ABSTRACT Temporal lobe epilepsy (TLE) is frequently associated with severe cognitive impairment and psychiatric comorbidities that are highly disabling and not targeted by anti-seizure medications, highlighting the need for therapies that target epileptogenesis rather than merely suppress seizures. Despite strong evidence implicating neuroinflammation in this process, anti-inflammatory approaches have not yielded such therapies yet. Infiltrating peripheral monocytes are widely viewed as detrimental amplifiers of post–status epilepticus (SE) inflammation, although emerging data suggest context-dependent protective roles. The cannabinoid receptor type 2 (CB2), highly expressed in myeloid cells, represents a potential immunomodulatory target linking leukocyte recruitment and inflammatory polarization. Using a juvenile rat model of TLE, we characterized hippocampal neuroinflammation and CB2 expression during epileptogenesis and evaluated the effects of transient CB2 activation with the selective agonist GP1a. SE induced a rapid but transient inflammatory response and robust recruitment of peripheral monocytes that persisted as anti-inflammatory monocyte-derived macrophages. CB2 activation did not suppress early cytokine induction but selectively enhanced recruitment of anti-inflammatory monocytes and modestly increased anti-inflammatory signaling. Importantly, transient CB2 stimulation preserved synaptic plasticity, improved cognitive performance, reduced anxiety-like behavior, and delayed seizure onset. These findings identify CB2-dependent modulation of peripheral myeloid cells as a potential disease-modifying axis in TLE.

OBJECTIVE:Evaluating the efficacy of an opioid antagonist, naloxone (NLX), to reduce the severity of post-ictal hypoxemia and immobility after focal to bilateral tonic-clonic seizures (FBTCS). METHODS:ENALEPSY is a double-blind placebo (PCB)-controlled trial conducted in patients with focal epilepsy undergoing long-term video-EEG monitoring (LTM). Patients with a FBTCS during LTM were randomized 1:1 to receive intravenous NLX or PCB within the 2 min following the end of FBTCS. After database lock, a discrepancy between the allocated arm and the received treatment was detected, resulting in a 4:1 NLX:PCB ratio. To further explore the efficacy of NLX, we used historical control (HC) data collected in patients included in the REPO2MSE study whose characteristics matched those of patients randomized in ENALEPSY. The efficacy of NLX was then assessed versus PCB and versus HC. The primary endpoint was the delay between the end of the seizure and recovery of SpO2 ≥ 90%. Secondary efficacy outcomes included desaturation nadir and duration of the post-ictal immobility. RESULTS:33 patients contributed to the NLX group, 7 to the PCB group, and 43 to the HC group. The proportion of FBTCS type 1 or 3 was 84% in NLX, 100% in PCB, and 84% in HC. NLX did not improve the delay of recovery of SpO2 ≥ 90% or the desaturation nadir. By contrast, the duration of the post-ictal immobility differed across groups. The time to mobility recovery within the first 5 min post-ictal was very similar in the PCB (200.3 ± 215.8 s) and HC (194.4 ± 192.0 s) groups, and significantly shorter in the NLX group (128.9 ± 151.1 s) when compared to HC (Hazard Ratio, 1.84; 95% CI, 1.11-3.05; p = 0.021). SIGNIFICANCE:NLX did not prevent post-ictal respiratory dysfunction but might reduce the duration of post-ictal immobility. Confirmation of this effect and its impact on SUDEP risk will require additional studies. PLAIN LANGUAGE SUMMARY:Release of endogenous opioids might participate in the severity of post-ictal hypoxemia and immobility after focal to bilateral tonic-clonic seizures (FBTCS). We conducted a multicenter double-blind randomized placebo-controlled trial evaluating the efficacy of an opioid antagonist, naloxone (NLX), administered within 2 min following the end of FBTCS. The efficacy of NLX was further explored with a comparison with historical control. NLX did not improve the delay of recovery or the severity of post-ictal hypoxemia. Post-ictal immobility was significantly shorter in the NLX group when compared to historical control. The impact of these results on SUDEP prevention will require additional studies.

