Seizure Termination Research Articles

The ictal wavefront is the spatiotemporal source of discharges during spontaneous human seizures.

The extensive distribution and simultaneous termination of seizures across cortical areas has led to the hypothesis that seizures are caused by large-scale coordinated networks spanning these areas. This view, however, is difficult to reconcile with most proposed mechanisms of seizure spread and termination, which operate on a cellular scale. We hypothesize that seizures evolve into self-organized structures wherein a small seizing territory projects high-intensity electrical signals over a broad cortical area. Here we investigate human seizures on both small and large electrophysiological scales. We show that the migrating edge of the seizing territory is the source of travelling waves of synaptic activity into adjacent cortical areas. As the seizure progresses, slow dynamics in induced activity from these waves indicate a weakening and eventual failure of their source. These observations support a parsimonious theory for how large-scale evolution and termination of seizures are driven from a small, migrating cortical area.

Impact of an ICU EEG monitoring pathway on timeliness of therapeutic intervention and electrographic seizure termination.

We aimed to determine whether implementation of a structured multidisciplinary electroencephalography (EEG) monitoring pathway improved the timeliness of administration of antiseizure medication in response to electrographic seizures in encephalopathic critically ill children. A multidisciplinary team developed a pathway to standardize EEG monitoring and seizure management in encephalopathic critically ill children, aiming to decrease the time from electrographic seizure onset to antiseizure medication administration. Data were collected to inform the team of improvement opportunities, which were then provided by an institutional pathway, staff education, and streamlined communication. Measurements were obtained before and after pathway implementation to assess for improvement. We collected data on 41 patients before and 21 after pathway implementation. There were no differences between the baseline and pathway groups in demographic characteristics, acute encephalopathy etiologies, or antiseizure medications utilized. The median duration [interquartile range, IQR] from seizure onset to antiseizure medication administration was shorter for patients treated with the pathway (64min [50, 101]) compared to patients treated prior to pathway implementation (139min [71, 189]; p=0.0006). The median [IQR] interval from seizure onset to antiseizure medication order was shorter for the pathway group (31min [20, 49]) than the baseline group (71min [33, 131]; p=0.003). The median [IQR] interval from antiseizure medication order to administration was shorter for the pathway group (30min [19, 40]) than the baseline group (40min [17, 68]) (p=0.047). Seizure termination was more likely to occur following initial antiseizure medication administration in the pathway than baseline group (67% vs. 27%, p=0.002). Implementation of the pathway resulted in a significant reduction in the duration between electrographic seizure onset and antiseizure medication administration, and a significant increase in the rate of electrographic seizure termination following an initial antiseizure medication. Further study is needed to determine whether these changes are associated with improved outcomes.

Adverse reactions of hyperbaric oxygen therapy - case description of a generalised seizure

Abstract Hyperbaric oxygen therapy (HBOT) is a safe treatment, provided fulfilling certain rules of patient qualifications to treatment, as well as supervision over the course of therapy by qualified medical staff. Side effects reported in the literature are rare, and are usually mild and transient. Professional medical staff allows minimising the adverse events occurrence. The scale of complications is unknown, especially in Polish hyperbaric center. Careful analysis could be used to develop prevention procedures for patients of hyperbaric oxygen therapy. Hyperbaric Oxygen Centre and Wound Treatment in Bydgoszcz during 28 months performed hyperbaric oxygen therapy (HBOT) in case of 423 patients. During this period, adverse events occurred occasionally. 17 cases have been reported. Authors described study case 77 year-old patient who was admitted due to non-healing wound-left lower abdomen (state after radiotherapy). During the fourth session, on decompression phase patient have had a generalized seizure (tonic-clonic). The decompression was stopped, the oxygen supply was disconnected but only after the drug administration seizures terminated. The most likely causative agent of the adverse reactions of the patient treated with HBOT was the oxygen toxic effect on the brain tissue. However, analyzing the circumstances of the seizure termination: phase of decompression at the pressure 2ATA and lack of oxygen disconnection response, it cannot be excluded other causes of this complication.

Local anesthetic systemic toxicity: Continuing Professional Development.

