Electroencephalographic Epileptiform Research Articles

Quantitative EEG analysis in typical absence seizures: unveiling spectral dynamics and entropy patterns.

A typical absence seizure is a generalized epileptic event characterized by a sudden, brief alteration of consciousness that serves as a hallmark for various generalized epilepsy syndromes. Distinguishing between similar interictal and ictal electroencephalographic (EEG) epileptiform patterns poses a challenge. However, quantitative EEG, particularly spectral analysis focused on EEG rhythms, shows potential for differentiation. This study was designed to investigate discernible differences in EEG spectral dynamics and entropy patterns during the pre-ictal and post-ictal periods compared to the interictal state. We analyzed 20 EEG ictal patterns from 11 patients with confirmed typical absence seizures, and assessed recordings made during the pre-ictal, post-ictal, and interictal intervals. Power spectral density (PSD) was used for the quantitative analysis that focused on the delta, theta, alpha, and beta bands. In addition, we measured EEG signal regularity using approximate (ApEn) and multi-scale sample entropy (MSE). Findings demonstrate a significant increase in delta and theta power in the pre-ictal and post-ictal intervals compared to the interictal interval, especially in the posterior brain region. We also observed a notable decrease in entropy in the pre-ictal and post-ictal intervals, with a more pronounced effect in anterior brain regions. These results provide valuable information that can potentially aid in differentiating epileptiform patterns in typical absence seizures. The implications of our findings are promising for precision medicine approaches to epilepsy diagnoses and patient management. In conclusion, our quantitative analysis of EEG data suggests that PSD and entropy measures hold promise as potential biomarkers for distinguishing ictal from interictal epileptiform patterns in patients with confirmed or suspected typical absence seizures.

1001 A Case of Unusual Nocturnal Movements Consistent with Paroxysmal Hypnogenic Dyskinesia

Abstract Introduction Paroxysmal hypnogenic dyskinesia (PHD) is a rare subset of paroxysmal dyskinesias characterized by recurring involuntary dystonic or choreoathetoid movements that occur during sleep or immediately after an arousal from sleep. These episodes often occur without loss of consciousness or trigger and lack association with epileptiform electroencephalography (EEG) activity. Report of case(s) A 61-year-old male with obstructive sleep apnea compliant with PAP was referred for abnormal nighttime movements for the past 9 years. The episodes were characterized by stereotyped involuntary dystonic posturing involving his upper extremities or his entire body lasting up to 15 seconds. The onset of the events occurred invariable during nighttime sleep and resulted in awakenings from sleep. He denied dream enactment as well as other symptoms suggestive of sleep-related movement disorders or parasomnias. Sleep deprived EEG demonstrated left temporal slowing during wakefulness and drowsiness and captured a typical event that occurred during NREM stage II sleep and had no ictal correlate. An MRI of the brain was unremarkable. During overnight polysomnogram, his current PAP settings were found to be effective, and three episodes of body stiffening consistent with his typical events were captured. These episodes were found to occur after awakening from REM sleep and lasted less than 10 seconds each. There was no EEG correlate, and REM atonia was preserved throughout. The patient was started on oxcarbazepine for the nocturnal movements, which reduced the frequency of events from 12 to 4 events per night. Oxcarbazepine was tapered and discontinued due to side effects and incomplete control of the events. Genetic testing for epilepsy syndromes is pending. Conclusion PHD is a rare syndrome of involuntary movements which begin during sleep or cause awakenings from sleep and can be misdiagnosed as a sleep disorder. It is crucial for the sleep physician to be aware of possible neurological causes of sleep-related movement disorders. Furthermore, our patient’s partial response to oxcarbazepine may further support that PHD may have an epileptic origin although not well characterized. Support (if any) Advancing Innovation in Residency Education (AIRE) Pilot Program Training Grant

Association of electroencephalogram epileptiform discharges during cardiac surgery with postoperative delirium: An observational study.

