The "state of the art" of intraoperative neurophysiological monitoring: An Italian neurosurgical survey

Introduction

Intraoperative Neurophysiological Monitoring (IOM) is widely used in neurosurgery but specific guidelines are lacking. Therefore, we can assume differences in IOM application between Neurosurgical centers.

Research question

The section of Functional Neurosurgery of the Italian Society of Neurosurgery realized a survey aiming to obtain general data on the current practice of IOM in Italy.

Materials and methods

A 22-item questionnaire was designed focusing on: volume procedures, indications, awake surgery, experience, organization and equipe. The questionnaire has been sent to Italian Neurosurgery centers.

Results

A total of 54 centers completed the survey. The annual volume of surgeries range from 300 to 2000, and IOM is used in 10-20% of the procedures. In 46% of the cases is a neurologist or a neurophysiologist who performs IOM. For supra-tentorial pathology, almost all perform MEPs (94%) SSEPs (89%), direct cortical stimulation (85%). All centers perform IOM in spinal surgery and 95% in posterior fossa surgery. Among the 50% that perform peripheral nerve surgery, all use IOM. Awake surgery is performed by 70% of centers. The neurosurgeon is the only responsible for IOM in 35% of centers. In 83% of cases IOM implementation is adequate to the request.

Discussion and conclusions

The Italian Neurosurgical centers perform IOM with high level of specialization, but differences exist in organization, techniques, and expertise. Our survey provides a snapshot of the state of the art in Italy and it could be a starting point to implement a consensus on the practice of IOM.

Decoding of unimanual and bimanual reach-and-grasp actions from EMG and IMU signals in persons with cervical spinal cord injury

Objective. Chronic motor impairments of arms and hands as the consequence of a cervical spinal cord injury (SCI) have a tremendous impact on activities of daily life. A considerable number of people however retain minimal voluntary motor control in the paralyzed parts of the upper limbs that are measurable by electromyography (EMG) and inertial measurement units (IMUs). An integration into human-machine interfaces (HMIs) holds promise for reliable grasp intent detection and intuitive assistive device control.Approach. We used a multimodal HMI incorporating EMG and IMU data to decode reach-and-grasp movements of groups of persons with cervical SCI (n = 4) and without (control, n = 13). A post-hoc evaluation of control group data aimed to identify optimal parameters for online, co-adaptive closed-loop HMI sessions with persons with cervical SCI. We compared the performance of real-time, Random Forest-based movement versus rest (2 classes) and grasp type predictors (3 classes) with respect to their co-adaptation and evaluated the underlying feature importance maps.Main results. Our multimodal approach enabled grasp decoding significantly better than EMG or IMU data alone (p<0.05). We found the 0.25 s directly prior to the first touch of an object to hold the most discriminative information. Our HMIs correctly predicted 79.3 ± STD 7.4 (102.7 ± STD 2.3 control group) out of 105 trials with grand average movement vs. rest prediction accuracies above 99.64% (100% sensitivity) and grasp prediction accuracies of 75.39 ± STD 13.77% (97.66 ± STD 5.48% control group). Co-adaption led to higher prediction accuracies with time, and we could identify adaptions in feature importances unique to each participant with cervical SCI.Significance. Our findings foster the development of multimodal and adaptive HMIs to allow persons with cervical SCI the intuitive control of assistive devices to improve personal independence.

Upper limb movement quality measures: comparing IMUs and optical motion capture in stroke patients performing a drinking task

Introduction

Clinical assessment of upper limb sensorimotor function post-stroke is often constrained by low sensitivity and limited information on movement quality. To address this gap, recent studies proposed a standardized instrumented drinking task, as a representative daily activity combining different components of functional arm use. Although kinematic movement quality measures for this task are well-established, and optical motion capture (OMC) has proven effective in their measurement, its clinical application remains limited. Inertial Measurement Units (IMUs) emerge as a promising low-cost and user-friendly alternative, yet their validity and clinical relevance compared to the gold standard OMC need investigation.

Method

In this study, we conducted a measurement system comparison between IMUs and OMC, analyzing 15 established movement quality measures in 15 mild and moderate stroke patients performing the drinking task, using five IMUs placed on each wrist, upper arm, and trunk.

Results

Our findings revealed strong agreement between the systems, with 12 out of 15 measures demonstrating clinical applicability, evidenced by Limits of Agreement (LoA) below the Minimum Clinically Important Differences (MCID) for each measure.

Discussion

These results are promising, suggesting the clinical applicability of IMUs in quantifying movement quality for mildly and moderately impaired stroke patients performing the drinking task.

Rage against the machine? Framing societal threat and efficacy in YouTube videos about artificial intelligence

Artificial intelligence (AI) has become a part of the mainstream public discourse beyond expert communities about its risks, benefits, and need for regulation. In particular, since 2014, the news media have intensified their coverage of this emerging technology and its potential impact on most domains of society. Although many studies have analyzed traditional media coverage of AI, analyses of social media, especially video-sharing platforms, are rare. In addition, research from a risk communication perspective remains scarce, despite the widely recognized potential threats to society from many AI applications. This study aims to detect recurring patterns of societal threat/efficacy in YouTube videos, analyze their main sources, and compare detected frames in terms of reach and response. Using a theoretical framework combining framing and risk communication, the study analyzed the societal threat/efficacy attributed to AI in easily accessible YouTube videos published in a year when public attention to AI temporarily peaked (2018). Four dominant AI frames were identified: the balanced frame, the high-efficacy frame, the high-threat frame, and the no-threat frame. The balanced and no-threat frames were the most prevalent, with predominantly positive and neutral AI narratives that neither adequately address the risks nor the necessary societal response from a normative risk communication perspective. The results revealed the specific risks and benefits of AI that are most frequently addressed. Video views and user engagement with AI videos were analyzed. Recommendations for effective AI risk communication and implications for risk governance were derived from the results.

