Electroencephalography microstates highlight specific mindfulness traits.

The present study aimed to investigate the spontaneous dynamics of large-scale brain networks underlying mindfulness as a dispositional trait, through resting-state electroencephalography (EEG) microstates analysis. Eighteen participants had attended a standardized mindfulness-based stress reduction training (MBSR), and 18 matched waitlist individuals (CTRL) were recorded at rest while they were passively exposed to auditory stimuli. Participants' mindfulness traits were assessed with the Five Facet Mindfulness Questionnaire (FFMQ). To further explore the relationship between microstate dynamics at rest and mindfulness traits, participants were also asked to rate their experience according to five phenomenal dimensions. After training, MBSR participants showed a highly significant increase in FFMQ score, as well as higher observing and non-reactivity FFMQ sub-scores than CTRL participants. Microstate analysis revealed four classes of microstates (A-D) in global clustering across all subjects. The MBSR group showed lower duration, occurrence and coverage of microstate C than the control group. Moreover, these microstate C parameters were negatively correlated to non-reactivity sub-scores of FFMQ across participants, whereas the microstate A occurrence was negatively correlated to FFMQ total score. Further analysis of participants' self-reports suggested that MBSR participants showed a better sensory-affective integration of auditory interferences. In line with previous studies, our results suggest that temporal dynamics of microstate C underlie specifically the non-reactivity trait of mindfulness. These findings encourage further research into microstates in the evaluation and monitoring of the impact of mindfulness-based interventions on the mental health and well-being of individuals.

[Mirror neurons, neural substrate of action understanding?] / Neurones miroirs, substrat neuronal de la compréhension de l'action?

In 1992, the Laboratory of Human Physiology at the University of Parma (Italy) publish a study describing "mirror" neurons in the macaque that activate both when the monkey performs an action and when it observes an experimenter performing the same action. The research team behind this discovery postulates that the mirror neurons system is the neural basis of our ability to understand the actions of others, through the motor mapping of the observed action on the observer's motor repertory (direct-matching hypothesis). Nevertheless, this conception met serious criticism. These critics attempt to relativize their function by placing them within a network of neurocognitive and sensory interdependencies. In short, the essential characteristic of these neurons is to combine the processing of sensory information, especially visual, with that of motor information. Their elementary function would be to provide a motor simulation of the observed action, based on visual information from it. They can contribute, with other non-mirror areas, to the identification/prediction of the action goal and to the interpretation of the intention of the actor performing it. Studying the connectivity and high frequency synchronizations of the different brain areas involved in action observation would likely provide important information about the dynamic contribution of mirror neurons to "action understanding". The aim of this review is to provide an up-to-date analysis of the scientific evidence related to mirror neurons and their elementary functions, as well as to shed light on the contribution of these neurons to our ability to interpret and understand others' actions.

Oscillations, Timing, Plasticity, and Learning in the Cerebellum.

The highly stereotyped, crystal-like architecture of the cerebellum has long served as a basis for hypotheses with regard to the function(s) that it subserves. Historically, most clinical observations and experimental work have focused on the involvement of the cerebellum in motor control, with particular emphasis on coordination and learning. Two main models have been suggested to account for cerebellar functioning. According to Llinás's theory, the cerebellum acts as a control machine that uses the rhythmic activity of the inferior olive to synchronize Purkinje cell populations for fine-tuning of coordination. In contrast, the Ito-Marr-Albus theory views the cerebellum as a motor learning machine that heuristically refines synaptic weights of the Purkinje cell based on error signals coming from the inferior olive. Here, we review the role of timing of neuronal events, oscillatory behavior, and synaptic and non-synaptic influences in functional plasticity that can be recorded in awake animals in various physiological and pathological models in a perspective that also includes non-motor aspects of cerebellar function. We discuss organizational levels from genes through intracellular signaling, synaptic network to system and behavior, as well as processes from signal production and processing to memory, delegation, and actual learning. We suggest an integrative concept for control and learning based on articulated oscillation templates.

