Electroencephalographic Seizure Research Articles

Does Electroencephalography Seizure Duration Account for an Adequate Treatment of Magnetic Seizure Therapy for Schizophrenia?

A seizure lasting >15 s has been considered to indicate treatment for magnetic seizure therapy (MST), a modification of electroconvulsive therapy (ECT), without much validation. This study aimed to investigate whether this seizure duration was suitable for the treatment of schizophrenia. Altogether, 34 and 33 in-patients with schizophrenia received 10 sessions of MST and ECT, respectively. Clinical symptoms were assessed using the Positive and Negative Symptom Scale at baseline and at the 4-week follow-up. Electroencephalogram (EEG) was monitored during each MST or ECT treatment using bifrontal electrodes. The proportion of participants who achieved the 15-second threshold was only 28.6% in the MST group, with a significant difference between responders and nonresponders. For patients receiving MST, the average EEG seizure duration correlated with the percentage of Positive and Negative Symptom Scale reduction (t(32) = 2.51, P = 0.017, uncorrected; t(32) = 2.00, P = 0.055, corrected with clinical characteristics). The average EEG seizure duration predicted the clinical response at a trend level (Z = 1.76, P = 0.078) with an optimal cutoff of 11.3 seconds. All patients in the ECT group achieved the 15-second threshold. However, their average EEG seizure duration was uncorrelated with clinical improvement. The duration of EEG seizures may be associated with the antipsychotic effects of MST. This association may have been influenced by various clinical and technical factors. More research is needed to define the specific criteria for adequate MST in schizophrenia in order to achieve personalized dosing.

Incomplete resection of the intracranial electroencephalographic seizure onset zone is not associated with postsurgical outcomes.

Delineation of seizure onset regions using intracranial electroencephalography (icEEG) is vital in the surgical workup of drug-resistant epilepsy cases. However, it is unknown whether the complete resection of these regions is necessary for seizure freedom, or whether postsurgical seizure recurrence can be attributed to the incomplete removal of seizure onset regions. To address this gap, we retrospectively analyzed icEEG recordings from 63 subjects, identifying seizure onset regions visually and algorithmically. We assessed onset region resection and correlated this with postsurgical seizure control. The majority of subjects had more than half of their onset regions resected (82.46% and 80.65% of subjects using visual and algorithmic methods, respectively). There was no association between the proportion of the seizure onset zone (SOZ) that was subsequently resected and better surgical outcomes (area under the receiver operating characteristic curve [AUC] < .7). Investigating the spatial extent of onset regions, we found no substantial evidence of an association with postsurgical seizure control (all AUC < .7). Although seizure onset regions are typically resected completely or in large part, incomplete resection is not associated with worse postsurgical outcomes. We conclude that postsurgical seizure recurrence cannot be attributed to an incomplete resection of the icEEG SOZ alone. Other network mechanisms beyond icEEG seizure onset likely contribute.

Seizure Duration and Electroconvulsive Therapy in Major Depressive Disorder

Electroconvulsive therapy (ECT), wherein a generalized epileptic seizure is induced, is a treatment for major depressive disorder (MDD). Currently, it is unclear whether there is an association between seizure length and treatment outcome. To explore the association between seizure duration, potential confounding variables, and ECT treatment outcome. This population-based cohort study obtained data from the Swedish National Quality Register for ECT. Patients treated for unipolar MDD with unilateral electrode placement between January 1, 2012, and December 31, 2019, were included. The electroencephalographic (EEG) seizure duration from the first ECT treatment session for each patient was used for analysis. Data analyses were performed between March 2021 and May 2024. The primary outcome was remission, defined as a cutoff score of less than 10 points on the self-assessment version of the Montgomery-Åsberg Depression Rating Scale within 1 week after ECT. Multivariate logistic regression analysis was performed to calculate odds ratios (ORs) between different seizure duration groups. Furthermore, the associations between concomitant use of pharmacological treatments, seizure duration, and remission rate were explored. Among the 6998 patients included, 4229 (60.4%) were female and the mean (SD) age was 55.2 (18.6) years. Overall, 2749 patients (39.3%) achieved remission after ECT. Patients with EEG seizure duration of 60 to 69 seconds had the highest remission rates compared with patients with seizure duration of less than 20 seconds (OR, 2.17; 95% CI, 1.63-2.88; P < .001). Anticonvulsant medications were associated with shorter seizure duration (eg, lamotrigine: β coefficient [SE], -6.02 [1.08]; P < .001) and lower remission rates (eg, lamotrigine: adjusted OR, 0.67; 95% CI, 0.53-0.84; P < .001). This study found an association between seizure length and remission from MDD. Use of anticonvulsant medication during ECT was associated with shorter seizure duration and lower remission rates after ECT.