Intermediate gray matter interneurons in the lumbar spinal cord play a critical and necessary role in coordinated locomotion

Locomotion is a complex task involving excitatory and inhibitory circuitry in spinal gray matter. While genetic knockouts examine the function of individual spinal interneuron (SpIN) subtypes, the phenotype of combined SpIN loss remains to be explored. We modified a kainic acid lesion to damage intermediate gray matter (laminae V-VIII) in the lumbar spinal enlargement (spinal L2-L4) in female rats. A thorough, tailored behavioral evaluation revealed deficits in gross hindlimb function, skilled walking, coordination, balance and gait two weeks post-injury. Using a Random Forest algorithm, we combined these behavioral assessments into a highly predictive binary classification system that strongly correlated with structural deficits in the rostro-caudal axis. Machine-learning quantification confirmed interneuronal damage to laminae V-VIII in spinal L2-L4 correlates with hindlimb dysfunction. White matter alterations and lower motoneuron loss were not observed with this KA lesion. Animals did not regain lost sensorimotor function three months after injury, indicating that natural recovery mechanisms of the spinal cord cannot compensate for loss of laminae V-VIII neurons. As gray matter damage accounts for neurological/walking dysfunction in instances of spinal cord injury affecting the cervical or lumbar enlargement, this research lays the groundwork for new neuroregenerative therapies to replace these lost neuronal pools vital to sensorimotor function.

The Global Study of COVID News: Scope, Findings, and Implications of Quantitative Content Analyses of the COVID-19 News Coverage in the First Two Years of the Pandemic

Researchers and practitioners have unanimously acknowledged the impact of legacy media coverage of past pandemics as well as COVID-19 and its importance for health-related risk communication. Therefore, this study provides scholars and health communication practitioners with a deeper understanding of the patterns, main themes, and limitations of media reporting and peer-reviewed research in the early stages of the COVID-19 pandemic in different national media environments. Because the objective is to evaluate patterns, this paper focuses on early quantitative and automated content analyses for theoretical contribution, geographic diversity, methodological rigor, and inclusion of risk and crisis communication theory. It also assesses whether authors deduced implications, for both theory and practice of health-related risk and crisis communication. We conducted a content analysis of 66 studies in peer-reviewed journals from the beginning of the pandemic until April 2022. The findings demonstrate that early quantitative analyses of the news coverage of COVID-19 are often not theory-driven, apply heterogeneous forms of framing analysis, and lack references to risk and crisis communication theory. Consequently, only few implications for health communication practice during pandemics were drawn. However, there is evidence of improvement in geographic scope compared to previous research. The discussion addresses the importance of developing a consistent approach to framing analyses of risk and crisis media coverage and the importance of well-designed cross-cultural research in a global pandemic.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

BACKGROUND

Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development.

METHODS

We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation.

FINDINGS

Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49).

INTERPRETATION

Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices.

FUNDING

National Institute for Health Research Global Health Research Group.

Characterization of atherosclerotic plaques in blood vessels with low oxygenated blood and blood pressure (Pulmonary trunk): role of growth differentiation factor-15 (GDF-15)

BACKGROUND

Growth differentiation factor (GDF)-15 is linked to inflammation, cancer, and atherosclerosis. GDF-15 is expressed in most tissues but is extremely induced under pathological conditions. Elevated serum levels are suggested as a risk factor and a marker for cardiovascular diseases. However, the cellular sources and the effects of GDF-15 on the cardiovascular system have not been completely elucidated including progression, and morphology of atherosclerotic plaques. Thus, this work aimed to characterize the influence of GDF-15 deficiency on the morphology of atherosclerotic plaques in blood vessels with low-oxygen blood and low blood pressure as the pulmonary trunk (PT), in hypercholesterolemic ApoE-/- mice.

METHODS

GDF-15-/- ApoE-/- mice were generated by crossbreeding of ApoE-/-- and GDF-15-/- mice. After feeding a cholesterol-enriched diet (CED) for 20 weeks, samples of the brachiocephalic trunk (BT) and PT were dissected and lumen stenosis (LS) was measured. Furthermore, changes in the cellularity of the PT, amounts of apoptosis-, autophagy-, inflammation- and proliferation-relevant proteins were immunohisto-morphometrically analyzed. Additionally, we examined an atherosclerotic plaque in a human post mortem sample of the pulmonary artery.

RESULTS

After CED the body weight of GDF-15-/-ApoE-/- was 22.9% higher than ApoE-/-. Double knockout mice showed also an 35.3% increase of plasma triglyceride levels, whereas plasma cholesterol was similar in both genotypes. LS in the BT and PT of GDF-15-/-ApoE-/- mice was significantly reduced by 19.0% and by 6.7% compared to ApoE-/-. Comparing LS in PT and BT of the same genotype revealed a significant 38.8% (ApoE-/-) or 26.4% (GDF-15-/-ApoE-/-) lower LS in the PT. Immunohistomorphometry of atherosclerotic lesions in PT of GDF-15-/-ApoE-/- revealed significantly increased levels (39.8% and 7.3%) of CD68 + macrophages (MΦ) and α-actin + smooth muscle cells than in ApoE-/-. The density of TUNEL + , apoptotic cells was significantly (32.9%) higher in plaques of PT of GDF-15-/-ApoE-/- than in ApoE-/-. Analysis of atherosclerotic lesion of a human pulmonary artery showed sm-α-actin, CD68+, TUNEL+, Ki67+, and APG5L/ATG+ cells as observed in PT. COX-2+ and IL-6+ immunoreactivities were predominantly located in endothelial cells and subendothelial space. In BT and PT of GDF15-/-ApoE-/- mice the necrotic area was 10% and 6.5% lower than in ApoE-/-. In BT and PT of GDF15-/-ApoE-/- we found 40% and 57% less unstable plaques than ApoE-/- mice.

