Levetiracetam or Phenytoin as Prophylaxis for Status Epilepticus: Secondary Analysis of the "Approaches and Decisions in Acute Pediatric Traumatic Brain Injury Trial" (ADAPT) Dataset, 2014-2017.

OBJECTIVES: To compare levetiracetam and phenytoin as prophylaxis for the short-term development of status epilepticus (SE) during care of pediatric patients with acute severe traumatic brain injury (TBI). DESIGN: Nonprespecified secondary analysis using propensity score matching. SETTING: We used the Approaches and Decisions in Acute Pediatric TBI Trial (ADAPT NCT04077411) dataset (2014-2017). SUBJECTS: Patients less than 18 years old with Glasgow Coma Scale Score less than or equal to 8 who received levetiracetam or phenytoin as a prophylactic anticonvulsant therapy. INTERVENTION: None. MEASUREMENT AND MAIN RESULTS: Of the 516 total patients who qualified for the case-control study, 372 (72.1%) patients received levetiracetam, and 144 (27.9%) received phenytoin. After propensity score matching, the pair-matched analysis with 133 in each group failed to identify an association between levetiracetam versus phenytoin use and occurrent of SE (3.8% vs. 0.8%, p = 0.22), or mortality (i.e., in-hospital, 30-d and 60-d). However, on closer inspection of the statistical testing, we cannot exclude the possibility that selecting levetiracetam rather than phenytoin for prophylaxis was associated with the following: up to a mean difference of 7.3% greater prevalence of SE; up to a mean difference of 13.9%, 12.1%, and 13.9% greater mortality during the hospital stay, and 30-, and 60-days after hospital arrival, respectively. Last, analysis of 6 months Glasgow Outcome Scale Extended score in those without premorbid comorbidities, there was an association between favorable outcomes and use of phenytoin rather than levetiracetam prophylaxis. CONCLUSIONS: In ADAPT, the decision to use prophylactic levetiracetam versus phenytoin failed to show an association with occurrence of subsequent SE, or mortality. However, we are unable to exclude the possibility that selecting levetiracetam rather than phenytoin for prophylaxis was associated with greater prevalence of SE and mortality. We are unable to make any recommendation about one prophylactic anticonvulsant medication over the other, but recommend that further larger, contemporary studies in severe pediatric TBI are carried out.

Treating status epilepticus in adults. / Behandling av status epilepticus hos voksne.

This clinical review examines the treatment of status epilepticus, a condition in which epileptic seizures are prolonged and pose a significant risk of brain damage and death. International guidelines recommend the use of benzodiazepines as first-line treatment, and these should be administered promptly and in appropriate doses. Second-line treatment involves the use of high-dose anti-seizure medications to stop and prevent seizures. If seizure activity persists, general anaesthesia should be administered as soon as possible. All neurological hospital departments should have established and rehearsed protocols for treating status epilepticus.

Detect, predict, and prevent acute seizures and status epilepticus.

Status epilepticus is one of the most frequent pediatric neurological emergencies. While etiology is often influencing the outcome, more easily modifiable risk factors of outcome include detection of prolonged convulsive seizures and status epilepticus and appropriately dosed and timely applied medication treatment. Unpredictability and delayed or incomplete treatment may at times lead to longer seizures, thereby affecting outcomes. Barriers in the care of acute seizures and status epilepticus include the identification of patients at greatest risk of convulsive status epilepticus, potential stigma, distrust, and uncertainties in acute seizure care, including caregivers, physicians, and patients. Furthermore, unpredictability, detection capability, and identification of acute seizures and status epilepticus, limitations in access to obtaining and maintaining appropriate treatment, and rescue treatment options pose challenges. Additionally, timing and dosing of treatment and related acute management algorithms, potential variations in care due to healthcare and physician culture and preference, and factors related to access, equity, diversity, and inclusion of care. We outline strategies for the identification of patients at risk of acute seizures and status epilepticus, improved status epilepticus detection and prediction, and acute closed-loop treatment and status epilepticus prevention. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

Enriched environment ameliorates chronic temporal lobe epilepsy-induced behavioral hyperexcitability and restores synaptic plasticity in CA3-CA1 synapses in male Wistar rats.