OBJECTIVE:This study was undertaken to evaluate the diagnostic value of a set of preselected candidate microRNAs (miRNAs) extracted from plasma-based extracellular vesicles (EVs) to identify patients with seizure-related respiratory dysfunction. METHODS:A two-step design was applied. Step 1 entailed selection of the relevant miRNAs based on the combination of a literature review and an exploratory study in epileptic rats with or without interictal respiratory dysfunction. Step 2 involved evaluation of the diagnostic value of this preselected panel of circulating exosomal miRNAs in a case-control study conducted in 25 healthy subjects and 50 patients with drug-resistant focal epilepsy undergoing video-electroencephalographic (EEG) monitoring. Based on video-EEG data, patients were separated into two groups: those with ictal/postictal hypoxemia (PIH; n = 24) and those without (noPIH; n = 26). Blood samples were collected in the interictal period (>24 h after the last seizure). Expression level of each miRNAs in EVs was compared (1) between all patients with epilepsy and controls and (2) between PIH and noPIH. Receiver operating characteristic (ROC) curves were generated, and the area under the curve (AUC) was calculated. RESULTS:Following Step 1, the final set of miRNAs selected for evaluation in the case-control study included 24 miRNAs, with nine selected from published data in patients because of their potential regulatory role in the serotoninergic pathway, brain response to hypoxia, or epilepsy and 15 selected from the preclinical study in epileptic rats. Three miRNAs significantly differed between patients with epilepsy and controls (ROC curve AUC: hsa-miR-22-3p, .74 [95% confidence interval (CI) = .63-.85]; hsa-miR-106b-5p, .69 [95% CI = .57-.82]; and hsa-miR-26a-5p, .72 [95% CI = .58-.85]). Only a trend toward higher expression levels was observed for hsa-miR-140-3p in PIH compared to noPIH (+5%, p = .064). SIGNIFICANCE:Whereas three miRNAs were robustly associated with epilepsy, none was significantly associated with seizure-related respiratory dysfunction. Additional studies are required, including analysis of the expression of plasmatic cell-free miRNAs, especially the miRNAs associated with interictal respiratory dysfunction in epileptic rats.

Neuroinflammation is central to temporal lobe epilepsy, yet the specific role of myeloid cells remains unclear. In status epilepticus (SE) models, circulating monocytes infiltrate the brain, although distinguishing them from microglia is challenging. Using a rat model, we traced infiltrating monocytes post-SE to investigate their persistence, phenotypic evolution during epileptogenesis and contribution to neuroinflammation. By tracking phagocytosed fluorescent nanoparticles and performing CD68 immunohistochemistry, we confirmed that monocytes entered the brain in significant numbers 24 hours post-SE, after the inflammatory peak occurred (7 hours). Their long-term presence and evolution into monocyte-macrophages (mo-mΦs) up to 7 weeks were monitored histologically using CD68. Distinct inflammatory profiles were further characterized after cell enrichment and fluorescence-activated cell sorting (FACS) distinguishing monocytes/mo-mΦs (CD11b+CD45hiCD11ahi) from microglia (CD11b+CD45loCD11alo). Microglia were the main drivers of the early pro-inflammatory response, with TNFα transcript levels nearly 14-fold higher in microglia than in monocytes 24h post-SE. In contrast, 24h post-SE, infiltrating monocytes transiently displayed an anti-inflammatory and neuroprotective phenotype, being the main source of IL-10, showing ~4-fold higher CD206, and expressing Arg1 absent in microglia. Tracked up to 7 weeks, these cells progressively adopted a microglia-like phenotype, contributed to the microglial scar and, although their expression of pro-inflammatory markers resembled nonactivated microglia, we hypothesize that their persistent presence might fuel the low-grade inflammation typical of chronic epilepsy. Importantly, since infiltrating monocytes initially engage in a transient anti-inflammatory response, strategies aiming to sustain or enhance this protective role in the context of epileptogenesis and epilepsy may open promising avenues for therapeutic intervention.