Modulation of the N30 generators of the somatosensory evoked potentials by the mirror neuron system.

The N30 component of the somatosensory evoked potential is known to be modulated by sensory interference, motor action, movement ideation and observation. We introduce a new paradigm in which the observation task of another person's hand movement triggers the somatosensory stimulus, inducing the N30 response in participants. In order to identify the possible contribution of the mirror neuron network (MNN) to this early sensorimotor processing, we analyzed the N30 topography, the event-related spectral perturbation and the inter-trial coherence on single electroencephalogram (EEG) trials, and we applied swLORETA to localize the N30 sources implicated in the time-frequency domain at rest and during observation, as well as the generators differentiating these two contextual brain states. We found that N30 amplitude increase correlated with increased contralateral precentral alpha, frontal beta, and contralateral frontal gamma power spectrum, and with central and precentral alpha and parietal beta phase-locking of ongoing EEG signals. We demonstrate specific activation of the contralateral post-central and parietal cortex where the angular gyrus (BA39), an important MNN node, is implicated in this enhancement during observation. We conclude that this part of the MNN, involved in proprioceptive processing and more complex body-action representations, is already active prior to somatosensory input and may enhance N30.

From spinal central pattern generators to cortical network: integrated BCI for walking rehabilitation.

Success in locomotor rehabilitation programs can be improved with the use of brain-computer interfaces (BCIs). Although a wealth of research has demonstrated that locomotion is largely controlled by spinal mechanisms, the brain is of utmost importance in monitoring locomotor patterns and therefore contains information regarding central pattern generation functioning. In addition, there is also a tight coordination between the upper and lower limbs, which can also be useful in controlling locomotion. The current paper critically investigates different approaches that are applicable to this field: the use of electroencephalogram (EEG), upper limb electromyogram (EMG), or a hybrid of the two neurophysiological signals to control assistive exoskeletons used in locomotion based on programmable central pattern generators (PCPGs) or dynamic recurrent neural networks (DRNNs). Plantar surface tactile stimulation devices combined with virtual reality may provide the sensation of walking while in a supine position for use of training brain signals generated during locomotion. These methods may exploit mechanisms of brain plasticity and assist in the neurorehabilitation of gait in a variety of clinical conditions, including stroke, spinal trauma, multiple sclerosis, and cerebral palsy.

Brain potential responses involved in decision-making in weightlessness.

The brain is essential to human adaptation to any environment including space. We examined astronauts' brain function through their electrical EEG brain potential responses related to their decision of executing a docking task in the same virtual scenario in Weightlessness and on Earth before and after the space stay of 6 months duration. Astronauts exhibited a P300 component in which amplitude decreased during, and recovered after, their microgravity stay. This effect is discussed as a post-value-based decision-making closing mechanism; The P300 amplitude decrease in weightlessness is suggested as an emotional stimuli valence reweighting during which orbitofrontal BA10 would play a major role. Additionally, when differentiating the bad and the good docks on Earth and in Weightlessness and keeping in mind that astronauts were instantaneously informed through a visual cue of their good or bad performance, it was observed that the good dockings resulted in earlier voltage redistribution over the scalp (in the 150-250 ms period after the docking) than the bad dockings (in the 250-400 ms) in Weightlessness. These results suggest that in Weightlessness the knowledge of positive or negative valence events is processed differently than on Earth.

Frontal phasic and oscillatory generators of the N30 somatosensory evoked potential.