Optimizing EEG monitoring in critically ill children at risk for electroencephalographic seizures

ObjectiveStrategies are needed to optimally deploy continuous EEG monitoring (CEEG) for electroencephalographic seizure (ES) identification and management due to resource limitations. We aimed to construct an efficient multi-stage prediction model guiding CEEG utilization to identify ES in critically ill children using clinical and EEG covariates. MethodsThe largest prospective single-center cohort of 1399 consecutive children undergoing CEEG was analyzed. A four-stage model was developed and trained to predict whether a subject required additional CEEG at the conclusion of each stage given their risk of ES. Logistic regression, elastic net, random forest, and CatBoost served as candidate methods for each stage and were evaluated using cross validation. An optimal multi-stage model consisting of the top-performing stage-specific models was constructed. ResultsWhen evaluated on a test set, the optimal multi-stage model achieved a cumulative specificity of 0.197 and cumulative F1 score of 0.326 while maintaining a high minimum cumulative sensitivity of 0.938. Overall, 11 % of test subjects with ES were removed from the model due to a predicted low risk of ES (falsely negative subjects). CEEG utilization would be reduced by 32 % and 47 % compared to performing 24 and 48 h of CEEG in all test subjects, respectively. We developed a web application called EEGLE (EEG Length Estimator) that enables straightforward implementation of the model. ConclusionsApplication of the optimal multi-stage ES prediction model could either reduce CEEG utilization for patients at lower risk of ES or promote CEEG resource reallocation to patients at higher risk for ES.

Retrospective Multicenter Cohort Study on Safety and Electroencephalographic Response to Lacosamide for Neonatal Seizures

BackgroundThere is growing evidence supporting the safety and effectiveness of lacosamide in older children. However, minimal data are available for neonates. We aimed to determine the incidence of adverse events associated with lacosamide use and explore the electroencephalographic seizure response to lacosamide in neonates. MethodsA retrospective cohort study was conducted using data from seven pediatric hospitals from January 2009 to February 2020. For safety outcomes, neonates were followed for ≤30 days from index date. Electroencephalographic response of lacosamide was evaluated based on electroencephalographic reports for ≤3 days. ResultsAmong 47 neonates, 98% received the first lacosamide dose in the intensive care units. During the median follow-up of 12 days, 19% of neonates died, and the crude incidence rate per 1000 patient-days (95% confidence interval) of the adverse events by diagnostic categories ranged from 2.8 (0.3, 10.2) for blood or lymphatic system disorders and nervous system disorders to 10.5 (4.2, 21.6) for cardiac disorders. Electroencephalographic seizures were observed in 31 of 34 patients with available electroencephalographic data on the index date. There was seizure improvement in 29% of neonates on day 1 and also in 29% of neonates on day 2. On day 3, there was no change in 50% of neonates and unknown change in 50% of neonates. ConclusionsThe results are reassuring regarding the safety of lacosamide in neonates. Although some neonates had fewer seizures after lacosamide administration, the lack of a comparator arm and reliance on qualitative statements in electroencephalographic reports limit the preliminary efficacy results.