CONCLUSIONS

Atherosclerotic lesions occur in both, BT and PT, however, the size is smaller in PT, possibly due to the effect of the low-oxygen blood and/or lower blood pressure. GDF-15 is involved in atherosclerotic processes in BT and PT, although different mechanisms (e.g. apoptosis) in these two vessels seem to exist.

Differentiating migraine, cervicogenic headache and asymptomatic individuals based on physical examination findings: a systematic review and meta-analysis

BACKGROUND

Migraine and cervicogenic headache (CGH) are common headache disorders, although the large overlap of symptoms between them makes differential diagnosis challenging. To strengthen differential diagnosis, physical testing has been used to examine for the presence of musculoskeletal impairments in both conditions. This review aimed to systematically evaluate differences in physical examination findings between people with migraine, CGH and asymptomatic individuals.

METHODS

The databases MEDLINE, PubMed, CINAHL, Web of Science, Scopus, EMBASE were searched from inception until January 2020. Risk of bias was assessed with the Downs and Black Scale for non-randomized controlled trials, and with the Quality Assessment of Diagnostic Accuracy Studies tool for diagnostic accuracy studies. When possible, meta-analyses with random effect models was performed.

RESULTS

From 19,682 articles, 62 studies were included in this review and 41 were included in the meta-analyses. The results revealed: a) decreased range of motion [°] (ROM) on the flexion-rotation test (FRT) (17.67, 95%CI:13.69,21.65) and reduced neck flexion strength [N] (23.81, 95%CI:8.78,38.85) in CGH compared to migraine; b) compared to controls, migraineurs exhibit reduced flexion ROM [°] (- 2.85, 95%CI:-5.12,-0.58), lateral flexion ROM [°] (- 2.17, 95% CI:-3.75,-0.59) and FRT [°] (- 8.96, 95%CI:-13.22,-4.69), reduced cervical lordosis angle [°] (- 0.89, 95%CI:-1.72,-0.07), reduced pressure pain thresholds over the cranio-cervical region [kg/cm²], reduced neck extension strength [N] (- 11.13, 95%CI:-16.66,-5.6) and increased activity [%] of the trapezius (6.18, 95%CI:2.65,9.71) and anterior scalene muscles (2.87, 95%CI:0.81,4.94) during performance of the cranio-cervical flexion test; c) compared to controls, CGH patients exhibit decreased neck flexion (- 33.70, 95%CI:-47.23,-20.16) and extension (- 55.78, 95%CI:-77.56,-34.00) strength [N].

CONCLUSION

The FRT and neck flexion strength could support the differential diagnosis of CGH from migraine. Several physical tests were found to differentiate both headache types from asymptomatic individuals. Nevertheless, additional high-quality studies are required to corroborate these findings.

STUDY REGISTRATION

Following indications of Prisma-P guidelines, this protocol was registered in PROSPERO on 21/05/2019 with the number CRD42019135269 . All amendments performed during the review were registered in PROSPERO, indicating the date and what and why was changed.

Online detection of movement during natural and self-initiated reach-and-grasp actions from EEG signals

Movement intention detection using electroencephalography (EEG) is a challenging but essential component of brain-computer interfaces (BCIs) for people with motor disabilities.Objective.The goal of this study is to develop a new experimental paradigm to perform asynchronous online detection of movement based on low-frequency time-domain EEG features, concretely on movement-related cortical potentials. The paradigm must be easily transferable to people without any residual upper-limb movement function and the BCI must be independent of upper-limb movement onset measurements and external cues.Approach. In a study with non-disabled participants, we evaluated a novel BCI paradigm to detect self-initiated reach-and-grasp movements. Two experimental conditions were involved. In one condition, participants performed reach-and-grasp movements to a target and simultaneously shifted their gaze towards it. In a control condition, participants solely shifted their gaze towards the target (oculomotor task). The participants freely decided when to initiate the tasks. After eye artefact correction, the EEG signals were time-locked to the saccade onset and the resulting amplitude features were exploited on a hierarchical classification approach to detect movement asynchronously.Main results. With regards to BCI performance, 54.1% (14.4% SD) of the movements were correctly identified, and all participants achieved a performance above chance-level (around 12%). An average of 21.5% (14.1% SD) of the oculomotor tasks were falsely detected as upper-limb movement. In an additional rest condition, 1.7 (1.6 SD) false positives per minute were measured. Through source imaging, movement information was mapped to sensorimotor, posterior parietal and occipital areas.Significance. We present a novel approach for movement detection using EEG signals which does not rely on upper-limb movement onset measurements or on the presentation of external cues. The participants' behaviour closely matches the natural behaviour during goal-directed reach-and-grasp movements, which also constitutes an advantage with respect to current BCI protocols.

A cavity optomechanical locking scheme based on the optical spring effect

We present a novel locking scheme for active length-stabilization and frequency detuning of a cavity optomechanical device based on the optical spring effect. The error signal is generated by utilizing the position measurement of a thermally driven intra-cavity nanomechanical device and employing its detuning-dependent frequency shift caused by the dispersive coupling to the cavity field. The scheme neither requires external modulation of the laser or the cavity nor does it demand for additional error signal readout, rendering its technical implementation rather simple for a large variety of existing optomechanical devices. Specifically, for large-linewidth microcavities or in situations where other locking schemes appear unfavorable conceptually or are hard to realize technically, the optical spring lock represents a potential alternative for stabilizing the cavity length. We explain the functional principle of the lock and characterize its performance in terms of bandwidth and gain profile.

