Antiseizure Efficacy Research Articles

A single exposure to brivaracetam or perampanel does not cause cell death in neonatal rats.

Exposure to a range of anti-seizure medications (ASMs) during early brain development adversely impacts neurodevelopmental outcomes in both animal models and in clinical studies. Many ASMs, including phenobarbital, phenytoin, valproate (VPA), and benzodiazepines, are associated with acute neurotoxicity (cell death), impaired synaptic development, and long-term behavioral changes following gestational or neonatal exposure in animals. This is mirrored in clinical studies which show lasting neurodevelopmental deficits following early-life or gestational exposure to these drugs. Brivaracetam (BRV) and perampanel (PER) are two newer generation anti-seizure medications and are of interest based on their mechanisms of action (SV2A modulator, AMPA antagonist, respectively), as other drugs with these mechanisms of action do not trigger acute neurotoxicity. Both BRV and PER show anti-seizure efficacy in developing animals, but potential neurotoxicity of these drugs is unexplored. To address this gap, we treated postnatal day (P)7 Sprague-Dawley rats with BRV (20, 40, 80 mg/kg) and PER (0.1, 0.9, 2.7 mg/kg), and assessed the induction of cell death across a range of vulnerable brain regions 24 h after exposure. Cell death was assessed using pathogreen staining. In each of the regions examined (dorsal striatum, nucleus accumbens, motor cortex, cingulate cortex, lateral thalamus, septum, hippocampus), VPA, which served as a positive control, significantly increased cell death as measured by the numer of pathogreen positive cells. By contrast, neither BRV nor PER increased the number of pathogreen positive cells in any region examined. Our results suggest that BRV and PER may have a positive safety profile-at least with respect to acute induction of cell death - and therefore may offer a safer option for the treatment of early life seizures.

Caspase-1 inhibitor CZL80 protects against acute seizures via amplifying the inhibitory neural transmission

Current anti-seizure medications (ASDs) primarily target ion channels or neurotransmissions; however, their practicability is limited by unwanted side-effects and pharmacoresistance. Cumulative evidence has proposed pro-inflammatory caspase-1 as a potential target for developing ASDs. In this study, we showed that the small-molecular caspase-1 inhibitor CZL80 can prevent seizures in various models including the maximal electroshock (MES), the pentylenetetrazol (PTZ), and the amygdaloid kindled models. Specifically, we discovered that CZL80 prevented death, reduced the duration of generalized seizures, and increased the threshold of generalized seizures in a dose-dependent manner in the MES model. In the PTZ model, CZL80 decreased the seizure stages, prolonged the latency to stage 4 seizures, and decreased the death rate. And in amygdaloid kindled rats, CZL80 inhibited the seizure stages, shortened the durations of both generalized seizures and after-discharges. And the anti-seizure efficacy of CZL80 was diminished in caspase-1 knockout mice. In vitro electrophysiology recordings revealed that CZL80 was able to decreased the excitability of glutamatergic pyramidal neurons, as denoted by reducing the spontaneous neuronal firings and increasing the rheobase injected currents to elicit action potentials. Furthermore, CZL80 was able to increase the amplitudes of inhibitory post-synaptic currents (IPSC), while the excitatory post-synaptic currents (EPSC) were not influenced. Lastly, daily administration of CZL80 for 3 weeks did not influence the normal locomotor functions in mice. In sum, our results highlighted CZL80 as a potential anti-seizure therapy with therapeutic significance.

Clinical efficacy and tolerability of zonisamide monotherapy in dogs with newly diagnosed idiopathic epilepsy: Prospective open-label uncontrolled multicenter trial.