Sequential levetiracetam and phenytoin in electroencephalographic neonatal seizures unresponsive to phenobarbital: a multicenter prospective observational study in India

Although levetiracetam and phenytoin are widely used antiseizure medications (ASM) in neonates, their efficacy on seizure freedom is unclear. We evaluated electroencephalographic (EEG) seizure freedom following sequential levetiracetam and phenytoin in neonatal seizures unresponsive to phenobarbital. We recruited neonates born ≥35 weeks and aged <72h who had continued electrographic seizures despite phenobarbital, from three Indian hospitals, between 20 June 2020 and 31 July 2022. The neonates were treated with intravenous levetiracetam (20mg/kg x 2 doses, second line) followed by phenytoin (20mg/kg x 2 doses, third line) if seizures persisted. The primary outcome was complete seizure freedom, defined as an absence of seizures on EEG for at least 60min within 40min from the start of infusion. Of the 206 neonates with continued seizures despite phenobarbital, 152 received levetiracetam with EEG. Of these one EEG was missing, 47 (31.1%) were in status epilepticus, and primary outcome data were available in 145. Seizure freedom occurred in 20 (13.8%; 95% CI 8.6%-20.5%) after levetiracetam; 16 (80.0%) responded to the first dose and 4 (20.0%) to the second dose. Of the 125 neonates with persisting seizures after levetiracetam, 114 received phenytoin under EEG monitoring. Of these, the primary outcome data were available in 104. Seizure freedom occurred in 59 (56.7%; 95% CI 46.7%-66.4%) neonates; 54 (91.5%) responded to the first dose and 5 (8.5%) to the second dose. With the conventional doses, levetiracetam was associated with immediate EEG seizure cessation in only 14% of phenobarbital unresponsive neonatal seizures. Additional treatment with phenytoin along with levetiracetam attained seizure freedom in further 57%. Safety and efficacy of higher doses of levetiracetam should be evaluated in well-designed randomised controlled trials. National Institute for Health and Care Research (NIHR) Research and Innovation for Global Health Transformation (NIHR200144).

A Novel Rat Infant Model of Medial Temporal Lobe Epilepsy Reveals New Insight into the Molecular Biology and Epileptogenesis in the Developing Brain.

Although several adult rat models of medial temporal lobe epilepsy (mTLE) have been described in detail, our knowledge of mTLE epileptogenesis in infant rats is limited. Here, we present a novel infant rat model of mTLE (InfRPil-mTLE) based on a repetitive, triphasic injection regimen consisting of low-dose pilocarpine administrations (180 mg/kg. i.p.) on days 9, 11, and 15 post partum (pp). The model had a survival rate of >80% and exhibited characteristic spontaneous recurrent electrographic seizures (SRES) in both the hippocampus and cortex that persisted into adulthood. Using implantable video-EEG radiotelemetry, we quantified a complex set of seizure parameters that demonstrated the induction of chronic electroencephalographic seizure activity in our InfRPil-mTLE model, which predominated during the dark cycle. We further analyzed selected candidate genes potentially relevant to epileptogenesis using a RT-qPCR approach. Several candidates, such as the low-voltage-activated Ca2+ channel Cav3.2 and the auxiliary subunits β 1 and β 2, which were previously reported to be upregulated in the hippocampus of the adult pilocarpine mTLE model, were found to be downregulated (together with Cav2.1, Cav2.3, M1, and M3) in the hippocampus and cortex of our InfRPil-mTLE model. From a translational point of view, our model could serve as a blueprint for childhood epileptic disorders and further contribute to antiepileptic drug research and development in the future.

Tactile stimulation of young WAG/Rij rats prevents development of depression but not absence epilepsy.

