Initial Status Epilepticus Research Articles

Dissociation Between the Epileptogenic Lesion and Primary Seizure Onset Zone in the Tetanus Toxin Model of Temporal Lobe Epilepsy.

Despite extensive temporal lobe epilepsy (TLE) research, understanding the specific limbic structures' roles in seizures remains limited. This weakness can be attributed to the complex nature of TLE and the existence of various TLE subsyndromes, including non-lesional TLE. Conventional TLE models like kainate and pilocarpine hinder precise assessment of the role of individual limbic structures in TLE ictogenesis due to widespread limbic damage induced by the initial status epilepticus. In this study, we used a non-lesional TLE model characterized by the absence of initial status and cell damage to determine the spatiotemporal profile of seizure initiation and limbic structure recruitment in TLE. Epilepsy was induced by injecting a minute dose of tetanus toxin into the right dorsal hippocampus in seven animals. Following injection, animals were implanted with bipolar recording electrodes in the amygdala, dorsal hippocampus, ventral hippocampus, piriform, perirhinal, and entorhinal cortices of both hemispheres. The animals were video-EEG monitored for four weeks. In total, 140 seizures (20 seizures per animal) were analyzed. The average duration of each seizure was 53.2+/-3.9 s. Seizure could initiate in any limbic structure. Most seizures initiated in the ipsilateral (41 %) and contralateral (18 %) ventral hippocampi. These two structures displayed a significantly higher probability of seizure initiation than by chance. The involvement of limbic structures in seizure initiation varied between individual animals. Surprisingly, only 7 % of seizures initiated in the injected dorsal hippocampus. The limbic structure recruitment into the seizure activity wasn't random and displayed consistent patterns of early recruitment of hippocampi and entorhinal cortices. Although ventral hippocampus represented the primary seizure onset zone, the study demonstrated the involvement of multiple limbic structures in seizure initiation in a non-lesional TLE model. The study also revealed the dichotomy between the primary epileptogenic lesion and main seizure onset zones and points to the central role of ventral hippocampi in temporal lobe ictogenesis.

The effects of Src tyrosine kinase inhibitor, saracatinib, on the markers of epileptogenesis in a mixed-sex cohort of adult rats in the kainic acid model of epilepsy.

Neurodegeneration and neuroinflammation are key processes of epileptogenesis in temporal lobe epilepsy (TLE). A considerable number (∼30%) of patients with epilepsy are resistant to currently available antiseizure drugs and thus there is a need to develop adjunct therapies to modify disease progression. A vast majority of interventional strategies to treat TLE have utilized males which limits the translational nature of the studies. In this study, we investigated the effects of repeated low-dose kainic acid (KA) injection on the initial status epilepticus (SE) and the effects of Src kinase inhibitor, saracatinib (SAR/AZD0530; 20 mg/kg, oral, daily for 7 days), in a mixed-sex cohort of adult Sprague Dawley rats during early epileptogenesis. There were no sex differences in response to KA-induced SE, and neither did the stage of estrus influence SE severity. KA-induced SE caused significant astrogliosis and microgliosis across the hippocampus, piriform cortex, and amygdala. SAR treatment resulted in a significant reduction of microgliosis across brain regions. Microglial morphometrics such as branch length and the endpoints strongly correlated with CD68 expression in the vehicle-treated group but not in the SAR-treated group, indicating mitigation by SAR. KA-induced SE caused significant neuronal loss, including parvalbumin-positive inhibitory neurons, in both vehicle (VEH) and SAR-treated groups. SAR treatment significantly mitigated FJB-positive neuronal counts as compared to the VEH group. There was an increase in C3-positive reactive astrocytes in the VEH-treated group, and SAR treatment significantly reduced the increase in the piriform cortex. C3-positive astrogliosis significantly correlated with CD68 expression in the amygdala (AMY) of VEH-treated rats, and SAR treatment mitigated this relationship. There was a significant increase of pSrc(Y419)-positive microglia in both KA-treated groups with a statistically insignificant reduction by SAR. KA-induced SE caused the development of classical glial scars in the piriform cortex (PIR) in both KA-treated groups, while SAR treatment led to a 42.17% reduction in the size of glial scars. We did not observe sex differences in any of the parameters in this study. SAR, at the dose tested in the rat kainate model for a week in this study mitigated some of the markers of epileptogenesis in both sexes.

Sex-based structural and functional MRI outcomes in the rat brain after soman (GD) exposure-induced status epilepticus.