BackgroundDelirium is a frequent and serious complication following cardiac surgery involving cardiopulmonary bypass (CPB). Electroencephalography reflects the electrical activity of the cerebral cortex. The impact of electroencephalographic epileptiform discharges during cardiac surgery on postoperative delirium remains unclear. This study was designed to investigate the relationship between intraoperative epileptiform discharges and postoperative delirium in patients undergoing cardiac surgery.MethodsA total of 76 patients who underwent cardiac surgery under CPB were included. The baseline cognitive status was measured before surgery. Electroencephalograms were monitored continuously from entry into the operating room to the end of surgery. The presence of delirium was assessed through the Confusion Assessment Method or the Confusion Assessment Method for the Intensive Care Unit on the first 3 days after surgery. Univariate and multivariate logistic regression analyses were performed to evaluate the association between epileptiform discharges and delirium.ResultsDelirium occurred in 31% of patients and epileptiform discharges were present in 26% of patients in the study. Patients with delirium had a higher incidence of epileptiform discharges (52.63% vs. 13.95%, P < 0.001) and longer durations of anesthesia and CPB (P = 0.023 and P = 0.015, respectively). In addition, patients with delirium had a longer length of hospital stay and a higher incidence of postoperative complications. Multivariate logistic regression analysis showed that age and epileptiform discharges were significantly associated with the incidence of postoperative delirium [odds ratio, 4.75 (1.26–17.92), P = 0.022; 5.00 (1.34–18.74), P = 0.017, respectively].ConclusionsPostoperative delirium is significantly related to the occurrence of epileptiform discharges during cardiac surgery.

Induction of anesthesia with sevoflurane in children: Curiosities and controversies.

Inhalational inductions with sevoflurane (up to 8% inspired concentration) have been the standard for inducing anesthesia in children for over three decades. However, when sevoflurane was first introduced, clinicians reported isolated cases of unexpected myoclonic jerking movements during the induction in children without epilepsy. These cases raised concerns regarding the widespread use of sevoflurane particularly after reports of seizures and epileptiform electroencephalographic (EEG) discharges surfaced. The latter reports prompted recommendations to reduce the concentration of sevoflurane during induction of anesthesia. More recently, a shift away from the use of nitrous oxide has prompted some to question whether sevoflurane has a role as an induction agent in children. The preponderance of evidence supports the practice of safely inducing anesthesia with 8% sevoflurane with or without nitrous oxide in children but recommended strategies to mitigate against epileptiform discharges may be more harmful than beneficial.

Developing an Asymmetry Method for Detecting Postictal Hyperperfusion in Poststroke Epilepsy.

Using dual single-photon emission computed tomography (SPECT) scanning, we recently found the postictal-interictal (P-I) subtraction method frequently detects prolonged postictal hyperperfusion in poststroke epilepsy (PSE) and thus may be valuable for auxiliary diagnosis. This study aimed to determine if the asymmetry method can localize hyperperfusion to reflect epileptic activity in PSE using a single postictal SPECT scan. Sixty-four patients with PSE who had undergone perfusion SPECT two times (postictal and interictal) were enrolled. We formulated a novel asymmetry method (subtraction analysis of reversed postictal SPECT from postictal SPECT, co-registered to magnetic resonance imaging) to identify paradoxical asymmetric increase, defined as a higher perfusion area adjacent to stroke lesions compared to the contralateral side. The postictal hyperperfusion area and detection rates were determined by the asymmetry and P-I subtraction methods independently. We subsequently calculated the sensitivity and specificity of the asymmetry method, compared to the gold standard P-I subtraction method. We also evaluated lateralization concordance between the asymmetry method and other clinical findings. Among 64 patients (median age, 75 years), prolonged postictal hyperperfusion was detected in 43 (67%) by the asymmetry, and 54 (84%) the P-I, method. The asymmetry method had high sensitivity (80%) and specificity (100%) in detecting postictal hyperperfusion, showing high lateralization concordance with seizure semiology (97%) and epileptiform electroencephalography findings (interictal/ictal epileptiform discharges or periodic discharges) (100%). The present study demonstrated the advantages of the objective asymmetry method for detecting prolonged hyperperfusion through using one postictal SPECT scan in PSE.