Analyzing and Decoding Natural Reach-and-Grasp Actions Using Gel, Water and Dry EEG Systems

Reaching and grasping is an essential part of everybody's life, it allows meaningful interaction with the environment and is key to independent lifestyle. Recent electroencephalogram (EEG)-based studies have already shown that neural correlates of natural reach-and-grasp actions can be identified in the EEG. However, it is still in question whether these results obtained in a laboratory environment can make the transition to mobile applicable EEG systems for home use. In the current study, we investigated whether EEG-based correlates of natural reach-and-grasp actions can be successfully identified and decoded using mobile EEG systems, namely the water-based EEG-Versatile ^TM system and the dry-electrodes EEG-Hero ^TM headset. In addition, we also analyzed gel-based recordings obtained in a laboratory environment (g.USBamp/g.Ladybird, gold standard), which followed the same experimental parameters. For each recording system, 15 study participants performed 80 self-initiated reach-and-grasp actions toward a glass (palmar grasp) and a spoon (lateral grasp). Our results confirmed that EEG-based correlates of reach-and-grasp actions can be successfully identified using these mobile systems. In a single-trial multiclass-based decoding approach, which incorporated both movement conditions and rest, we could show that the low frequency time domain (LFTD) correlates were also decodable. Grand average peak accuracy calculated on unseen test data yielded for the water-based electrode system 62.3% (9.2% STD), whereas for the dry-electrodes headset reached 56.4% (8% STD). For the gel-based electrode system 61.3% (8.6% STD) could be achieved. To foster and promote further investigations in the field of EEG-based movement decoding, as well as to allow the interested community to make their own conclusions, we provide all datasets publicly available in the BNCI Horizon 2020 database (http://bnci-horizon-2020.eu/database/data-sets).

Applying intuitive EEG-controlled grasp neuroprostheses in individuals with spinal cord injury: Preliminary results from the MoreGrasp clinical feasibility study

The aim of the MoreGrasp project is to develop a non-invasive, multimodal user interface including a brain-computer interface (BCI) for control of a grasp neuroprostheses in individuals with high spinal cord injury (SCI). The first results of the ongoing MoreGrasp clinical feasibility study involving end users with SCI are presented. This includes BCI screening sessions, in which we investigate the electroencephalography (EEG) patterns associated with single, natural movements of the upper limb. These patterns will later be used to control the neuroprosthesis. Additionally, the MoreGrasp grasp neuroprosthesis consisting of electrode arrays embedded in an individualized textile forearm sleeve is presented. The general feasibility of this electrode array in terms of corrections of misalignments during donning is shown together with the functional results in end users of the electrode forearm sleeve.

Perturbation-evoked potentials can be classified from single-trial EEG

OBJECTIVE

Loss of balance control can have serious consequences on interaction between humans and machines as well as the general well-being of humans. Perceived balance perturbations are always accompanied by a specific cortical activation, the so-called perturbation-evoked potential (PEP). In this study, we investigate the possibility to classify PEPs from ongoing EEG.

APPROACH

Fifteen healthy subjects were exposed to seated whole-body perturbations. Each participant performed 120 trials; they were rapidly tilted to the right and left, 60 times respectively.

MAIN RESULTS

We achieved classification accuracies of more than 85% between PEPs and rest EEG using a window-based classification approach. Different window lengths and electrode layouts were compared. We were able to achieve excellent classification performance (87.6 ± 8.0% accuracy) by using a short window length of 200 ms and a minimal electrode layout consisting of only the Cz electrode. The peak classification accuracy coincides in time with the strongest component of PEPs, called N1.

SIGNIFICANCE

We showed that PEPs can be discriminated against ongoing EEG with high accuracy. These findings can contribute to the development of a system that can detect balance perturbations online.

Decoding hand movements from human EEG to control a robotic arm in a simulation environment

OBJECTIVE

Daily life tasks can become a significant challenge for motor impaired persons. Depending on the severity of their impairment, they require more complex solutions to retain an independent life. Brain-computer interfaces (BCIs) are targeted to provide an intuitive form of control for advanced assistive devices such as robotic arms or neuroprostheses. In our current study we aim to decode three different executed hand movements in an online BCI scenario from electroencephalographic (EEG) data.

APPROACH

Immersed in a desktop-based simulation environment, 15 non-disabled participants interacted with virtual objects from daily life by an avatar's robotic arm. In a short calibration phase, participants performed executed palmar and lateral grasps and wrist supinations. Using this data, we trained a classification model on features extracted from the low frequency time domain. In the subsequent evaluation phase, participants controlled the avatar's robotic arm and interacted with the virtual objects in case of a correct classification.

MAIN RESULTS

On average, participants scored online 48% of all movement trials correctly (3-condition scenario, adjusted chance level 40%, alpha = 0.05). The underlying movement-related cortical potentials (MRCPs) of the acquired calibration data show significant differences between conditions over contralateral central sensorimotor areas, which are retained in the data acquired from the online BCI use.

SIGNIFICANCE

We could show the successful online decoding of two grasps and one wrist supination movement using low frequency time domain features of the human EEG. These findings can potentially contribute to the development of a more natural and intuitive BCI-based control modality for upper limb motor neuroprostheses or robotic arms for people with motor impairments.

4304Fast-SENC quantifies segmental right ventricular intramyocardial strain to assess subclinical RV dysfunction prior to changes in RV ejection fraction

Methods

A single center, prospective registry of MRI scans acquired with a 1.5T scanner were evaluated for conventional CMR diagnostics including RVEF. In addition, fSENC scans were acquired and processed with the MyoStrain software to quantify intramyocardial RV strain. Two short axis scans (basal & midventricular) were used to calculate strain in 6 longitudinal RV segments while two long axis scans (3-chamber & 4-chamber) were used to calculate 5 circumferential RV segments.