Regional anesthesia is enjoying a renaissance due in part to the advent of ultrasound guidance and the development of new techniques such as tissue plane blocks and local infiltration analgesia. The purpose of this Continuing Professional Development module is to provide practitioners with an understanding of the current state of knowledge surrounding local anesthetic systemic toxicity (LAST) in order to help them prevent and manage this complication more effectively. The causes of LAST are multifactorial, but recognized risks include patient factors, drug doses, pharmacokinetics, and choice of regional anesthetic technique. Local anesthetic systemic toxicity produces a biphasic course of clinical events that generally begin with central nervous system excitation followed by inhibition. At the same time, it causes cardiovascular compromise due to dysrhythmias, myocardial depression, and reduced systemic vascular resistance. Clinical presentation can be highly variable, however, and atypical presentations are not uncommon. Local anesthetic systemic toxicity is prevented by careful choice and dosing of drugs, aspiration before injection, dose fractionation, use of intravascular markers and ultrasound guidance. The management of LAST includes adequate oxygenation and ventilation, seizure termination, maintenance of circulation, and intravenous lipid emulsion therapy. Local anesthetic systemic toxicity is a potentially lethal condition with protean manifestations, and anesthesiologists must understand its risks, prevention, and safe management.

Analysis of cortical rhythms in intracranial EEG by temporal difference operators during epileptic seizures

Abstract Brain oscillations have traditionally been studied by time-frequency analysis of the electrophysiological signals. In this work we demonstrated the usefulness of two nonlinear combinations of differential operators on intracranial EEG (iEEG) recordings to study abnormal oscillations in human brain during intractable focal epileptic seizures. Each one dimensional time domain signal was visualized as the trajectory of a particle moving in a force field with one degree of freedom. Modeling of the temporal difference operators to be applied on the signals was inspired by the principles of classical Newtonian mechanics. Efficiency of one of the nonlinear combinations of the operators in distinguishing the seizure part from the background signal and the artifacts was established, particularly when the seizure duration was long. The resultant automatic detection algorithm is linear time executable and detects a seizure with an average delay of 5.02 s after the electrographic onset, with a mean 0.05/h false positive rate and 94% detection accuracy. The area under the ROC curve was 0.959. Another nonlinear combination of differential operators detects spikes (peaks) and inverted spikes (troughs) in a signal irrespective of their shape and size. It was shown that in a majority of the cases simultaneous occurrence of all the spikes and inverted spikes across the focal channels was more after the seizure offset than during the seizure, where the duration after the offset was taken equal to the duration of the seizure. It has been explained in terms of GABAergic inhibition of seizure termination.

Comparison of Intranasal Midazolam and Rectal Diazepam as Anticonvulsant in Children

Introduction: Rectal diazepam is reputed as the gold-standard management of childhood seizures. Otherwise, intranasal (IN) midazolam has no first-pass metabolism and faster onset of action. The effectiveness and easier route of these drugs are important choices for faster seizure cessation. The aim of this study was to clarify the effectiveness of intranasal midazolam compared with rectal diazepam for seizure termination.Material and Methods: The children, one month until 18 years of age, presented with acute seizures. Patients were randomly classified into two groups with either received intranasal midazolam or rectal diazepam for seizure termination. Interval time of drug administration to cease seizure was compared. The log-rank analysis was used for statistical analysis. Side effect of both drugs were evaluated.Results: There were 60 patients enrolled the study, 30 in each group. The median time interval for seizures cessation with intranasal midazolam was 42 seconds, otherwise in rectal diazepam group was 180 seconds. There was statistically significant difference interval time between two groups (p<0.01). None of the both groups had any significant side effects statistically.Conclusion: Intranasal midazolam is effective to terminate a seizure in children. It can be used as an alternative treatment for seizures in patients with intravenous or rectal route difficulties.J Nepal Paediatr Soc 2015;35(2):117-122

Association of seizure duration and outcome in refractory status epilepticus.