EEG abnormalities and clinical phenotypes in pre-school children with autism spectrum disorder

BackgroundAbnormalities on electroencephalography (EEG) results have been reported in a high percentage of children with Autism Spectrum Disorder (ASD). The purpose of this study was to explore the prevalence of EEG abnormalities in a clinical population of pre-school children with Autism Spectrum Disorder and the differences in terms of the following phenotypic characteristics: adaptive behavior, executive functioning, severity of Autism Spectrum Disorder core symptoms, and comorbidity symptoms. MethodsA cross-sectional analysis of 69 children who attended the Autism Spectrum Disorder early diagnosis program with electroencephalography and clinical diagnosis was performed. A battery of questionnaires was also made to parents to evaluate emotions, behavior, and functional skills for daily living. ResultsOut of 69 pre-school children with Autism Spectrum Disorder, twenty nine (42%) had abnormalities in electroencephalography results. The group with abnormal epileptiform electroencephalography exhibited more impairment in executive functioning and social-relationship coexisting symptoms. ConclusionsThe presence of an abnormal epileptiform electroencephalography in pre-school children with ASD already suggests a worse development in clinical features.

Antiseizure Medication Treatment and Outcomes in Patients with Subarachnoid Hemorrhage Undergoing Continuous EEG Monitoring.

Patients with aneurysmal subarachnoid hemorrhage (aSAH) with electroencephalographic epileptiform activity (seizures, periodic and rhythmic patterns, and sporadic discharges) are frequently treated with antiseizure medications (ASMs). However, the safety and effectiveness of ASM treatment for epileptiform activity has not been established. We used observational data to investigate the effectiveness of ASM treatment in patients with aSAH undergoing continuous electroencephalography (cEEG) to develop a causal hypothesis for testing in prospective trials. This was a retrospective single-center cohort study of patients with aSAH admitted between 2011 and 2016. Patients underwent ≥ 24h of cEEG within 4days of admission. All patients received primary ASM prophylaxis until aneurysm treatment (typically within 24h of admission). Treatment exposure was defined as reinitiation of ASMs after aneurysm treatment and cEEG initiation. We excluded patients with non-cEEG indications for ASMs (e.g., epilepsy, acute symptomatic seizures). Outcomes measures were 90-day mortality and good functional outcome (modified Rankin Scale scores 0-3). Propensity scores were used to adjust for baseline covariates and disease severity. Ninety-four patients were eligible (40 continued ASM treatment; 54 received prophylaxis only). ASM continuation was not significantly associated with higher 90-day mortality (propensity-adjusted hazard ratio [HR] = 2.01 [95% confidence interval (CI) 0.57-7.02]). ASM continuation was associated with lower likelihood for 90-day good functional outcome (propensity-adjusted HR = 0.39 [95% CI 0.18-0.81]). In a secondary analysis, low-intensity treatment (low-dose single ASM) was not significantly associated with mortality (propensity-adjusted HR = 0.60 [95% CI 0.10-3.59]), although it was associated with a lower likelihood of good outcome (propensity-adjusted HR = 0.37 [95% CI 0.15-0.91]), compared with prophylaxis. High-intensity treatment (high-dose single ASM, multiple ASMs, or anesthetics) was associated with higher mortality (propensity-adjusted HR = 6.80 [95% CI 1.67-27.65]) and lower likelihood for good outcomes (propensity-adjusted HR = 0.30 [95% CI 0.10-0.94]) compared with prophylaxis only. Our findings suggest the testable hypothesis that continuing ASMs in patients with aSAH with cEEG abnormalities does not improve functional outcomes. This hypothesis should be tested in prospective randomized studies.

Anterior temporal lobectomy: A cross-sectional observational study of potential surgical candidates at a single institute.

Background: Epilepsy is a common neurological disorder, associated with serious cognitive, physical, and psychosocial burdens. Mesial temporal lobe epilepsy (mTLE) is the commonest form of focal epilepsy. The aim of this study was to establish the incidence of patients with electroencephalographic epileptiform discharges consistent with mTLE attending a tertiary hospital in South Africa, and determine whether these patients may be candidates for anterior temporal lobectomy.Methods: This was a cross-sectional observational study of all patients receiving scalp electroencephalograms (EEG) performed at the Groote Schuur Hospital Neurophysiology laboratory during the period January 1, 2017–December 31, 2019. Where magnetic resonance imaging (MRI) brain scans had been performed, these were assessed for corroborative evidence of mTLE.Results: Over the 3-year period, 4 342 EEGs were assessed. A total of 411 (11%) showed epileptiform discharges consistent with all epilepsy types. Of these, 327 (69%) were of focal onset and 108 (33% of all focal onset epilepsies) were consistent with mTLE. Of the patients with electroencephalographic features of mTLE, only 27 (25%) had had MRI brain scans performed according to an epilepsy surgery protocol. None of these patients had been considered for surgery.Conclusion: Surgery, especially anterior temporal lobectomy, is widely acknowledged to be an efficacious and cost-effective intervention in patients with drug-resistant mTLE. The findings of our study suggest that patients with mTLE in our setting are under-investigated for potential surgery; and that it is under-utilized. These findings are in line with similar studies in both well-resourced and resource-constrained countries. Our study also highlights the utility of EEG as a practical screening tool to identify potential surgical candidates, as well as the establishment of an EEG and MRI database to assist in recognizing these patients.