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsies. Pharmacoresistance and comorbidities pose significant challenges to its treatment necessitating the development of non-pharmacological approaches. In an earlier study, exposure to enriched environment (EE) reduced seizure frequency and duration and ameliorated chronic epilepsy-induced depression in rats. However, the cellular basis of beneficial effects of EE remains unknown. Accordingly, in the current study, we evaluated the effects of EE in chronic epilepsy-induced changes in behavioral hyperexcitability, synaptic transmission, synaptophysin (SYN), and calbindin (CB) expression, hippocampal subfield volumes and cell density in male Wistar rats. Epilepsy was induced by lithium-pilocarpine-induced status epilepticus. Chronic epilepsy resulted in behavioral hyperexcitability, decreased basal synaptic transmission, increased paired-pulse facilitation ratio, decreased hippocampal subfields volumes. Moreover, epileptic rats showed decreased synaptophysin and CB expression in the hippocampus. Six weeks post-SE, epileptic rats were exposed to EE for 2 weeks, 6 hr/day. EE significantly reduced the behavioral hyperexcitability and restored basal synaptic transmission correlating with increased expression of SYN and CB. Our results reaffirm the beneficial effects of EE on behavior in chronic epilepsy and establishes some of the putative cellular mechanisms. Since drug resistance and comorbidities are a major concern in TLE, we propose EE as a potent non-pharmacological treatment modality to mitigate these changes in chronic epilepsy.

Intramuscularly administered A1 adenosine receptor agonists as delayed treatment for organophosphorus nerve agent-induced Status Epilepticus.

Exposure to organophosphorus nerve agents (NAs) like sarin (GB) and soman (GD) can lead to sustained seizure activity, or status epilepticus (SE). Previous research has shown that activation of A1 adenosine receptors (A1ARs) can inhibit neuronal excitability, which could aid in SE termination. Two A1AR agonists, 2-Chloro-N6-cyclopentyladenosine (CCPA) and N-Bicyclo(2.2.1)hept-2-yl-5'-chloro-5'-deoxyadenosine (ENBA), were effective in terminating GD-induced SE in rats when administered via intraperitoneal (IP) injection. However, IP injection is not a clinically relevant route of administration. This study evaluated the efficacy of these agonists in terminating NA-induced SE when administered via intramuscular (IM) route. Adult male rats were exposed subcutaneously (SC) to either GB (150 µg/kg) or GD (90 µg/kg) and were treated with ENBA or CCPA at 15, 30, or 60 min after seizure onset or left untreated. Up to 7 days after exposure, deeply anesthetized rats were euthanized and perfused brains were removed for histologic assessment of neuropathology (i.e., neuronal damage) in six brain regions (amygdala, cerebral cortex, piriform cortex, thalamus, dorsal hippocampus, and ventral hippocampus). A total neuropathy score (0-24) was determined for each rat by adding the scores from each of the six regions. The higher the total score the more severe the neuropathology. With the GB model and 60 min treatment delay, ENBA-treated rats experienced 78.6% seizure termination (N = 14) and reduced neuropathology (11.6 ± 2.6, N = 5), CCPA-treated rats experienced 85.7% seizure termination (N = 14) and slightly reduced neuropathology (20.7 ± 1.8, N = 6), and untreated rats experienced no seizure termination (N = 13) and severe neuropathology (22.3 ± 1.0, N = 4). With the GD model and 60 min treatment delay, ENBA-treated rats experienced 92.9% seizure termination (N = 14) and reduced neuropathology (13.96 ± 1.8, N = 9), CCPA-treated rats experienced 78.6% seizure termination (N = 14) and slightly reduced neuropathology (22.0 ± 0.9, N = 10); and untreated rats experienced 16.7% seizure termination (N = 12) and severe neuropathology (22.0 ± 1.8, N = 5). While ENBA and CCPA both demonstrate a clear ability to terminate SE when administered up to 60 min after seizure onset, ENBA offers more neuroprotection, making it a promising candidate for NA-induced SE.

Pretreatment with Methylene Blue Protects Against Acute Seizure and Oxidative Stress in a Kainic Acid-Induced Status Epilepticus Model.

