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Background For a better understanding of the factors underlying the Post-Acute COVID Syndrome, we studied the relationship between symptoms and functional alterations in COVID-19 patients 10 months after hospitalization. Methods One-hundred-one patients hospitalized between March 1st and June 30th 2020 participated in a follow-up visit for an assessment of clinical history, comorbidities, lung function, physical capacity and symptoms, including the SGRQ for health-related quality of life, PHQ-9-D for depression, and SOMS-2 J for somatoform disorders. Data were analyzed by univariate comparisons and multiple logistic regression analyses. Results Median age was 60 years, 42% were female, 76% had at least one comorbidity, the median length of the hospital stay was 8 days, 19% had been on the ICU. The most prevalent symptoms included shortness of breath (49%), fatigue (49%) and cognitive impairment (39%). Signs of major depression (PHQ-9-D ≥ 10) occurred in 28%/2% (p

Non-union after fracture depicts a devastating complication in trauma surgery and studies assessing patient-reported outcome measures after stable bone consolidation are rare. Therefore, we aimed to evaluate the long-term impact of aseptic long bone non-union on the patients' physical health state and psychological wellbeing. For this purpose, quality of life after successful surgical treatment of long bone non-union was assessed.Sixty-one patients with aseptic long bone non-union surgically treated in our department between November 2009 and March 2019 with achieved bone consolidation were included. Quality of life was evaluated with the EQ-5D and SF-36 outcome instruments as well as with an ICD-10 based symptom rating (ISR) and compared to normative data.With a minimum follow-up time of one year after the last surgery (mean 4.7 ± 2.7 years) the mean physical health component score of the SF-36 was 38.9 ± 13.7 and the mean mental health component score of the SF-36 was 49.0 ± 5.9, indicating lower quality of life compared to German normative values of 48.4 ± 9.4 (p .001) and 50.9 ± 8.8 (p = 1.61), respectively. The mean EQ-5D index value reached 0.827 ± 0.18 with an EQ-5D VAS rating of 64.4 ± 21.5 compared to scores of 0.922 (p .001) and 72.9 ± 1.1 (p .001) obtained from an age-matched reference population. Mean scores of the ISR did not reveal significant psychological symptom burden in any scale, while an individual analysis showed moderate to severe impairments in 11.5% of the patients in total.Even 4.7 years on average after surgically successful treatment of aseptic long bone non-union, patients still report significant lower quality of life in comparison to normative data. Future clinical studies on non-unions should focus on patient-related outcome measures. Newly emerging treatment strategies and interdisciplinary approaches should be implemented to improve the overall quality of life of non-union patients.

Neuronal interactions coupled by phase synchronization have been studied in a wide range of frequency bands, but fluctuations below the delta frequency have often been neglected. In the present study, phase synchrony in slow cortical potentials (SCPs, 0.01–0.1 Hz) was examined during two different mental states; a resting state and a breath-focused mindfulness meditation. SCP phase synchrony in 9 long-term expert meditators (on average 22 years of experience) were compared with the data obtained from 11 novices. Additionally, after the novices attended an 8-week mindfulness-based stress reduction (MBSR) program, SCP phase synchrony was measured again. While expert meditators and novices exhibited the same amount of SCP phase synchrony in the resting state, decreased synchronization was found during meditation among expert meditators as well as novices who had participated in the MBSR program (but not prior to the program). These findings suggest that phase synchrony in slow cortical activity is context-dependent and could provide crucial information in the study of the human mind.

The readiness potential is an ongoing negativity in the EEG preceding a self-initiated movement by approximately 1.5 s. So far it has predominantly been interpreted as a preparatory signal with a causal link to the upcoming movement. Here a different hypothesis is suggested which we call the selective slow cortical potential sampling hypothesis. In this review of recent research results we argue that the initiation of a voluntary action is more likely during negative fluctuations of the slow cortical potential and that the sampling and averaging of many trials leads to the observed negativity. That is, empirical evidence indicates that the early readiness potential is not a neural correlate of preconscious motor preparation and thus a determinant of action. Our hypothesis thereafter challenges the classic interpretation of the Libet experiment which is often taken as proof that there is no free will. We furthermore suggest that slow cortical potentials are related to an urge to act but are not a neural indicator of the decision process of action initiation.

Meditation practice involves attention regulation, and thus is thought to facilitate attention control mechanisms. Studies on meditation techniques using a behavioral measurement of the Attention Network Test (ANT) have shown enhanced attention control, but neural features remain unknown. In the present study, event-related potentials (ERPs) and behavioral data from twenty long-term meditators were examined, compared to data obtained from twenty matched controls. Results showed that meditators made fewer error responses than controls, especially during the incongruent target condition, suggesting higher accuracy in executive attention control among meditators. The P3 amplitude in the parietal area remained constant in the congruent and incongruent target conditions among meditators, indicating a higher parietal P3 amplitude during the incongruent target condition relative to matched controls. The findings that meditators exhibited fewer error responses on the ANT and a lack of parietal P3 modulation irrespective of reaction time are discussed in the context of attentional resource allocation.