Modulation in time of the interictal spiking pattern related to epileptic seizures

ObjectiveTo test the hypothesis that significant changes in the occurrence of interictal epileptiform electroencephalography (EEG) discharges (EDs) are associated with seizures: while some EDs are pro-convulsive, increasing at seizure-occurrence, others are protective, showing decrease related to seizures. MethodsWe analyzed 102 consecutive, long-term video-EEG monitoring sessions, from 98 patients. Using a semi-automated spike-detection method, we quantified the occurrence of EDs, grouped according to their location and morphology (clusters) and we constructed graphical representation of data, showing changes in time of the spiking patterns (spike-histograms). We compared the spike-histograms with the time-points of the seizures (pre-, peri- and postictal changes). ResultsTotally 179 ED-clusters were identified. Modulation of the spiking pattern, associated with seizures, was observed in 66 clusters (37%), from 47 patients (48%). Most of these changes (40 clusters; 61%) were related to increase in the spiking-pattern. ConclusionsChanges in spiking-pattern were associated with more than one third of the EDs. Both increasing and decreasing patterns were observed. SignificanceEDs are more often pro-convulsive, with increasing spiking patterns associated with seizures. However, in more than one third of the ED clusters modulated by seizures, the spiking pattern decreased, raising the possibility of an anticonvulsive function of these discharges.

The effect of rehabilitation treatment on the electroencephalography results and the course of epilepsy in children with cerebral palsy

Introduction. Cerebral palsy is often combined with epilepsy and epileptiform electroencephalographic (EEG) activity. Currently, the question of how rehabilitation with cerebral palsy is dangerous in relation to the provocation of epileptic seizures is relevant. Objective: to study the effect of cerebral palsy rehabilitation on epilepsy in a standard rehabilitation center. Material and methods. We examined 80 children with various forms of cerebral palsy and epileptiform EEG activity. The patients were divided into two groups: children of Group 1 never had epileptic seizures, children of Group 2 had a history of epileptic seizures of more than 6 months ago. The follow-up was 12 months during which children underwent EEG before and after rehabilitation courses. Depending on the risks associated with provoking epileptic seizures, patients were prescribed rehabilitation procedures of various intensities: Vojta kinesiotherapy, massage, physiotherapeutic treatment in the form of transcranial micropolarization and paraffin therapy. Results. During the study, epileptic seizures developed in 5 patients (12.5%) from Group 1 and in 7 children (17.5%) from Group 2. In all cases, rare focal seizures were recorded (1–2 times a year). All patients with seizures during our study had a history of seizures under the age of 1 year. The onset of seizures was quickly stopped by the basic antiepileptic drugs in monotherapy. Epileptic seizures developed in children with moderate to severe cerebral palsy on GMFCS (Gross Motor Function Classification System) and a history of neonatal seizures. We attributed both of these to risk factors. In children with cerebral palsy and epilepsy in remission of 6 months or more, massage and Vojta therapy did not provoke epileptic seizures. The effect of epileptiform activity on the severity of motor status and on cognitive functions in cerebral palsy has not been established in our study. Conclusion. According to our data, rehabilitation measures do not have a significant impact on the risk of developing epilepsy.