Exposure to the nerve agent, soman (GD), induces status epilepticus (SE), epileptogenesis, and even death. Although rodent models studying the pathophysiological mechanisms show females to be more reactive to soman, no tangible sex differences in brains postexposure have been reported. In this study, we used multimodal imaging using MRI in adult rats to determine potential sex-based biomarkers of soman effects. Male and female Sprague Dawley rats were challenged with 1.2 × LD50 soman followed by medical countermeasures. Ten weeks later, the brains were analyzed via structural and functional MRI. Despite no significant sex differences in the initial SE severity after soman exposure, long-term MRI-based structural and functional differences were evident in the brains of both sexes. While T2 MRI showed lesser soman-induced neurodegeneration, large areas of T1 enhancements occurred in females than in males, indicating a distinct pathophysiology unrelated to neurodegeneration. fMRI-based resting-state functional connectivity (RSFC), indicated greater reductions in soman-exposed females than in males, associating with the T1 enhancements (unrelated to neurodegeneration) rather than T2-hyperintensity or T1-hypointensity (representing neurodegeneration). The wider T1 enhancements associating with the decreased spontaneous neuronal activity in multiple resting-state networks in soman-exposed females than males suggest that neural changes unrelated to cellular atrophy impinge on brain function postexposure. Taken together with lower spontaneous neural activity in soman-exposed females, the results indicate some form of neuroprotective state that was not present in males. The results indicate that endpoints other than neurodegeneration may need to be considered to translate sex-based nerve agent effects in humans.

Integration of the CA2 region in the hippocampal network during epileptogenesis.

The CA2 pyramidal cells are mostly resistant to cell death in mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis, but they are aberrantly integrated into the epileptic hippocampal network via mossy fiber sprouting. Furthermore, they show increased excitability in vitro in hippocampal slices obtained from human MTLE specimens or animal epilepsy models. Although these changes promote CA2 to contribute to epileptic activity (EA) in vivo, the role of CA2 in the epileptic network within and beyond the sclerotic hippocampus is still unclear. We used the intrahippocampal kainate mouse model for MTLE, which recapitulates most features of the human disease including pharmacoresistant epileptic seizures and hippocampal sclerosis, with preservation of dentate gyrus (DG) granule cells and CA2 pyramidal cells. In vivo recordings with electrodes in CA2 and the DG showed that EA occurs at high coincidence between the ipsilateral DG and CA2 and current source density analysis of silicon probe recordings in dorsal ipsilateral CA2 revealed CA2 as a local source of EA. Cell-specific viral tracing in Amigo2-icreERT2 mice confirmed the preservation of the axonal projection from ipsilateral CA2 pyramidal cells to contralateral CA2 under epileptic conditions and indeed, EA propagated from ipsi- to contralateral CA2 with increasing likelihood with time after KA injection, but always at lower intensity than within the ipsilateral hippocampus. Furthermore, we show that CA2 presents with local theta oscillations and like the DG, shows a pathological reduction of theta frequency already from 2 days after KA onward. The early changes in activity might be facilitated by the loss of glutamic acid decarboxylase 67 (Gad67) mRNA-expressing interneurons directly after the initial status epilepticus in ipsi- but not contralateral CA2. Together, our data highlight CA2 as an active player in the epileptic network and with its contralateral connections as one possible router of aberrant activity.

Temporal and spatial changes in synaptic vesicle glycoprotein 2A (SV2A) under kainic acid induced epileptogenesis: An autoradiographic study

Synaptic Vesicle Glycoprotein 2A (SV2A) has been proposed as a presynaptic marker in several neurological disorders. Not only is SV2A the target for the antiepileptic drug levetiracetam, but also considered a marker of mature pre-synapses. In this study, we aimed to assess the binding of [3H]UCB-J as a selective radioligand for SV2A to visualize and determine changes during different stages of epileptogenesis by in-vitro autoradiography in rat models of temporal lobe epilepsy. Two different kainic acid (KA) injection routes were used to model temporal lobe epilepsy in the rat; a systemic (10 mg/kg KA injected intraperitoneally) and a local model (1.875 mM KA injected intrahippocampally). Brain tissue was sampled at different time points after the initial status epilepticus and semi-quantitative [3H]UCB-J autoradiography was performed to determine temporal and spatial changes under the progression of epileptogenesis. A decrease in [3H]UCB-J binding was observed in many brain areas in the acute phases after both types of kainic acid administration. Peak reductions occurred slightly before in systemic-treated animals (within 3–10 days) than after local-treated animals (within 5–15 days). Interestingly in the systemic model, we observed a full restoration in the binding level 30 days after the treatment in most areas probably reflecting neuronal reorganization. However, after the local injection in the hippocampus, the binding in the hippocampus, and in temporal and piriform cortices did not return to basal levels. The time-course profile displayed lateralization in the local model. These results demonstrate changes in the amount of a presynaptic SV2A binding site after seizures and suggest that SV2A may have importance in eliciting spontaneous seizures and/or be a biomarker for epileptogenesis. The present study shows that SV2A is a biomarker of acute phase epileptogenesis in specific brain regions.