The aim of the study was to identify factors influencing long-term outcome and to evaluate the prognostic power of the Status Epilepticus Severity Score (STESS) in refractory status epilepticus (RSE). We retrospectively extracted data on baseline characteristics, RSE details, and hospital course including complications from all patients treated for RSE in our institution between January 2001 and January 2013. Functional outcome was assessed using the modified Rankin Scale (mRS) and was defined as good when either RSE did not lead to functional decline or when the resulting mRS score was 2 or below. Seventy-one episodes in 65 patients were analyzed. The median follow-up time was 12 weeks (IQR 6-35), two patients were lost to follow-up. Poor functional long-term outcome was observed in 42/69 (60.9%) episodes. In-hospital mortality occurred in 13/71 (18.3%) episodes. Multivariable analysis revealed that STESS ≥ 3, longer RSE duration, and sepsis were independently related to poor functional long-term outcome. Receiver operating characteristics (ROC) curve analyses confirmed the cut-off dichotomization into STESS ≥ 3 and STESS < 3 for optimal discrimination between good and poor outcome (AUC = 0.671, p = 0.002, YI = 0.368, NPV = 0.607, PPV = 0.756) and revealed an RSE duration of 10 days as a significant cut-off point associated with outcome (AUC = 0.712, p = 0.012, YI = 0.310; NPV = 0.545, PPV = 0.750). In conclusion, STESS and RSE duration represent relevant scores and parameters impacting long-term outcome after RSE. A shorter RSE duration is associated with better outcome and, therefore, rapid and adequate treatment for seizure termination should be enforced.

Interaction between Thalamus and Hippocampus in Termination of Amygdala-Kindled Seizures in Mice.

The thalamus and hippocampus have been found both involved in the initiation, propagation, and termination of temporal lobe epilepsy. However, the interaction of these regions during seizures is not clear. The present study is to explore whether some regular patterns exist in their interaction during the termination of seizures. Multichannel in vivo recording techniques were used to record the neural activities from the cornu ammonis 1 (CA1) of hippocampus and mediodorsal thalamus (MDT) in mice. The mice were kindled by electrically stimulating basolateral amygdala neurons, and Racine's rank standard was employed to classify the stage of behavioral responses (stage 1~5). The coupling index and directionality index were used to investigate the synchronization and information flow direction between CA1 and MDT. Two main results were found in this study. (1) High levels of synchronization between the thalamus and hippocampus were observed before the termination of seizures at stage 4~5 but after the termination of seizures at stage 1~2. (2) In the end of seizures at stage 4~5, the information tended to flow from MDT to CA1. Those results indicate that the synchronization and information flow direction between the thalamus and the hippocampus may participate in the termination of seizures.

Intravenous levetiracetam versus phenobarbital in children with status epilepticus or acute repetitive seizures.

PurposeThis study compared the efficacy and tolerability of intravenous (i.v.) phenobarbital (PHB) and i.v. levetiracetam (LEV) in children with status epilepticus (SE) or acute repetitive seizure (ARS).MethodsThe medical records of children (age range, 1 month to 15 years) treated with i.v. PHB or LEV for SE or ARS at our single tertiary center were retrospectively reviewed. Seizure termination was defined as seizure cessation within 30 minutes of infusion completion and no recurrence within 24 hours. Information on the demographic variables, electroencephalography and magnetic resonance imaging findings, previous antiepileptic medications, and adverse events after drug infusion was obtained.ResultsThe records of 88 patients with SE or ARS (median age, 18 months; 50 treated with PHB and 38 with LEV) were reviewed. The median initial dose of i.v. PHB was 20 mg/kg (range, 10–20 mg/kg) and that of i.v. LEV was 30 mg/kg (range, 20–30 mg/kg). Seizure termination occurred in 57.9% of patients treated with i.v. LEV (22 of 38) and 74.0% treated with i.v. PHB (37 of 50) (P=0.111). The factor associated with seizure termination was the type of event (SE vs. ARS) in each group. Adverse effects were reported in 13.2% of patients treated with i.v. LEV (5 of 38; n=4, aggressive behavior and n=1, vomiting), and 28.0% of patients treated with i.v. PHB (14 of 50).ConclusionIntravenous LEV was efficacious and safe in children with ARS or SE. Further evaluation is needed to determine the most effective and best-tolerated loading dose of i.v. LEV.

COMPLIANCE ASSESSMENT IN PATIENTS WITH EPILEPSY IN SMOLENSK REGION

The purpose of epilepsy treatment is complete termination of seizures or maximum reduction of their number with minimal side effects from treatment. One of the reasons of treatment failure is low patient compliance. The objective of our study was the analysis of compliance of patients with epilepsy in the Smolensk region, depending on patient’s age. Objective: the analysis of compliance of patients with epilepsy in the Smolensk region, depending on the age of the patient. Materials and methods: a selected group of patients, where there is used or counting the remaining pills, questioning patients and their relatives, check diaries episodes and the diary of taking AEDs. Results: the patient groups with the highest and lowest compliance. Conclusion: the failure of drug-free remission, when clicking on some analogues caused the violation of the therapeutic interaction doctor — patient in all age groups.