CMR and fSENC metrics were compared based on progression of heart failure in which the ACC/AHA Heart Failure stage was determined by CMR findings including LGE in cases in which contrast was injected. HF Stages B and C were separated into different degrees of structural heart disease with “−” representing lower levels and “+” higher levels to provide better delineation of progression of heart dysfunction leading to heart failure.

Results

A total of 977 scans in 779 patients were included in the study. Patients had an average (± stdev) age of 55 (17) yrs and BMI of 26 (5) kg/m2; 48% had arterial hypertension, 12% diabetes mellitus, 33% moderate or severe valvular heart disease, 25% cancer, 7% atrial fibrillation, and 24% coronary artery disease.

Figure 1 shows the relationship between % normal RV myocardium (RV fSENC <−17%) and CMR RVEF in the y-axis versus modified ACC/AHA Heart Failure Stage in the x-axis respectively.

Figure 1

Conclusion

Segmental fSENC detects subclinical RV dysfunction well before changes in RVEF. The ability to directly measure intramyocardial RV strain allows quantification various subclinical right heart diseases, the impact and monitoring of pharmacological therapiesand device interventions on RV function.

Decoding natural reach-and-grasp actions from human EEG

OBJECTIVE

Despite the high number of degrees of freedom of the human hand, most actions of daily life can be executed incorporating only palmar, pincer and lateral grasp. In this study we attempt to discriminate these three different executed reach-and-grasp actions utilizing their EEG neural correlates.

APPROACH

In a cue-guided experiment, 15 healthy individuals were asked to perform these actions using daily life objects. We recorded 72 trials for each reach-and-grasp condition and from a no-movement condition.

MAIN RESULTS

Using low-frequency time domain features from 0.3 to 3 Hz, we achieved binary classification accuracies of 72.4%, STD  ±  5.8% between grasp types, for grasps versus no-movement condition peak performances of 93.5%, STD  ±  4.6% could be reached. In an offline multiclass classification scenario which incorporated not only all reach-and-grasp actions but also the no-movement condition, the highest performance could be reached using a window of 1000 ms for feature extraction. Classification performance peaked at 65.9%, STD  ±  8.1%. Underlying neural correlates of the reach-and-grasp actions, investigated over the primary motor cortex, showed significant differences starting from approximately 800 ms to 1200 ms after the movement onset which is also the same time frame where classification performance reached its maximum.

SIGNIFICANCE

We could show that it is possible to discriminate three executed reach-and-grasp actions prominent in people's everyday use from non-invasive EEG. Underlying neural correlates showed significant differences between all tested conditions. These findings will eventually contribute to our attempt of controlling a neuroprosthesis in a natural and intuitive way, which could ultimately benefit motor impaired end users in their daily life actions.

Unimanual and Bimanual Reach-and-Grasp Actions Can Be Decoded From Human EEG

While most tasks of daily life can be handled through a small number of different grasps, many tasks require the action of both hands. In these bimanual tasks, the second hand has either a supporting role (e.g. for fixating a jar) or a more active role (e.g. grasping a pot on both handles). In this study we attempt to discriminate the neural correlates of unimanual (performed with left and right hand) from bimanual reach-and-grasp actions using the low-frequency time-domain electroencephalogram (EEG). In a self-initiated movement task, 15 healthy participants were asked to perform unimanual (palmar and lateral grasps with left and right hand) and bimanual (double lateral, mixed palmar/lateral) reach-and-grasps on objects of daily life. Using EEG time-domain features in the frequency range of 0.3-3 Hz, we achieved multiclass-classification accuracies of 38.6 ± 6.6% (7 classes, 17.1% chance level) for a combination of 6 movements and 1 rest condition. The grand average confusion matrix shows highest true positive rates (TPR) for the rest (63%) condition while TPR for the movement classes varied between 33 to 41%. The underlying movement-related cortical potentials (MRCPs) show significant differences between unimanual (e.g left hand vs. right hand grasps) as well unimanual vs. bimanual conditions which both can be attributed to lateralization effects. We believe that these findings can be exploited and further used for attempts in providing persons with spinal cord injury a form of natural control for bimanual neuroprostheses.

Direct comparison of supervised and semi-supervised retraining approaches for co-adaptive BCIs

For Brain-Computer interfaces (BCIs), system calibration is a lengthy but necessary process for successful operation. Co-adaptive BCIs aim to shorten training and imply positive motivation to users by presenting feedback already at early stages: After just 5 min of gathering calibration data, the systems are able to provide feedback and engage users in a mutual learning process. In this work, we investigate whether the retraining stage of co-adaptive BCIs can be adapted to a semi-supervised concept, where only a small amount of labeled data is available and all additional data needs to be labeled by the BCI itself. The aim of the current work was to evaluate whether a semi-supervised co-adaptive BCI could successfully compete with a supervised co-adaptive BCI model. In a supporting two-class (190 trials per condition) BCI study based on motor imagery tasks, we evaluated both approaches in two separate groups of 10 participants online, while we simulated the other approach in each group offline. Our results indicate that despite the lack of true labeled data, the semi-supervised driven BCI did not perform significantly worse (p > 0.05) than the supervised counterpart. We believe that these findings contribute to developing BCIs for long-term use, where continuous adaptation becomes imperative for maintaining meaningful BCI performance.