Zonisamide (ZNS) is a newer generation antiseizure medication (ASM) used to treat epilepsy in dogs and cats. However, scientific and clinical information, particularly regarding monotherapy, is limited. To evaluate the antiseizure efficacy and tolerability of ZNS monotherapy in dogs with newly diagnosed idiopathic epilepsy (IE). Study included 56 client-owned dogs newly diagnosed with IE. This was a prospective multicenter, open-label, uncontrolled study. All dogs were ASM-naïve and had ≥2 seizures within 12 weeks. Dogs were administered 2.7-14.4 mg/kg ZNS PO q12h and followed up for ≥12 weeks. Data from the 12-week maintenance treatment period were compared with those from the 4- to 12-week pretreatment period for efficacy evaluation. Data from the entire ZNS administration period were used to assess tolerability. Fifty-six dogs were included in our study. Of the dogs, 53 were assessed for efficacy; 40 (76%) had a ≥ 50% reduction in seizure frequency, and 29 (55%) achieved seizure freedom. For 90% of the dogs with ≥50% reduction in seizure frequency, the mean ZNS dose was 4.8 (range, 2.7-8.6) mg/kg q12h and the mean trough plasma ZNS concentration was 18.9 (range, 8.0-48.0) μg/mL. In 7 of the 56 dogs (13%), reduced activity, decreased appetite, vomiting, hindlimb weakness, soft stools, or constipation was observed, albeit mild and temporary. Laboratory tests revealed no relevant changes. Our study suggests that ZNS monotherapy is effective and well-tolerated in dogs with newly diagnosed IE.

Additional Results from Two Randomized, Placebo-Controlled Trials of Stiripentol in Dravet Syndrome Highlight a Rapid Antiseizure Efficacy with Longer Seizure-Free Periods.

The efficacy of stiripentol in Dravet syndrome children was evidenced in two randomized, double-blind, placebo-controlled, phase 3 studies, namely STICLO France (October 1996-August 1998) and STICLO Italy (April 1999-October 2000), but data were not fully exploited at the time. This post-hoc analysis used additional information, notably collected during the open-label extension (OLE) month, or reported by caregivers in individual diaries, to evaluate new outcomes. Overall, 64 patients were included (31 in the placebo group, 33 in the stiripentol group) of whom 34 (53.1%) were female. Patients' mean and median (25%; 75%) age were 9.2years (range 3.0-20.7years) and 8.7years (6.0; 12.1) respectively. At the end of the double-blind treatment period, 72% of the patients in the stiripentol group had a≥50% decrease in generalized tonic-clonic seizure (GTCS) frequency, versus 7% in the placebo group (P<0.001), 56% had a profound (≥75%) decrease versus 3% in the placebo group (P<0.001), and 38% were free of GTCS, but none in the placebo group (P<0.001). The onset of stiripentol efficacy was rapid, significant from the fourth day of treatment onwards. The median longest period of consecutive days with no GTCS was 32days in the stiripentol group compared to 8.5days in the placebo group (P<0.001). Further to the switch to the third month OLE, an 80.2% decrease in seizure frequency from baseline was observed in patients previously receiving placebo, while no change in efficacy was observed in those already on stiripentol. Adverse events were more frequent in the stiripentol group, with significantly more episodes of somnolence, anorexia, and weight decrease than in the placebo group. Altogether these new analyses of the STICLO data reinforce the evidence for a remarkable efficacy of stiripentol in Dravet syndrome, with a demonstrated rapid onset of action and sustained response, as also evidenced in further post-randomized trials.

Testing of putative antiseizure medications in a preclinical Dravet syndrome zebrafish model.

Dravet syndrome is a severe genetic epilepsy primarily caused by de novo mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications. Preclinical Dravet syndrome animal models are a valuable tool to identify candidate anti-seizure medications for these patients. Among these, scn1lab mutant zebrafish, exhibiting spontaneous seizure-like activity, are particularly amenable to large-scale drug screening. Thus far, we have screened more than 3000 drug candidates in scn1lab zebrafish mutants, identifying valproate, stiripentol, and fenfluramine e.g. Food and Drug Administration-approved drugs, with clinical application in the Dravet syndrome population. Successful phenotypic screening in scn1lab mutant zebrafish is rigorous and consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behaviour and (ii) an electrophysiology-based assay, using in vivo local field potential recordings, to quantify electrographic seizure-like events. Historically, nearly 90% of drug candidates fail during translation from preclinical models to the clinic. With such a high failure rate, it becomes necessary to address issues of replication and false positive identification. Leveraging our scn1lab zebrafish assays is one approach to address these problems. Here, we curated a list of nine anti-seizure drug candidates recently identified by other groups using preclinical Dravet syndrome models: 1-Ethyl-2-benzimidazolinone, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in scn1lab mutant zebrafish identified only 1-Ethyl-2-benzimidazolinone, chlorzoxazone and lisuride. However, second-stage local field potential recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of anti-seizure medications.

