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Objective: The COVID-19 pandemic affected today more than 3,000,000 worldwide, and more than half of humanity has been placed in quarantine. The scientific community and the political authorities fear an epidemic of suicide secondary to this crisis. The aim of this review is to analyze the impact of the COVID-19 pandemic on the dimensions of the suicidal process and its interaction with the various risk factors. We also propose innovative strategies to manage suicidal behavior in the context of pandemic., Methods: We carried out a narrative review of international publications dealing with major pandemics (COVID-19, SARS) and their influence on suicidal vulnerability., Results: Many factors are likely to increase the emergence of suicidal ideation and suicide attempts during this crisis. Social distancing and quarantine could increase the feeling of disconnection and the perception of social pain in vulnerable individuals. Some populations at high suicidal risk could be further impacted by the current pandemic: the elderly, medical staff and individuals exposed to economic insecurity. Several innovative tools adapted to the constraints of social distancing and quarantine may prevent suicide risk: e-health, VigilanS, buddhist-derived practices and art engagement., Conclusions: This unprecedented crisis may interact with certain dimensions of the suicidal process. However, it is time to innovate. Several suicide prevention tools all have their place in new modes of care and should be tested on a large scale., (Copyright © 2020 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.)

Do the neural circuits for reading vary across culture? Reading of visually complex writing systems such as Chinese has been proposed to rely on areas outside the classical left-hemisphere network for alphabetic reading. Here, however, we show that, once potential confounds in cross-cultural comparisons are controlled for by presenting handwritten stimuli to both Chinese and French readers, the underlying network for visual word recognition may be more universal than previously suspected. Using functional magnetic resonance imaging in a semantic task with words written in cursive font, we demonstrate that two universal circuits, a shape recognition system (reading by eye) and a gesture recognition system (reading by hand), are similarly activated and show identical patterns of activation and repetition priming in the two language groups. These activations cover most of the brain regions previously associated with culture-specific tuning. Our results point to an extended reading network that invariably comprises the occipitotemporal visual word-form system, which is sensitive to well-formed static letter strings, and a distinct left premotor region, Exner's area, which is sensitive to the forward or backward direction with which cursive letters are dynamically presented. These findings suggest that cultural effects in reading merely modulate a fixed set of invariant macroscopic brain circuits, depending on surface features of orthographies.

Introduction: The first descriptions of transient global amnesia (TGA) were made in 1956 and 1958. Considering the large number of TGA reported since these original descriptions, it is not conceivable that TGA arose as a new entity in the mid-20th century. Many authors thus tried to understand why it had not been described by the authors of the late 19th and early 20th century. It was considered that TGA "was immersed in the literature on psychogenic amnesia" (Hodges, 1991) and particularly hysterical amnesia. But, can we consider that confusion between transient global amnesia and psychogenic amnesia truly existed?, Methods: The book of Paul Sollier, a student of Charcot and Ball, emphasizes the memory problems that were discussed in the second part of the 19th century., Results: The author presents a clear differentiation between hysterical amnesia and amnesia triggered by an emotional shock. The cases he proposed include characteristic descriptions of transient global amnesia observed after a violent emotional shock. Sollier, like Ball and his student Rouillard, also considered transient amnesias such as post-traumatic amnesias occurring after mild head trauma. The triggering role was assigned to the "moral emotion" that can provoke a modification of the encephalic circulation., Discussion: While TGA was not yet recognized as an entity, some French neurologists of the 19th century reported cases of temporary amnesias different from hysterical amnesia and occurring after an emotional shock, which were the first observations of the entity later recognized as TGA., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

The role of the insular lobe in temporal lobe epilepsy (TLE) has often been suggested but never directly demonstrated. In this article, we review data from recent literature and from our own stereo-electroencephalographic (SEEG) recordings in patients referred for temporal lobe epilepsy surgery. Our description of the clinical features of insular lobe seizures is based on data from video and SEEG ictal recordings and direct electric cortical stimulation in a population of 50 consecutive patients whose seizures, on the basis of scalp video EEG recordings, were suspected to originate from, or to rapidly propagate to, the perisylvian cortex. One hundred and forty-four intrainsular electrodes have been implanted in this series of patients. In six patients a stereotyped sequence of ictal symptoms could be identified on the basis of electroclinical correlations. The clinical presentation of insular lobe seizures is that of simple partial seizures occurring in full consciousness, beginning with a sensation of laryngeal constriction followed by paresthesiae that were often unpleasant and affected large cutaneous territories. These initial symptoms were eventually followed by dysarthric speech and/or elementary auditory hallucinations, and seizures often ended with focal dystonic postures. The insular origin of these symptoms was supported by the data from functional cortical mapping of the insula using direct cortical stimulations from a total of 472 intrainsular electrodes in 164 consecutive patients. We were able to reproduce several of the spontaneous ictal symptoms in the six patients with insular seizures. Moreover, from the whole set of insular stimulations that we performed it could be concluded that the insular cortex is involved in somatic, vegetative and visceral functions to which spontaneous ictal insular symptoms are related. The observation of the insular symptoms sequence at the onset of seizures in patients who are candidates for TLE surgery strongly suggests that the epileptic focus is located in the insular lobe. It entails the risk of unsuccessful temporal lobectomy and should lead to reconsider the indication of temporal lobectomy and to explore directly the ictal activity of both mesiotemporal and insular cortices before making any decision regarding epilepsy surgery.