Saracatinib, a Src Tyrosine Kinase Inhibitor, as a Disease Modifier in the Rat DFP Model: Sex Differences, Neurobehavior, Gliosis, Neurodegeneration, and Nitro-Oxidative Stress.

Diisopropylfluorophosphate (DFP), an organophosphate nerve agent (OPNA), exposure causes status epilepticus (SE) and epileptogenesis. In this study, we tested the protective effects of saracatinib (AZD0530), a Src kinase inhibitor, in mixed-sex or male-only Sprague Dawley rats exposed to 4–5 mg/kg DFP followed by 2 mg/kg atropine and 25 mg/kg 2-pralidoxime. Midazolam (3 mg/kg) was given to the mixed-sex cohort (1 h post-DFP) and male-only cohort (~30 min post-DFP). Saracatinib (20 mg/kg, oral, daily for 7 days) or vehicle was given two hours later and euthanized eight days or ten weeks post-DFP. Brain immunohistochemistry (IHC) showed increased microgliosis, astrogliosis, and neurodegeneration in DFP-treated animals. In the 10-week post-DFP male-only group, there were no significant differences between groups in the novel object recognition, Morris water maze, rotarod, or forced swim test. Brain IHC revealed significant mitigation by saracatinib in contrast to vehicle-treated DFP animals in microgliosis, astrogliosis, neurodegeneration, and nitro-oxidative stressors, such as inducible nitric oxide synthase, GP91phox, and 3-Nitrotyrosine. These findings suggest the protective effects of saracatinib on brain pathology seem to depend on the initial SE severity. Further studies on dose optimization, including extended treatment regimen depending on the SE severity, are required to determine its disease-modifying potential in OPNA models.

Status epilepticus outcomes among vaccinated and unvaccinated children: A population-based study

AimTo determine the proportion of first status epilepticus (SE) cases that are vaccine-proximate (VP-) and compare clinical outcomes to non-vaccine-proximate (NVP-) cases. MethodsBirth records for 1,440,807 Australian children born in 1998–2012, were probabilistically linked to hospitalizations, deaths, and vaccination history available to 2013. First SE coded hospitalizations were categorized as VP-SE or NVP-SE; clinical severity and post-SE vaccination coverage were compared. SE rates were calculated. ResultsOf 867 first SE cases (7.9 per 100,000 person-years), 31 (3.6%) were VP-SE; 16 followed dose-1 measles vaccine (1.2 SE per 100,000 doses). Compared with NVP-SE, VP-SE cases were younger (1.0 vs 2.6 years, P < 0.0001) and had longer hospitalizations (4 vs 3 days, P = 0.005). There was no difference in the proportion of VP-SE cases with a coinfection diagnosis compared to NVP-SE (25.8% vs 19.9%, P = 0.42). Controlling for age and history of hospitalization for a neurological condition, intensive care unit (ICU) admission had a stronger association with coinfection (aOR 2.52 (95%CI 1.78–3.57)) than having VP-SE (aOR 1.41 (0.66–3.01)). Groups had similar SE recurrence rates at 12-months (12.9% VP vs 16.9% NVP, P = 0.56) and reduced vaccine uptake following initial SE (from 93.5% to 56.3%). ConclusionProportionally few first SE cases were VP-SE, with higher ICU admission rates mostly explained by younger age and higher coinfection rates. Vaccination plans are needed to improve vaccine uptake following SE.

Ventriculitis: A Severe Complication of Central Nervous System Infections.