Investigations in Wistar Albino Glaxo from Rijswijk (WAG/Rij) rats that are susceptible to genetic absence epilepsy have demonstrated that environmental modifications affect absence seizures. Previously, we showed that neonatal tactile stimulations produce disease-modifying effect on genetically determined absence epilepsy and associated depression in Wag/Rij rats. The study presented here examined the effect of TS during late ontogenesis (adolescence and young adulthood) on epilepsy and depression outcomes in this genetically epileptic rat strain. On postnatal day (PND) 38, male WAG/Rij rats randomly were assigned to either the tactile stimulation (TS), handled or control group (unhandled) with 8 animals in each group. Following a 7-day adaptation period to their new surroundings, the animals were submitted to tactile stimulation from PND 45 to PND 90, five days per week, for 5 min daily. The tactile-stimulated rat was removed from its cage, placed on the experimenter's lap, and had its neck and back gently stroked by the researcher. The handled rats were taken to another cage and left alone for 5 min daily from PND 45 to PND 90. The control rats were left undisturbed in their home cage, except for regular cage cleaning. After PND 90, all rats were left undisturbed until behavioral testing and EEG recording. When the animals were 7 months old, they were subjected to the sucrose consumption test (SCT) and the forced swimming test (FST). Electroencephalogram (EEG) recordings were made at 8 months of age in order to measure electroencephalographic seizure activity, thus, the spike-wave discharges (SWDs). Tactile-stimulated rats showed increased sucrose consumption and number of approaches to the sucrose solution in the SCT when compared with the handled and control rats. In the FST, rats in TS group showed lower immobility time and greater immobility latency, active swimming time and diving frequency than the handled and control rats. The duration and the number of seizures were not different amongst the groups. The data obtained suggest that TS in young rats is able to prevent depression in WAG/Rij rats.

Etomidate versus propofol for electroconvulsive therapy: An intraindividual comparative study during the COVID-19 pandemic

ObjectivesThe Coronavirus disease 2019 (COVID-19) pandemic markedly influenced mental health care practices, notably regarding electroconvulsive therapy (ECT). This was due to the redistribution of anesthetic agents used during ECT such as propofol, for intensive care units. Because in our center propofol was switched to etomidate to avoid ECT activity discontinuation, we undertook this study in order to compare Propofol and Etomidate regarding electroencephalographic seizure duration and stimulus intensity. MethodsWe performed a retrospective and comparative study, each patient being its own control. We included patients with at least two courses of ECT on propofol and two others with etomidate over the period from September 2019 to April 2021, regardless of the psychiatric diagnosis. Our data collection process notably targeted stimulus intensity, seizure duration recorded using electroencephalography, and medication used for anesthetic induction. ResultsOverall, we included 18 patients with a male: female ratio of 1:2.6 and a mean (and standard deviation) age of 62.7±13.4 years. We found that the mean intensity of stimulation was significantly lower with etomidate when compared to propofol (425.3±250.0 vs. 658.9±280.2 mC, P=0.001). The mean duration of electroencephalographic seizure was significantly higher with etomidate in comparison to propofol (53.5±16.6 vs. 35.0±12.2seconds, P<0.001). ConclusionBy using each patient as its own control, our study found that etomidate, while compared to propofol, was related to a lower level of stimulatory intensity and a longer electroencephalographic seizure duration.

Incidence of postoperative seizures in neonates following cardiac surgery with regional cerebral perfusion and deep hypothermic circulatory arrest

ObjectivesHistorically, our center has primarily used deep hypothermic circulatory arrest, but in recent years some surgeons have selectively used regional cerebral perfusion as an alternative. We aimed to compare the incidence of postoperative electroencephalographic seizure incidence in neonates undergoing surgery with regional cerebral perfusion and deep hypothermic circulatory arrest. MethodsA retrospective analysis was performed in neonates who underwent surgery between 2012 and 2022 with either deep hypothermic circulatory arrest or regional cerebral perfusion with routine postoperative continuous electroencephalography monitoring for 48 hours. Propensity matching was performed to compare postoperative seizure risk between the 2 groups. ResultsAmong 1136 neonates undergoing cardiac surgery with cardiopulmonary bypass, regional cerebral perfusion was performed in 99 (8.7%) and deep hypothermic circulatory arrest in 604 (53%). The median duration of regional cerebral perfusion was 49 minutes (interquartile range, 38-68) and deep hypothermic circulatory arrest was 41 minutes (interquartile range, 31-49). The regional cerebral perfusion group had significantly longer total support, cardiopulmonary bypass, and aortic crossclamp times. Overall seizure incidence was 11% (N = 76) and 13% (N = 35) in the most recent era (2019-2022). The unadjusted seizure incidence was similar in neonates undergoing regional cerebral perfusion (N = 12, 12%) and deep hypothermic circulatory arrest (N = 64, 11%). After propensity matching, the seizure incidence was similar in neonates undergoing regional cerebral perfusion (N = 12, 12%) and deep hypothermic circulatory arrest (N = 37, 12%) (odds ratio, 0.97; 95% CI, 0.55-1.71; P = .92). ConclusionsIn this contemporary single-center experience, the incorporation of regional cerebral perfusion did not result in a change in seizure incidence in comparison with deep hypothermic circulatory arrest. However, unmeasured confounders may have impacted these findings. Further studies are needed to determine the impact, if any, of regional cerebral perfusion on postoperative seizure incidence.