Neuroprotective Potential of Orientin with Antiepileptic Drugs against Pentylenetetrazole-induced Kindling Model and Evaluation of Behavioral Assessment in Mice

Background:: The neuroprotective effect of bioflavonoids has been demonstrated in epileptic disorder. Objective:: The objective of this study was to investigate the anticonvulsant and adjuvant effects of the bioflavonoid and explore behavioural responses of orientin (Ore) on kindled mice induced by pentylenetetrazole [PTZ]. Methods:: Albino Swiss mice weighing 20-30 g were divided into nine groups [n=6]. Prior to the PTZ dose, alternatively, ore [10 mg/kg, i.p.] was given for 7 days, dissolved in 6% w/v carboxymethylcellulose [CMC] salt. On the 7th day, saline was solubilized with Lamotrigine [Lmt], Phenobarbital [Pb], and Gabapentin [Gbp] and administered as separate intraperitoneal [i.p.] injections 30 minutes prior to the PTZ dose. For the development of kindling seizures in mice, PTZ [30 mg/kg, i.p.] was delivered to all the mice for 12 days, alternatively until the animals appeared to develop full motor muscle jerking seizures. Mice who survived from complete motor seizures were selected for further experimentation. Results:: Data showed that anticonvulsive activity was exhibited by the control. Ore [10 mg/kg] with PB [40 mg/kg, i.p.] was administered on the 12th day and showed an increase in transfer delays [ITL and RTL]. Conclusion:: Anti-seizure efficacy of drugs was investigated at the effective dose of ore at 10 mg/kg + PB 40mg/kg in group 7 and was found to have promising therapeutic outcomes and potency in therapeutic strategies and associated concerns.

BAER-101, a selective potentiator of α2- and α3-containing GABAA receptors, fully suppresses spontaneous cortical spike-wave discharges in Genetic Absence Epilepsy Rats from Strasbourg (GAERS).

BAER-101 (formerly AZD7325) is a selective partial potentiator of α2/3-containing γ-amino-butyric acid A receptors (GABAARs) and produces minimal sedation and dizziness. Antiseizure effects in models of Dravet and Fragile X Syndromes have been published. BAER-101 has been administered to over 700 healthy human volunteers and patients where it was found to be safe and well tolerated. To test the extent of the antiseizure activity of BAER-1010, we tested BAER-101 in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) model, a widely used and translationally relevant model. GAERS rats with recording electrodes bilaterally located over the frontal and parietal cortices were used. Electroencepholographic (EEG) signals in freely moving awake rats were analyzed for spike-wave discharges (SWDs). BAER-101 was administered orally at doses of 0.3-100 mg/kg and diazepam was used as a positive control using a cross-over protocol with a wash-out period between treatments. The number of SWDs was dose-dependently reduced by BAER-101 with 0.3 mg/kg being the minimally effective dose (MED). The duration of and total time in SWDs were also reduced by BAER-101. Concentrations of drug in plasma achieved an MED of 10.1 nM, exceeding the Ki for α2 or α3, but 23 times lower than the Ki for α5-GABAARs. No adverse events were observed up to a dose 300×MED. The data support the possibility of antiseizure efficacy without the side effects associated with other GABAAR subtypes. This is the first report of an α2/3-selective GABA PAM suppressing seizures in the GAERS model. The data encourage proceeding to test BAER-101 in patients with epilepsy.

The Unconventional Effects of the Ketogenic Diet (KD) in Preclinical Epilepsy.

The integration of metabolic therapeutics in the available clinical armory is becoming more commonplace in health care as our understanding about the dependence of disease on metabolism continues to deepen and evolve. In the epilepsy field, we often think about the ketogenic diet (KD, high fat: carbohydrate ratio) in terms of its anti-seizure efficacy. The aim of this article is to review what we've learned from preclinical studies about the KD's more unconventional effects, including its neuroprotective effects, anti-epileptogenic and disease-modifying effects, and how the KD influences comorbidities associated with epilepsy. As time moves us into the future and metabolic therapies become more common place, the effects of the KD considered unconventional herein, may end up being referred to as traditional.