Since its detection in the brain, the cannabinoid receptor type 2 (CB2) has been considered a promising therapeutic target for various neurological and psychiatric disorders. However, precise brain mapping of its expression is still lacking. Using magnetic cell sorting, calibrated RT-qPCR and single-nucleus RNAseq, we show that CB2 is expressed at a low level in all brain regions studied, mainly by few microglial cells, and by neurons in an even lower proportion. Upon lipopolysaccharide stimulation, modeling neuroinflammation in non-sterile conditions, we demonstrate that the inflammatory response is associated with a transient reduction in CB2 mRNA levels in brain tissue, particularly in microglial cells. This result, confirmed in the BV2 microglial cell line, contrasts with the positive correlation observed between CB2 mRNA levels and the inflammatory response upon stimulation by interferon-gamma, modeling neuroinflammation in sterile condition. Discrete brain CB2 expression might thus be up- or down-regulated depending on the inflammatory context.

Germinal activity persists throughout life within the ventricular-subventricular zone (V-SVZ) of the postnatal forebrain due to the presence of neural stem cells (NSCs). Accumulating evidence points to a recruitment for these cells following early brain injuries and suggests their amenability to manipulations. We used chronic hypoxia as a rodent model of early brain injury to investigate the reactivation of cortical progenitors at postnatal times. Our results reveal an increased proliferation and production of glutamatergic progenitors within the dorsal V-SVZ. Fate mapping of V-SVZ NSCs demonstrates their contribution to de novo cortical neurogenesis. Transcriptional analysis of glutamatergic progenitors shows parallel changes in methyltransferase 14 (Mettl14) and Wnt/β-catenin signaling. In agreement, manipulations through genetic and pharmacological activation of Mettl14 and the Wnt/β-catenin pathway, respectively, induce neurogenesis and promote newly-formed cell maturation. Finally, labeling of young adult NSCs demonstrates that pharmacological NSC activation has no adverse effects on the reservoir of V-SVZ NSCs and on their germinal activity.

Because of its involvement in breathing control and neuronal excitability, dysregulation of the serotonin (5-HT) 2C receptor (5-HT2C) might play a key role in sudden unexpected death in epilepsy. Seizure-induced respiratory arrest is thus prevented by a 5-HT2B/C agonist in different seizure model. However, the specific contribution of 5-HT2C in chronic epilepsy-related respiratory dysfunction remains unknown. In a rat model of temporal lobe epilepsy (EPI rats), in which we previously reported interictal respiratory dysfunctions and a reduction of brainstem 5-HT tone, quantitative reverse transcriptase polymerase chain reaction showed overexpression of TPH2 (5-HT synthesis enzyme), SERT (5-HT reuptake transporter), and 5-HT2C transcript levels in the brainstem of EPI rats, and of RNA-specific adenosine deaminase (ADAR1, ADAR2) involved in the production of 5-HT2C isoforms. Interictal ventilation was assessed with whole-body plethysmography before and 2 h after administration of SB242084 (2 mg/kg), a specific antagonist of 5-HT2C. As expected, SB242084 administration induced a progressive decrease in ventilatory parameters and an alteration of breathing stability in both control and EPI rats. However, the size of the SB242084 effect was lower in EPI rats than in controls. Increased 5-HT2C gene expression in the brainstem of EPI rats could be part of a compensatory mechanism against epilepsy-related low 5-HT tone and expression of 5-HT2C isoforms for which 5-HT affinity might be lower.