Varying Wave-Shape Component Decomposition: Algorithm and Applications

The decomposition problem for multiple sinusoidal component signals has been developed in the past decades. However, many complex time series are made up of wave-shape components, which invalidates signal decomposition methods based on sinusoidal components. Since wave-shape components are time-varying from one cycle to the other and often contaminated by strong noise, robustly decomposing a signal into wave-shape components is still a challenging task. In this paper, a varying wave-shape component decomposition (VWCD) method is proposed to extract time-varying and weak characteristics of wave-shape components from a multicomponent signal. Specifically, instantaneous frequencies (IFs) of varying wave-shape components are no longer inter multiples of a fundamental IF allowing the VWCD method more flexible in practical applications. We propose an instantaneous amplitudes and fundamental component phases estimation method based on an intrinsic chirp signal model and a regression coefficients initialization method by a fixed wave-shape signal model. The potential and effectiveness of the proposed VWCD method are verified by some simulated signals with different signal-to-noise ratios, a real-world electroencephalography seizure signal, and an experimental chest wall vibration signal from a microwave vital sign monitoring system.

Non-Traumatic Coma in Children- A Review

Coma is defined as the unintentional failure of the patient to open their eyes spontaneously or in response to noise and inability to open for commands or localised painful stimuli with or without the ability to express comprehensible words or language response, whereas the Non traumatic coma is without any injury to the brain, and the Glasgow coma scale below 12. The Non traumatic coma causes due to the infections(tubercular meningitis, bacterial meningitis, encephalitis) and other metabolic conditions ,status epilepticus intracranial bleed, miscellaneous, hypoxic ischemic insults, Electrical shock, shunt dysfunction, Inborn error of metabolism. The monitoring parameters are Heart rate, Respiratory rate and pattern, Blood pressure, Temperature, coma severity using GCS, pupillary size, extra ocular movements, corneal reflex, posture, and motor pattern. The main symptoms are ataxia or weakness, isolated cranial nerve palsy, mild alteration of tone, poor pulse volume, apnea, abnormal pupillary size and reaction, dizziness, Headache, abnormal extra ocular movements absent corneal reflex. Management of non-traumatic coma patients at hospital includes Monitoring of Intracranial pressure, Maintenance of an adequate cerebral perfusion pressure, Management of persistent intracranial hypertension and Monitoring of Electroencephalographic Seizure activity. Infections are the most common cause for the non-traumatic coma in several cases. The pattern of infectious caused are CNS infections &gt; metabolic toxic exposure &gt; encephalitis &gt; Intoxication &gt; hypoxic ischemic insults &gt; Intracranial haemorrhages&gt;miscellaneous&gt;unknown cases. 40% of children are prone to Non traumatic coma per 10000 general population per year.

Deep net detection and onset prediction of electrographic seizure patterns in responsive neurostimulation.