BACKGROUND The aim of the present study was to investigate the potential anticonvulsant effect of methylene blue (MB) in a kainic acid (KA)-induced status epilepticus (SE) model. The effects of MB on levels of oxidative stress and glutamate (Glu) also were explored. MATERIAL AND METHODS Sixty C57BL/6 mice were randomly divided into 5 equal-sized groups: (1) controls; (2) KA; (3) MB 0.5 mg/kg+KA; (4) MB 1 mg/kg+KA; and (5) vehicle+KA. The SE model was established by intra-amygdala microinjection of KA. Behavioral observations and simultaneous electroencephalographic records of the seizures in different groups were analyzed to determine the potential anticonvulsant effect of MB. The influences of MB on oxidative stress markers and glutamate were also detected to explore the possible mechanism. RESULTS MB afforded clear protection against KA-induced acute seizure, as measured by the delayed latency of onset of generalized seizures and SE, decreased percentage of SE, and increased survival rate in mice with acute epilepsy. MB markedly increased the latency to first onset of epileptiform activity and decreased the average duration of epileptiform events, as well as the percentage of time during which the epileptiform activity occurred. Administration of MB prevented KA-induced deterioration of oxidative stress markers and Glu. CONCLUSIONS MB is protective against acute seizure in SE. This beneficial effect may be at least partially related to its potent antioxidant ability and influence on Glu level.

Decreased expression of Rev-Erbα in the epileptic foci of temporal lobe epilepsy and activation of Rev-Erbα have anti-inflammatory and neuroprotective effects in the pilocarpine model.

BACKGROUND: A hallmark of temporal lobe epilepsy (TLE) is brain inflammation accompanied by neuronal demise. Accumulating evidence demonstrates that Rev-Erbα is involved in regulating neuroinflammation and determining the fate of neurons. Therefore, we studied the expression and cellular distribution of Rev-Erbα in the epileptogenic zone of TLE and the effect of treatment with the Rev-Erbα specific agonist SR9009 in the pilocarpine model. METHODS: The expression pattern of Rev-Erbα was investigated by western blotting, immunohistochemistry, and immunofluorescence labeling in patients with TLE. Next, the effects of SR9009 on neuroinflammation, neuronal apoptosis, and neuronal loss in the mouse hippocampus 7 days after status epilepticus (SE) were assessed by western blotting, immunofluorescence labeling staining, and TUNEL staining. RESULTS: The western blotting, immunohistochemistry, and immunofluorescence labeling results revealed that Rev-Erbα was downregulated in the epileptogenic zone of TLE patients and mainly localized in neurons, astrocytes, and presumably microglia. Meanwhile, the expression of Rev-Erbα was decreased in the hippocampus and temporal neocortex of mice treated with pilocarpine in the early post-SE and chronic phases. Interestingly, the expression of Rev-Erbα in the normal hippocampus showed a 24-h rhythm; however, the rhythmicity was disturbed in the early phase after SE, and this disturbance was still present in epileptic animals. Our further findings revealed that treatment with SR9009 inhibited NLRP3 inflammasome activation, inflammatory cytokine (IL-1ß, IL-18, IL-6, and TNF-α) production, astrocytosis, microgliosis, and neuronal damage in the hippocampus after SE. CONCLUSIONS: Taken together, these results suggested that a decrease in Rev-Erbα in the epileptogenic zone may contribute to the process of TLE and that the activation of Rev-Erbα may have anti-inflammatory and neuroprotective effects.

Targeting oxidative stress improves disease outcomes in a rat model of acquired epilepsy.

Epilepsy therapy is based on antiseizure drugs that treat the symptom, seizures, rather than the disease and are ineffective in up to 30% of patients. There are no treatments for modifying the disease-preventing seizure onset, reducing severity or improving prognosis. Among the potential molecular targets for attaining these unmet therapeutic needs, we focused on oxidative stress since it is a pathophysiological process commonly occurring in experimental epileptogenesis and observed in human epilepsy. Using a rat model of acquired epilepsy induced by electrical status epilepticus, we show that oxidative stress occurs in both neurons and astrocytes during epileptogenesis, as assessed by measuring biochemical and histological markers. This evidence was validated in the hippocampus of humans who died following status epilepticus. Oxidative stress was reduced in animals undergoing epileptogenesis by a transient treatment with N-acetylcysteine and sulforaphane, which act to increase glutathione levels through complementary mechanisms. These antioxidant drugs are already used in humans for other therapeutic indications. This drug combination transiently administered for 2 weeks during epileptogenesis inhibited oxidative stress more efficiently than either drug alone. The drug combination significantly delayed the onset of epilepsy, blocked disease progression between 2 and 5 months post-status epilepticus and drastically reduced the frequency of spontaneous seizures measured at 5 months without modifying the average seizure duration or the incidence of epilepsy in animals. Treatment also decreased hippocampal neuron loss and rescued cognitive deficits. Oxidative stress during epileptogenesis was associated with de novo brain and blood generation of high mobility group box 1 (HMGB1), a neuroinflammatory molecule implicated in seizure mechanisms. Drug-induced reduction of oxidative stress prevented HMGB1 generation, thus highlighting a potential novel mechanism contributing to therapeutic effects. Our data show that targeting oxidative stress with clinically used drugs for a limited time window starting early after injury significantly improves long-term disease outcomes. This intervention may be considered for patients exposed to potential epileptogenic insults.