Although rejected for the most part of the 20th Century, the idea of brain plasticity began to receive wide acceptance from the 1970s. Yet there has been relatively little theoretical comment on the definition and use of "plasticity" in the field of neurobiology. An early exception to this lack of critical reflection on neural plasticity was provided by Jacques Paillard in a seminal paper that he published in 1976 [Paillard J. Réflexions sur l'usage du concept de plasticité en neurobiology. J Psychol 1976;1:33-47]. As this valuable contribution was published in French, the present authors provide an English adaptation to help convey his ideas to an international audience, together with a contemporary commentary on this paper. Paillard's definition of the term "plasticity" is probably as pertinent today as it was 30 years ago, especially in terms of its relevance to multiple levels of analysis of brain function (molecular, cellular, systemic). Sadly, Jacques Paillard died in 2006; our comments therefore also include a brief biographical tribute to this outstanding neuroscientist.

In this paper we present a methodology to address the problem of brain tissue deformation referred to as 'brain-shift'. This deformation occurs throughout a neurosurgery intervention and strongly alters the accuracy of the neuronavigation systems used to date in clinical routine which rely solely on pre-operative patient imaging to locate the surgical target, such as a tumour or a functional area. After a general description of the framework of our intra-operative image-guided system, we describe a procedure to generate patient specific finite element meshes of the brain and propose a biomechanical model which can take into account tissue deformations and surgical procedures that modify the brain structure, like tumour or tissue resection.

One of the functions of everyday human language is to communicate meaning. Thus, when one hears or reads the sentence, "John gave a book to Mary," some aspect of an event concerning the transfer of possession of a book from John to Mary is (hopefully) transmitted. One theoretical approach to language referred to as construction grammar emphasizes this link between sentence structure and meaning in the form of grammatical constructions. The objective of the current research is to (1) outline a functional description of grammatical construction processing based on principles of psycholinguistics, (2) develop a model of how these functions can be implemented in human neurophysiology, and then (3) demonstrate the feasibility of the resulting model in processing languages of typologically diverse natures, that is, English, French, and Japanese. In this context, particular interest will be directed toward the processing of novel compositional structure of relative phrases. The simulation results are discussed in the context of recent neurophysiological studies of language processing.

The studies of Paul Bert, presented in his book "La Pression Barométrique" in 1878, were at the origin of the modern hyperbaric physiology. Indeed his research demonstrated the effects of oxygen at high pressure, that compression effects must be dissociated from decompression effects, and that neurological troubles and death of divers during or after decompression were due to the fast rate of decompression. However, it is only in 1935 that the work of Behnke et al. attributed the complaints reported at 3 bars and above in compressed air or nitrogen-oxygen mixture to the increase in partial pressure of nitrogen which induces nitrogen narcosis. Little is known about the origins and mechanisms of this narcosis. The traditional view was that anaesthesia or narcosis occurred when the volume of a hydrophobic membrane site was caused to expand beyond a critical amount by the absorption of molecules of a narcotic gas. The observation of the pressure reversal effect during general anaesthesia has long supported this lipid theory. However, recently, protein theories have met with increasing recognition since results with gaseous anaesthetics have been interpreted as evidence for a direct gas-protein interaction. The question is to know whether inert gases, that disrupt dopamine and GABA neurotransmissions and probably glutamatergic neurotransmission, act by binding to neurotransmitter protein receptors.