Managing the progress of drug-resistant epilepsy patients implanted with the Responsive Neurostimulation (RNS) System requires the manual evaluation of hundreds of hours of intracranial recordings. The generation of these large amounts of data and the scarcity of experts' time for evaluation necessitate the development of automatic tools to detect intracranial electroencephalographic (iEEG) seizure patterns (iESPs) with expert-level accuracy. We developed an intelligent system for identifying the presence and onset time of iESPs in iEEG recordings from the RNS device. An iEEG dataset from 24 patients (36 293 recordings) recorded by the RNS System was used for training and evaluating a neural network model (iESPnet). The model was trained to identify the probability of seizure onset at each sample point of the iEEG. The reliability of the net was assessed and compared to baseline methods, including detections made by the device. iESPnet performance was measured using balanced accuracy and the F1 score for iESP detection. The prediction time was assessed via both the error and the mean absolute error. The model was evaluated following a hold-one-out strategy, and then validated in a separate cohort of 26 patients from a different medical center. iESPnet detected the presence of an iESP with a mean accuracy value of 90% and an onset time prediction error of approximately 3.4 s. There was no relationship between electrode location and prediction outcome. Model outputs were well calibrated and unbiased by the RNS detections. Validation on a separate cohort further supported iESPnet applicability in real clinical scenarios. Importantly, RNS device detections were found to be less accurate and delayed in nonresponders; therefore, tools to improve the accuracy of seizure detection are critical for increasing therapeutic efficacy. iESPnet is a reliable and accurate tool with the potential to alleviate the time-consuming manual inspection of iESPs and facilitate the evaluation of therapeutic response in RNS-implanted patients.

771 Levetiracetam Dosing for Seizure Prophylaxis in Neurocritical Care Patients

INTRODUCTION: Levetiracetam has emerged as a safer alternative to phenytoin for seizure prophylaxis in patients presenting with subarachnoid hemorrhage (SAH) or traumatic brain injury (TBI). However, it remains unclear which Levetiracetam dosing regimen is most effective at preventing seizures. METHODS: A retrospective cohort study captured adult patients at a quaternary care center presenting with SAH or TBI who received levetiracetam as a total daily dose (TDD) equivalent to or greater than 1000 mg. The primary outcome was the combined seizure incidence, including clinical and subclinical seizures. RESULTS: Among the 139 patients identified, 49.6% were male, and the mean age was 53 years. For patients receiving 1000 mg TDD levetiracetam, the administration was 500 mg twice daily. For patients receiving &gt;1000 mg TDD, 77/78 patients received 1000 mg twice daily, and the remaining patient received 750 mg twice daily. A higher seizure incidence was observed, 11.5% vs 1.3%, in patients receiving 1000 mg TDD compared with doses &gt;1000 mg TDD, respectively (p = 0.01), despite no difference in examined confounders, including history of alcoholism (14.8% vs. 19.2%, p = 0.49), benzodiazepine use (65.6% vs. 73.1%, p = 0.28), or propofol use (62.3% vs. 62.8%, p = 0.17). No difference in adverse effects were observed (anemia 1.6% vs. 3.8%, p = 0.44; leukopenia 6.6% vs. 9.0%, p = 0.60; thrombocytopenia 1.6% vs. 1.3%, p = 0.86). CONCLUSIONS: Patients may experience a reduced incidence of clinical and electroencephalographic seizures with levetiracetam dosing greater than 1000 mg TDD.

Pinniped electroencephalography: Methodology and findings in California sea lions (Zalophus californianus).

This study was designed to identify abnormalities in the electroencephalograms (EEGs) recorded from stranded California sea lions (Zalophus californianus) with suspected domoic acid (DA) toxicosis. Recordings from animals presenting for non-neurological issues were also obtained to better understand the normal EEG (background activity and transient events) in this species, as, to date, studies have focused on examining natural sleep in pinnipeds. Most animals were sedated for electrode placement and EEG acquisition with some receiving antiepileptic medications or isoflurane during the procedure. A total of 103 recordings were read and scored from 0 (normal) to 3 (severely abnormal). Epileptiform discharges, consisting of spikes, sharp waves, slow waves, and/or spike waves, were present in all EEGs with scores of 1, 2, or 3. The distribution of these events over the scalp varied. While often generalized, others were lateralized over one hemisphere, bifrontal, bioccipital, and/or bitemporal, while some discharges were multifocal. Findings were different between sea lions and occasionally changed within the EEG on a given sea lion. No clinical seizures were observed during the recording but a few sea lions had findings consistent with electroencephalographic seizures. When available, supporting diagnostic results obtained from magnetic resonance imaging (MRI) and/or necropsy/histopathology were described, as well as the status of those sea lions that recovered and were released with satellite tags.