Graphical abstract

Combining frequency and time-domain EEG features for classification of self-paced reach-and-grasp actions

Brain-computer interfaces (BCIs) might provide an intuitive way for severely motor impaired persons to operate assistive devices to perform daily life activities. Recent studies have shown that complex hand movements, such as reach-and-grasp tasks, can be decoded from the low frequency of the electroencephalogram (EEG). In this work we investigated whether additional features extracted from the frequency-domain of alpha and beta bands could improve classification performance of rest vs. palmar vs. lateral grasp. We analysed two multi-class classification approaches, the first using features from the low frequency time-domain, and the second in which we combined the time-domain with frequency-domain features from alpha and beta bands. We measured EEG of ten participants without motor disability which performed self-paced reach-and-grasp actions on objects of daily life. For the time-domain classification approach, participants reached an average peak accuracy of 65%. For the combined approach, an average peak accuracy of 75% was reached. In both approaches and for all subjects, performance was significantly higher than chance level (38.1%, 3-class scenario). By computing the confusion matrices as well as feature rankings through the Fisher score, we show that movement vs. rest classification performance increased considerably in the combined approach and was the main responsible for the multi-class higher performance. These findings could help the development of BCIs in real-life scenarios, where decreasing false movement detections could drastically increase the end-user acceptance and usability of BCIs.

Attempted Arm and Hand Movements can be Decoded from Low-Frequency EEG from Persons with Spinal Cord Injury

We show that persons with spinal cord injury (SCI) retain decodable neural correlates of attempted arm and hand movements. We investigated hand open, palmar grasp, lateral grasp, pronation, and supination in 10 persons with cervical SCI. Discriminative movement information was provided by the time-domain of low-frequency electroencephalography (EEG) signals. Based on these signals, we obtained a maximum average classification accuracy of 45% (chance level was 20%) with respect to the five investigated classes. Pattern analysis indicates central motor areas as the origin of the discriminative signals. Furthermore, we introduce a proof-of-concept to classify movement attempts online in a closed loop, and tested it on a person with cervical SCI. We achieved here a modest classification performance of 68.4% with respect to palmar grasp vs hand open (chance level 50%).

Prophylactic enlargement of the thecal sac volume by spinal expansion duroplasty in patients with unresectable malignant intramedullary tumors and metastases prior to radiotherapy

Unresectable malignant intramedullary tumors and metastases usually require radiotherapy which intensifies spinal cord edema and might result in neurological decline. Spinal expansion duroplasty before radiotherapy enlarges the intrathecal volume and might thus prevent neurological deficits. The study aims to evaluate the clinical course of patients undergoing expansion duroplasty. This retrospective analysis (2007-2016) included all patients with unresectable intramedullary tumors who underwent spinal expansion duroplasty. To assess the degree of preoperative cord enlargement, we calculated the "diameter ratio": diameter of the spinal cord below and above the tumor / diameter of the tumor × 2. The presence of perimedullary cerebrospinal fluid (CSF) at the affected levels was analyzed on the preoperative magnetic resonance imaging (MRI). We recorded the occurrence of neurological deficits, wound breakdown, and CSF fistula. We screened 985 patients, 11 of which were included. Eight patients had an intramedullary metastasis, three patients a spinal malignant glioma. A diameter ratio ≤ 0.8 representing a significant preoperative intramedullary enlargement was seen in 10 cases (90.9%). Postoperative imaging was available in 9 patients, demonstrating successful decompression in 8 of the 9 patients (88.9%). The postoperative course was uneventful in 9 patients (81.8%). Mean overall survival was 13.4 (SD 16.2) months. Spinal expansion duroplasty prior to radiotherapy is a previously undescribed concept. Despite neoadjuvant radiation, no wound breakdown or CSF fistula occurred. In unresectable intramedullary tumors and metastases, spinal expansion duroplasty seems to be a safe procedure with the potential to prevent neurological decline due to radiation-induced cord swelling.

Evaluation of fine organic mixtures for treatment of acid mine drainage in sulfidogenic reactors

The performance of passive biochemical reactors in acid mine drainage (AMD) treatment could be enhanced by using fine organic substrates in new reactor designs, such as diffusive exchange reactors. This work evaluated the effect of fine cellulosic components in organic mixtures and of enrichment with inoculum, on sulfate and metals removal in discontinuous cultures for three types of synthetic AMD. The cellulosic substrates evaluated were sawdust, microcrystalline cellulose, and forestry cellulose fibers, supplemented with cow manure and leaf compost. Using microcrystalline cellulose and forestry cellulose fibers with the less concentrated AMD, high sulfate reduction rates (73 mg/L-d and 58.2 mg/L-d, respectively) were achieved. Correspondingly, iron concentrations were reduced by 69% and 86.6%. Based on their higher sulfate reducing capacity, cellulose fibers obtained as fiber boards from a local kraft pulp mill were selected for treating a synthetic AMD with a high copper concentration (273 mg/L) and pH 4.94. In batch culture, low sulfate reducing activity (13.10 mg/L-d) was only observed at the highest substrate/AMD ratio (0.5:10) tested. Results show that the use of forestry cellulose fibers in reactive mixtures supplemented with inoculum could be an alternative for optimization of diffusive exchange reactors for AMD treatment.

Optimization of analgesia for piglet castration under isoflurane anaesthesia with parenteral butorphanol, meloxicam or intratesticular lidocaine

INTRODUCTION

This blinded prospective study investigated analgesic effects of intramuscular (IM) butorphanol, meloxicam or intratesticular (IT) lidocaine for castration of 7-14 days old piglets under isoflurane anaesthesia. 66 piglets were randomly injected with: meloxicam IM (0.4 mg/kg; group M), butorphanol IM (0.2 mg/kg; group B), or both (group BM) 20 minutes prior to castration, or lidocaine IT (4 mg/kg (group ML4) or 8 mg/kg (group ML8)) together with meloxicam IM (0.4 mg/kg) under anaesthesia with 1.8% end-tidal isoflurane. Heart rate, respiratory rate, mean arterial blood pressure and end-tidal carbon dioxide were recorded. Anaesthesia quality was scored and postoperative behaviour assessed. As butorphanol caused unacceptable side effects, its use was stopped. Group M showed worse anaesthesia quality than ML4 and ML8 (higher incidence of movements: 11/17, 3/18 and 4/17, respectively). There were no significant differences between groups regarding parameters measured during castration. Postoperative behaviour did not differ between groups. For castration of 7-14 days old piglets under isoflurane anaesthesia, IT lidocaine provides an additional side effect free analgesia.