Persistent Kv7.2/7.3 downregulation in the rat pilocarpine model of mesial temporal lobe epilepsy

Mutations within the Kv7.2 and Kv7.3 genes are well described causes for genetic childhood epilepsies. Knowledge on these channels in acquired focal epilepsy, especially in mesial temporal lobe epilepsy (mTLE), however, is scarce. Here, we used the rat pilocarpine model of drug-resistant mTLE to elucidate both expression and function by quantitative polymerase-chain reaction, immunohistochemistry, and electrophysiology, respectively. We found transcriptional downregulation of Kv7.2 and Kv7.3 as well as reduced Kv7.2 expression in epileptic CA1. Consequences were altered synaptic transmission, hyperexcitability which consisted of epileptiform afterpotentials, and increased susceptibility to acute GABAergic disinhibition. Importantly, blocking Kv7 channels with XE991 increased hyperexcitability in control tissue, but not in chronically epileptic tissue suggesting that the Kv7 deficit had precluded XE991 effects in this tissue. Conversely, XE991 resulted in comparable reduction of the paired-pulse ratio in both experimental groups implying preserved presynaptic Kv7.2 function of Schaffer collateral terminals. Consistent with Kv7.2/7.3 downregulation, the Kv7.3 channel opener β-hydroxybutyrate failed to mitigate hyperexcitability. Our findings demonstrate that compromised Kv7 function is not only relevant in genetic epilepsy, but also in acquired focal epilepsy. Moreover, they help explain reduced anti-seizure efficacy of Kv7 channel openers in drug-resistant epilepsy.

New Imidazodiazepine Analogue, 5-(8-Bromo-6-(pyridin-2-yl)-4H-benzo[f]imidazo[1,5-a][1,4]diazepin-3-yl)oxazole, Provides a Simplified Synthetic Scheme, High Oral Plasma and Brain Exposures, and Produces Antiseizure Efficacy in Mice, and Antiepileptogenic Activity in Neural Networks in Brain Slices from a Patient with Mesial Temporal Lobe Epilepsy.

KRM-II-81 (1) is an imidazodiazepine GABAA receptor (GABAAR) potentiator with broad antiseizure efficacy and a low sedative burden. A brominated analogue, DS-II-73 (5), was synthesized and pharmacologically characterized as a potential backup compound as KRM-II-81 moves forward into development. The synthesis from 2-amino-5-bromophenyl)(pyridin-2yl)methanone (6) was processed in five steps with an overall yield of 38% and without the need for a palladium catalyst. GABAAR binding occurred with a Ki of 150 nM, and only 3 of 41 screened binding sites produced inhibition ≥50% at 10 μM, and the potency to induce cytotoxicity was ≥240 mM. DS-II-73 was selective for α2/3/5- over that of α1-containing GABAARs. Oral exposure of plasma and brain of rats was more than sufficient to functionally impact GABAARs. Tonic convulsions in mice and lethality induced by pentylenetetrazol were suppressed by DS-II-73 after oral administration and latencies to clonic and tonic seizures were prolonged. Cortical slice preparations from a patient with pharmacoresistant epilepsy (mesial temporal lobe) showed decreases in the frequency of local field potentials by DS-II-73. As with KRM-II-81, the motor-impairing effects of DS-II-73 were low compared to diazepam. Molecular docking studies of DS-II-73 with the α1β3γ2L-configured GABAAR showed low interaction with α1His102 that is suggested as a potential molecular mechanism for its low sedative side effects. These findings support the viability of DS-II-73 as a backup molecule for its ethynyl analogue, KRM-II-81, with the human tissue data providing translational credibility.

Comparison of various doses of oral cannabidiol for treating refractory epilepsy indications: a network meta-analysis.