Pediatric emergency department visit characteristics of the patients on the ketogenic diet.

BACKGROUND: The ketogenic diet (KD) has been frequently used for the patients with drug-resistant epilepsy in recent years. The management of these patients in emergency departments (EDs) has some difficulties due to the special needs of KD. We aimed to determine the characteristics and the management of the patients on the KD in the pediatric ED setting. METHODS: Patients who were on the KD and admitted to the ED were included in the study. Demographic, clinical, and laboratory data of all patients were retrospectively reviewed and recorded. RESULTS: There were 105 emergency admissions of 27 patients. The median age of all patients was 55.0 (IQR: 29.0-91.0) months. The most common symptom was vomiting (43.8%). Four patients had upper gastrointestinal bleeding, and one patient had hyperammonemic acute hepatic failure while receiving KD. Of the patients, 41.9% had seizure-related ED admission. Infections were present in 41.9% of the ED visits. The frequency of status epilepticus was significantly lower in the patients who were on the KD for more than 6 months (p < 0.01). In 42.9% of all ED admissions, dextrose containing maintenance fluids was administered mistakenly; although ketosis rate was lower, no seizure was observed in this group. CONCLUSION: The patients on the KD can be admitted to EDs with intercurrent illnesses or adverse effects of the KD. For accurate management, emergency physicians must be aware of the common reasons for ED admission of these patients and the effects of the KD.

Comparison of intranasal midazolam versus intravenous lorazepam for seizure termination and prevention of seizure clusters in the adult epilepsy monitoring unit.

OBJECTIVE: The objective of the study was to compare the performance of intravenous (IV) lorazepam (IVL) and intranasal midazolam (INM) for seizure termination and prevention of seizure clusters in adults admitted to the epilepsy monitoring unit (EMU) in whom seizures were captured on continuous video-electroencephalogram. METHODS: Retrospective cohort of consecutive adults (≥18 years) with epilepsy admitted to the EMU at a single tertiary academic center, who experienced epileptic seizures (confirmed electroencephalographically) and required rescue therapy. The study spanned from January 2015 until December 2016, which included one year before and one year after transitioning from IVL to INM as the standard rescue therapy at our institution. RESULTS: A total of 50 subjects received rescue therapy and were included in the analysis. In the first year, out of 216 patients with epilepsy admitted to the EMU, 27 (13%) received IVL; in the second year, 23/217 (11%) received INM. There were no differences in baseline characteristics and markers of epilepsy severity, the median duration of index seizure (1.7 min [interquartile range (IQR): 1.1-2.7] in IVL vs. 2.0 min [IQR: 1.5-2.6] in INM group, p = 0.20), or in the number of subjects requiring repeat benzodiazepine administrations (IVL 8/27 [29.6%] vs. INM 7/23 [30.4%], p = 0.95). There were no differences in the median number of recurrent seizures in 24 h (1 [IQR: 1-3] in IVL vs. 2 [IQR: 1-4] in INM, p = 0.27), occurrence of status epilepticus (IVL 4/27 [14.8%] subjects vs. INM 1/23 [4.3%] subjects, p = 0.36), incidence of seizure clusters (IVL 8/27 [29.6%] subjects vs. INM 7/23 [30.4%] subjects, p = 0.95), need for transfer to an intensive care unit (ICU), or other adverse events. SIGNIFICANCE: In our retrospective study, INM was comparable with IVL for seizure termination and prevention of seizure clusters in the adult EMU. Intranasal midazolam circumvents the need for IV access to be maintained throughout hospitalization and is an attractive alternative to IVL as a rescue therapy in this setting. Ideally, future large, prospective, randomized, and double blind studies are needed to confirm these findings.

Chemokine CCL2-CCR2 Signaling Induces Neuronal Cell Death via STAT3 Activation and IL-1ß Production after Status Epilepticus.