Abstract Background Attention‐deficit hyperactivity disorder (ADHD) is a frequent comorbidity in children with epilepsy, which management mostly relies on the usual treatments of ADHD, especially methylphenidate. Supplementation with polyunsaturated n‐3 Fatty Acid (PUFA) has been proposed as an alternative therapeutic approach in ADHD without epilepsy but has never been evaluated in epilepsy‐associated ADHD. Methods A multicenter double blind randomized placebo‐controlled trial evaluating supplementation with PUFA, in eicosapentaenoic‐ and docosahexaenoic‐acid form, conjugated to a phospholipid vector (PS‐Omega3) in children aged >6 and <16‐years old, and suffering from any type of epilepsy and ADHD (inattentive or combined type) according to DSM‐V. After a 4‐week baseline period, patients were allocated (1:1) either to placebo group or to PS‐Omega 3 group and entered a 12 week‐double‐blind treatment period which was followed by a 12 week‐open‐label treatment period. The primary outcome was the reduction of the ADHD‐rating scale IV attention‐deficit subscore after 12 weeks of treatment. Results The study was stopped early because of lack of eligible participants and the expected sample size was not reached. Seventy‐four patients were randomized, 44 in PS‐Omega3, and 30 in the placebo group. The reduction after 12 weeks of treatment in the inattention subscore of the ADHD‐IV scale was −1.57 in the PS‐Omega3 group, and −2.90 in the placebo group (p = 0.33, α = 5%). Results were similar after 24 weeks of treatment and for all other ADHD‐related secondary outcomes, with no difference between placebo and PS‐Omega3. Conclusion Our study remaining underpowered, no formal conclusion about the effect of Ps‐Omega3 could be drawn. However, our data strongly suggested that the PS‐Omega 3 formulation used in the current study did not improve ADHD symptoms in children with epilepsy. Plain Language Summary Supplementation with polyunsaturated n‐3 Fatty Acid (PUFA) has been proposed in ADHD but has never been evaluated in patients with both epilepsy and ADHD. To address this issue, we conducted a multicenter double blind randomized placebo‐controlled trial evaluating supplementation with PUFA in children with epilepsy and ADHD. The study was stopped early because of lack of eligible participants, hampering formal conclusion. However, the evolution of the ADHD symptoms at 12 and 24 weeks did not differ between placebo and PUFA supplementation, strongly suggesting that PUFA did not improve ADHD symptoms in children with epilepsy.

Despite low levels of cannabinoid receptor type 2 (CB2R) expression in the central nervous system in human and rodents, a growing body of evidence shows CB2R involvement in many processes at the behavioral level, through both immune and neuronal modulations. Recent in vitro and in vivo evidence have highlighted the complex role of CB2R under physiological and inflammatory conditions. Under neuroinflammatory states, its activation seems to protect the brain and its functions, making it a promising target in a wide range of neurological disorders. Here, we provide a complete and updated overview of CB2R function in the central nervous system of rodents, spanning from modulation of immune function in microglia but also in other cell types, to behavior and neuronal activity, in both physiological and neuroinflammatory contexts.

The function of cannabinoid receptor type 2 (CB2R), mainly expressed by leukocytes, has long been limited to its peripheral immunomodulatory role. However, the use of CB2R-specific ligands and the availability of CB2R-Knock Out mice revealed that it could play a functional role in the CNS not only under physiological but also under pathological conditions. A direct effect on the nervous system emerged when CB2R mRNA was detected in neural tissues. However, accurate mapping of CB2R protein expression in the nervous system is still lacking, partly because of the lack of specificity of antibodies available. This review examines the regions and cells of the nervous system where CB2R protein is most likely present by cross-referencing mRNA and protein data published to date. Of the many antibodies developed to target CB2R, only a few have partially passed specificity tests and detected CB2R in the CNS. Efforts must be continued to support the development of more specific and better validated antibodies in each of the species in which CB2R protein is sought or needs to be quantified.