The belief in free will has been frequently challenged since Benjamin Libet published his famous experiment in 1983. Although Libet’s experiment is highly dependent upon subjective reports, no study has been conducted that focused on a first-person or introspective perspective of the task. We took a neurophenomenological approach in an N = 1 study providing reliable and valid measures of the first-person perspective in conjunction with brain dynamics. We found that a larger readiness potential (RP) is attributable to more frequent occurrences of self-initiated movements during negative deflections of the slow cortical potentials (SCP). These negative deflections occur in parallel with an inner impulse reported by an expert meditator which may in turn lead to a voluntary act. We demonstrate in this proof-of-principle approach that the first-person perspective obtained by an expert meditator in conjunction with neural signal analysis can contribute to our understanding of the neural underpinnings of voluntary acts.

Brain–computer interfaces (BCIs) can be used for communication in writing without muscular activity or for learning to control seizures by voluntary regulation of brain signals such as the electroencephalogram (EEG). Three of five patients with epilepsy were able to spell their names with electrocorticogram (ECoG) signals derived from motor-related areas within only one or two training sessions. Imagery of finger or tongue movements was classified with support-vector classification of autoregressive coefficients derived from the ECoG signals. After training of the classifier, binary classification responses were used to select letters from a computer-generated menu. Offline analysis showed increased theta activity in the unsuccessful patients, whereas the successful patients exhibited dominant sensorimotor rhythms that they could control. The high spatial resolution and increased signal-to-noise ratio in ECoG signals, combined with short training periods, may offer an alternative for communication in complete paralysis, locked-in syndrome, and motor restoration.

Objective : Direct brain-computer communication utilizes self-regulation of brain potentials to select letters, words or symbols from a computer menu. Selection of letters or words with brain potentials requires simultaneous processing of several tasks such as production of certain brain potentials at predefined time points simultaneously with processing of presented letter strings. This study addresses the question of whether the self-regulation of slow cortical potentials (SCP) automatizes with practice and can thus be considered as a skill comparable to motor or cognitive skills. Methods : Two nearly completely paralysed patients learned over several months to produce electrocortically negative and positive SCP by means of visual feedback. Improved performance and a reduction in performance variability were regarded as behavioural indicators for automaticity, while the topographic focalization of cortical activation was considered as a neurophysiological indicator for automaticity. Different indicators of automaticity were expected to covary along with practice. Results : In patient 1, performance measured as the percentage of correct SCP shifts increased simultaneously with the topographic focalization of cortical activation. His performance became more stable with practice. For this patient the criteria for automaticity were all met. In patient 2, performance also improved, but his cortical activity became topographically less focal. His performance was less stable than that of patient 1. Conclusions : The present findings, albeit on only two subjects, provide preliminary evidence that SCP self-regulation may automatize with long-term practice and can therefore be considered a skill.

Direct brain-computer communication utilises self-regulation of brain potentials to select letters, words or symbols from a computer menu. In this study a completely paralysed (locked-in) patient learnt to produce slow cortical potential (SCP) shifts to operate a binary spelling device. After hundreds of training sessions he gave a detailed description of his mental strategies for self-regulation. His cognitive strategies matched with the electrocortical changes perfectly. Thus he produced a contingent negative variation (CNV) with images of preparation such as an arrow being drawn on a bow. To produce a positive potential shift he imagined the arrow shooting up from the bow. To suppress potential shifts he tried to stop thinking. The study demonstrates that patients become sensitive for their brain states with increasing self-regulation practice. The use of conscious cognitive strategies may, however, be incompatible with the complete automatization of the self-regulation skill.

When a voluntary action causes a sensory outcome, actions and their subsequent effects are perceived as being closer together in time, this effect being called intentional binding. Since studies on perceived time are highly dependent on subjective reports, an avenue to gain more reliable subjective reports regarding the precise moment of a temporal event is to work with experienced meditators. It has been shown in many studies that experienced meditators are able to keep attention more consistently on a task and they have increased attentional control and report more accurately their body sensations. In this study, we performed an intentional binding paradigm with twenty experienced meditators and compared the results with matched controls. Moreover, the pre-supplementary area (SMA) is regarded as key structure for voluntary movement and contributing to the sense of agency. For example, it has been shown that disrupting neural activity in the SMA leads to less intentional binding. Therefore, brain dynamic (EEG) was recorded and a single-trial analysis technique of the task was performed to estimate whether intentional binding is correlated with spontaneous slow cortical potentials (SCP). We observed that self-initiated movements following positive and negative potential shifts of SCPs in meditators, which are related to SMA activation, have different effects on intentional binding, especially the error regarding timing of sensory outcome rises. The difference between groups in timing accuracy and its correlate of brain dynamics will be discussed in detail.