Elevated levels of chemokine C-C motif ligand 2 (CCL2) and its receptor CCR2 have been reported in patients with temporal lobe epilepsy and in experimental seizures. However, the functional significance and molecular mechanism underlying CCL2-CCR2 signaling in epileptic brain remains largely unknown. In this study, we found that the upregulated CCL2 was mainly expressed in hippocampal neurons and activated microglia from mice 1 d after kainic acid (KA)-induced seizures. Taking advantage of CX3CR1GFP/+:CCR2RFP/+ double-transgenic mice, we demonstrated that CCL2-CCR2 signaling has a role in resident microglial activation and blood-derived monocyte infiltration. Moreover, seizure-induced degeneration of neurons in the hippocampal CA3 region was attenuated in mice lacking CCL2 or CCR2. We further showed that CCR2 activation induced STAT3 (signal transducer and activator of transcription 3) phosphorylation and IL-1ß production, which are critical for promoting neuronal cell death after status epilepticus. Consistently, pharmacological inhibition of STAT3 by WP1066 reduced seizure-induced IL-1ß production and subsequent neuronal death. Two weeks after KA-induced seizures, CCR2 deficiency not only reduced neuronal loss, but also attenuated seizure-induced behavioral impairments, including anxiety, memory decline, and recurrent seizure severity. Together, we demonstrated that CCL2-CCR2 signaling contributes to neurodegeneration via STAT3 activation and IL-1ß production after status epilepticus, providing potential therapeutic targets for the treatment of epilepsy.SIGNIFICANCE STATEMENT Epilepsy is a global concern and epileptic seizures occur in many neurological conditions. Neuroinflammation associated with microglial activation and monocyte infiltration are characteristic of epileptic brains. However, molecular mechanisms underlying neuroinflammation in neuronal death following epilepsy remain to be elucidated. Here we demonstrate that CCL2-CCR2 signaling is required for monocyte infiltration, which in turn contributes to kainic acid (KA)-induced neuronal cell death. The downstream of CCR2 activation involves STAT3 (signal transducer and activator of transcription 3) phosphorylation and IL-1ß production. Two weeks after KA-induced seizures, CCR2 deficiency not only reduced neuronal loss, but also attenuated seizure-induced behavioral impairments, including anxiety, memory decline, and recurrent seizure severity. The current study provides a novel insight on the function and mechanisms of CCL2-CCR2 signaling in KA-induced neurodegeneration and behavioral deficits.

The Novel Effect of Immunomodulator-Glatiramer Acetate on Epileptogenesis and Epileptic Seizures.

BACKGROUND/AIMS: Immunological mechanisms can be triggered as a response to central nervous system insults and can lead to seizures. In this study an investigation was made to determine if glatiramer acetate (GA), an immunomodulator currently used in the treatment of multiple sclerosis, could protect rats from pilocarpine-induced seizures and chronic epilepsy. METHODS: Two groups of adult male Sprague-Dawley rats, experimental (GA) and control, were used in the study. The systemic IL-1α and IL-1ß levels at baseline were checked as well as status epilepticus (SE), and the spontaneous recurrent seizure (SRS) stage by enzyme-linked immunosorbent assay. The GA group was given GA (150 µg/kg, ip) and the control group was given a saline injection prior to pilocarpine-induced seizures. Seizure susceptibility, severity and mortality were evaluated, using Racine seizure classification and hippocampal damage was evaluated by Nissl staining. The GA group received GA (150 µg/kg/day, ip) daily after SE, and the chronic spontaneous seizures were evaluated by long-term video recording, and mossy fiber sprouting was evaluated by Timm staining. The IL-1α and IL-1ß levels were correlated with seizure activities. The TNF-α level in the hippocampus was determined at the SRS stage by immunohistochemistry. The effect of GA on ionic currents and action potentials (APs) in NG108-15 differentiated neurons was investigated using patch-clamp technology. RESULTS: It was found that latency to severe seizures was significantly longer in the GA (p < 0.01) group, which also had SE of shorter duration and less frequent SRS (p < 0.01). GA attenuated acute hippocampal neuron loss and chronic mossy fiber sprouting in the CA3 and the SRS-reduction correlated with the reduction of IL-1α, but not with IL-1ß or TNF-α levels. Mechanistically, GA reduced the peak amplitude of voltage-gated Na+ current (INa), with a negative shift in the inactivation curve of INa and reduced the amplitude of APs along with decreased firing of APs. CONCLUSION: GA might serve as a neuroexcitability modulator which attenuates pilocarpine-induced acute and chronic excitotoxicity. Sodium channel attenuation was partially independent of the immunomodulatory effect.