[Evaluation of a field-suitable injection anesthesia protocol for the castration of 8 to 14 days old piglets]

INTRODUCTION

The aim of this study was to find an intramuscularly (IM) injectable anaesthetic combination for 8 to 14-days old piglets, that guarantees a calm induction and sufficient quality of anaesthesia without excitations with a maximum of two hours long lasting recovery. In preliminary dose finding trials, different combinations of -ketamine, azaperone and romifidine were compared. A constant dose of 0.2 mg/kg of butorphanol was added to each combination and all piglets received 0.4 mg/kg meloxicam. Subsequently a dosage algorithm for the main trial was developed. In case of insufficient analgesia, lidocaine 2% (0.25 ml) was injected intratesticular. If two piglets showed an insufficient anaesthetic induction phase, depth of anaesthesia or recovery, the next dosage in the algorithm was tried. With the combination of 3 mg/kg azaperone, 0.2 mg/kg romifidine, 15 mg/kg ketamine and 0.2 mg/kg butorphanol the requirement of a smooth anaesthesia induction, sufficient anaesthesia and a recovery without excitation was fulfilled but the recovery lasted more than 120 minutes.

Hyperfibrinolysis diagnosed with rotational thromboelastometry and treated with tranexamic acid in a dog with acute traumatic coagulopathy

INTRODUCTION

A 4-year old male Australian Cattle Dog involved in a road traffic accident was presented with severe polytrauma to the Small Animal Clinic, University of Zurich. He was presented in hemorrhagic shock, with an initial lactate of 10.3mmol/l and ongoing bleeding from multiple injury sites. Acute traumatic coagulopathy diagnosed with ROTEM within one hour after accident showed marked hypocoagulation and hyperfibrinolysis. Treatment with a total dose of 40mg/kg of tranexamic acid intravenously resulted in successful elimination of hyperfibrinolysis in the following, serially measured ROTEM tracings.

Bindung des monoklonalen Antikörpers BW 250/183 an menschliche Granulozyten

Für den szintigraphischen Nachweis entzündlicher Herde wird seit einiger Zeit die spezifische Bindung geeigneter monoklonaler Antikörper an menschliche Granulozyten ausgenutzt. Mit dem Antikörper BW 250/183 wurde versucht, die hierbei zugrundeliegende Bindungskinetik aufzuklären. Als wichtigste Voraussetzung für eine spezifische Zellbindung konnte gezeigt werden, daß der Markierungsvorgang die Immunreaktivität nicht beeinflußt. Bindungsstudien ergaben für den Antikörper eine Affinitätskonstante von 2 × 109l/mol. Üblicherweise werden pro Patient 0,25-1,0 mg des 99mTc-markierten Antikörpers eingesetzt. Nach intravenöser Applikation stellte sich bei den beschriebenen Untersuchungen rasch ein Gleichgewichtszustand im Blut ein, bei dem etwa 1/4 der Aktivität in zellgebundener Form vorlag. Der übrige Aktivitätsanteil fand sich in Form des markierten IgG im Plasma und konnte so direkt mit den Granulozyten, die bereits im Entzündungsherd kumuliert waren, reagieren. Auch eine drastische Reduktion der applizierten Antikörpermenge änderte an diesem Gleichgewichtszustand nichts, das Massenwirkungsgesetz scheint hier nicht unmittelbar anwendbar zu sein. Interferenzen mit Plasmabestandteilen können als Ursache für dieses Verhalten ausgeschlossen werden. Appliziert man statt der Antikörper Granulozyten, die in vitro mit dem Antikörper markiert wurden und bei denen der nicht gebundene Antikörperanteil durch Waschschritte entfernt wurde, so stellt sich bereits innerhalb der ersten 10 min ebenfalls dasselbe Bindungsgleichgewicht im Plasma ein. Interessanterweise verlängerte sich die intravasale Verweildauer der Aktivität hierbei deutlich.

Decoding natural reach-and-grasp actions from human EEG

OBJECTIVE

Despite the high number of degrees of freedom of the human hand, most actions of daily life can be executed incorporating only palmar, pincer and lateral grasp. In this study we attempt to discriminate these three different executed reach-and-grasp actions utilizing their EEG neural correlates.

APPROACH

In a cue-guided experiment, 15 healthy individuals were asked to perform these actions using daily life objects. We recorded 72 trials for each reach-and-grasp condition and from a no-movement condition.

MAIN RESULTS

Using low-frequency time domain features from 0.3 to 3 Hz, we achieved binary classification accuracies of 72.4%, STD  ±  5.8% between grasp types, for grasps versus no-movement condition peak performances of 93.5%, STD  ±  4.6% could be reached. In an offline multiclass classification scenario which incorporated not only all reach-and-grasp actions but also the no-movement condition, the highest performance could be reached using a window of 1000 ms for feature extraction. Classification performance peaked at 65.9%, STD  ±  8.1%. Underlying neural correlates of the reach-and-grasp actions, investigated over the primary motor cortex, showed significant differences starting from approximately 800 ms to 1200 ms after the movement onset which is also the same time frame where classification performance reached its maximum.

SIGNIFICANCE

We could show that it is possible to discriminate three executed reach-and-grasp actions prominent in people's everyday use from non-invasive EEG. Underlying neural correlates showed significant differences between all tested conditions. These findings will eventually contribute to our attempt of controlling a neuroprosthesis in a natural and intuitive way, which could ultimately benefit motor impaired end users in their daily life actions.