The N30 component of somatosensory evoked potentials has been recognized as a crucial index of brain sensorimotor processing and has been increasingly used clinically. Previously, we have shown that the N30 is accompanied by both an increase of the power spectrum of the ongoing beta-gamma EEG (event related synchronization, ERS) and by a reorganization (phase-locking) of the spontaneous phase of this rhythm (inter-trials coherency, ITC). In order to localize its sources taking into account both the phasic and oscillatory aspects of the phenomenon, we here apply swLORETA methods on averaged signals of the event-related potential (ERP) from a 128 scalp-electrodes array in time domain and also on raw EEG signals in frequency domain at the N30 peak latency. We demonstrate that the two different mechanisms that generate the N30 component power increase (ERS) and phase locking (ITC) across EEG trials are spatially localized in overlapping areas in the precentral cortex, namely the motor cortex (BA4) and the premotor cortex (BA6). From this common region, the generator of the N30 event-related potential expands toward the posterior part of BA4, the anterior part of BA6 and the prefrontal cortex (BA9). These latter areas also present significant ITC sources in the beta-gamma frequency range, but without significant power increase of this rhythm. This demonstrates that N30 results from network activity that depends on distinct oscillating and phasic generators localized in the frontal cortex.

Efficacy of fascia iliaca nerve block in daily routine for children with femoral fractures in a pediatric emergency department.

OBJECTIVES: We aimed to evaluate the efficacy of fascia iliaca nerve block (FINB), routinely used for children with femoral fractures, in a pediatric emergency department (PED). METHODS: This retrospective, single-center, observational study examined FINB using ropivacaine and a 1% lidocaine hydrochloride solution, in all patients under 18 years of age admitted with a femoral fracture from January 2012 to December 2016. Pain was assessed using two validated pediatric pain scales: EVENDOL or a visual analog scale. A level of ≥ 4 on either scale indicates the need for an analgesic. The primary outcome was the percentage of patients who were pain free after the FINB procedure defined by a pain score of < 4. Secondary outcomes were the time spent between PED admission and FINB, the need of additional analgesics, side effects, and the success rate of FINB. RESULTS: Of 161 patients screened, 144 were included. The median age was 3.2 years (range 2 months to 16 years) and 74% were boys. The number of children determined to be pain free (pain score < 4) increased from 36 (25%) before the FINB to 123 (85%) after the FINB (absolute risk difference 60%, 95% CI: 51%-70%). Overall, 21 children (15%) required a second analgesic after the FINB. CONCLUSION: The routine use of FINB with ropivacaine and lidocaine by pediatric ED physicians provided effective pain relief for children admitted for a femoral fracture in the emergency department. Our data support the efficiency and feasibility of FINB for the antalgic management of children with femoral fracture.

Length of the treatment and number of doses per day as major determinants of child adherence to acute treatment.

OBJECTIVE: To determine the rate of aftercare adherence to prescriptions from a paediatric emergency department and to identify predictors for nonadherence. METHODS: Patients discharged from a French paediatric emergency department with at least one oral drug prescription were included. A telephone interview questionnaire was used to determine whether the child had received the treatments according to the prescription. Adherence was assessed according to three items: frequency of drug administration, length of treatment and drug administering method. Complete adherence was defined as adherence to the three items mentioned above, and nonadherent as nonadherent to at least one of the items. Influence of age, sex, pathology, language spoken at home, type of medical insurance, type of medication prescribed, diagnosis, dissatisfaction with the explanation of the medical problem, number of prescribed medications, length of the treatment and number of doses per day was assessed. RESULTS: One hundred and five telephone interviews were exploited. The children were 60 boys (57%) and 45 girls (43%). The ages of these 105 children were between 0.2 and 12 years. The most common diagnoses were asthma and pulmonary infection. Complete adherence with the prescription was 36.2%. Three factors were significantly associated with nonadherence (p < 0.05): length of treatment, number of doses per day and male sex. CONCLUSION: This study suggests that simplifying treatment schedules is an effective strategy for improving compliance in paediatric emergency departments.

2009 pandemic influenza A(H1N1) outbreak in a complex of schools in Paris, France, June 2009.

