Faculty Bibliography

OBJECTIVE:To analyze the association between peri-ictal brainstem posturing semiologies with post-ictal generalized electroencephalographic suppression (PGES) and breathing dysfunction in generalized convulsive seizures (GCS). METHODS:Prospective, multicenter analysis of GCS. Ictal brainstem semiology was classified as (1) decerebration: bilateral symmetric tonic arm extension, (2) decortication: bilateral symmetric tonic arm flexion only, (3) hemi-decerebration: unilateral tonic arm extension with contralateral flexion and (4) absence of ictal tonic phase. Post-ictal posturing was also assessed. Respiration was monitored using thoraco-abdominal belts, video and pulse oximetry. RESULTS:= 0.035). CONCLUSIONS:recovery. Peri-ictal brainstem posturing may be surrogate biomarkers for GCS severity identifiable without in-hospital monitoring. CLASSIFICATION OF EVIDENCE/METHODS:This study provides Class III evidence that peri-ictal brainstem posturing is associated with the GCS with more prolonged PGES and more severe breathing dysfunction.

PURPOSE OF REVIEW/OBJECTIVE:The mental health toll on populations exposed to COVID-19 is alarming, and there is a need to address this with urgency. This current review provides insights on how individuals, communities, and specific populations, such as healthcare workers and patients are leveraging pre-COVID-19 and peri-COVID-19 factors to reinforce their psychological resilience during the global public health crisis. RECENT FINDINGS/RESULTS:Examination of the extant literature indicated that populations around the world rely often on support from their loved-ones, closed significant others, outdoor and physical activities, and spirituality to cope with the COVID-19-related distress. Increased sense of meaning/purpose since the COVID-19 pandemic was also reported. SUMMARY/CONCLUSIONS:A portion of publications provided intervention models to reinforce resilience among specific populations during the COVID-19 pandemic. Nevertheless, it is not convincing that some of these models can be applied universally. Additionally, it is important to note that in this category, translational data was scarce.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare, relapsing-remitting neuroinflammatory disorder of the central nervous system. Advances in the understanding of NMOSD pathogenesis and identification of the NMO-specific pathogenic anti-AQP4 autoantibody have led to the development of highly effective disease-modifying strategies. Five placebo-controlled, randomized trials for NMOSD have been successfully completed as of 2020. These trials support the efficacy of rituximab and tocilizumab and led to the FDA approval of eculizumab, satralizumab and inebilizumab for NMOSD. Our review provides an update on these evidence-based disease-modifying therapies and discussed the treatment of acute relapses in NMOSD.

Analyzing neuronal activity during human seizures is pivotal to understanding mechanisms of seizure onset and propagation. These analyses, however, invariably using extracellular recordings, are greatly hindered by various phenomena that are well established in animal studies: changes in local ionic concentration, changes in ionic conductance, and intense, hypersynchronous firing. The first two alter the action potential waveform, whereas the third increases the "noise"; all three factors confound attempts to detect and classify single neurons. To address these analytical difficulties, we developed a novel template-matching based spike sorting method, which enabled identification of 1,239 single neurons in 27 patients (13 female) with intractable focal epilepsy, that were tracked throughout multiple seizures. These new analyses showed continued neuronal firing with widespread intense activation and stereotyped action potential alterations in tissue that was invaded by the seizure: neurons displayed increased waveform duration (p < 0.001) and reduced amplitude (p < 0.001), consistent with prior animal studies. By contrast, neurons in "penumbral" regions (those receiving intense local synaptic drive from the seizure but without neuronal evidence of local seizure invasion) showed stable waveforms. All neurons returned to their pre-ictal waveforms after seizure termination. We conclude that the distinction, between "core" territories invaded by the seizure, versus "penumbral" territories, is evident at the level of single neurons. Furthermore, the increased waveform duration and decreased waveform amplitude are neuron-intrinsic hallmarks of seizure invasion that impede traditional spike sorting and could be used as defining characteristics of local recruitment.SIGNIFICANCE STATEMENTAnimal studies consistently show marked changes in action potential waveform during epileptic discharges, but acquiring similar evidence in humans has proven difficult. Assessing neuronal involvement in ictal events is pivotal to understanding seizure dynamics and in defining clinical localization of epileptic pathology. Using a novel method to track neuronal firing, we analyzed microelectrode array recordings of spontaneously occurring human seizures, and here report two dichotomous activity patterns. In cortex that is recruited to the seizure, neuronal firing rates increase and waveforms become longer in duration and shorter in amplitude as the neurons are recruited to the seizure, while penumbral tissue shows stable action potentials, in keeping with the "dual territory" model of seizure dynamics.