Bone scintigraphy and clinical outcome in rheumatoid gonarthritis

Aim: For evaluation of the effect of radiosynoviorthesis (RSO) on the early and delayed uptake of 99mTc-biphosphonates and its relation to clinical outcome we studied these variables before and after radiosynoviorthesis performed on 41 knees affected by rheumatoid arthritis. Method: Thirty-seven patients with rheumatoid gonarthritis were treated by intraarticular injection with 185 MBq yttrium-90 citrate. In four of them both knees were treated so that 41 therapies were evaluated. On the average 35 days before and 120 days after radiosynoviorthesis, the early and delayed uptake of 99mTc-diphosphonate (DPD) was measured with a planar gamma camera. Early and late DPD uptake was quantified as a ratio between count values derived from rectangular ROIs placed on the knee treated and on the ipsilateral thigh. The severity of clinical symptoms was assessed on two 3-point rating scales averaged. Results: 30 of the 41 cases favorably responded to radiosynovior-thesis. There was a significant correlation between clinical outcome and pretherapeutic early DPD uptake (EDU) (p <0.05), but not between outcome and pretherapeutic late DPD uptake (DDU). In the whole group, EDU decreased in approximately 76% of cases after therapy (p <0.05), DDU in 54% (p >0.05). In 25 of the 30 responders EDU decreased; EDU increased or remained constant in five of the eleven non-responders. The correlation between outcome and the difference in EDU was significant (r = 0.344; p <0.05). There was no such significant relationship between the difference between pre- and posttherapeutic DDU and clinical course. Conclusion: Three-phase bone scintigraphy may contribute to predict and assess the success of radiosynovior-thesis in rheumatoid arthritis of the knee joint.

Klinische Anwendung der Computertomographie beim Rind

Die Computertomographie liefert mithilfe von Röntgenstrahlen Schnittbilder von Körperregionen. Diese zeigen eine überlagerungsfreie, zweidimensionale Darstellung aller gewünschten Ebenen und ermöglichen auch eine dreidimensionale Rekonstruktion interessierender Körperregionen. Berichte über die Computertomographie beim Rind finden sich nur vereinzelt. Hohe Kosten, medikamentöse Restriktionen und die notwendige Allgemeinanästhesie limitieren die Anwendungen. Indikationen beim Rind sind vor allem Erkrankungen des Kopfes – wie Zahnerkrankungen oder Otitis media – sowie neurologische Erkrankungen, weniger oft Erkrankungen der Wirbelsäule und Gliedmaßen. Bei wertvollen Rindern, bei denen eine operative Therapie geplant ist, kann die Computertomographie Befunde liefern, die für die Durchführung des Eingriffs entscheidend sind. Die computertomographischen Befunde können andererseits auch dazu beitragen, eine ungünstige Prognose zu erkennen und so unnötige Operationen zu vermeiden.

Cybathlon experiences of the Graz BCI racing team Mirage91 in the brain-computer interface discipline

BACKGROUND

In this work, we share our experiences made at the world-wide first CYBATHLON, an event organized by the Eidgenössische Technische Hochschule Zürich (ETH Zürich), which took place in Zurich in October 2016. It is a championship for severely motor impaired people using assistive prototype devices to compete against each other. Our team, the Graz BCI Racing Team MIRAGE91 from Graz University of Technology, participated in the discipline "Brain-Computer Interface Race". A brain-computer interface (BCI) is a device facilitating control of applications via the user's thoughts. Prominent applications include assistive technology such as wheelchairs, neuroprostheses or communication devices. In the CYBATHLON BCI Race, pilots compete in a BCI-controlled computer game.

METHODS

We report on setting up our team, the BCI customization to our pilot including long term training and the final BCI system. Furthermore, we describe CYBATHLON participation and analyze our CYBATHLON result.

RESULTS

We found that our pilot was compliant over the whole time and that we could significantly reduce the average runtime between start and finish from initially 178 s to 143 s. After the release of the final championship specifications with shorter track length, the average runtime converged to 120 s. We successfully participated in the qualification race at CYBATHLON 2016, but performed notably worse than during training, with a runtime of 196 s.

DISCUSSION

We speculate that shifts in the features, due to the nonstationarities in the electroencephalogram (EEG), but also arousal are possible reasons for the unexpected result. Potential counteracting measures are discussed.

CONCLUSIONS

The CYBATHLON 2016 was a great opportunity for our student team. We consolidated our theoretical knowledge and turned it into practice, allowing our pilot to play a computer game. However, further research is required to make BCI technology invariant to non-task related changes of the EEG.

A rare case of intramedullary solitary juvenile xanthogranuloma of the lumbar spine in the adult: a case report

Solitary juvenile xanthogranuloma (SJX) of the spine is an extremely rare proliferative histiocytic disorder with only few cases reported in literature. We present the first case of intramedullary spinal SJX. A 22-year-old male presented with a nine-month history of progressively worsening sphincteric disturbances and saddle hypoesthesia. Magnetic resonance imaging showed an intra-axial lesion located in the conus medullaris; T1 hypointense, T2 iso-hyperintense and uniformly enhancing after contrast administration. The lesion was removed through a T12-L1 laminectomy and a median myelotomy with neurophysiological monitoring. Histological examination and immunohistochemical testing confirmed the diagnosis of SJX. Due to the intramedullary localization and the absence of a clear cleavage plane, radical removal was not possible. The tumor subsequently recurred and new surgical procedures were necessary followed by adjuvant radiotherapy. Patient made good neurological recovery. Three years after the latest treatment, MRI showed no recurrence. In accordance with the literature, the treatment of choice for SJX its radical removal, or subtotal removal followed by adjuvant radiotherapy.