BackgroundVentriculitis, a dreaded complication of brain abscess, meningitis, and various neurosurgical procedures, has attracted limited attention in the medical literature.MethodsThis is a retrospective, single-center study. We screened the medical files of all patients who had a brain imaging report that included the word “ventriculitis” during years 2005–2019. Only patients with clinical, microbiological, and imaging features of ventriculitis were included. Data were collected through a standardized questionnaire.ResultsNinety-eight patients fulfilled inclusion criteria: 42 women and 56 men, and the median age was 60 years (interquartile range, 48–68). The primary mechanism for ventriculitis was classified as follows: brain abscess (n = 29, 29.6%), meningitis (n = 27, 27.6%), intraventricular catheter-related (n = 17, 17.3%), post-neurosurgery (n = 13, 13.3%), and hematogenous (n = 12, 12.2%). The main neuroimaging features were intraventricular pus (n = 81, 82.7%), ependymal enhancement (n = 70, 71.4%), and intraventricular loculations (n = 15, 15.3%). The main pathogens were streptococci (n = 44, 44.9%), Gram-negative bacilli (n = 27, 27.6%), and staphylococci (n = 15, 15.3%). In-hospital and 1-year mortality rates were 30.6% (n = 30) and 38.8% (n = 38), respectively. Neurological sequelae were reported in 34 of 55 (61.8%) survivors, including cognitive impairment (n = 11), gait disturbances (n = 9), paresis (n = 7), behavior disorder (n = 6), and epilepsy (n = 5). On multivariate analysis, age >65 years, Glasgow Coma Scale score <13 at initial presentation, status epilepticus, hydrocephalus, and positive cerebrospinal fluid culture were associated with 1-year mortality. We built a scoring system to stratify patients with ventriculitis into low risk (12.5%), intermediate risk (36.5%), and high risk (71.4%) of death.ConclusionsVentriculitis is a severe complication of brain abscess, meningitis, or neurosurgery, with an in-hospital mortality rate of 30% and neurological sequelae in 60% of survivors.

S2k-Leitlinie: Status Epilepticus im Erwachsenenalter

Diese S2k-Leitlinie (LL) zum Status epilepticus (SE) im Erwachsenenalter schreibt die letzte DGN-LL zum SE von 2012 fort. Neue Definitionen und Evidenz wurden bei der Erstellung der LL und des Clinical Pathway berücksichtigt. Jeder epileptische Anfall, der länger als 5 Minuten anhält (oder ≥ 2 Anfälle über einen Zeitraum von mehr als 5 Minuten ohne Wiedererlangen des neurologischen Ausgangsstatus), soll als SE behandelt werden.In der Diagnostik sollte initial eine CCT oder, wenn möglich, eine MRT erfolgen. Das EEG spielt bei der Diagnosestellung und beim Therapiemonitoring von non-konvulsiven SE und zum Ausschluss bzw. Nachweis psychogener nichtepileptischer Anfälle eine wesentliche Rolle. Der prognostische Einfluss von insbesondere entzündlichen Begleiterkrankungen (z. B. Pneumonie) wurde besser belegt, weshalb entsprechende Laborparameter auch im Verlauf kontrolliert werden sollten und ggf. frühzeitig eine antibiotische Therapie initiiert werden sollte.Die Therapie erfolgt in 4 Stufen: 1. Initialer SE: Gabe eines ausreichend hoch dosierten Benzodiazepins i. m., i. v. oder i. n.; 2. Benzodiazepin-refraktärer SE: 1. Wahl ist die i.v. Gabe von Levetiracetam oder Valproat; 3. Refraktärer SE (RSE) und 4. Superrefraktärer SE (SRSE): I.v. Propofol oder Midazolam alleine oder in Kombination oder Thiopental in anästhetischen Dosen. Beim fokalen non-konvulsiven RSE kann unter Umständen auf die Einleitung eines therapeutischen Komas verzichtet werden. Bei SRSE sollte die ketogene Diät zum Einsatz kommen. I.v. Ketamin oder inhalatives Isofluran kann erwogen werden. In Einzelfällen kann die elektrokonvulsive Therapie und, bei resektabler epileptogener Zone, ein Epilepsie chirurgischer Eingriff erwogen werden. I.v. Allopregnanolon oder die Hyperthermie sollen nicht eingesetzt werden.

Parallel pathways of seizure generalization.