Since its detection in the brain, the cannabinoid receptor type 2 (CB2) has been deemed a promising therapeutic target for various neurological and psychiatric disorders. However, precise brain mapping of CB2 expression is currently lacking. Using magnetic cell sorting, calibrated reverse transcription-quantitative PCR, and single-nucleus RNA-seq, we revealed the low level of CB2 expression in all brain regions examined, mainly by a few microglial cells and by neurons in an even lower proportion. Upon lipopolysaccharide stimulation to simulate non-sterile neuroinflammatory conditions, we demonstrated that the inflammatory response was associated with a transient reduction in CB2 mRNA levels in the brain tissue, particularly in microglia. This result, confirmed in the BV2 microglial cells, contrasts with the positive correlation observed between CB2 mRNA levels and the inflammatory response upon stimulation by interferon-gamma, which models sterile inflammatory conditions. Thus, discrete brain CB2 expression may be upregulated or downregulated depending on the inflammatory context.

Although animal models have helped to elaborate meaningful hypotheses about the pathophysiology of sudden and unexpected death in epilepsy (SUDEP), specific prevention strategies are still lacking, potentially reflecting the limitations of these models and the intrinsic difficulties of investigating SUDEP. The interpretation of preclinical data and their translation to diagnostic and therapeutic developments in patients thus require a high level of confidence in their relevance to model the human situation. Preclinical models of SUDEP are heterogeneous and include rodent and nonrodent species. A critical aspect is whether the animals have isolated seizures exclusively induced by a specific trigger, such as models where seizures are elicited by electrical stimulation, pharmacological intervention, or DBA mouse strains, or whether they suffer from epilepsy with spontaneous seizures, with or without spontaneous SUDEP, either of nongenetic epilepsy etiology or from genetically based developmental and epileptic encephalopathies. All these models have advantages and potential disadvantages, but it is important to be aware of these limitations to interpret data appropriately in a translational perspective. The majority of models with spontaneous seizures are of a genetic basis, whereas SUDEP cases with a genetic basis represent only a small proportion of the total number. In almost all models, cardiorespiratory arrest occurs during the course of the seizure, contrary to that in patients observed at the time of death, potentially raising the issue of whether we are studying models of SUDEP or models of periseizure death. However, some of these limitations are impossible to avoid and can in part be dependent on specific features of SUDEP, which may be difficult to model. Several preclinical tools are available to address certain gaps in SUDEP pathophysiology, which can be used to further validate current preclinical models.

Patients with drug-resistant epilepsy can experience respiratory alterations, notably during seizures. The mechanisms underlying long-term alterations in respiratory function remain unclear. As the brainstem 5-HT system is a prominent modulator of respiratory function, this study aimed at determining whether epilepsy is associated with alterations in both the respiratory function and brainstem serotonin (5-HT) system in rats. Epilepsy was triggered by pilocarpine-induced status epilepticus in rats. Our results showed that 30–50% of epileptic (EPI) rats exhibited a sharp decrease in oxygen consumption (SDOC), low metabolic rate of oxygen, and slow regular ventilation (EPI/SDOC + rats). These alterations were detected only in rats with chronic epilepsy, independent of behavioral seizures, were persistent over time, and not associated with death. In these rats, 5-HT fiber density in the nucleus tractus solitarius was lower than that in the control and EPI/SDOC− rats. Both EPI/SDOC + rats and DBA/2 mice that present with audiogenic-induced seizure followed by fatal respiratory arrest—a model of sudden and expected death in epilepsy—had increased transcript levels of tryptophan hydroxylase 2 and 5-HT presynaptic transporter. Thus, our data support that 5-HT alterations are associated with chronic and acute epilepsy-related respiratory dysfunction.

