Nearly one-third of patients with epilepsy continue to have seizures despite optimal medication management. Systems employed to detect seizures may have the potential to improve outcomes in these patients by allowing more tailored therapies and might, additionally, have a role in accident and SUDEP prevention. Automated seizure detection and prediction require algorithms which employ feature computation and subsequent classification. Over the last few decades, methods have been developed to detect seizures utilizing scalp and intracranial EEG, electrocardiography, accelerometry and motion sensors, electrodermal activity, and audio/video captures. To date, it is unclear which combination of detection technologies yields the best results, and approaches may ultimately need to be individualized. This review presents an overview of seizure detection and related prediction methods and discusses their potential uses in closed-loop warning systems in epilepsy.

Objectives: We aimed to determine the incidence of electrographic seizures in children in the pediatric intensive care unit who underwent EEG monitoring, risk factors for electrographic seizures, and whether electrographic seizures were associated with increased odds of mortality.Methods: Eleven sites in North America retrospectively reviewed a total of 550 consecutive children in pediatric intensive care units who underwent EEG monitoring. We collected data on demographics, diagnoses, clinical seizures, mental status at EEG onset, EEG background, interictal epileptiform discharges, electrographic seizures, intensive care unit length of stay, and in-hospital mortality.Results: Electrographic seizures occurred in 162 of 550 subjects (30%), of which 61 subjects (38%) had electrographic status epilepticus. Electrographic seizures were exclusively subclinical in 59 of 162 subjects (36%). A multivariable logistic regression model showed that independent risk factors for electrographic seizures included younger age, clinical seizures prior to EEG monitoring, an abnormal initial EEG background, interictal epileptiform discharges, and a diagnosis of epilepsy. Subjects with electrographic status epilepticus had greater odds of in-hospital death, even after adjusting for EEG background and neurologic diagnosis category.Conclusions: Electrographic seizures are common among children in the pediatric intensive care unit, particularly those with specific risk factors. Electrographic status epilepticus occurs in more than one-third of children with electrographic seizures and is associated with higher in-hospital mortality. Neurology â 2013;81:383-391 GLOSSARY CEEG 5 continuous EEG; CI 5 confidence interval; IQR 5 interquartile range; OR 5 odds ratio; PICU 5 pediatric intensive care unit.

Summary Purpose To examine patterns of use, efficacy and safety of intravenous ketamine for the treatment of refractory status epilepticus (RSE). Methods Multicenter retrospective review of medical records and EEG reports in ten academic medical centers in North America and Europe, including 58 subjects, representing 60 episodes of RSE were identified between 1999 and 2012. Seven episodes occurred after anoxic brain injury. Key findings Permanent control of RSE was achieved in 57% (34/60) of episodes. Ketamine was felt to have contributed to permanent control (“possible” or “likely” responses) in 32% (19/60) including seven (12%) in which ketamine was the last drug added (likely responses). Four of the seven likely responses, but none of the 12 possible ones, occurred in patients with post-anoxic brain injury. No likely responses were observed when infusion rates were lower than 0.9mg/kg/h; when ketamine was introduced at least eight days after SE onset; or after failure of seven or more drugs. Ketamine was discontinued due to possible adverse events in five patients. Complications were mostly attributed to concurrent drugs, especially other anesthetics. Mortality rate was 43% (26/60), but was lower when SE was controlled within 24h of ketamine initiation (16% vs. 56%, p=0.0047). Significance Ketamine appears to be a relatively effective and safe drug for the treatment of RSE. This retrospective series provides preliminary data on effective dose and appropriate time of intervention to aid in the design of a prospective trial to further define the role of ketamine in the treatment of RSE.

Epilepsy affects almost 1% of the population and most of the approximately 20-30% of patients with refractory epilepsy have one or more seizures per month. Seizure detection devices allow an objective assessment of seizure frequency and a treatment tailored to the individual patient. A rapid recognition and treatment of seizures through closed-loop systems could potentially decrease morbidity and mortality in epilepsy. However, no single detection device can detect all seizure types. Therefore, the choice of a seizure detection device should consider the patient-specific seizure semiologies. This review of the literature evaluates seizure detection devices and their effectiveness for different seizure types. Our aim is to summarize current evidence, offer suggestions on how to select the most suitable seizure detection device for each patient and provide guidance to physicians, families and researchers when choosing or designing seizure detection devices. Further, this review will guide future prospective validation studies.