To evaluate the comparative efficacy and safety of various doses of oral cannabidiol (CBD) in treating refractory epilepsy indications, thus providing more informative evidence for clinical decision-making. A literature search of PubMed, Embase, the Cochrane library, and Web of Science (WoS) was performed to retrieve relevant randomized controlled trials (RCTs) that compared different doses of oral CBD with placebo or each other in refractory epilepsy indications. The search was limited from the inception of each database to January 3, 2023. Relative risk [RR] with a 95% confidence interval [CI] was used to express results. STATA/SE 14 was employed for network meta-analysis. Six RCTs involving 972 patients were included in the final data analysis. Network meta-analysis showed that, CBD10 (10 mg/kg/day) (RR: 1.77, 95%CI: 1.28 to 2.44), CBD20 (20 mg/kg/day) (RR: 1.91, 95%CI: 1.49 to 2.46), CBD25 (25 mg/kg/day) (RR: 1.61, 95%CI: 0.96 to 2.70), and CBD50 (50 mg/kg/day) (RR: 1.78, 95%CI: 1.07 to 2.94) were associated with higher antiseizure efficacy although the pooled result for CBD25 was only close to significant. In addition, in terms of the risk of treatment-emergent adverse events (TEAEs), the difference between different doses is not significant. However, CBD20 ranked first in terms of antiseizure efficacy, followed by CBD50, CBD10, and CBD25. For TEAEs, CBD25 ranked first, followed by CBD10, CBD50, CBD5, and CBD20. For refractory indications, CBD20 may be optimal option for antiseizure efficacy; however, CBD25 may be best for TEAEs. Therefore, an appropriate dose of oral CBD should be selected based on the actual situation. Due to the limitations of eligible studies and the limited sample size, more studies are needed in the future to validate our findings.

Effect of dietary supplementation with Lactobacillus helveticus R0052 on seizure thresholds and antiseizure potency of sodium valproate in mice

ObjectiveBoth animal and human studies, though limited, showed that multi-strain probiotic supplementation may reduce the number of seizures and/or seizure severity. Here, we evaluated the effect of a single strain probiotic supplementation on seizure susceptibility, antiseizure efficacy of sodium valproate, and several behavioral parameters in mice.MethodsLactobacillus helveticus R0052 was given orally for 28 days. Its influence on seizure thresholds was evaluated in the ivPTZ- and electrically-induced seizure tests. The effect on the antiseizure potency of valproate was assessed in the scPTZ test. We also investigated the effects of probiotic supplementation on anxiety-related behavior (in the elevated plus maze and light/dark box tests), motor coordination (in the accelerating rotarod test), neuromuscular strength (in the grip-strength test), and spontaneous locomotor activity. Serum and brain concentrations of valproate as well as cecal contents of SCFAs and lactate were determined using HPLC method.ResultsL. helveticus R0052 significantly increased the threshold for the 6 Hz-induced psychomotor seizure. There was also a slight increase in the threshold for myoclonic and clonic seizure in the ivPTZ test. L. helveticus R0052 did not affect the threshold for tonic seizures both in the maximal electroshock- and ivPTZ-induced seizure tests. No changes in the antiseizure potency of valproate against the PTZ-induced seizures were reported. Interestingly, L. helveticus R0052 increased valproate concentration in serum, but not in the brain. Moreover, L. helveticus R0052 did not produce any significant effects on anxiety-related behavior, motor coordination, neuromuscular strength, and locomotor activity. L. helveticus R0052 supplementation resulted in increased concentrations of total SCFAs, acetate, and butyrate.ConclusionsAltogether, this study shows that a single-strain probiotic – L. helveticus R0052 may decrease seizure susceptibility and this effect can be mediated, at least in part, by increased production of SCFAs. In addition, L. helveticus R0052 may affect bioavailability of valproate, which warrants further investigations.

Treatment of Status Epilepticus after Traumatic Brain Injury Using an Antiseizure Drug Combined with a Tissue Recovery Enhancer Revealed by Systems Biology.