Sensitivity of Continuous Electroencephalography to Detect Ictal Activity After Cardiac Arrest

Epileptiform electroencephalographic (EEG) patterns are common after resuscitation from cardiac arrest, are associated with patient outcome, and may require treatment. It is unknown whether continuous EEG monitoring is needed to detect these patterns or if brief intermittent monitoring is sufficient. If continuous monitoring is required, the necessary duration of observation is unknown. To quantify the time-dependent sensitivity of continuous EEG for epileptiform event detection, and to compare continuous EEG to several alternative EEG-monitoring strategies for post-cardiac arrest outcome prediction. This observational cohort study was conducted in 2 academic medical centers between September 2010 and January 2018. Participants included 759 adults who were comatose after being resuscitated from cardiac arrest and who underwent 24 hours or more of EEG monitoring. Epileptiform EEG patterns associated with neurological outcome at hospital discharge, such as seizures likely to cause secondary injury. Overall, 759 patients were included in the analysis; 281 (37.0%) were female, and the mean (SD) age was 58 (17) years. Epileptiform EEG activity was observed in 414 participants (54.5%), of whom only 26 (3.4%) developed potentially treatable seizures. Brief intermittent EEG had an estimated 66% (95% CI, 62%-69%) to 68% (95% CI, 66%-70%) sensitivity for detection of prognostic epileptiform events. Depending on initial continuity of the EEG background, 0 to 51 hours of monitoring were needed to achieve 95% sensitivity for the detection of prognostic epileptiform events. Brief intermittent EEG had a sensitivity of 7% (95% CI, 4%-12%) to 8% (95% CI, 4%-12%) for the detection of potentially treatable seizures, and 0 to 53 hours of continuous monitoring were needed to achieve 95% sensitivity for the detection of potentially treatable seizures. Brief intermittent EEG results yielded similar information compared with continuous EEG results when added to multivariable models predicting neurological outcome. Compared with continuous EEG monitoring, brief intermittent monitoring was insensitive for detection of epileptiform events. Monitoring EEG results significantly improved multimodality prediction of neurological outcome, but continuous monitoring appeared to add little additional information compared with brief intermittent monitoring.

Association of antiepileptic drugs with resolution of epileptiform activity after cardiac arrest

IntroductionWe tested the impact of antiepileptic drug (AED) administration on post-cardiac arrest epileptiform electroencephalographic (EEG) activity. MethodsWe studied an observational cohort of comatose subjects treated at a single academic medical center after cardiac arrest from September 2010 to January 2018. We aggregated the observed EEG patterns into 5 categories: suppressed; discontinuous background with superimposed epileptiform activity; discontinuous background without epileptiform features; continuous background with epileptiform activity; and continuous background without epileptiform activity. We calculated overall probabilities of transitions between EEG states in a multistate model, then used Aalen’s additive regression to test if AEDs or hypothermia are associated with a change in these probabilities. ResultsOverall, 828 subjects had EEG-monitoring for 42,840 h with a median of 40 [IQR 23–64] h per subject. Among patients with epileptiform findings on initial monitoring, 50% transitioned at least once to a non-epileptiform, non-suppressed state. By contrast, 19% with non-epileptiform initial activity transitioned to an epileptiform state at least once. Overall, 568 (78%) patients received at least one AED. Among patients with continuous EEG background activity, valproate, levetiracetam and lower body temperature were each associated with an increased probability of transition from epileptiform states to non-epileptiform states, where patients with discontinuous EEG background activity no agent linked to an increased probability of transitioning from epileptiform states. ConclusionAfter cardiac arrest, the impact of AEDs may depend on the presence of continuous cortical background activity. These data serve to inform experimental work to better define the opportunities to improve neurologic care post-cardiac arrest.

Levetiracetam Protects Against Cognitive Impairment of Subthreshold Convulsant Discharge Model Rats by Activating Protein Kinase C (PKC)-Growth-Associated Protein 43 (GAP-43)-Calmodulin-Dependent Protein Kinase (CaMK) Signal Transduction Pathway.