BackgroundGraph theory has been recently introduced to characterize complex brain networks, making it highly suitable to investigate altered connectivity in neurologic disorders. A current model proposes autism spectrum disorder (ASD) as a developmental disconnection syndrome, supported by converging evidence in both non-syndromic and syndromic ASD. However, the effects of abnormal connectivity on network properties have not been well studied, particularly in syndromic ASD. To close this gap, brain functional networks of electroencephalographic (EEG) connectivity were studied through graph measures in patients with Tuberous Sclerosis Complex (TSC), a disorder with a high prevalence of ASD, as well as in patients with non-syndromic ASD.MethodsEEG data were collected from TSC patients with ASD (n = 14) and without ASD (n = 29), from patients with non-syndromic ASD (n = 16), and from controls (n = 46). First, EEG connectivity was characterized by the mean coherence, the ratio of inter- over intra-hemispheric coherence and the ratio of long- over short-range coherence. Next, graph measures of the functional networks were computed and a resilience analysis was conducted. To distinguish effects related to ASD from those related to TSC, a two-way analysis of covariance (ANCOVA) was applied, using age as a covariate.ResultsAnalysis of network properties revealed differences specific to TSC and ASD, and these differences were very consistent across subgroups. In TSC, both with and without a concurrent diagnosis of ASD, mean coherence, global efficiency, and clustering coefficient were decreased and the average path length was increased. These findings indicate an altered network topology. In ASD, both with and without a concurrent diagnosis of TSC, decreased long- over short-range coherence and markedly increased network resilience were found.ConclusionsThe altered network topology in TSC represents a functional correlate of structural abnormalities and may play a role in the pathogenesis of neurological deficits. The increased resilience in ASD may reflect an excessively degenerate network with local overconnection and decreased functional specialization. This joint study of TSC and ASD networks provides a unique window to common neurobiological mechanisms in autism.

Objective: To describe the time elapsed from onset of pediatric convulsive status epilepticus (SE) to administration of antiepileptic drug (AED).Methods: This was a prospective observational cohort study performed from June 2011 to June 2013. Pediatric patients (1 month-21 years) with convulsive SE were enrolled. In order to study timing of AED administration during all stages of SE, we restricted our study population to patients who failed 2 or more AED classes or needed continuous infusions to terminate convulsive SE. Results:We enrolled 81 patients (44 male) with a median age of 3.6 years. The first, second, and third AED doses were administered at a median (p 25 -p 75 ) time of 28 (6-67) minutes, 40 (20-85) minutes, and 59 (30-120) minutes after SE onset. Considering AED classes, the initial AED was a benzodiazepine in 78 (96.3%) patients and 2 (2-3) doses of benzodiazepines were administered before switching to nonbenzodiazepine AEDs. The first and second doses of nonbenzodiazepine AEDs were administered at 69 (40-120) minutes and 120 (75-296) minutes. In the 64 patients with out-of-hospital SE onset, 40 (62.5%) patients did not receive any AED before hospital arrival. In the hospital setting, the first and second in-hospital AED doses were given at 8 (5-15) minutes and 16 (10-40) minutes after SE onset (for patients with in-hospital SE onset) or after hospital arrival (for patients with out-of-hospital SE onset). Conclusions:The time elapsed from SE onset to AED administration and escalation from one class of AED to another is delayed, both in the prehospital and in-hospital settings. Status epilepticus (SE) is one of the most common pediatric neurologic emergencies.1 It has a mortality of 0%-3% 2-7 and morbidity that includes cognitive and neurodevelopmental impairments, epilepsy, and recurrent SE.2,8-10 SE is often refractory to the initial antiepileptic drugs (AEDs), 11,12 and refractory SE is associated with poor outcome. 12 Patient age, etiology, and SE duration all affect outcome, 5,9,13 but only SE duration is a potentially modifiable factor by rapid AED treatment. By convention, the treatment of convulsive SE is a sequence of AEDs, typically