This paper introduces a method to study the variation of brain functional connectivity networks with respect to experimental conditions in fMRI data. It is related to the psychophysiological interaction technique introduced by Friston et al. and extends to networks of correlation modulation (CM networks). Extended networks containing several dozens of nodes are determined in which the links correspond to consistent correlation modulation across subjects. In addition, we assess inter-subject variability and determine networks in which the condition-dependent functional interactions can be explained by a subject-dependent variable. We applied the technique to data from a study on syntactical production in bilinguals and analysed functional interactions differentially across tasks (word reading or sentence production) and across languages. We find an extended network of consistent functional interaction modulation across tasks, whereas the network comparing languages shows fewer links. Interestingly, there is evidence for a specific network in which the differences in functional interaction across subjects can be explained by differences in the subjects' syntactical proficiency. Specifically, we find that regions, including ones that have previously been shown to be involved in syntax and in language production, such as the left inferior frontal gyrus, putamen, insula, precentral gyrus, as well as the supplementary motor area, are more functionally linked during sentence production in the second, compared with the first, language in syntactically more proficient bilinguals than in syntactically less proficient ones. Our approach extends conventional activation analyses to the notion of networks, emphasizing functional interactions between regions independently of whether or not they are activated. On the one hand, it gives rise to testable hypotheses and allows an interpretation of the results in terms of the previous literature, and on the other hand, it provides a basis for studying the structure of functional interactions as a whole, and hence represents a further step towards the notion of large-scale networks in functional imaging.

Background: There is no consensus method for determining progression of disability in patients with multiple sclerosis (MS) when each patient has had only a single assessment in the course of the disease., Methods: Using data from two large longitudinal databases, the authors tested whether cross-sectional disability assessments are representative of disease severity as a whole. An algorithm, the Multiple Sclerosis Severity Score (MSSS), which relates scores on the Expanded Disability Status Scale (EDSS) to the distribution of disability in patients with comparable disease durations, was devised and then applied to a collection of 9,892 patients from 11 countries to create the Global MSSS. In order to compare different methods of detecting such effects the authors simulated the effects of a genetic factor on disability., Results: Cross-sectional EDSS measurements made after the first year were representative of overall disease severity. The MSSS was more powerful than the other methods the authors tested for detecting different rates of disease progression., Conclusion: The Multiple Sclerosis Severity Score (MSSS) is a powerful method for comparing disease progression using single assessment data. The Global MSSS can be used as a reference table for future disability comparisons. While useful for comparing groups of patients, disease fluctuation precludes its use as a predictor of future disability in an individual.

Objective: To estimate the statistical distribution of the incubation period of Creutzfeldt-Jakob disease (CJD) in human growth hormone (hGH) recipients in France., Background: Published papers suggest that the median incubation period of hGH-related CJD is approximately 15 years, but there are as yet no statistical data that support this assertion., Methods: Of the 1,361 hGH recipients who were included in this study, 55 had developed CJD at the time of the study. Individual data on hGH treatment history were available. Different mathematical models were used to estimate the statistical distribution of the incubation period. One main feature of the models was to take into account the occurrence of future CJD cases., Results: Models showed that the mean incubation period was 9 to 10 years, and the 95th percentile of the distribution was 15 to 16 years. Data and models indicated that the incubation period was significantly shorter in homozygotes at codon 129 of the prion protein gene than in heterozygotes., Conclusions: The short mean incubation period of CJD in French hGH recipients may be due to high infectivity in hormone lots. Estimates of the 95th percentile indicate that the number of hGH-related CJD cases may continue to increase in the coming years.

It is now 83 years that Guillain, Barré and Strohl described the first two cases of an acute paralytic illness with the typical "dissociation albumino-cytologique" in the cerebrospinal fluid. Since then, the full spectrum of GBS has been documented in hundreds of cases ranging from acute inflammatory demyelinating polyneuropathy to the pure motor variants and the Miller Fisher syndrome. During the last 10 years, detailed immunopathologic features have been described and new triggering and possibly causative agents identified, the most prominent being the enteritic bacterium Campylobacter jejuni. Besides the pathogenic role of cell-mediated immunity, IgG antibodies have now been discovered which block neuromuscular transmission. Established treatments include plasma exchange therapy and intravenous immunoglobulin G. Together with sophisticated intensive care measures, mortality has now been reduced to below 5p. 100 with these treatment modalities. Several treatment strategies that proved effective in the animal model of GBS need to be studied in future clinical trials.

During his entire career Jean Martin Charcot published or lectured on aphasia and brain localization in man. He contributed case studies during the early 1860s, while in the 1870s he became the leading French promoter of localizationism. It was in 1883 and 1884 that he summarized his thoughts on aphasia in a series of 14 lectures he delivered at the Salpêtrière Hospice. His paramount ambition was to achieve didactic clarity. His proposed "bell diagram" was widely criticized for its simplicity, but nevertheless gained considerable popularity in France. His teaching borrowed extensively from the writings of contemporary researchers and was clearly associationist in nature. Charcot's major contribution in the history of aphasiology is that he introduced the works of "diagram-makers" to the French scientific community at large. Charcot's lecture series also played a key role in renewing interest in psychology. Charcot's dismissal of experimental physiology as a legitimate means of investigating central nervous functions in man allowed him to define a separate field of research for a new psychology, one, he believed, which should depart from introspection and turn to his clinicoanatomic method for guidance.