Attenuating M-current suppression in vivo by a mutant Kcnq2 gene knock-in reduces seizure burden and prevents status epilepticus-induced neuronal death and epileptogenesis.

OBJECTIVES: The M-current is a low-threshold voltage-gated potassium current generated by Kv7 subunits that regulates neural excitation. It is important to note that M-current suppression, induced by activation of Gq-coupled neurotransmitter receptors, can dynamically regulate the threshold of action-potential firing and firing frequency. Here we sought to directly examine whether M-current suppression is involved in seizures and epileptogenesis. METHODS: Kv7.2 knock-in mice lacking the key protein kinase C (PKC) phosphorylation acceptor site for M-current suppression were generated by introducing an alanine substitution at serine residue 559 of mouse Kv7.2, mKv7.2(S559A). Basic electrophysiologic properties of the M-current between wild-type and Kv7.2(S559A) knock-in mice were analyzed in primary cultured neurons. Homozygous Kv7.2(S559A) knock-in mice were used to evaluate the protective effect of mutant Kv7.2 channel against chemoconvulsant-induced seizures. In addition, pilocarpine-induced neuronal damage and spontaneously recurrent seizures were evaluated after equivalent chemoconvulsant-induced status epilepticus was achieved by coadministration of the M-current-specific channel inhibitor, XE991. RESULT: Neurons from Kv7.2(S559A) knock-in mice showed normal basal M-currents. Knock-in mice displayed reduced M-current suppression when challenged by a muscarinic agonist, oxotremorine-M. Kv7.2(S559A) mice were resistant to chemoconvulsant-induced seizures with no mortality. Administration of XE991 transiently exacerbated seizures in knock-in mice equivalent to those of wild-type mice. Valproate, which disrupts neurotransmitter-induced M-current suppression, showed no additional anticonvulsant effect in Kv7.2(S559A) mice. After experiencing status epilepticus, Kv7.2(S559A) knock-in mice did not show seizure-induced cell death or spontaneous recurring seizures. SIGNIFICANCE: This study provides evidence that neurotransmitter-induced suppression of M-current generated by Kv7.2-containing channels exacerbates behavioral seizures. In addition, prompt recovery of M-current after status epilepticus prevents subsequent neuronal death and the development of spontaneously recurrent seizures. Therefore, prompt restoration of M-current activity may have a therapeutic benefit for epilepsy.

Increased Superoxide Dismutase 2 by Allopregnanolone Ameliorates ROS-Mediated Neuronal Death in Mice with Pilocarpine-Induced Status Epilepticus.

Excessive production of reactive oxygen species (ROS), along with dysfunction of the antioxidant defense system, such as that involving superoxide dismutase (SOD), may play a major role in neuronal death following status epilepticus (SE). Neurosteroids, which are allosteric modulators of the GABAA receptor in cerebral metabolism, have been suggested as being neuroprotective in various animal models; however, their effect to preventing ROS has not been examined. Herein, we investigate the neuroprotective role of allopregnanolone, the prototypical neurosteroid in the brain, in relation to the ROS-mediated neuronal injury. Adult male C57BL/6 mice were subjected to SE and treated with allopregnanolone. Hippocampal cell death was assessed by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay, and ROS production was investigated by in situ detection of oxidized hydroethidine. SOD2 expression was analyzed by both western blot and immunofluorescent staining in the hippocampal subfields. In mice treated with allopregnanolone after SE, hippocampal cell death, DNA fragmentation, oxidative DNA damage, and ROS production were reduced significantly compared to mice subjected to vehicle treatment after SE. Hippocampal SOD2 expression was significantly increased by allopregnanolone. These finding suggest that allopregnanolone plays a neuroprotective role, with not only anticonvulsant but also antioxidant effects, by increasing SOD2 in pilocarpine-induced SE model.

Impact of timing of continuous intravenous anesthetic drug treatment on outcome in refractory status epilepticus.