Postictal generalized EEG suppression after generalized convulsive seizures: A double-edged sword.

The aim of this study is to investigate the key facilitating factors for postictal generalized EEG suppression (PGES) in a large cohort of patients with generalized convulsive seizures (GCSs). We retrospectively reviewed the data of consecutive patients who had GCSs in the epilepsy monitoring units of two epilepsy centers. Statistical analysis was performed to assess specific variables as potential risk factors for PGES. Among the 208 enrolled patients with 366 seizures, PGES was observed in 109 (51.9%) patients and 168 (45.9%) GCSs. The mean duration of PGES was 33.2 ± 12.0 s (34 s, 3-70 s). PGES or severe PGES (>20 s) was associated with more severe postictal coma and temporal lobe epilepsy. Moreover, PGES was independently associated with a longer tonic duration, shorter total seizure duration, and lower habitual seizure frequency. PGES is strongly correlated not only with longer tonic duration, but also with shorter total seizure duration and lower habitual seizure frequency. PGES may represent a switch-off inhibitory mechanism in seizure termination; moreover, it may indicate the efficacy of a long-lasting inhibitory network that suppresses GCS ictogenesis.

Dynamic Network Drivers of Seizure Generation, Propagation and Termination in Human Neocortical Epilepsy.

The epileptic network is characterized by pathologic, seizure-generating ‘foci’ embedded in a web of structural and functional connections. Clinically, seizure foci are considered optimal targets for surgery. However, poor surgical outcome suggests a complex relationship between foci and the surrounding network that drives seizure dynamics. We developed a novel technique to objectively track seizure states from dynamic functional networks constructed from intracranial recordings. Each dynamical state captures unique patterns of network connections that indicate synchronized and desynchronized hubs of neural populations. Our approach suggests that seizures are generated when synchronous relationships near foci work in tandem with rapidly changing desynchronous relationships from the surrounding epileptic network. As seizures progress, topographical and geometrical changes in network connectivity strengthen and tighten synchronous connectivity near foci—a mechanism that may aid seizure termination. Collectively, our observations implicate distributed cortical structures in seizure generation, propagation and termination, and may have practical significance in determining which circuits to modulate with implantable devices.

Extracellular levels of ATP and acetylcholine during lithium-pilocarpine induced status epilepticus in rats

Acetylcholine (ACh) and ATP are rapidly acting neurotransmitters with a putative role in epileptic seizures. In the present study we investigated extracellular concentrations of both neurotransmitters in parallel by microdialysis in rat hippocampus. We found that infusion of neostigmine increases, while calcium-free perfusion and infusion of tetrodotoxin (TTX) decreases, ACh levels. Calcium-free perfusion also decreased ATP levels which were, however, not affected by neostigmine or TTX. During status epilepticus, ACh levels were increased threefold but returned to baseline after the termination of seizures by diazepam. ATP levels were unchanged during status epilepticus but a several-fold increase was seen when AOPCP, an inhibitor of 5′-endonucleotidase, was infused. The results demonstrate an increase of ATP levels during epileptic seizures which, however, was not of neuronal origin.

Current Trends in Treatment of Status Epilepticus and Refractory Status Epilepticus.

Status epilepticus is a heterogeneous disorder with varied definitions and presentations. Taken together, all forms of status epilepticus carry significant morbidity and mortality, much of which is dictated by the underlying etiology. Generalized convulsive status epilepticus, which represents a common form, is a true neurologic emergency that requires emergent management. Treatment focuses on stabilizing the patient and aggressive medical management to achieve the timely termination of seizures. For other forms of status epilepticus including nonconvulsive and focal status epilepticus, the goal remains early seizure termination, but the use of intravenous medications should be weighed against the risks associated with these therapies. The diagnostic evaluation of status epilepticus is guided by the patient's history and should be broad, including a screen for toxins, electrolytes, structural abnormalities, and central nervous system infectious and autoimmune/inflammatory etiologies. Considerable research is still needed to improve our understanding of the mechanisms, consequences, and therapy of status epilepticus.

Plasmodium Vivax Cerebral Malaria - A Rare Cause of Multi Organ Dysfunction

Cerebral malaria is the most severe complication of plasmodium falciparum infection. It is a clinical syndrome characterized by unarousable coma at least one hour after termination of seizures and asexual forms of the parasite in peripheral blood smear with no other explainable causes of coma. Usually cerebral malaria is caused by P. f alciparum, but rarely it is seen as a complication of plasmodium vivax infection. We report a case of cerebral malaria caused by Plasmodium vivax complicated by seizures and multiorgan dysfunction. It was successfully treated with parenteral artesunate, mechanical ventilation and other supportive measures without any sequelae.