An outbreak of 2009 pandemic influenza A(H1N1), involving 81 cases with symptoms of influenza-like illness, was confirmed in June 2009 in a complex of schools in Paris, France. At that time, there was no community transmission in France. The index case, a 10-year-old girl, had travelled to the United Kingdom with her school class. Of the 81 symptomatic cases, 35 were confirmed and 46 were probable; 48 of the cases were female. Three were adults and 78 were children (median age of the children was 7.9 years, range: 6 months to 12 years). Control measures were implemented as soon as a new case was confirmed in a school, which included active case finding among the pupils in the same class as the index case, setting up a dedicated influenza outpatient clinic that families were recommended to consult if necessary, prophylactic treatment of contacts and school closure. A retrospective study was conducted on all confirmed cases and all symptomatic cases who had consulted the dedicated outpatient clinic from 17 to 27 June 2009. Further work is needed to better define conditions under which the pandemic virus can be transmitted in schools and in households.

EEG dynamics and neural generators of psychological flow during one tightrope performance.

Psychological "flow" emerges from a goal requiring action, and a match between skills and challenge. Using high-density electroencephalographic (EEG) recording, we quantified the neural generators characterizing psychological "flow" compared to a mindful "stress" state during a professional tightrope performance. Applying swLORETA based on self-reported mental states revealed the right superior temporal gyrus (BA38), right globus pallidus, and putamen as generators of delta, alpha, and beta oscillations, respectively, when comparing "flow" versus "stress". Comparison of "stress" versus "flow" identified the middle temporal gyrus (BA39) as the delta generator, and the medial frontal gyrus (BA10) as the alpha and beta generator. These results support that "flow" emergence required transient hypo-frontality. Applying swLORETA on the motor command represented by the tibialis anterior EMG burst identified the ipsilateral cerebellum and contralateral sensorimotor cortex in association with on-line control exerted during both "flow" and "stress", while the basal ganglia was identified only during "flow".

Spatiotemporal brain signal associated with high and low levels of proactive motor response inhibition.

Proactive motor response inhibition is used to strategically restrain actions in preparation for stopping. In this study, we first examined the event related potential (ERP) elicited by low and high level of proactive response inhibition, as assessed by the stop-signal task. Corroborating previous studies, we found an increased amplitude of the contingent negative variation (CNV) in the high level of proactive inhibition. As the main goal of the present study, swLORETA was used to determine the neural generators characterising CNV differences between low and high levels of proactive inhibition. Results showed that the higher level of proactive inhibition involved numerous generators, including within the middle and medial frontal gyrus. Importantly, we observed that the lower level of proactive inhibition also involved a specific neural generator, within the frontopolar cortex. Altogether, present findings identified the specific brain sources of ERP signals involved in the later phase of motor preparation under low or high levels of proactive motor response inhibition.

Diagnostic evaluation and management of seizures and status epilepticus in children with known epilepsy or new-onset seizures: A retrospective and comparative analysis.

OBJECTIVES: The purpose of this study was to describe and compare the initial management, including clinical/biological investigation and treatment, of new-onset seizures and status epilepticus (SE) in children versus seizures and SE in those with known epilepsy. METHODS: This was a retrospective, single-center, observational study conducted in an urban pediatric hospital in Paris. All patients, aged from 1 month to 18 years, admitted to the pediatric intensive care unit, the high-dependency care unit, and those who required hospitalization in the short-term unit of the emergency department between January 1 and December 31, 2014 for seizures and/or SE were included. RESULTS: We analyzed the data of 190 children: new-onset seizures (N=118; group A) versus those with known epilepsy (N=72; group B). At least one diagnostic test was performed on 156 patients (82.1%) (group A, N=104, 88.1%; group B, N=52, 72.2%; P=0.05). In group B, blood levels of antiepileptic drugs were measured in 14 of the 38 patients with SE, of whom six were under dosed. Treatments were: first line, diazepam (group A, 80%; group B, 46%; P<0.001); second line, diazepam (group A, 56%; group B, 34%; P=0.02) or clonazepam (group A, 24%; group B, 46%; P=0.001); third line, phenytoin (group A, 54%; group B, 22%; P<0.001) or clonazepam (group A, 18%; group B, 61%; P<0.001). CONCLUSION: Diagnostic evaluation and treatment should be individualized for children with known epilepsy.