BACKGROUND: Patients in refractory status epilepticus (RSE) may require treatment with continuous intravenous anesthetic drugs (cIVADs) for seizure control. The use of cIVADs, however, was recently associated with poor outcome in status epilepticus (SE), raising the question of whether cIVAD therapy should be delayed for attempts to halt seizures with repeated non-anesthetic antiepileptic drugs. In this study, we aimed to determine the impact of differences in therapeutic approaches on RSE outcome using timing of cIVAD therapy as a surrogate for treatment aggressiveness. METHODS: This was a retrospective cohort study over 14 years (n = 77) comparing patients with RSE treated with cIVADs within and after 48 h after RSE onset, and functional status at last follow-up was the primary outcome (good = return to premorbid baseline or modified Rankin Scale score of less than 3). Secondary outcomes included discharge functional status, in-hospital mortality, RSE termination, induction of burst suppression, use of thiopental, duration of RSE after initiation of cIVADs, duration of mechanical ventilation, and occurrence of super-refractory SE. Analysis was performed on the total cohort and on subgroups defined by RSE severity according to the Status Epilepticus Severity Score (STESS) and by the variables contained therein. RESULTS: Fifty-three (68.8%) patients received cIVADs within the first 48 h. Early cIVAD treatment was independently associated with good outcome (adjusted risk ratio [aRR] 3.175, 95% confidence interval [CI] 1.273-7.918; P = 0.013) as well as lower chance of both induction of burst suppression (aRR 0.661, 95% CI 0.507-0.861; P = 0.002) and use of thiopental (aRR 0.446, 95% CI 0.205-0.874; P = 0.043). RSE duration after cIVAD initiation was shorter in the early cIVAD cohort (hazard ratio 1.796, 95% CI 1.047-3.081; P = 0.033). Timing of cIVAD use did not impact the remaining secondary outcomes. Subgroup analysis revealed early cIVAD impact on the primary outcome to be driven by patients with STESS of less than 3. CONCLUSIONS: Patients with RSE treated with cIVADs may benefit from early initiation of such therapy.

The M1 Muscarinic Receptor Antagonist VU0255035 Delays the Development of Status Epilepticus after Organophosphate Exposure and Prevents Hyperexcitability in the Basolateral Amygdala.

Exposure to organophosphorus toxins induces seizures that progress to status epilepticus (SE), which can cause brain damage or death. Seizures are generated by hyperstimulation of muscarinic receptors, subsequent to inhibition of acetylcholinesterase; this is followed by glutamatergic hyperactivity, which sustains and reinforces seizure activity. It has been unclear which muscarinic receptor subtypes are involved in seizure initiation and the development of SE in the early phases after exposure. Here, we show that pretreatment of rats with the selective M1 receptor antagonist, VU0255035 [N-(3-oxo-3-(4-(pyridine-4-yl)piperazin-1-yl)propyl)-benzo[c][1,2,5]thiadiazole-4 sulfonamide], significantly suppressed seizure severity and prevented the development of SE for about 40 minutes after exposure to paraoxon or soman, suggesting an important role of the M1 receptor in the early phases of seizure generation. In addition, in in vitro brain slices of the basolateral amygdala (a brain region that plays a key role in seizure initiation after nerve agent exposure), VU0255035 blocked the effects produced by bath application of paraoxon-namely, a brief barrage of spontaneous inhibitory postsynaptic currents, followed by a significant increase in the ratio of the total charge transferred by spontaneous excitatory postsynaptic currents over that of the inhibitory postsynaptic currents. Furthermore, paraoxon enhanced the hyperpolarization-activated cation current Ih in basolateral amygdala principal cells, which could be one of the mechanisms underlying the increased glutamatergic activity, an effect that was also blocked in the presence of VU0255035. Thus, selective M1 antagonists may be an efficacious pretreatment in contexts in which there is risk for exposure to organophosphates, as these antagonists will delay the development of SE long enough for medical assistance to arrive.

Carvacrol after status epilepticus (SE) prevents recurrent SE, early seizures, cell death, and cognitive decline.