Generalized convulsive status epilepticus is a life-threatening emergency, because recurrent convulsions can cause death or injury. A common form of generalized convulsive status epilepticus is of focal onset. The neuronal circuits activated during seizure spread from the hippocampus, a frequent site of seizure origin, to the bilateral motor cortex, which mediates convulsive seizures, have not been delineated. Status epilepticus was initiated by electrical stimulation of the hippocampus. Neurons transiently activated during seizures were labelled with tdTomato and then imaged following brain slice clearing. Hippocampus was active throughout the episode of status epilepticus. Neuronal activation was observed in hippocampus parahippocampal structures: subiculum, entorhinal cortex and perirhinal cortex, septum, and olfactory system in the initial phase status epilepticus. The tdTomato-labelled neurons occupied larger volumes of the brain as seizures progressed and at the peak of status epilepticus, motor and somatosensory cortex, retrosplenial cortex, and insular cortex also contained tdTomato-labelled neurons. In addition, motor thalamic nuclei such as anterior and ventromedial, midline, reticular, and posterior thalamic nuclei were also activated. Furthermore, circuits proposed to be crucial for systems consolidation of memory: entorhinal cortex, retrosplenial cortex, cingulate gyrus, midline thalamic nuclei and prefrontal cortex were intensely active during periods of generalized tonic-clonic seizures. As the episode of status epilepticus waned, smaller volume of brain was activated. These studies suggested that seizure spread could have occurred via canonical thalamocortical pathway and many cortical structures involved in memory consolidation. These studies may help explain retrograde amnesia following seizures.

Status Epilepticus: Behavioral and Electroencephalography Seizure Correlates in Kainate Experimental Models.

Various etiological factors, such as head injury, chemical intoxication, tumors, and gene mutation, can induce epileptogenesis. In animal models, status epilepticus (SE) triggers epileptogenesis. In humans, convulsive SE for >30 min can be a life-threatening medical emergency. The duration and severity of convulsive SE are highly variable in chemoconvulsant animal models. A continuous video-electroencephalography (EEG) recording, and/or diligent direct observation, facilitates quantification of exact duration of different stages of convulsive seizures (Racine stages 3–5) to determine the severity of SE. A continuous convulsive SE for >30 min usually causes high mortality in some rodents and results in widespread brain damage in the surviving animals, in spite of treating with antiepileptic drugs (AEDs). AEDs control behavioral seizures but not EEG seizures. The severity of initial SE impacts epileptogenesis and cognitive function; therefore, quantitative assessment of behavioral SE and EEG in animal models will help to understand the impact of SE severity on epileptogenesis. There are several excellent reviews on experimental models of seizure/SE/epilepsy. This review focusses on the comparison of induction and characterization of behavioral SE and EEG correlates in mice and rats induced by kainate. We also discuss the advantages of repeated low dose of kainate (i.p. route), which minimizes variability in the initial SE severity between animals and reduces mortality rate. A refined approach to induce SE with kainate also addresses the two of the 3Rs (i.e., refinement and reduction), the guiding principles for ethical and scientific standpoint of animal research.

SRF modulates seizure occurrence, activity induced gene transcription and hippocampal circuit reorganization in the mouse pilocarpine epilepsy model

A hallmark of temporal lobe epilepsy (TLE) is hippocampal neuronal demise and aberrant mossy fiber sprouting. In addition, unrestrained neuronal activity in TLE patients induces gene expression including immediate early genes (IEGs) such as Fos and Egr1.We employed the mouse pilocarpine model to analyze the transcription factor (TF) serum response factor (SRF) in epileptogenesis, seizure induced histopathology and IEG induction. SRF is a neuronal activity regulated TF stimulating IEG expression as well as nerve fiber growth and guidance. Adult conditional SRF deficient mice (SrfCaMKCreERT2) were more refractory to initial status epilepticus (SE) acquisition. Further, SRF deficient mice developed more spontaneous recurrent seizures (SRS). Genome-wide transcriptomic analysis uncovered a requirement of SRF for SE and SRS induced IEG induction (e.g. Fos, Egr1, Arc, Npas4, Btg2, Atf3). SRF was required for epilepsy associated neurodegeneration, mossy fiber sprouting and inflammation. We uncovered MAP kinase signaling as SRF target during epilepsy. Upon SRF ablation, seizure evoked induction of dual specific phosphatases (Dusp5 and Dusp6) was reduced. Lower expression of these negative ERK kinase regulators correlated with altered P-ERK levels in epileptic Srf mutant animals.Overall, this study uncovered an SRF contribution to several processes of epileptogenesis in the pilocarpine model.