We tested a hypothesis that in silico-discovered compounds targeting traumatic brain injury (TBI)-induced transcriptomics dysregulations will mitigate TBI-induced molecular pathology and augment the effect of co-administered antiseizure treatment, thereby alleviating functional impairment. In silico bioinformatic analysis revealed five compounds substantially affecting TBI-induced transcriptomics regulation, including calpain inhibitor, chlorpromazine, geldanamycin, tranylcypromine, and trichostatin A (TSA). In vitro exposure of neuronal-BV2-microglial co-cultures to compounds revealed that TSA had the best overall neuroprotective, antioxidative, and anti-inflammatory effects. In vivo assessment in a rat TBI model revealed that TSA as a monotherapy (1 mg/kg/d) or in combination with the antiseizure drug levetiracetam (LEV 150 mg/kg/d) mildly mitigated the increase in plasma levels of the neurofilament subunit pNF-H and cortical lesion area. The percentage of rats with seizures during 0-72 h post-injury was reduced in the following order: TBI-vehicle 80%, TBI-TSA (1 mg/kg) 86%, TBI-LEV (54 mg/kg) 50%, TBI-LEV (150 mg/kg) 40% (p < 0.05 vs. TBI-vehicle), and TBI-LEV (150 mg/kg) combined with TSA (1 mg/kg) 30% (p < 0.05). Cumulative seizure duration was reduced in the following order: TBI-vehicle 727 ± 688 s, TBI-TSA 898 ± 937 s, TBI-LEV (54 mg/kg) 358 ± 715 s, TBI-LEV (150 mg/kg) 42 ± 64 (p < 0.05 vs. TBI-vehicle), and TBI-LEV (150 mg/kg) combined with TSA (1 mg/kg) 109 ± 282 s (p < 0.05). This first preclinical intervention study on post-TBI acute seizures shows that a combination therapy with the tissue recovery enhancer TSA and LEV was safe but exhibited no clear benefit over LEV monotherapy on antiseizure efficacy. A longer follow-up is needed to confirm the possible beneficial effects of LEV monotherapy and combination therapy with TSA on chronic post-TBI structural and functional outcomes, including epileptogenesis.

Identification of New Antiseizure Medication Candidates in Preclinical Animal Studies.

Epilepsy is a multifactorial neurologic disease that often leads to many devastating disabilities and an enormous burden on the healthcare system. Until now, drug-resistant epilepsy has presented a major challenge for approximately 30% of the epileptic population. The present article summarizes the validated rodent models of seizures employed in pharmacological researches and comprehensively reviews updated advances of novel antiseizure candidates in the preclinical phase. Newly discovered compounds that demonstrate antiseizure efficacy in preclinical trials will be discussed in the review. It is inspiring that several candidates exert promising antiseizure activities in drug-resistant seizure models. The representative compounds consist of derivatives of hybrid compounds that integrate multiple approved antiseizure medications, novel positive allosteric modulators targeting subtype-selective γ-Aminobutyric acid type A receptors, and a derivative of cinnamamide. Although the precise molecular mechanism, pharmacokinetic properties, and safety are not yet fully clear in every novel antiseizure candidate, the adapted approaches to design novel antiseizure medications provide new insights to overcome drug-resistant epilepsy.

Novel therapeutic strategies in glioma targeting glutamatergic neurotransmission

High grade gliomas carry a poor prognosis despite aggressive surgical and adjuvant approaches including chemoradiotherapy. Recent studies have demonstrated a mitogenic association between neuronal electrical activity and glioma growth involving the PI3K-mTOR pathway. As the predominant excitatory neurotransmitter of the brain, glutamate signalling in particular has been shown to promote glioma invasion and growth. The concept of the neurogliomal synapse has been established whereby glutamatergic receptors on glioma cells have been shown to promote tumour propagation.Targeting glutamatergic signalling is therefore a potential treatment option in glioma. Antiepileptic medications decrease excess neuronal electrical activity and some may possess anti-glutamate effects. Although antiepileptic medications continue to be investigated for an anti-glioma effect, good quality randomised trial evidence is lacking. Other pharmacological strategies that downregulate glutamatergic signalling include riluzole, memantine and anaesthetic agents.Neuromodulatory interventions possessing potential anti-glutamate activity include deep brain stimulation and vagus nerve stimulation – this contributes to the anti-seizure efficacy of the latter and the possible neuroprotective effect of the former. A possible role of neuromodulation as a novel anti-glioma modality has previously been proposed and that hypothesis is extended to include these modalities. Similarly, the significant survival benefit in glioblastoma attributable to alternating electrical fields (Tumour Treating Fields) may be a result of disruption to neurogliomal signalling. Further studies exploring excitatory neurotransmission and glutamatergic signalling and their role in glioma origin, growth and propagation are therefore warranted.

Estradiol- and Progesterone-Associated Changes in microRNA-Induced Silencing and Reduced Antiseizure Efficacy of an Antagomir in Female Mice.

