Simultaneous stereo-EEG and high-density scalp EEG recordings to study the effects of intracerebral stimulation parameters

BACKGROUND

Cortico-cortical evoked potentials (CCEPs) recorded by stereo-electroencephalography (SEEG) are a valuable tool to investigate brain reactivity and effective connectivity. However, invasive recordings are spatially sparse since they depend on clinical needs. This sparsity hampers systematic comparisons across-subjects, the detection of the whole-brain effects of intracortical stimulation, as well as their relationships to the EEG responses evoked by non-invasive stimuli.

OBJECTIVE

To demonstrate that CCEPs recorded by high-density electroencephalography (hd-EEG) provide additional information with respect SEEG alone and to provide an open, curated dataset to allow for further exploration of their potential.

METHODS

The dataset encompasses SEEG and hd-EEG recordings simultaneously acquired during Single Pulse Electrical Stimulation (SPES) in drug-resistant epileptic patients (N = 36) in whom stimulations were delivered with different physical, geometrical, and topological parameters. Differences in CCEPs were assessed by amplitude, latency, and spectral measures.

RESULTS

While invasively and non-invasively recorded CCEPs were generally correlated, differences in pulse duration, angle and stimulated cortical area were better captured by hd-EEG. Further, intracranial stimulation evoked site-specific hd-EEG responses that reproduced the spectral features of EEG responses to transcranial magnetic stimulation (TMS). Notably, SPES, albeit unperceived by subjects, elicited scalp responses that were up to one order of magnitude larger than the responses typically evoked by sensory stimulation in awake humans.

CONCLUSIONS

CCEPs can be simultaneously recorded with SEEG and hd-EEG and the latter provides a reliable descriptor of the effects of SPES as well as a common reference to compare the whole-brain effects of intracortical stimulation to those of non-invasive transcranial or sensory stimulations in humans.

Excimer laser technology in percutaneous coronary interventions: Cardiovascular laser society's position paper

Excimer Laser Coronary Atherectomy (ELCA) is a well-established therapy that emerged for the treatment of peripheral vascular atherosclerosis in the late 1980s, at a time when catheters and materials were rudimentary and associated with the most serious complications. Refinements in catheter technology and the introduction of improved laser techniques have led to their effective use for the treatment of a wide spectrum of complex coronary lesions, such as thrombotic lesions, severe calcific lesions, non-crossable or non-expandable lesions, chronic occlusions, and stent under-expansion. The gradual introduction of high-energy strategies combined with the contrast infusion technique has enabled us to treat an increasing number of complex cases with a low rate of periprocedural complications. Currently, the use of the ELCA has also been demonstrated to be effective in acute coronary syndrome (ACS), especially in the context of large thrombotic lesions.

Prognostic value of SARS-CoV-2 on patients undergoing cardiac surgery

Objective

To analyze Italian Cardiac Surgery experience during the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) identifying risk factors for overall mortality according to coronavirus disease 2019 (COVID‐19) status.

Methods

From February 20 to May 31, 2020, 1354 consecutive adult patients underwent cardiac surgery at 22 Italian Centers; 589 (43.5%), patients came from the red zone. Based on COVID‐19 status, 1306 (96.5%) were negative to SARS‐CoV‐2 (COVID‐N), and 48 (3.5%) were positive to SARS‐CoV‐2 (COVID‐P); among the COVID‐P 11 (22.9%) and 37 (77.1%) become positive, before and after surgery, respectively. Surgical procedures were as follows: 396 (29.2%) isolated coronary artery bypass grafting (CABG), 714 (52.7%) isolated non‐CABG procedures, 207 (15.3%) two associate procedures, and three or more procedures in 37 (2.7%). Heart failure was significantly predominant in group COVID‐N (10.4% vs. 2.5%, p = .01).

Results

Overall in‐hospital mortality was 1.6% (22 cases), being significantly higher in COVID‐P group (10 cases, 20.8% vs. 12, 0.9%, p < .001). Multivariable analysis identified COVID‐P condition as a predictor of in‐hospital mortality together with emergency status. In the COVID‐P subgroup, the multivariable analysis identified increasing age and low oxygen saturation at admission as risk factors for in‐hospital mortality.

Conclusion

As expected, SARS‐CoV‐2 infection, either before or soon after cardiac surgery significantly increases in‐hospital mortality. Moreover, among COVID‐19‐positive patients, older age and poor oxygenation upon admission seem to be associated with worse outcomes.