Management Of Post Stroke Seizures

The incidence of seizures in relation to stroke is 8.9%, with a frequency of 10.6 and 8.6% in haemorrhagic and ischaemic stroke, respectively. In subarachnoid haemorrhage the incidence is 8.5%. Due to the fact that infarcts are significantly more frequent than haemorrhages, seizures are mainly related to occlusive vascular disease of the brain. The general view is to consider stroke-related seizures as harmless complications in the course of a prolonged vascular disease involving the heart and brain. Seizures can be classified as those of early and those of late onset in a paradigm comparable to post-traumatic epilepsy, with an arbitrary dividing point of two weeks after the event. Most early-onset seizures occur during the first day after the stroke. Late-onset seizures occur three times more often than early-onset ones. A first late-onset epileptic event is most likely to take place between six months and two years after the stroke. However, up to 28% of patients develop their first seizure several years later. Simple partial seizures, with or without secondary generalisation, account for about 50% of total seizures, while complex partial spells, with or without secondary generalisation, and primary generalised tonic–clonic insults account for approximately 25% each. Status epilepticus occurs in 12% of stroke patients, but the recurrence rate after an initial status epilepticus is not higher than after a single seizure. Inhibitory seizures, mimicking transient ischaemic attacks, are observed in 7.1% of cases. The only clinical predictor of late-onset seizures is the initial presentation of partial anterior circulation syndrome due to a territorial infarct. Patients with total anterior circulation syndrome have less chance of developing epileptic spells, not only due to their shorter life expectancy but also due to the fact that the large infarcts are sharply demarcated in these patients. The optimal timing and type of antiepileptic drug treatment for patients with post-stroke seizures is still a controversial issue. Prospective studies in the literature showed that immediate treatment after a first unprovoked seizure does not improve the long-term remission rate. However, because of the physical and psychological influences of recurrent seizures, prophylactic treatment should be considered after a first unprovoked event in an elderly person at high risk of recurrence, taking into consideration the individuality of the patient and a discussion with the patient and his/her family about the risks and benefits of both options latest studies regarding post-stroke seizure treatment showed that 'new-generation' drugs, such as lamotrigine, gabapentin and levetiracetam, in low doses would be reasonable. Although several studies suggest that seizures alter the functional recovery after a stroke, it remains difficult to determine whether or not the occurrence of a second seizure in an untreated stroke patient might hamper the overall outcome. However, repeated seizures and status epilepticus worsen the neurological and mental condition of stroke patienton The decision to initiate antiepileptic drug treatment after a first or a second post-stroke seizure should therefore be individualized, primarily based on the functional impact of the first seizure episode and the patient's preference. Several converging findings suggest that the majority of first-generation antiepileptic drugs, particularly phenytoin, are not the most appropriate choice in stroke patients because of their potential harmful impact on functional recovery and bone health, their suboptimal pharmacokinetic profile and interaction with anticoagulants or salicylates, their greater likelihood to be poorly tolerated, and the lack of level A evidence regarding their specific use in elderly patients. Among the new-generation drugs that do not interact with anticoagulants, antiplatelet agents, or bone health, lamotrigine and gabapentine are the only two drugs that proved to be more effective than immediate-release carbamazepine in elderly patients, providing level A evidence for their use in this indication. In addition, gabapentin remains the only drug that has been specifically evaluated in stroke patients, demonstrating a high rate of long-term seizure freedom. At present, low-dose lamotrigine or gabapentin appears to represent the optimal first-line therapy for post-stroke seizure and epilepsy in elderly patients or in younger patients requiring anticoagulants. However, low-dose extended-release carbamazepine might be a reasonable and less expensive option in patients with appropriate bone health who do not requiring anticoagulat. Based on the stroke management guidelines antiepileptic drugs should not be administered as preventive management in any type of stroke patients without seizure.

Knockout of P-glycoprotein does not alter antiepileptic drug efficacy in the intrahippocampal kainate model of mesial temporal lobe epilepsy in mice