Systemic autoimmune disorders occur more frequently in patients with epilepsy than in the general population, suggesting shared disease mechanisms. The risk of epilepsy is elevated across the spectrum of systemic autoimmune disorders but is highest in systemic lupus erythematosus and type 1 diabetes mellitus. Vascular and metabolic factors are the most important mediators between systemic autoimmune disorders and epilepsy. Systemic immune dysfunction can also affect neuronal excitability, not only through innate immune activation and blood-brain barrier dysfunction in most epilepsies but also adaptive immunity in autoimmune encephalitis. The presence of systemic autoimmune disorders in subjects with acute seizures warrants evaluation for infectious, vascular, toxic and metabolic causes of acute symptomatic seizures, but clinical signs of autoimmune encephalitis should not be missed. Immunosuppressive medications may have antiseizure properties and trigger certain drug interactions with antiseizure treatments. A better understanding of mechanisms underlying the co-existence of epilepsy and systemic autoimmune disorders is needed to guide new antiseizure and anti-epileptogenic treatments. This review aims to summarize the epidemiological evidence for systemic autoimmune disorders as comorbidities of epilepsy, explore potential immune and non-immune mechanisms, and provide practical implications on diagnostic and therapeutic approach to epilepsy in those with comorbid systemic autoimmune disorders.

This article is based on a consensus conference, promoted and supported by the International Federation of Clinical Neurophysiology (IFCN), which took place in Siena (Italy) in October 2018. The meeting intended to update the ten-year-old safety guidelines for the application of transcranial magnetic stimulation (TMS) in research and clinical settings (Rossi et al., 2009). Therefore, only emerging and new issues are covered in detail, leaving still valid the 2009 recommendations regarding the description of conventional or patterned TMS protocols, the screening of subjects/patients, the need of neurophysiological monitoring for new protocols, the utilization of reference thresholds of stimulation, the managing of seizures and the list of minor side effects. New issues discussed in detail from the meeting up to April 2020 are safety issues of recently developed stimulation devices and pulse configurations; duties and responsibility of device makers; novel scenarios of TMS applications such as in the neuroimaging context or imaging-guided and robot-guided TMS; TMS interleaved with transcranial electrical stimulation; safety during paired associative stimulation interventions; and risks of using TMS to induce therapeutic seizures (magnetic seizure therapy). An update on the possible induction of seizures, theoretically the most serious risk of TMS, is provided. It has become apparent that such a risk is low, even in patients taking drugs acting on the central nervous system, at least with the use of traditional stimulation parameters and focal coils for which large data sets are available. Finally, new operational guidelines are provided for safety in planning future trials based on traditional and patterned TMS protocols, as well as a summary of the minimal training requirements for operators, and a note on ethics of neuroenhancement.

OBJECTIVE:Emerging data indicates an increased risk for cerebrovascular events with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus and highlights the potential impact of coronavirus disease (COVID-19) on the management and outcomes of acute stroke. We conducteda systematic review and meta-analysis to evaluate the aforementioned considerations. METHODS:We performed a meta-analysis of observational cohort studies reporting on the occurrence and/or outcomes of patients with cerebrovascular events in association with their SARS-CoV-2 infection status. We used a random-effects model. Summary estimates were reported as odds ratios (ORs) and corresponding 95% confidence intervals (95%CI). RESULTS:=45%). INTERPRETATION/CONCLUSIONS:SARS-CoV-2 appears to be associated with an increased risk of ischemic stroke, and potentially cryptogenic stroke in particular. It may also be related to an increased mortality risk. This article is protected by copyright. All rights reserved.