OBJECTIVE: Carvacrol is a naturally occurring monoterpenic phenol that has been suggested to have an action at transient receptor potential cation subfamily M7 (TRPM7) channels, γ-aminobutyric acid (GABAA receptors, and sodium channels, and has been shown to be antiinflammatory. Carvacrol is neuroprotective in models of cerebral ischemia in vivo and in vitro, probably through its action at TRPM7 channels. We therefore aimed to determine the effect of carvacrol on status epilepticus (SE), chronic epilepsy, cell death, and post-SE cognitive decline. METHODS: We performed long-term, continuous wireless electroencephalography (EEG) monitoring in vivo in rats who underwent perforant path stimulation (PPS) to induce SE and were then randomized to treatment with carvacrol or saline. We also evaluated TRPM7 receptor expression and quantified seizure-induced cell death. The alternating T-maze paradigm was used to assess memory function. RESULTS: Immunostaining showed that TRPM7 channels are widely expressed in neurons within the hippocampus. We found that carvacrol inhibited recurrent SE and early seizures in vivo, but had no detectable effect in the hippocampus on paired-pulse inhibition or the fiber volley, indicating that it was not acting through sodium channel inhibition or GABA receptors. Although the development and severity of chronic epilepsy were not altered by carvacrol, cognitive decline was significantly improved in animals treated with carvacrol. In keeping with preserved memory functions in animals treated with carvacrol, carvacrol had a protective effect against SE-induced cell death in CA1 and hilus, the hippocampal regions most affected by cell loss in the PPS epilepsy model. SIGNIFICANCE: Carvacrol, a naturally occurring inhibitor of TRPM7 channels, is a novel, promising treatment to prevent early recurrence of SE, SE-related neuronal damage, and cognitive decline.

Intranasal pitavastatin attenuates seizures in different experimental models of epilepsy in mice.

This study was carried out to evaluate the effect of intranasal pitavastatin (PVS) on pentylenetetrazole (PTZ)-induced seizures, increasing current electroshock (ICES) seizures, and status epilepticus in mice. Intranasal PVS, 0.5 and 1.0mg/kg, showed significant increase in latency to PTZ-induced seizures and ICES seizure threshold compared to control; however, the effects were dose-dependent and were more significant at higher dose. Further, intranasal PVS (1.0mg/kg) but not intravenous PVS (50.0mg/kg) showed effective protection against PTZ-induced status epilepticus. No impairment in cognitive functions was observed following intranasal PVS (1.0mg/kg), thus making it a prospective therapeutic approach for acute seizures and status epilepticus.

[The risk of epileptic seizures during antibiotic therapy].

Numerous antibiotics may trigger epileptic seizures or status epilepticus by decreasing inhibitory transmission in the brain, thus lowering the seizure threshold. The most potent seizurogenic effect is exerted by penicillins, cephalosporins, fluorochinolons and carbapenems. Predisposing factors that facilitate development of epileptic seizures in the course of antibiotic therapy comprise all conditions accompanied by damage to the blood-brain barrier (including cerebral trauma and encephalitis), a high dose of an antibiotic or lack of adequate dose adjustment in patients with renal failure. A particularly dangerous and difficult to diagnose complication is nonconvulsive status epilepticus in patients treated with cephalosporins. For this reason, in case the patient presents with alterations of consciousness in the course of cephalosporin therapy, an EEG test should be performed. Some antibiotics, such as carbapenems, macrolides and antitubercular medications enter into pharmacokinetic interactions with antiepileptic agents, causing a decrease or increase in the plasma concentration of the latter and in consequence lead to possible epileptic seizures or drug-associated neurotoxicity. In patients with risk of epileptic seizures or with diagnosed epilepsy, one should select an antibiotic with a low proconvulsive potential and administer it in an adequately adjusted dose, especially in individuals with renal failure. Employing antibiotics interacting with antiepileptic medications with which the patient is treated should be avoided.

Protective Effects of Thymoquinone Against Convulsant Activity Induced by Lithium-Pilocarpine in a model of Status Epilepticus.

Inflammation plays a pivotal role in status epilepticus (SE). Thymoquinone (TQ) is a bioactive monomer extracted from black seed (Nigella sativa) oil, which has anti-inflammatory properties in the context of various diseases. This study explored the protective effects of TQ in SE and used a lithium-pilocarpine model of SE to investigate the underlying mechanism, which was related to inflammation mediated by the NF-κB signaling pathway. In the present study, latency to SE increased in the TQ-pretreated group compared with the SE group, and the incidence of SE was significantly reduced. The seizure severity score measured on the Racine scale was significantly decreased in the TQ group compared with the SE group. Moreover, the results of the behavioral tests suggested that TQ may also have a protective effect on learning and memory functions. Finally, we further investigated the protective mechanism of TQ. The results showed that TQ-pretreatment significantly downregulated the protein levels of COX-2 and TNF-α in the brain, in a manner mediated by the NF-κB signaling pathway. These findings demonstrate that TQ attenuates convulsant activity via an anti- inflammation signaling pathway in a model of SE.