Pharmacoresistance to antiepileptic drugs (AEDs) is a major challenge in epilepsy therapy, affecting at least 30% of patients. Thus, there is considerable interest in the mechanisms responsible for such pharmacoresistance, with particular attention on the specific cellular and molecular factors that lead to reduced drug sensitivity. Current hypotheses of refractory epilepsy include the multidrug transporter hypothesis, which posits that increased expression or function of drug efflux transporters, such as P-glycoprotein (Pgp), in brain capillaries reduces the local concentration of AEDs in epileptic brain regions to subtherapeutic levels. In the present study, this hypothesis was addressed by evaluating the efficacy of six AEDs in wildtype and Pgp deficient Mdr1a/b−/− mice in the intrahippocampal kainate model of mesial temporal lobe epilepsy. In this model, frequent focal electrographic seizures develop after an initial kainate-induced status epilepticus. These seizures are resistant to major AEDs, but the mechanisms of this resistance are unknown. In the present experiments, the focal nonconvulsive seizures were resistant to carbamazepine and phenytoin, whereas high doses of valproate and levetiracetam exerted moderate and phenobarbital and diazepam marked anti-seizure effects. All AEDs suppressed generalized convulsive seizures. No significant differences between wildtype and Pgp-deficient mice were observed in anti-seizure drug efficacies. Also, the individual responder and nonresponder rates in each experiment did not differ between mouse genotypes. This does not argue against the multidrug transporter hypothesis in general, but indicates that Pgp is not involved in the mechanisms explaining that focal electrographic seizures are resistant to some AEDs in the intrahippocampal mouse model of partial epilepsy. This was substantiated by the finding that epileptic wildtype mice do not exhibit increased Pgp expression in this model.

High-Throughput LC-MS/MS Proteomic Analysis of a Mouse Model of Mesiotemporal Lobe Epilepsy Predicts Microglial Activation Underlying Disease Development.

Uncovering the molecular mechanisms of mesiotemporal lobe epilepsy (MTLE) is critical to identify therapeutic targets. In this study, we performed global protein expression analysis of a kainic acid (KA) MTLE mouse model at various time-points (1, 3, and 30 days post-KA injection -dpi), representing specific stages of the syndrome. High-resolution liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), in combination with label-free protein quantification using three processing approaches for quantification, was applied. Following comparison of KA versus NaCl-injected mice, 22, 53, and 175 proteins were differentially (statistically significant) expressed at 1, 3 and 30dpi, respectively, according to all three quantification approaches. Selected findings were confirmed by multiple reaction monitoring LC-MS/MS. As a positive control, the astrocyte marker GFAP was found to be upregulated (3dpi: 1.9 fold; 30dpi: 12.5 fold), also verified by IHC. The results collectively suggest that impairment in synaptic transmission occurs even right after initial status epilepticus (1dpi), with neurodegeneration becoming more extensive during epileptogenesis (3dpi) and sustained at the chronic phase (30dpi), where also extensive glial- and astrocyte-mediated inflammation is evident. This molecular profile is in line with observed phenotypic changes in human MTLE, providing the basis for future studies on new molecular targets for the disease.

Recurrent status epilepticus in posterior reversible encephalopathy syndrome as initial feature of pediatric lupus: A newly diagnosed case and literature review

IntroductionPosterior reversible encephalopathy syndrome (PRES) is a recently described clinico-neuroradiological syndrome with several predisposing conditions. Systemic lupus erythematosus (SLE), beginning in 15–20% in childhood, is considered as a potential underlying etiology of PRES. In children, status epilepticus (SE) rarely complicates PRES, and exceptionally occurs in SLE. MethodsWe report on an illustrative case of PRES complicating pediatric lupus revealed by recurrent SE, and we further review through a Pubmed search the previously reported cases of pediatric SLE, PRES and SE. ResultsWe describe the case of a 12-year old girl who presented with recurrent status epilepticus associated to high blood pressure and renal involvement. Brain imaging showed classical aspects of PRES. Immunological tests including antinuclear, anti-DNA, and anticardiolipin antibodies were positive. The diagnosis of SLE was established. The Pubmed search identified a total number of 9 children with SE in SLE, and 26 with PRES, including our patient. ConclusionsWe discussed the clinical and paraclinical features of PRES in SLE with epilepsy, their underlying pathophysiological aspects, and their management challenges. PRES should be considered in initial recurrent SE in children, justifying a battery of tests comprising immunological testing. Anticardiolipin antibodies seem to play a crucial role in epilepsy, PRES and renal involvement in pediatric SLE. Further studies are needed to clarify whether PRES should be considered one of the neuropsychiatric manifestations of SLE or a consequence of active disease in other organ systems or its treatment.

Should Barbiturates be Used in Refractory Status Epilepticus?

