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.

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.

[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.

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.

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.

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".

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.

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.

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.

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.

"Cerebellar contribution to visuo-attentional alpha rhythm: insights from weightlessness".

Human brain adaptation in weightlessness follows the necessity to reshape the dynamic integration of the neural information acquired in the new environment. This basic aspect was here studied by the electroencephalogram (EEG) dynamics where oscillatory modulations were measured during a visuo-attentional state preceding a visuo-motor docking task. Astronauts in microgravity conducted the experiment in free-floating aboard the International Space Station, before the space flight and afterwards. We observed stronger power decrease (~ERD: event related desynchronization) of the ~10 Hz oscillation from the occipital-parietal (alpha ERD) to the central areas (mu ERD). Inverse source modelling of the stronger alpha ERD revealed a shift from the posterior cingulate cortex (BA31, from the default mode network) on Earth to the precentral cortex (BA4, primary motor cortex) in weightlessness. We also observed significant contribution of the vestibular network (BA40, BA32, and BA39) and cerebellum (lobule V, VI). We suggest that due to the high demands for the continuous readjustment of an appropriate body posture in free-floating, this visuo-attentional state required more contribution from the motor cortex. The cerebellum and the vestibular network involvement in weightlessness might support the correction signals processing necessary for postural stabilization, and the increased demand to integrate incongruent vestibular information.

[Accidental amphetamine poisoning in an 11-month-old boy]. / Intoxication involontaire aux amphétamines chez un nourrisson de 11 mois.

INTRODUCTION: In France, the use of illicit drugs is increasing and therefore accidental poisoning may occur in infants and children. We report on a case of ecstasy poisoning in an infant who presented with atypical neurological symptoms. CASE REPORT: An 11-month-old infant suddenly developed agitation with eye rolling and unreactive bilateral mydriasis. All neurologic causes were excluded. The search for toxicants revealed an intoxication with an amphetamine and MDMA. Progression was favorable in 24h. CONCLUSION: Although rare, pediatric intoxications by ecstasy have become more common in recent years, due to its consumption within households, exposing young children and infants to accidental ingestion of a tablet of ecstasy.

Traumatic spinal epidural hematoma in a 1-year-old boy.

Traumatic spinal epidural hematoma is uncommon in children, making rapid diagnosis difficult. In this report, we present a case of traumatic cervical epidural hematoma in a 1-year-old boy, diagnosed with computed tomography scanning and magnetic resonance imaging (MRI). Management was conservative and the lesion regressed spontaneously. The presentation in childhood is often nonspecific. MRI is the imaging modality of choice for diagnosing these lesions. Conservative treatment has to be considered in cases with a benign clinical course and provided that the patient is followed up neurologically with repeated MRI.

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.

[Recurrent laryngeal papillomatosis complicated by decompensated respiratory failure in two children]. / Papillomatose laryngée récurrente compliquée d'insuffisance respiratoire décompensée chez deux enfants.

Laryngeal papillomatosis is a rare, potentially severe cause of recurrent laryngeal dyspnea. It should be known as a cause of laryngeal dyspnea resistant to the usual treatments. We report on two pediatric cases of severe laryngeal papillomatosis with respiratory distress and failure. These observations illustrate the importance of early adequate treatment.

Oscillations in the human brain during walking execution, imagination and observation.

Gait is an essential human activity which organizes many functional and cognitive behaviors. The biomechanical constraints of bipedalism implicating a permanent control of balance during gait are taken into account by a complex dialog between the cortical, subcortical and spinal networks. This networking is largely based on oscillatory coding, including changes in spectral power and phase-locking of ongoing neural activity in theta, alpha, beta and gamma frequency bands. This coding is specifically modulated in actual gait execution and representation, as well as in contexts of gait observation or imagination. A main challenge in integrative neuroscience oscillatory activity analysis is to disentangle the brain oscillations devoted to gait control. In addition to neuroimaging approaches, which have highlighted the structural components of an extended network, dynamic high-density EEG gives non-invasive access to functioning of this network. Here we revisit the neurophysiological foundations of behavior-related EEG in the light of current neuropsychological theoretic frameworks. We review different EEG rhythms emerging in the most informative paradigms relating to human gait and implications for rehabilitation strategies.

Sensorimotor and cognitive involvement of the beta-gamma oscillation in the frontal N30 component of somatosensory evoked potentials.

The most consistent negative cortical component of somatosensory evoked potentials (SEPs), namely the frontal N30, can be considered more multidimensional than a strict item of standard somatosensory investigation, dedicated to tracking the afferent volley from the peripheral sensory nerve potentials to the primary somatosensory cortex. In this review, we revisited its classical sensorimotor implication within the framework of the recent oscillatory model of ongoing electroencephalogram (EEG) rhythms. Recently, the N30 component was demonstrated to be related to an increase in the power of beta-gamma EEG oscillation and a phase reorganization of the ongoing EEG oscillations (phase locking) in this frequency band. Thanks to high density EEG recordings and the inverse modeling method (swLORETA), it was shown that different overlapping areas of the motor and premotor cortex are specifically involved in generating the N30 in the form of a beta gamma oscillatory phase locking and power increase. This oscillatory approach has allowed a re-investigation of the movement gating behavior of the N30. It was demonstrated that the concomitant execution of finger movements by a stimulated hand impinges the temporal concentration of the ongoing beta/gamma EEG oscillations and abolished the N30 component. It was hypothesized that the involvement of neuronal populations in both the sensorimotor cortex and other related areas were unable to respond to the phasic sensory activation so could not phase-lock their oscillatory signals to the external sensory input during the movement. In this case, the actual movement has primacy over the artificial somatosensory input. The contribution of the ongoing oscillatory activity in the N30 emergence calls for a reappraisal of fundamental and clinical interpretations of the frontal N30 component. An absent or reduced amplitude of the N30 can now be viewed not only as a deficit in the activation of the somatosensory synaptic network in response to sensory input, but also as a global alteration of the beta-gamma ongoing oscillation and/or of the phase-locking mechanism itself. In addition, it has lately been shown that the N30 amplitude increases during the observation of another person's hand movement. A new paradigm in which the experimenter's hand movement, observed by the participant, triggered the electric stimulation of the subject's hand has been introduced. This has allowed the identification of different cortical areas which are closely related to those involved in the mirror neuron system. This contribution of N30 behavior has paved the way for future investigation of the integration of sensory input into cognitive context.