Severe and fatal forms of COVID-19 in children.

OBJECTIVES: The aim of this study was to describe severe forms of novel coronavirus disease 2019 in children, including patient characteristics, clinical, laboratory, and imaging findings, as well as the disease management and outcomes. METHODS: This was a retrospective, single-center, observational study conducted in a pediatric intensive and high-dependency care unit (PICU, HDU) in an urban hospital in Paris. All patients, aged from 1 month to 18 years, admitted for confirmed or highly suspected SARS-CoV-2 were included. RESULTS: We analyzed the data of 27 children. Comorbidities (n=19, 70%) were mainly neurological (n=7), respiratory, (n=4), or sickle cell disease (n=4). SARS-CoV-2 PCR results were positive in 24 children (nasopharyngeal swabs). The three remaining children had a chest CT scan consistent with COVID-19. Respiratory involvement was observed in 24 patients (89%). Supportive treatments were invasive mechanical ventilation (n=9), catecholamine (n=4), erythropheresis (n=4), renal replacement therapy (n=1), and extracorporeal membrane oxygenation (n=1). Five children died, of whom three were without past medical history. CONCLUSION: This study highlighted the large spectrum of clinical presentation and time course of disease progression as well as the non-negligible occurrence of pediatric life-threatening and fatal cases of COVID-19 mostly in patients with comorbidities. Additional laboratory investigations are needed to further analyze the mechanism underlying the variability of SARS-Cov-2 pathogenicity in children.

Cervical trauma in children: Be aware of the risk of infection.

Neck abscesses after a cervical trauma rarely occur, especially in children. Cervical abscesses are more generally complications of otolaryngological infections. Progression to severe complication or death may be rapid. We describe a case of a sternocleidomastoid muscle and retropharyngeal abscess that developed after a minor cervical trauma from being struck in the neck. The patient was surgically treated and received antibiotics, but returned with a recurrence of the cervical infection. We discuss the superinfection of the hematoma, cervical abscess management, and its treatment in children.

Cerebellar network plasticity: from genes to fast oscillation.

The role of the cerebellum has been increasingly recognized not only in motor control but in sensory, cognitive and emotional learning and regulation. Purkinje cells, being the sole output from the cerebellar cortex, occupy an integrative position in this network. Plasticity at this level is known to critically involve calcium signaling. In the last few years, electrophysiological study of genetically engineered mice has demonstrated the topical role of several genes encoding calcium-binding proteins (calretinin, calbindin, parvalbumin). Specific inactivation of these genes results in the emergence of a fast network oscillation (ca. 160 Hz) throughout the cerebellar cortex in alert animals, associated with ataxia. This oscillation is produced by synchronization of Purkinje cells along the parallel fiber beam. It behaves as an electrophysiological arrest rhythm, being blocked by sensorimotor stimulation. Pharmacological manipulations showed that the oscillation is blocked by GABA(A) and NMDA antagonists as well as gap junction blockers. This cerebellar network oscillation has also been documented in mouse models of human conditions with complex developmental cerebellar dysfunction, such as Angelman syndrome and fetal alcohol syndrome. Recent evidence suggests a relationship between fast oscillation and cerebellar long term depression (LTD). This may have major implications for future therapeutic targeting.

Bowel obstruction due to ingestion of a water-absorbing bead.

Foreign body ingestion is a common pediatric complaint. Most foreign bodies pass spontaneously through the gastrointestinal tract, but bowel obstruction is a rare complication that can occur. We report a case of a 14-month-old infant with complete bowel obstruction due to ingestion of a polymer bead used for botanical arrangements. A laparotomy was performed to remove the object, resolving the symptoms. Polymer beads are brightly coloured and are of a size that is easy to swallow by very young children, increasing the risk of accidental ingestion. They increase in size over a short period of time during their passage through the gastrointestinal tract, causing significant morbidity.