Levetiracetam dosing for seizure prophylaxis in neurocritical care patients

ABSTRACT Background/Objective Levetiracetam is used for seizure prophylaxis in patients presenting with subarachnoid hemorrhage (SAH) or traumatic brain injury (TBI). We aim to characterize the optimal levetiracetam dosage for seizure prophylaxis. Methods This retrospective cohort study included adult patients at an academic tertiary hospital presenting with SAH or TBI who received levetiracetam at a total daily dose (TDD) equivalent to or greater than 1000 mg. The primary outcome was combined seizure incidence, including clinical and subclinical seizures. Results We identified 139 patients (49.6% male, mean age 53 years) for inclusion. For patients receiving a 1000-mg TDD, the administration was 500 mg twice daily. For patients receiving >1000-mg TDD, 77/78 patients received 1000 mg twice daily and one patient received 750 mg twice daily. Patients receiving 1000-mg TDD had a higher seizure incidence than those receiving >1000-mg TDD (p = 0.01), despite no difference in examined confounders, including history of alcoholism (p = 0.49), benzodiazepine use (p = 0.28), or propofol use (p = 0.17). No difference in adverse effects was observed (anemia, p = 0.44; leukopenia, p = 0.60; thrombocytopenia, p = 0.86). Conclusions Patients may experience a reduced incidence of clinical and electroencephalographic seizures with levetiracetam dosing >1000-mg TDD.

A library of quantitative markers of seizure severity.

Understanding fluctuations in seizure severity within individuals is important for determining treatment outcomes and responses to therapy, as well as assessing novel treatments for epilepsy. Current methods for grading seizure severity rely on qualitative interpretations from patients and clinicians. Quantitative measures of seizure severity would complement existing approaches to electroencephalographic (EEG) monitoring, outcome monitoring, and seizure prediction. Therefore, we developed a library of quantitative EEG markers that assess the spread and intensity of abnormal electrical activity during and after seizures. We analyzed intracranial EEG (iEEG) recordings of 1009 seizures from 63 patients. For each seizure, we computed 16 markers of seizure severity that capture the signal magnitude, spread, duration, and postictal suppression of seizures. Quantitative EEG markers of seizure severity distinguished focal versus subclinical seizures across patients. In individual patients, 53% had a moderate to large difference (rank sum , ) between focal and subclinical seizures in three or more markers. Circadian and longer term changes in severity were found for the majority of patients. We demonstrate the feasibility of using quantitative iEEG markers to measure seizure severity. Our quantitative markers distinguish between seizure types and are therefore sensitive to established qualitative differences in seizure severity. Our results also suggest that seizure severity is modulated over different timescales. We envisage that our proposed seizure severity library will be expanded and updated in collaboration with the epilepsy research community to include more measures and modalities.

Convulsant doses of abused synthetic cannabinoid receptor agonists AB-PINACA, 5F-AB-PINACA, 5F-ADB-PINACA and JWH-018 do not elicit electroencephalographic (EEG) seizures in male mice.

Synthetic cannabinoid receptor agonists (SCRAs) are found in illicit smoking products, such as "K2" or "Spice." Convulsions are commonly reported adverse effects of SCRAs but are poorly understood. We determined convulsant effects of SCRAs AB-PINACA, and 5F-ADB-PINACA in adult male NIH Swiss mice, and then determined if convulsant effects of AB-PINACA, 5F-AB-PINACA, 5F-ADB-PINACA, and JWH-018 elicited seizure-like effects using EEG. Mice were administered SCRAs or pentylenetetrazole (PTZ) and placed in observation chambers where convulsant effects were scored. The capacity of the CB1R antagonist rimonabant, the benzodiazepine diazepam, or the non-specific CYP450 inhibitor 1-aminobenzotriazole (1-ABT) to attenuate convulsant effects was determined. Other mice were prepared with EEG headmounts to ascertain whether observed convulsions occurred concurrently with seizure-like effects by assessing root-mean-square (RMS) power, high amplitude EEG spike analysis, and videography. Mice receiving AB-PINACA or 5F-ADB-PINACA exhibited dose-dependent convulsant effects that were blocked by 10mg/kg rimonabant pretreatment but not by pretreatment with 10mg/kg diazepam; these convulsant effects were not altered in the presence of 100mg/kg 1-ABT. Repeated administration of 10mg/kg AB-PINACA and 3mg/kg 5F-ADB-PINACA produced partial tolerance to convulsant effects but did not lead to cross-tolerance to PTZ-induced convulsions. In EEG studies, convulsant doses of AB-PINACA, 5F-AB-PINACA, 5F-ADB-PINACA, and JWH-018 did not produce seizures concomitantly with convulsions. These data extend previous findings of convulsant effects of SCRAs and suggest that convulsant effects of AB-PINACA, 5F-AB-PINACA, 5F-ADB-PINACA, and JWH-018 are CB1R-mediated but are not associated with electroencephalographic seizures. These results further suggest that benzodiazepines may not effectively treat convulsions elicited by SCRA use in humans.