Resected Brain Tissue, Seizure Onset Zone and Quantitative EEG Measures: Towards Prediction of Post-Surgical Seizure Control.

BackgroundEpilepsy surgery is a potentially curative treatment option for pharmacoresistent patients. If non-invasive methods alone do not allow to delineate the epileptogenic brain areas the surgical candidates undergo long-term monitoring with intracranial EEG. Visual EEG analysis is then used to identify the seizure onset zone for targeted resection as a standard procedure.MethodsDespite of its great potential to assess the epileptogenicty of brain tissue, quantitative EEG analysis has not yet found its way into routine clinical practice. To demonstrate that quantitative EEG may yield clinically highly relevant information we retrospectively investigated how post-operative seizure control is associated with four selected EEG measures evaluated in the resected brain tissue and the seizure onset zone. Importantly, the exact spatial location of the intracranial electrodes was determined by coregistration of pre-operative MRI and post-implantation CT and coregistration with post-resection MRI was used to delineate the extent of tissue resection. Using data-driven thresholding, quantitative EEG results were separated into normally contributing and salient channels.ResultsIn patients with favorable post-surgical seizure control a significantly larger fraction of salient channels in three of the four quantitative EEG measures was resected than in patients with unfavorable outcome in terms of seizure control (median over the whole peri-ictal recordings). The same statistics revealed no association with post-operative seizure control when EEG channels contributing to the seizure onset zone were studied.ConclusionsWe conclude that quantitative EEG measures provide clinically relevant and objective markers of target tissue, which may be used to optimize epilepsy surgery. The finding that differentiation between favorable and unfavorable outcome was better for the fraction of salient values in the resected brain tissue than in the seizure onset zone is consistent with growing evidence that spatially extended networks might be more relevant for seizure generation, evolution and termination than a single highly localized brain region (i.e. a “focus”) where seizures start.

Efficacy of nonvenous medications for acute convulsive seizures: A network meta-analysis.

This is a network meta-analysis of nonvenous drugs used in randomized controlled trials (RCTs) for treatment of acute convulsive seizures and convulsive status epilepticus. Literature was searched according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines for RCTs examining treatment of acute convulsive seizures or status epilepticus with at least one of the study arms being a nonvenous medication. After demographic and outcome data extraction, a Bayesian network meta-analysis was performed and efficacy results were summarized using treatment effects and their credible intervals (CrI). We also calculated the probability of each route-drug combination being the most clinically effective for a given outcome, and provided their Bayesian hierarchical ranking. This meta-analysis of 16 studies found that intramuscular midazolam (IM-MDZ) is superior to other nonvenous medications regarding time to seizure termination after administration (2.145 minutes, 95% CrI 1.308-3.489), time to seizure cessation after arrival in the hospital (3.841 minutes, 95% CrI 2.697-5.416), and time to initiate treatment (0.779 minutes, 95% CrI 0.495-1.221). Additionally, intranasal midazolam (IN-MDZ) was adjudged most efficacious for seizure cessation within 10 minutes of administration (90.4% of participants, 95% CrI 79.4%-96.9%), and persistent seizure cessation for ≥1 hour (78.5% of participants, 95% CrI 59.5%-92.1%). Paucity of RCTs produced evidence gaps resulting in small networks, routes/drugs included in some networks but not others, and some trials not being connected to any network. Despite the evidence gaps, IM-MDZ and IN-MDZ exhibit the best efficacy data for the nonvenous treatment of acute convulsive seizures or status epilepticus.

Susceptibility-weighted imaging in acute-stage pediatric convulsive disorders.