; for the Pediatric Status Epilepticus Research Group IMPORTANCE Treatment delay for seizures can lead to longer seizure duration. Whether treatment delay is associated with major adverse outcomes, such as death, remains unknown. OBJECTIVE To evaluate whether untimely first-line benzodiazepine treatment is associated with unfavorable short-term outcomes. DESIGN, SETTING, AND PARTICIPANTS This multicenter, observational, prospective cohort study included 218 pediatric patients admitted between June 1, 2011, and July 7, 2016, into the 11 tertiary hospitals in the United States within the Pediatric Status Epilepticus Research Group. Patients, ranging in age from 1 month to 21 years, with refractory convulsive status epilepticus (RCSE) that did not stop after the administration of at least 2 antiseizure medications were included. Patients were divided into 2 cohorts: those who received the first-line benzodiazepine treatment in less than 10 minutes and those who received it 10 or more minutes after seizure onset (untimely). Data were collected and analyzed from June 1, 2011, to July 7, 2016. MAIN OUTCOMES AND MEASURES The primary outcome was death during the related hospital admission. The secondary outcome was the need for continuous infusion for seizure termination. Multivariate analysis of mortality controlled for structural cause, febrile RCSE, age, and previous neurological history (including previous RCSE events). Use of continuous infusions was additionally adjusted for generalized RCSE, continuous RCSE, and 5 or more administrations of antiseizure medication. RESULTS A total of 218 patients were included, among whom 116 (53.2%) were male and the median (interquartile range) age was 4.0 (1.2-9.6) years. The RCSE started in the prehospital setting for 139 patients (63.8%). Seventy-four patients (33.9%) received their first-line benzodiazepine treatment in less than 10 minutes, and 144 (66.1%) received untimely first-line benzodiazepine treatment. Multivariate analysis showed that patients who received untimely first-line benzodiazepine treatment had higher odds of death (adjusted odds ratio [AOR], 11.0; 95% CI, 1.43 to ϱ; P = .02), had greater odds of receiving continuous infusion (AOR, 1.8; 95% CI, 1.01-3.36; P = .047), had longer convulsive seizure duration (AOR, 2.6; 95% CI, 1.38-4.88; P = .003), and had more frequent hypotension (AOR 2.3; 95% CI, 1.16-4.63; P = .02). In addition, the timing of the first-line benzodiazepine treatment was correlated with the timing of the second-line (95% CI, 0.64-0.95; P < .001) and third-line antiseizure medications (95% CI, 0.25-0.78; P < .001). CONCLUSIONS AND RELEVANCE Among pediatric patients with RCSE, an untimely first-line benzodiazepine treatment is independently associated with a higher frequency of death, use of continuous infusions, longer convulsion duration, and more frequent hypotension. Results of this study raise the question as to whether poor outcomes could, in part, be prevented by earlier administration of treatment.

Electrical status epilepticus in sleep involves an electroencephalographic pattern where interictal epileptiform activity is potentiated in the transition from wakefulness to sleep. Near-continuous spikes and waves that occupy a significant proportion of nonrapid eye movement sleep appear as a result of sleep-potentiated epileptiform activity. This electroencephalographic pattern appears in different electroclinical syndromes that present three common characteristics with different degrees of severity: seizures, sleep-potentiated epileptiform activity, and neuropsychologic regression. Continuous spikes and waves during sleep comprise the severest epileptic encephalopathy in the electroclinical spectrum. Landau-Kleffner syndrome presents with intermediate severity. Some "benign" pediatric focal epileptic syndromes represent the mildest end of this continuum. Based on published data, we provide a framework for clinical and electrical events. The underlying mechanisms leading to sleep potentiation of epileptiform activity in electrical status epilepticus in sleep are incompletely understood. A genetic basis or acquired early developmental insult may disrupt the normal maturation of neuronal networks. These factors may dynamically alter normal processes of brain development, leading to an age-related pattern of electroclinical expression of electrical status epilepticus in sleep.