Objective Caffeine is an antagonist of the adenosine pathway, which is involved in regulation of breathing. Extracellular concentrations of adenosine are increased in the immediate aftermath of a seizure. Seizure-related overstimulation of adenosine receptors might promote peri-ictal apnea. However, the relation between caffeine consumption and risk of seizure-related respiratory dysfunction in patients with drug-resistant focal epilepsy remains unknown. Methods We performed a cross-sectional analysis of data collected in patients included in the SAVE study in Lyon's epilepsy monitoring unit at the Adult Epilepsy Department of the Lyon University Hospital between February 2016 and October 2018. The video-electroencephalographic recordings of 156 patients with drug-resistant focal epilepsy included in the study were reviewed to identify those with >= 1 focal seizure (FS), valid pulse oximetry (SpO(2)) measurement, and information about usual coffee consumption. This latter was collected at inclusion using a standardized self-questionnaire and further classified into four groups: none, rare (<= 3 cups/week), moderate (4 cups/week to 3 cups/day), and high (>= 4 cups/day). Peri-ictal hypoxemia (PIH) was defined as SpO(2) < 90% for at least 5 s occurring during the ictal period, the post-ictal period, or both. Results Ninety patients fulfilled inclusion criteria, and 323 seizures were analyzed. Both the level of usual coffee consumption (p = .033) and the level of antiepileptic drug withdrawal (p = .004) were independent risk factors for occurrence of PIH. In comparison with FS in patients with no coffee consumption, risk of PIH was four times lower in FS in patients with moderate consumption (odds ratio [OR] = .25, 95% confidence interval [CI] = .07-.91, p = .036) and six times lower in FS in patients with high coffee consumption (OR = .16, 95% CI = .04-.66, p = .011). However, when PIH occurred, its duration was longer in patients with moderate or high consumption than in those with no coffee consumption (p = .042). Significance Coffee consumption may be a protective factor for seizure-related respiratory dysfunction, with a dose-dependent effect.

ABSTRACTThere is still a lack of robust data, acquired identically and reliably from tissues either surgically resected from patients with mesial temporal lobe epilepsy (mTLE) or collected in animal models, to answer the question of whether the degree of inflammation of the hippocampus differs between mTLE patients, and between epilepsy and epileptogenesis. Here, using highly calibrated RTqPCR, we show that neuroinflammatory marker expression was highly variable in the hippocampus and the amygdala of mTLE patients. This variability was not associated with gender, age, duration of epilepsy, seizure frequency, and anti-seizure drug treatments. In addition, it did not correlate between the two structures and was reduced when the inflammatory status was averaged between the two structures. We also show that brain tissue not frozen within minutes after resection had significantly decreased housekeeping gene transcript levels, precluding the possibility of using post-mortem tissues to assess physiological baseline transcript levels in the hippocampus. We thus used rat models of mTLE, induced by status epilepticus (SE), that have the advantage of providing access to physiological baseline values. They indisputably indicated that inflammation measured during the chronic phase of epilepsy was much lower than the explosive inflammation occurring after SE, and was only detected when epilepsy was associated with massive neurodegeneration and gliosis. Comparison between the inter-individual variability measured in patients and that established in all epileptic and control rats suggests that some mTLE patients may have very low inflammation in the hippocampus, close to control values. However, the observation of elevated inflammation in the amygdala of some patients indicates that inflammation should be studied not only at the epileptic hippocampus, but also in the associated brain structures in order to have a more integrated view of the degree of inflammation present in brain networks involved in mesial temporal lobe epilepsy.

Objective To identify which cortical regions are associated with direct electrical stimulation (DES)-induced alteration of breathing significant enough to impair pulse oximetry (SpO(2)). Methods Evolution of SpO(2)after 1,352 DES was analyzed in 75 patients with refractory focal epilepsy who underwent stereo-EEG recordings. For each DES, we assessed the change in SpO(2)from 30 seconds prior to DES onset to 120 seconds following the end of the DES. The primary outcome was occurrence of stimulation-induced transient hypoxemia as defined by decrease of SpO(2)>= 5% within 60 seconds after stimulation onset as compared to pre-DES SpO(2)or SpO(2)nadir Results A stimulation-induced transient hypoxemia was observed after 16 DES (1.2%) in 10 patients (13%), including 6 in whom SpO(2)nadir was <90%. Among these 16 DES, 7 (44%) were localized within the perisylvian cortex. After correction for individual effects and the varying number of DES contributed by each person, significant decrease of SpO(2)was significantly associated with the localization of DES (p= 0.019). Conclusion Though rare, a significant decrease of SpO(2)could be elicited by cortical direct electrical stimulation outside the temporo-limbic structures, most commonly after stimulation of the perisylvian cortex.