Prior knowledge profoundly influences perceptual processing. Previous studies have revealed consistent suppression of predicted stimulus information in sensory areas, but how prior knowledge modulates processing higher up in the cortical hierarchy remains poorly understood. In addition, the mechanism leading to suppression of predicted sensory information remains unclear, and studies thus far have revealed a mixed pattern of results in support of either the 'sharpening' or 'dampening' model. Here, using 7T fMRI in humans (both sexes), we observed that prior knowledge acquired from fast, one-shot perceptual learning sharpens neural representation throughout the ventral visual stream, generating suppressed sensory responses. In contrast, the frontoparietal (FPN) and default-mode (DMN) networks exhibit similar sharpening of content-specific neural representation but in the context of unchanged and enhanced activity magnitudes, respectively-a pattern we refer to as 'selective enhancement'. Together, these results reveal a heretofore unknown macroscopic gradient of prior knowledge's sharpening effect on neural representations across the cortical hierarchy.SIGNIFICANCE STATEMENT:A fundamental question in neuroscience is how prior knowledge shapes perceptual processing. Perception is constantly informed by internal priors in the brain acquired from past experiences, but the neural mechanisms underlying this process are poorly understood. To date, research on this question has focused on early visual regions, reporting a consistent downregulation when predicted stimuli are encountered. Here, using a dramatic one-shot perceptual learning paradigm, we observed that prior knowledge results in sharper neural representations across the cortical hierarchy of the human brain through a gradient of mechanisms. In visual regions, neural responses tuned away from internal predictions are suppressed. In frontoparietal regions, neural activity consistent with priors is selectively enhanced. These results deepen our understanding of how prior knowledge informs perception.

Neural activity exhibits complex dynamics related to various brain functions, internal states and behaviors. Understanding how neural dynamics explain specific measured behaviors requires dissociating behaviorally relevant and irrelevant dynamics, which is not achieved with current neural dynamic models as they are learned without considering behavior. We develop preferential subspace identification (PSID), which is an algorithm that models neural activity while dissociating and prioritizing its behaviorally relevant dynamics. Modeling data in two monkeys performing three-dimensional reach and grasp tasks, PSID revealed that the behaviorally relevant dynamics are significantly lower-dimensional than otherwise implied. Moreover, PSID discovered distinct rotational dynamics that were more predictive of behavior. Furthermore, PSID more accurately learned behaviorally relevant dynamics for each joint and recording channel. Finally, modeling data in two monkeys performing saccades demonstrated the generalization of PSID across behaviors, brain regions and neural signal types. PSID provides a general new tool to reveal behaviorally relevant neural dynamics that can otherwise go unnoticed.

OBJECTIVE:To better characterize COVID-19 patients most at risk for severe, outpatient thrombosis by defining patients hospitalized with COVID-19 with an arterial or venous thrombosis diagnosed at admission METHODS AND RESULTS: We conducted a single center retrospective analysis of COVID-19 patients. There was a shift in the proportions of thrombosis subtypes from 2019 to 2020, with declines in STEMI (from 22.0% to 10.1% of thrombotic events) and stroke (from 48.6% to 37.2%), and an increase in the proportion of patients with VTE (29.4% to 52.7%). COVID-associated thrombosis were younger (58 years vs. 64 years, p=0.043), trended to be less frequently female (31.3% vs. 43.9%, p =0.16), but there was no difference body mass index or major comorbidities between those with and without COVID-19. COVID-19-associted thrombosis was correlated with a higher mortality (15.2% vs. 4.3%, p=0.016). The biometric profile of patients admitted with COVID-associated thrombosis compared to regular thrombosis had significant changes in the complete blood count, liver function tests, d-dimer, c-related protein, ferritin, and coagulation panels. CONCLUSIONS:Outpatients with COVID-19 who developed thrombosis requiring hospitalization have an increased mortality over non-COVID-19 outpatients who develop thrombosis requiring hospitalization. Given the significantly higher inflammatory markers, it is possible this is related to different mechanisms of thrombotic disease in these patients. The inflammation may be a target to reduce the risk of or aid in the treatment of thrombosis. We call for more studies elucidating the role immunothrombosis maybe playing in COVID.