EEG Dynamics and Neural Generators in Implicit Navigational Image Processing in Adults with ADHD.

In contrast to childhood ADHD that is characterized by inattention, impulsivity and hyperactivity, most adults with ADHD predominantly exhibit inattention. We used a new oddball paradigm using implicit navigational images and analyzed EEG dynamics with swLORETA inverse modeling of the evoked potential generators to study cortical processing in adults with ADHD and age-matched controls. In passive observation, we demonstrated that P350 amplitude, alpha-beta oscillation event-related synchronization (ERS) anticipation, and beta event-related desynchronization (ERD) were significantly smaller in ADHD. In the active condition, P100 duration was reduced and N140 amplitude increased for both deviant and frequent conditions in the ADHD. Alpha ERS and delta-theta ERS were reduced in the ADHD in the deviant condition. The left somatosensory area (BA2) and the right parietal lobe (BA31, BA40) contributed more to the P100 generators in the control than in the ADHD group, while the left frontal lobe (BA10) contributed more to the P100 generators in the ADHD. The left inferior parietal lobe (BA40) contributed more to the N140 generators in the control than the ADHD group while the right posterior cingulate (BA30) contributed more to the N140 generators in the ADHD. These findings reinforce the notion that earlier cortical stages of visual processing are compromised in adult ADHD by inducing the emergence of different even-related potential generators and EEG dynamics in ADHD. Considering that classical approaches for ADHD diagnosis are based on qualitative clinical investigation possibly biased by subjectivity, EEG analysis is another objective tool that might contribute to diagnosis, future neurofeedback or brain stimulation therapies.

[Postnatal diagnosis of gastric volvulus revealing congenital diaphragmatic hernia]. / Diagnostic post-natal d'un volvulus gastrique révélant une hernie diaphragmatique congénitale.

Postnatally diagnosed congenital diaphragmatic hernias (CDH) are rare and have a better prognosis than those diagnosed prenatally. Postnatal symptoms can be respiratory, digestive, or mixed. Gastric volvulus can reveal CDH. Symptoms are pain, abdominal distension, and/or vomiting. Upper gastrointestinal barium X-ray radiography provides the diagnosis. Prognosis is related to early surgical management in complicated forms with intestinal occlusion or sub-occlusion. We report on an infant who presented with vomiting, which revealed gastric volvulus associated with a CDH. Progression was favorable after surgical treatment.

Effect of gravity on human spontaneous 10-Hz electroencephalographic oscillations during the arrest reaction.

Electroencephalographic oscillations at 10 Hz (alpha and mu rhythms) are the most prominent rhythms observed in awake, relaxed (eye-closed) subjects. These oscillations may be considered as a marker of cortical inactivity or an index of the active inhibition of the sensory information. Different cortical sources may participate in the 10-Hz oscillation and appear to be modulated by the sensory context and functional demands. In microgravity, the marked reduction in multimodal graviceptive inputs to cortical networks participating in the representation of space could be expected to affect the 10-Hz activity. The effect of microgravity on this basic oscillation has heretofore not been studied quantitatively. Because the alpha rhythm has a functional role in the regulation of network properties of the visual areas, we hypothesised that the absence of gravity would affect its strength. Here, we report the results of an experiment conducted over the course of 3 space flights, in which we quantified the power of the 10-Hz activity in relation to the arrest reaction (i.e., in 2 distinct physiological states: eyes open and eyes closed). We observed that the power of the spontaneous 10-Hz oscillation recorded in the eyes-closed state in the parieto-occipital (alpha rhythm) and sensorimotor areas (mu rhythm) increased in the absence of gravity. The suppression coefficient during the arrest reaction and the related spectral perturbations produced by eye-opening/closure state transition also increased in on orbit. These results are discussed in terms of current theories on the source and the importance of the alpha rhythm for cognitive function.