BackgroundSubclinical epileptiform discharges (SEDs) are defined as epileptiform electroencephalographic (EEG) discharges without clinical signs of seizure in patients. The subthreshold convulsant discharge (SCD) is a frequently used model for SEDs. This study aimed to investigate the effect of levetiracetam (LEV), an anti-convulsant drug, on cognitive impairment of SCD model rats and to assess the associated mechanisms.Material/MethodsA SCD rat model was established. Rats were divided into an SCD group, an SCD+ sodium valproate (VPA) group, and an SCD+ levetiracetam (LEV) group. The Morris water maze was used to evaluate the capacity of positioning navigation and space exploration. The field excitatory post-synaptic potentials (fEPSPs) were evaluated using a bipolar stimulation electrode. NCAM, GAP43, PS95, and CaMK II levels were detected using Western blot and RT-PCR, respectively. PKC activity was examined by a non-radioactive method.ResultsLEV shortens the latency of platform seeking in SCD rats in positioning navigation. fEPSP slopes were significantly lower in the SCD group, and LEV treatment significantly enhanced the fEPSP slopes compared to the SCD group (P<0.05). The NCAM and GAP-43 levels were increased and PSD-95 levels were increased in SCD rats (P<0.05), which were improved by LEV treatment. The PKC activity and CaMK II levels were decreased in SCD rats and LEV treatment significantly enhanced PKC activity and increased CaMK II levels.ConclusionsCognitive impairment in of SCD model rats may be caused by decreased PKC activity, low expression of CaMK II, and inhibition of LTP formation. LEV can improve cognitive function by activating the PKC-GAP-43-CaMK signal transduction pathway.

The effect of estradiol on sevoflurane-induced epileptiform cortical EEG waves in neonatal rats

Objective To investigate the effect of estradiol on sevoflurane-induced epileptiform cortical EEG waves in neonatal rats. Methods Forty neonatal rats, aged 4-6 days, weighting 8-15 g, were divided into 5 groups according to random number table: normal saline control group (group C), estradiol group (group E), ICI182780 (group I), Formestane group (group O) and estradiol + ICI182780 (group EI). After establishing the monitoring model of cortical electroencephalogram in neonatal rats, EEG was recorded continuously for 30 minutes, then different treatment drugs were given according to different groups. After 30 minutes of continuous recording of EEG, anesthesia induction was started with inhalation of 6% sevoflurane for 3 minutes, followed by inhalation of 2.1% sevoflurane to maintain anesthesia. Sevoflurane anesthesia lasted for 1 hour.The righting reflex disappearance time was recorded after sevoflurane anesthesia.The total duration, single duration and frequency of EEG convulsion waves were recorded.Spike frequencies were recorded at different periods.Animal respiratory rate was recorded after sevoflurane induction. Results One rat in group I and one rat in group EI showed convulsion wave before treatment, which were excluded from the study.The righting reflex disappearance time of group S, group E, group I, group O and group EI were (24.4±2.5)s, (16.4±4.2)s, (31.8±5.2)s, (29.8±1.8)s, (24.8±2.7)s respectively, and there were statistically significant differences among the 5 groups (F=16.693, P 0.05). Compared with group S, the total duration, single duration and frequency of convulsion wave were significantly increased in group E during anesthesia, and the differences were statistically significant (P<0.05). Compared with group E and group S, the total duration, single duration and frequency of convulsion wave during anesthesia were significantly reduced in group I, group O and group EI, and the differences were statistically significant (P<0.05). Compared with group S, the spike frequency of group E increased significantly in each period, and the differences were statistically significant (P<0.05). The frequency of spike wave in group I, group O and group EI at 65-70 min and 90-95 min were lower than that in group S, and the differences were statistically significant (P<0.05). The frequency of spike wave between group O and group EI during 115-120 min was statistically different with group S and group E(P<0.05). Conclusion The mechanism of epileptiform EEG wave induced by sevoflurane anesthesia may be related with neuroactive steroidal estradiol. Key words: Sevoflurane; Neonatal rats; Epileptiform electroencephalography; Estradiol

Landau Kleffner Syndrome and Misdiagnosis of Autism Spectrum Disorder: A Mini-Review

Autism spectrum disorders (ASD) is the name for a group of developmental disorders including a wide range of signs, symptoms and disability. Landau kleffner syndrome (LKS) or acquired epileptic aphasia is a pediatric disorder characterized by the association of epileptiform electroencephalographic (EEG) abnormalities and acquired aphasia. The early stages of the LKS may be manifested by the symptoms of the autism leading to misdiagnosis. Since LKS is a progressive disease, its misdiagnosis leads to a greater neurocognitive deterioration which may result in seizure in the final stages. The purpose of this review was to provide an overview of available researchs on ASD population and patients with LKS and relationship between these two diseases.