How to cope in heterogeneous coastal environments: Spatio-temporally endogenous circadian rhythm of valve gaping by mussels

Transitional coastal zones are subject to high degrees of temporal fluctuation in environmental conditions, with these patterns varying in space. Gaining an in depth understanding of how sessile organisms cope with and respond to such environmental changes at multiple scales is needed to i) advance fundamental knowledge, ii) predict how organisms may react to stressors and iii) support the management of halieutic resources in transitional coastal areas. We addressed this question using mussels (Mytilus galloprovincialis) as model system. Valve-gaping sensor were deployed at multiple sites within the southern Venice Lagoon over a period of 6 months, to investigate the existence of periodicity in valve-gaping and its relationship with environmental variables, such as temperature and chlorophyll-a. Gaping behaviour was found to have periodic rhythms, of ~12 h and ~ 24 h, which were most pronounced in the inner part of lagoon part and were strongest during summer months. In autumn, the dual periodicity became weaker and mostly the 12 h remained. Gaping was closely linked with tide, but the relationship in terms of phasing varied upon location. Surprisingly, no clear direct relationships were found with chlorophyll-a, but food delivery may be mediated by tide itself. The results highlight the heterogeneity of behaviour and the endogenic nature of circadian rhythms in space and time. These findings have important implications for management of transitional areas where tidal alteration may have impacts on key behaviours, and emphasize the importance of characterizing their rhythms before using these as stress indicator. Moreover, the described tidal relationships should be included in growth models of bivalves in these systems.

Focal lesions induce large-scale percolation of sleep-like intracerebral activity in awake humans

Focal cortical lesions are known to result in large-scale functional alterations involving distant areas; however, little is known about the electrophysiological mechanisms underlying these network effects. Here, we addressed this issue by analysing the short and long distance intracranial effects of controlled structural lesions in humans. The changes in Stereo-Electroencephalographic (SEEG) activity after Radiofrequency-Thermocoagulation (RFTC) recorded in 21 epileptic subjects were assessed with respect to baseline resting wakefulness and sleep activity. In addition, Cortico-Cortical Evoked Potentials (CCEPs) recorded before the lesion were employed to interpret these changes with respect to individual long-range connectivity patterns. We found that small structural ablations lead to the generation and large-scale propagation of sleep-like slow waves within the awake brain. These slow waves match those recorded in the same subjects during sleep, are prevalent in perilesional areas, but can percolate up to distances of 60 mm through specific long-range connections, as predicted by CCEPs. Given the known impact of slow waves on information processing and cortical plasticity, demonstrating their intrusion and percolation within the awake brain add key elements to our understanding of network dysfunction after cortical injuries.

The rise of organ donation after circulatory death: a narrative review

Solid organ transplantation saves and transforms lives. The original type of organ donation from deceased patients was controlled donation after circulatory death, previously referred to as non-heart beating organ donation. The rise of donation after circulatory death in the UK came about through advances in critical care and transplant medicine and support from several key organisations in developing a robust ethical, legal and professional framework. The transplant waiting list reached a historic peak in 2009-2010 of 8000 patients, but fell by 25% to 6000 in 2017-2018. There has also been a steady rise in the number of deceased donors and the number of donations after circulatory death. The contribution of donation after circulatory death to the total number of donations rose steadily between 2000 and 2012 and has remained about 40% since. Although the situation has improved for patients waiting for a transplant, deaths and long waits remain common. Changes to legislative, technical and peri-mortem procedures may greatly change future practices in donation after circulatory death in the UK.

Intercepting Parkinson disease non-motor subtypes: A proof-of-principle study in a clinical setting

The construct of non-motor symptoms (NMS) subtyping in Parkinson Disease (PD) is emerging as a line of research in the light of its potential role in etiopathological interpretation of PD heterogeneity. Different approaches of NMS subtyping have been proposed: an anatomical model suggests that NMS aggregate according to the underpinning pathology; other researchers find aggregation of NMS according to the motor phenotype; the contribution of genetic background to NMS has also been assessed, primarily focusing on cognitive impairment. We have analyzed NMS burden assessed through an extensive clinical and neuropsychological battery in 137 consecutive non-demented PD patients genotyped for MAPT haplotypes (H1/H1 vs H2 carriers) in order to explore the applicability of the "anatomo-clinical", "motor" or "genetic" models for subtyping PD in a clinical setting; a subsequent independent analysis was conducted to verify a possible cluster distribution of NMS. No clear-cut NMS profiles according to the previously described models emerged: in our population, the autonomic dysfunctions and depressive symptoms represent the leading determinant of NMS clusters, which seems to better fit with the hypothesis of a "neurotransmitter-based" model. Selective preferential neurotransmitter network dysfunctions may account for heterogeneity of PD and could address translational research.