The aim of this preliminary study was to investigate the clinical use of acute-stage susceptibility-weighted imaging (SWI) in children with prolonged convulsive disorder. Ten children with prolonged convulsive disorder who underwent SWI within 2 h after termination of seizure (acute-stage SWI group) and 15 control children who underwent SWI > 2 h after their seizures terminated or for other purposes were enrolled. The cerebral venous vasculature was compared between the groups. The acute-stage SWI group was further divided into three subgroups: normal group, those with regional low signals in the cerebral veins (regional group) and those with diffuse low signals in the cerebral veins (generalized group). Inter-ictal electroencephalography (EEG) and venous blood gas findings during seizure activity were compared between these subgroups. All patients in the acute-stage SWI group had low cerebral vein signal. Four patients were assigned to the regional group and six patients to the generalized group. Decrease of venous pH and the increase of venous pCO2 during seizure activity was more prominent in the regional group than in the generalized group. In the regional group, low-signal areas in the cerebral veins were consistent with abnormal areas on EEG; these low-signal areas resolved completely in all patients on follow-up SWI. Ten patients in the control group had normal SWI, and five had a generalized low signal. Acute-stage SWI may be a useful alternative for identifying lateralization of seizures in children with prolonged convulsive disorder.

Safety and efficacy of intranasally administered medications in the emergency department and prehospital settings.

The safety and efficacy of medications that may be administered via the intranasal route in adult patients in the prehospital and emergency department (ED) settings are reviewed. When medications of appropriate molecular character and concentration are delivered intranasally, they are quickly transported across this capillary network and delivered to the systemic circulation, thereby avoiding the absorption-limiting effects of first-pass metabolism. Therapeutic drug concentrations are rapidly attained in the cerebrospinal fluid, making intranasal administration a very effective mode of delivery. To optimize the bioavailability of intranasally administered drugs, providers must minimize the barriers to absorption, minimize the volume by maximizing the concentration, maximize the absorptive surface of the nasal mucosa, and use a delivery system that maximizes drug dispersion and minimizes drug runoff. Medications can be instilled into the nasal cavity with syringes or droppers by applying a few drops at a time or via atomization. The intranasal route of administration may be advantageous for patients who require analgesia, sedation, anxiolysis, termination of seizures, hypoglycemia management, narcotic reversal, and benzodiazepine reversal in the ED or prehospital settings. Medications that have been studied in the adult population include fentanyl, sufentanil, hydromorphone, ketamine, midazolam, haloperidol, naloxone, flumazenil, and glucagon. The available data do indicate, however, that intranasal administration may be a safe, effective, and well tolerated route of administration. Based on the published literature, intranasal administration of fentanyl, sufentanil, ketamine, hydromorphone, midazolam, haloperidol, naloxone, glucagon, and, in limited cases, flumazenil may be a safe, effective, and well-tolerated alternative to intramuscular or intravenous administration in the prehospital and ED settings.

A definition and classification of status epilepticus--Report of the ILAE Task Force on Classification of Status Epilepticus.

The Commission on Classification and Terminology and the Commission on Epidemiology of the International League Against Epilepsy (ILAE) have charged a Task Force to revise concepts, definition, and classification of status epilepticus (SE). The proposed new definition of SE is as follows: Status epilepticus is a condition resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms, which lead to abnormally, prolonged seizures (after time point t1 ). It is a condition, which can have long-term consequences (after time point t2 ), including neuronal death, neuronal injury, and alteration of neuronal networks, depending on the type and duration of seizures. This definition is conceptual, with two operational dimensions: the first is the length of the seizure and the time point (t1 ) beyond which the seizure should be regarded as "continuous seizure activity." The second time point (t2 ) is the time of ongoing seizure activity after which there is a risk of long-term consequences. In the case of convulsive (tonic-clonic) SE, both time points (t1 at 5min and t2 at 30min) are based on animal experiments and clinical research. This evidence is incomplete, and there is furthermore considerable variation, so these time points should be considered as the best estimates currently available. Data are not yet available for other forms of SE, but as knowledge and understanding increase, time points can be defined for specific forms of SE based on scientific evidence and incorporated into the definition, without changing the underlying concepts. A new diagnostic classification system of SE is proposed, which will provide a framework for clinical diagnosis, investigation, and therapeutic approaches for each patient. There are four axes: (1) semiology; (2) etiology; (3) electroencephalography (EEG) correlates; and (4) age. Axis 1 (semiology) lists different forms of SE divided into those with prominent motor systems, those without prominent motor systems, and currently indeterminate conditions (such as acute confusional states with epileptiform EEG patterns). Axis 2 (etiology) is divided into subcategories of known and unknown causes. Axis 3 (EEG correlates) adopts the latest recommendations by consensus panels to use the following descriptors for the EEG: name of pattern, morphology, location, time-related features, modulation, and effect of intervention. Finally, axis 4 divides age groups into neonatal, infancy, childhood, adolescent and adulthood, and elderly.