either represent personal trait feedback from a human or to be randomly generated by a computer. Results showed a strong impact of perceived sender. Regardless of content, the notion of receiving feedback from a human enhanced all components, starting with the P2 and encompassing early posterior negativity (EPN), P3, and the late positive potential (LPP). Moreover, negative feedback by the "human sender" elicited a larger EPN, whereas positive feedback generally induced a larger LPP. Source estimations revealed differences between "senders" in visual areas, particularly the bilateral fusiform gyri. Likewise, emotional content enhanced activity in these areas. These results specify how even implied sender identity changes the processing of single words in seemingly realistic communicative settings, amplifying their processing in the visual brain. This suggests that the concept of motivated attention extends from stimulus significance to simultaneous appraisal of contextual relevance. Finally, consistent with distinct stages of emotional processing, at least in contexts perceived as social, humans are initially alerted to negative content, but later process what is perceived as positive feedback more intensely.

It's all in your head - how anticipating evaluation affects the processing of emotional trait adjectives.

Language has an intrinsically evaluative and communicative function. Words can serve to describe emotional traits and states in others and communicate evaluations. Using electroencephalography (EEG), we investigate how the cerebral processing of emotional trait adjectives is modulated by their perceived communicative sender in anticipation of an evaluation. 16 students were videotaped while they described themselves. They were told that a stranger would evaluate their personality based on this recording by endorsing trait adjectives. In a control condition a computer program supposedly randomly selected the adjectives. Actually, both conditions were random. A larger parietal N1 was found for adjectives in the supposedly human-generated condition. This indicates that more visual attention is allocated to the presented adjectives when putatively interacting with a human. Between 400 and 700 ms a fronto-central main effect of emotion was found. Positive, and in tendency also negative adjectives, led to a larger late positive potential (LPP) compared to neutral adjectives. A centro-parietal interaction in the LPP-window was due to larger LPP amplitudes for negative compared to neutral adjectives within the 'human sender' condition. Larger LPP amplitudes are related to stimulus elaboration and memory consolidation. Participants responded more to emotional content particularly when presented in a meaningful 'human' context. This was first observed in the early posterior negativity window (210-260 ms). But the significant interaction between sender and emotion reached only trend-level on post hoc tests. Our results specify differential effects of even implied communicative partners on emotional language processing. They show that anticipating evaluation by a communicative partner alone is sufficient to increase the relevance of particularly emotional adjectives, given a seemingly realistic interactive setting.

Will time heal? A long-term follow-up of severe disorders of consciousness.

OBJECTIVE: Little is known about the long-term outcome of patients with disorders of consciousness (DOCs) such as unresponsive wakefulness syndrome (UWS) or minimally conscious state (MCS). We describe the disease course of a large group of DOC patients 2-14 years after brain damage. METHODS: In 102 patients (59 UWS, 43 MCS), clinical and demographic variables from disorder onset were related to the patients' outcomes 2-14 years after discharge. Etiology, age at event, time since onset, gender, and home care versus institutional care were assessed as predictors and similarities and differences between UWS and MCS determined. RESULTS: Seventy-one percent of the patients had passed away or showed no improvement in condition. Twenty-nine percent regained consciousness and developed some communicative capacities. The time a syndrome persisted did not predict clinical outcome in either condition. Six patients regained consciousness after more than 3 years. Of these, five had been UWS (42% of recovered UWS, three traumatic origins, one tumor, one hypoxia) and one MCS (5% of recovered MCS, traumatic origin). In UWS, younger patients, those cared for at home, and in tendency those with traumatic origins, were more likely to recover. In MCS, no reliable outcome predictors were found. INTERPRETATION: Current predictors are too vague for single patient predictions. This study identifies a subgroup of late-recovering patients, casting doubt on the 12-month boundary, after which UWS is stated to be permanent. Routine reexamination, use of more reliable outcome predictors and research determining optimal care settings are needed to inform the crucial decisions made for these patients.

Neural correlates of training-induced improvements of calculation skills in patients with brain lesions.

PURPOSE: The loss of calculation skills due to brain lesions leads to a major reduction in the quality of life and is often associated with difficulties of returning to work and a normal life. Very little is known about the neural mechanisms underlying performance improvement due to calculation training during rehabilitation. The current study investigates the neural basis of training-induced changes in patients with acalculia following ischemic stroke or traumatic brain lesions. METHODS: Functional hemodynamic responses (fMRI) were recorded in seven patients during calculation and perceptual tasks both before and after acalculia training. RESULTS: Despite the heterogeneity of brain lesions associated with acalculia in our patient sample, a common pattern of training-induced changes emerged. Performance improvements were associated with widespread deactivations in the prefrontal cortex. These deactivations were calculation-specific and only observed in patients exhibiting a considerable improvement after training. CONCLUSION: These findings suggest that the training-induced changes in our patients rely on an increase of frontal processing efficiency.

N400 predicts recovery from disorders of consciousness.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. INTERPRETATION: 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.