Functional Clustering approach for the analysis of Stereo-EEG activity patterns in correspondence of epileptic seizures

In this study, a functional clustering approach is proposed and tested for the identification of brain functional networks emerging during sleep-related seizures. Stereo-EEG signals recorded in patients with Type II Focal Cortical Dysplasia (FCD type II), were analyzed. This novel approach is able to identify the network configuration changes in pre-ictal and early ictal periods, by grouping Stereo-EEG signals on the basis of the Cluster Index, after wavelet multiscale decomposition. Results showed that the proposed method is able to detect clusters of interacting leads, mainly overlapped on the Epileptogenic Zone (EZ) identified by a clinical expert, with distinctive configurations related to analyzed frequency ranges. This suggested the presence of coupling activities between the elements of the epileptic system at different frequency scales.

Adaptation and psychometric properties of the Italian version of the Non-Motor Symptoms Questionnaire for Parkinson's disease

Although non-motor symptoms (NMS) of Parkinson's disease (PD) are very common also in early stages of the disease, they are still under-recognized. Screening tools for non-motor symptoms, such as non-motor symptoms questionnaire (NMSQuest), help clinicians to recognize NMS and to evaluate if patients could require further assessment or specific treatments. To validate an adapted Italian version of NMSQuest and study its psychometric properties, Italian PD patients self-completed Italian NMSQuest, and then underwent a standard clinical evaluation including motor assessment (by Hoehn and Yahr staging, unified Parkinson's disease rating scale part III) and non-motor assessment (by Montreal cognitive assessment, Beck depression inventory, neuropsychiatric inventory, Epworth sleepiness scale, scale for outcomes in Parkinson's disease-Autonomic and movement disorder society-sponsored revision of the unified Parkinson's disease rating scale part I). Somatic comorbidities were quantified using the modified cumulative illness rating scale (CIRS). Seventy-one subjects were assessed (mean age years 69.8 ± 9.6 SD; 31% women; mean duration of disease 6.3 ± 4.6 years; H&Y median 2). Italian NMSQuest showed adequate satisfactory clinimetrics in terms of data quality, precision, acceptability, internal consistency and reliability. A significant correlation was found between NMSQuest and most of non-motor assessment scales, while no significant correlation appeared with motor severity as well as with age of patients, disease duration, levodopa equivalent daily dose, L-DOPA/dopamine agonists assumption and CIRS total score. The Italian version of the NMSQuest resulted as a reliable instrument for screening NMS in Italian PD patients.

Validation of viscoelastic coagulation tests during cardiopulmonary bypass

BACKGROUND

Viscoelastic point-of-care tests such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are increasingly used to guide hemostatic therapy after cardiac surgery. The aim of this study was to assess their clinical utility during cardiopulmonary bypass to predict postbypass coagulation status and to guide therapy.

METHODS

In this prospective study, TEG and ROTEM tests were performed in 52 adult patients undergoing elective cardiac surgery at two time points: near the end of cardiopulmonary bypass and after heparin reversal with protamine. The 95% confidence intervals of the mean difference were compared with a prespecified clinically relevant limit of ± 20% of the value after protamine.

RESULTS

Both viscoelastic fibrinogen assays were well within the prespecified clinically relevant limit (≥ 79% of patients). The laboratory Clauss fibrinogen was much lower during cardiopulmonary bypass than after protamine (mean difference 1.2 g L(-1) , 95% CI 1.03-1.4, which was outside a clinically acceptable difference. For intrinsically activated tests, clotting times (CT) were different and outside the prespecified limit on TEG (mean difference -1.2 min, 95% CI -1.8 to -0.6) but not on ROTEM (mean difference 2.3 sec, 95% CI -8.6 to 13.2), while clot strength was well within the clinical limit on both devices (≥ 94% of patients). For extrinsically activated tests, clot strength on both TEG and ROTEM was within the pre-specified limit in 98% of patients.

CONCLUSIONS

Results from TEG and ROTEM tests performed toward the end of cardiopulmonary bypass are similar to results after reversal of heparin. Amplitudes indicating clot strength were the most stable parameters across all tests, whereas CT showed more variability. In contrast, laboratory testing of fibrinogen using the Clauss assay was essentially invalid during cardiopulmonary bypass.