The influence of anaesthetic choice on seizure duration of electroconvulsive therapy; etomidate versus methohexital

BackgroundMany of the anaesthetic drugs used for electroconvulsive therapy have anticonvulsant properties and may influence efficacy of electroconvulsive therapy. With this study we aim to provide more information on the effect of etomidate and methohexital on seizure duration. We explore the relationship between induction drug, motor and electroencephalography seizure duration. Moreover, we study the relationship of seizure duration and number of therapies.MethodsIn this retrospective study we collected data from patient records from 2005 until 2016. Inclusion criteria were the use of etomidate and/or methohexital and documentation of dosage, electroconvulsive therapy dosage and seizure duration. Exclusion criteria were missing data on either induction drug, dosage or seizure duration.ResultsThirty seven patients were analysed. The mean age was 52 years and seventy six percent were female. Most patients were suffering from affective disorders (81%). Motor and electroencephalography seizure duration were analysed in 679 and 551 electroconvulsive therapies, respectively. Compared to methohexital, motor and electroencephalography seizures under etomidate were 7 and 13 s longer, respectively. Furthermore, there was a negative association between seizure duration and number of treatment and a negative association between seizure duration and electroconvulsive therapy dosage.ConclusionsThis study demonstrates significant longer motor and electroencephalography seizure duration using etomidate compared to methohexital. Etomidate might therefore increase the effectiveness of electroconvulsive therapy. Moreover, we observed a negative association between seizure duration, number of treatment and electroconvulsive therapy dosage. With this study we contribute to the available literature comparing methohexital and etomidate as induction agents for electroconvulsive therapy.

A Combination of Curcuma longa and Diazepam Attenuates Seizures and Subsequent Hippocampal Neurodegeneration.

Epilepsy is one of the most common neurological disorders, which occurs due to the instability in the inhibitory and excitatory synaptic transmissions in the brain. However, many patients develop resistance to the available drugs, which results in cell degeneration caused due to inadequate control of the seizures. Curcumin, Curcuma longa, is known to be effective for the treatment of organic disorders and may prevent seizures, reduce oxidative stress, and decrease brain damage. Given this, the present study evaluated the antiepileptic effects of C. longa in comparison with both the diazepam and the combined application of these two substances, in terms of their effects on the brain activity and the potential histopathological changes in the hippocampus. This study used male Wistar rats (age: 10–12 weeks; weight: 260 ± 20 g), which were pretreated for 4 days with either saline, C. longa, diazepam, or C. longa + diazepam; and on the fifth day, pentylenetetrazol (PTZ) was administered to induce the seizure. In the C. longa group, a significant increase was observed in the latency of the onset of seizure-related behavior. Surprisingly, however, the combined treatment resulted in the best control of the seizure-related behavior, with the greatest latency of the onset of spasms and isolated clonic seizures. This group also obtained the best results in the electroencephalographic trace and seizure control, with a reduction in the frequency and amplitude of the spike-waves. In the saline group, PTZ significantly reduced the number of cells present in the CA1 and CA3 regions of the hippocampus, while the combined treatment obtained the best results in terms of the preservation of the neuron-like cells. These findings indicate that C. longa may contribute to the control of both seizures and the cell damage induced by PTZ, and that its association with diazepam may be a potentially effective option for the treatment of epilepsy in the future.