Status epilepticus (SE) is a frequent neurologic emergency, one third of patients do not respond to treatment with benzodiazepines followed by a second antiepileptic drug. While initial treatment of complex partial SE is accordant to that of generalized convulsive SE, further management of refractory SE depends on the risk for acute complications and long-term clinical consequences. These risks are low in complex partial SE; therefore, in this clinical form anesthetics commonly are not used. Generalized convulsive SE-even in its early course-is a potentially life-threatening condition; therefore, prompt use of anesthetics is urgently required. Drugs of choice are barbiturates, midazolam, and propofol, all of which exhibit specific advantages and disadvantages. Up to now, data from clinical studies do not allow to prefer or to discard one of these anesthetics, therefore also barbiturates still should be used in refractory SE. A widely accepted in-house protocol for the management of initial and refractory SE is highly recommended.

English

Purpose: The goal of this retrospective study is to identify early predictors of intractable epilepsy.Methods: This case-control study conducted from January 2007 to December 2012 included 106 patients with drug-resistant epilepsy and 212 controls with well-controlled epilepsy. Univariate and multivariate analysis of predictive factors of refractoriness were performed using logistic regression.Results: In the final model, four factors significantly associated with intractable epilepsy were identified: aetiology (p = 0.001) high initial seizure frequency (p < 10-4), status epilepticus (p = 0.002), and initial myoclonic seizures (p < 10-4).Conclusion: Our findings suggest that the risk of developing drug resistant epilepsy could be predicted at an early stage of the disease by some clinical features. This could help the clinicians to make the best therapy decisions and improve patient’s quality of life.

Reactive oxygen species mediate cognitive deficits in experimental temporal lobe epilepsy

Cognitive dysfunction is an important comorbidity of temporal lobe epilepsy (TLE). However, no targeted therapies are available and the mechanisms underlying cognitive impairment, specifically deficits in learning and memory associated with TLE remain unknown. Oxidative stress is known to occur in the pathogenesis of TLE but its functional role remains to be determined. Here, we demonstrate that oxidative stress and resultant processes contribute to cognitive decline associated with epileptogenesis. Using a synthetic catalytic antioxidant, we show that pharmacological removal of reactive oxygen species (ROS) prevents 1) oxidative stress, 2) deficits in mitochondrial oxygen consumption rates, 3) hippocampal neuronal loss and 4) cognitive dysfunction without altering the intensity of the initial status epilepticus (SE) or epilepsy development in a rat model of SE-induced TLE. Moreover, the effects of the catalytic antioxidant on cognition persisted beyond the treatment period suggestive of disease-modification. The data implicate oxidative stress as a novel mechanism by which cognitive dysfunction can arise during epileptogenesis and suggest a potential disease-modifying therapeutic approach to target it.

P90 – 2900: Menkes disease with atypical findings in neuroimaging: It's not only gold that glitters

Objectives To present a case of Menkes disease (MD) with atypical findings in neuroimaging and review the publications related to these findings. Method Systematic literature review and retrospective description of the case seen at our center. Results We present the case of a 3-month-old infant admitted at our Intensive Care Unit with status epilepticus. Initial brain magnetic resonance (MR) studies revealed the coexistence of an extensive T2 hyperintensity in the temporal white matter (WM) and in both caudate nuclei. Neurological examination showed marked psychomotor retardation, with no exploratory behaviour, severe hypotonia and swallowing difficulties. Complementary tests revealed decreased ceruloplasmin levels (3.6 mg/dL-normal: 39–51 mg/dL), increased lactate in cerebrospinal fluid (40 mg/dL), “Pili torti” on microscopic examination of the hair and a mutation in the gene ATP7A, which confirmed the diagnosis of MD. Treatment was iniciated with copper histidinate and three antiepileptic drugs (Levetiracetam, Lacosamide, and Clobazam). By the age of 6 months, MR studies revealed the disappearance of hyperintensities on WM and basal ganglia (BG), with marked atrophy and bilateral subdural hygromas. A rapidly deteriorating condition led to exitus at 8 months. Conclusion Neuroradiological atypical findings in MD published so far involve leukoencephalopathies (located in the temporal lobe, periventricular or diffuse), and BG anomalies, such as infarcts or cytotoxic lesions. As the presented case shows, and according to other cases published, there can be early damage in WM and BG in MD instead of the typically observed cortical atrophy and vascular abnormalities. The pathogenic mechanism could involve vasogenic edema caused by the initial status epilepticus, and cytotoxic damage of both caudates as a result from energetic failure. Thus, predominant diffuse involvement of the WM in the absence of cortical atrophy or vascular tortuosity should not exclude the diagnosis of MD, even in late infancy, when the clinical and biochemical picture supports it.