About one-third of individuals living with epilepsy have treatment-resistant seizures. Alternative therapeutic strategies are thus urgently needed. One potential novel treatment target is miRNA-induced silencing, which is differentially regulated in epilepsy. Inhibitors (antagomirs) of specific microRNAs (miRNAs) have shown therapeutic promise in preclinical epilepsy studies; however, these studies were mainly conducted in male rodent models, and research into miRNA regulation in females and by female hormones in epilepsy is scarce. This is problematic because female sex and the menstrual cycle can affect the disease course of epilepsy and may, therefore, also alter the efficacy of potential miRNA-targeted treatments. Here, we used the proconvulsant miRNA miR-324-5p and its target, the potassium channel Kv4.2, as an example to test how miRNA-induced silencing and the efficacy of antagomirs in epilepsy are altered in female mice. We showed that Kv4.2 protein is reduced after seizures in female mice similar to male mice; however, in contrast to male mice, miRNA-induced silencing of Kv4.2 is unchanged, and miR-324-5p activity, as measured by the association with the RNA-induced silencing complex, is reduced in females after seizure. Moreover, an miR-324-5p antagomir does not consistently reduce seizure frequency or increase Kv4.2 in female mice. As a possible underlying mechanism, we found that miR-324-5p activity and the silencing of Kv4.2 in the brain were differentially correlated with plasma levels of 17β-estradiol and progesterone. Our results suggest that hormonal fluctuations in sexually mature female mice influence miRNA-induced silencing and could alter the efficacy of potential future miRNA-based treatments for epilepsy in females.

Anti-seizure efficacy of perampanel in two established rodent models of early-life epilepsy

Early-life seizures can be refractory to conventional antiseizure medications (ASMs) and can also result in chronic epilepsy and long-term behavioral and cognitive deficits. Treatments targeting age-specific mechanisms contributing to epilepsy would be of clinical benefit. One such target is the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) subtype of excitatory glutamate receptor, which is upregulated in the developing brain. Perampanel is a non-competitive, selective AMPAR antagonist that is FDA-approved for focal onset seizures (FOS) or primary generalized tonic-clonic seizures (PGTC) in children and adults. However, the efficacy of perampanel treatment in epilepsy patients younger than 4 years has been less documented. We thus tested the efficacy of perampanel in two early-life seizure models: (1) a rat model of hypoxia-induced neonatal seizures and (2) a mouse model of Dravet syndrome with hyperthermia-induced seizures. Pretreatment with perampanel conferred dose-dependent protection against early-life seizures in both experimental models. These findings suggest that AMPAR-mediated hyperexcitability could be involved in the pathophysiology of early-life seizures, which may be amenable to treatment with perampanel.

12 Comparison of induction agents for rapid sequence intubation in refractory status epilepticus

OBJECTIVES/GOALS: Multiple induction agents can facilitate rapid sequence intubation (RSI) in management of refractory status epilepticus (rSE), many which have anti-seizure properties. We examine the anti-seizure efficacy and safety of induction agents used during RSI in the management of rSE. METHODS/STUDY POPULATION: We conducted a single-center retrospective review of patients admitted to the neuro-ICU intubated for management of rSE. Propofol, ketamine and benzodiazepines were considered anti-seizure medication (ASMs), etomidate was not. Patients were treated with propofol or midazolam following intubation. Our primary outcome was clinical or electrographic recurrence of SE within 12 hours of intubation. Exploratory outcomes included time to recover command following, duration of mechanical ventilation (MV) and complications related to intubation. We used multivariable logistical regression to evaluate outcomes between patients induced with ASMs and etomidate. A Fisher exact test was used to compare rSE cessation in a subset of patients with continuous electroencephalography (cEEG) at the time of intubation. RESULTS/ANTICIPATED RESULTS: We identified 149 induced for RSI in management of rSE: 88 patients intubated using ASMs (propofol,n=56; ketamine,n=14; benzodiazepines,n=18) and 61 patients intubated with etomidate. Forty-one patients had recurrence (29.9% ASMS, 24.6% etomidate). The induction agent was not associated with recurrence of SE, time to command following, or duration of MV. Twenty-seven patients had cEEG monitoring at the time of intubation. Sixteen of the 22 patients induced with ASMs had cessation of rSE with induction, while 1 of 5 intubated with etomidate had cessation (Fisher exact test, p=0.047). There were 34 patients with post-induction hypotension (22.9% ASMs, 22.9% etomidate (Fisher exact test, p=1)). DISCUSSION/SIGNIFICANCE: Induction with an anti-seizure medication during intubation was more likely to halt rSE, but did not decrease the likelihood of clinical or electrographic recurrence of rSE and may not affect time to recovery of command following or duration of MV.