Objective To identify which cortical regions are associated with direct electrical stimulation (DES)–induced alteration of breathing significant enough to impair pulse oximetry (SpO2). Methods Evolution of SpO2 after 1,352 DES was analyzed in 75 patients with refractory focal epilepsy who underwent stereo-EEG recordings. For each DES, we assessed the change in SpO2 from 30 seconds prior to DES onset to 120 seconds following the end of the DES. The primary outcome was occurrence of stimulation-induced transient hypoxemia as defined by decrease of SpO2 ≥5% within 60 seconds after stimulation onset as compared to pre-DES SpO2 or SpO2 nadir <90% during at least 5 seconds. Localization of the stimulated contacts was defined according to MarsAtlas brain parcellation and Freesurfer segmentation. Results A stimulation-induced transient hypoxemia was observed after 16 DES (1.2%) in 10 patients (13%), including 6 in whom SpO2 nadir was <90%. Among these 16 DES, 7 (44%) were localized within the perisylvian cortex. After correction for individual effects and the varying number of DES contributed by each person, significant decrease of SpO2 was significantly associated with the localization of DES (p = 0.019). Conclusion Though rare, a significant decrease of SpO2 could be elicited by cortical direct electrical stimulation outside the temporo-limbic structures, most commonly after stimulation of the perisylvian cortex.

Legionella pneumophila is a human pathogen responsible for a severe form of pneumonia named Legionnaire disease. Its natural habitat is aquatic environments, being in a free state or intracellular parasites of free-living amoebae, such as Acanthamoeba castellanii. This pathogen is able to replicate within some amoebae. Willaertia magna C2c Maky, a non-pathogenic amoeba, was previously demonstrated to resist to L. pneumophila and even to be able to eliminate the L. pneumophila strains Philadelphia, Lens, and Paris. Here, we studied the induction of seven virulence genes of three L. pneumophila strains (Paris, Philadelphia, and Lens) within W. magna C2c Maky in comparison within A. castellanii and with the gene expression level of L. pneumophila strains alone used as controls. We defined a gene expression-based virulence index to compare easily and without bias the transcript levels in different conditions and demonstrated that W. magna C2c Maky did not increase the virulence of L. pneumophila strains in contrast to A. castellanii. These results confirmed the non-permissiveness of W. magna C2c Maky toward L. pneumophila strains.

Objective To analyze the factors that determine the occurrence or severity of postictal hypoxemia in the immediate aftermath of a generalized convulsive seizure (GCS). Methods We reviewed the video-EEG recordings of 1,006 patients with drug-resistant focal epilepsy included in the REPO2MSE study to identify those with ≥1 GCS and pulse oximetry (SpO2) measurement. Factors determining recovery of SpO2 ≥ 90% were investigated using Cox proportional hazards models. Association between SpO2 nadir and person- or seizure-specific variables was analyzed after correction for individual effects and the varying number of seizures. Results A total of 107 GCS in 73 patients were analyzed. A transient hypoxemia was observed in 92 GCS (86%). Rate of GCS with SpO2 <70% dropped from 40% to 21% when oxygen was administered early (p = 0.046). Early recovery of SpO2 ≥90% was associated with early administration of oxygen (p = 0.004), absence of postictal generalized EEG suppression (PGES) (p = 0.014), and extratemporal lobe epilepsy (p = 0.001). Lack of early administration of O2 (p = 0.003), occurrence of PGES (p = 0.018), and occurrence of ictal hypoxemia during the focal phase (p = 0.022) were associated with lower SpO2 nadir. Conclusion Postictal hypoxemia was observed in the immediate aftermath of nearly all GCS but administration of oxygen had a strong preventive effect. Severity of postictal hypoxemia was greater in temporal lobe epilepsy and when hypoxemia was already observed before the onset of secondary GCS.