(+)-Borneol enantiomer ameliorates epileptic seizure via decreasing the excitability of glutamatergic transmission.

Epilepsy is one common brain disorder, which is not well controlled by current pharmacotherapy. In this study we characterized the therapeutic potential of borneol, a plant-derived bicyclic monoterpene compound, in the treatment of epilepsy and elucidated the underlying mechanisms. The anti-seizure potency and properties of borneol were assessed in both acute and chronic mouse epilepsy models. Administration of (+)-borneol (10, 30, 100 mg/kg, i.p.) dose-dependently attenuated acute epileptic seizure in maximal-electroshock seizure (MES) and pentylenetetrazol (PTZ)-induced seizure models without obvious side-effect on motor function. Meanwhile, (+)-borneol administration retarded kindling-induced epileptogenesis and relieved fully kindled seizures. Importantly, (+)-borneol administration also showed therapeutic potential in kainic acid-induced chronic spontaneous seizure model, which was considered as a drug-resistant model. We compared the anti-seizure efficacy of 3 borneol enantiomers in the acute seizure models, and found (+)-borneol being the most satisfying one with long-term anti-seizure effect. In electrophysiological study conducted in mouse brain slices containing the subiculum region, we revealed that borneol enantiomers displayed different anti-seizure mechanisms, (+)-borneol (10 μM) markedly suppressed the high frequency burst firing of subicular neurons and decreased glutamatergic synaptic transmission. In vivo calcium fiber photometry analysis further verified that administration of (+)-borneol (100 mg/kg) inhibited the enhanced glutamatergic synaptic transmission in epilepsy mice. We conclude that (+)-borneol displays broad-spectrum anti-seizure potential in different experimental models via decreasing the glutamatergic synaptic transmission without obvious side-effect, suggesting (+)-borneol as a promising anti-seizure compound for pharmacotherapy in epilepsy.

DBS of the ANT for refractory epilepsy: A single center experience of seizure reduction, side effects and neuropsychological outcomes.

Evaluation of the antiseizure efficacy, side effects and neuropsychological effects of Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT). ANT-DBS is a treatment option for patients with difficult-to-treat epilepsy. Though several works outline the cognitive and/or mood effects of ANT-DBS for the treatment of epilepsy, data on the intersection between antiseizure efficacy, cognitive and undesired effects are scarce. We retrospectively analyzed the data of our cohort of 13 patients. Post-implantation seizure frequencies were measured at 6 months, 12 months and last follow-up, as well as averaged throughout follow-up. These values were then compared with mean seizure frequencies in the 6 months before implantation. To address acute cognitive effects of DBS a baseline assessment was performed after implantation and before stimulation, and a follow-up assessment was conducted under DBS. The long-term effects of DBS on cognition were assessed by comparing the preoperative neuropsychological profile with a long-term follow-up under DBS. In the entire cohort, 54.5% of patients were responders, with an average seizure reduction of 73.6%. One of these patients achieved temporary seizure freedom and near-total seizure reduction during the entire follow-up. Seizure reduction of <50% was achieved in 3 patients. Non-responders suffered an average seizure increase of 27.3%. Eight of twenty-two active electrodes (36,4%) were off-target. Two of our patients had both electrodes implanted off-target. When removing these two patients from the analysis and averaging seizure frequency during the entire follow-up period, four patients (44.4%) were responders and three experienced a seizure reduction of <50%. Intolerable side effects arose in 5 patients, mostly psychiatric. Regarding acute cognitive effects of DBS, only one patient showed a significant decline in executive functions. Long-term neuropsychological effects included significant intraindividual changes in verbal learning and memory. Figural memory, attention and executive functions, confrontative naming and mental rotation were mostly unchanged, and improved in few cases. In our cohort, more than half of patients were responders. Psychiatric side effects seem to have been more prevalent compared to other published cohorts. This may be partially explained by a relatively high occurrence of off-target electrodes.