Landau Kleffner Syndrome and Misdiagnosis of Autism Spectrum Disorder: A Mini-Review

Autism spectrum disorders (ASD) is the name for a group of developmental disorders including a wide range of signs, symptoms and disability. Landau kleffner syndrome (LKS) or acquired epileptic aphasia is a pediatric disorder characterized by the association of epileptiform electroencephalographic (EEG) abnormalities and acquired aphasia. The early stages of the LKS may be manifested by the symptoms of the autism leading to misdiagnosis. Since LKS is a progressive disease, its misdiagnosis leads to a greater neurocognitive deterioration which may result in seizure in the final stages. The purpose of this review was to provide an overview of available researchs on ASD population and patients with LKS and relationship between these two diseases.

Frequency of post-stroke electroencephalographic epileptiform activity - a systematic review and meta-analysis of observational studies.

Cerebrovascular diseases are the most frequent risk factor for epilepsy in the elderly, and epileptic phenomenon following stroke is known to worsen the prognosis. Although electroencephalography is the gold standard epilepsy biomarker, it is rarely used in post-stroke studies, and the frequency of post-stroke epileptiform activity is still uncertain. We analysed studies indexed to MEDLINE, Embase, Web of Science, PsycINFO and OpenGrey (up to March 2015), reporting post-stroke electroencephalographic epileptiform activity frequency in adults. Epileptiform activity was classified as ictal (electrographic seizures) and interictal (non-periodic spikes and sharp waves). Data selection, extraction and appraisal were done in duplicate. Random-effects meta-analysis was used to pool frequencies. The pooled frequency of post-stroke ictal and interictal epileptiform activity was 7% (95% CI 3%-12%) and 8% (95% CI 4%-13%), respectively. The use of continuous electroencephalogram was not associated with an increased frequency of electrographic seizures (p = 0.05), nor did the management setting (Intensive Care Unit versus non- Intensive Care Unit, p = 0.31). However, studies with continuous electroencephalogram showed a higher frequency of interictal epileptiform activity (p = 0.01). This study provides the best available estimates of the frequency of post-stroke electroencephalographic epileptiform activity. Due to detection bias, it was not possible to correlate clinical and electrographic seizures. The frequency of ictal and interictal epileptiform activity in the electroencephalogram was comparable with previous frequency analyses of clinical seizures. The frequency of ictal epileptiform activity did not change with continuous record or clinical setting, while the frequency of interictal epileptiform activity increased with continuous record.

Psychogenic nonepileptic seizures

IntroductionPsychogenic nonepileptic seizures (PNES) are defined as a somatoform conversion disorder manifesting as paroxysmal events not associated with electroencephalographic (EEG) epileptiform correlates. This entity is poorly understood and often misdiagnosed as epilepsy. It is important to recognize that misdiagnosis leads to inappropriate use of antiepileptic drugs, which may worsen the course of the disease.Recent studies have suggested that the frequency of psychogenic nonepileptic seizures ranges from 10 to 23% of referrals to a pediatric epilepsy center, as well as 60% of children with PNES achieve symptom improvement and event freedom of symptoms following appropriate treatment.ObjectivesThe aim of this study is to conduct a literature review of studies which the purpose was better understand the etiologies, features, and care outcomes of psychogenic nonepileptic seizures (PNESs) in a pediatric setting.ConclusionA early identification of the risk factors for comorbid psychopathology, diagnosis and appropriate care for PNESs reduces inappropriate medical investigation and therapy, expedites rates of remission, and decreases health-care utilization in a pediatric setting.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Analysis of the clinical experience with perampanel in the Moscow Region: Efficacy, tolerability, individual choice priorities

Objective: to analyze our clinical experience with perampanel (PER), by evaluating the efficacy, tolerability, and individual choice priorities. Patients and methods. The investigation enrolled 28 patients with drug-resistant focal epilepsy; the patients' mean age was 38.3±10.7 years. The proportion of men was 46.4%; the disease duration was 8 to 33 years (mean 20.2 years). Antiepileptic drugs (AEDs) were changed 7–10 times in 66% of the patients and 5–6 times in 23%. The efficacy and tolerability of AEDs and the electroclinical features of epilepsy were compared in two groups: responders and non-responders. Results and discussion. The responder and non-responder groups had a substantial preponderance of patients with frontal lobe epilepsy and diffuse epileptiform electroencephalographic (EEG) patterns (80%:46% and 80%:38%, respectively; p = 0.0001), but those with temporal lobe epilepsy and isolated regional EEG patterns were 2–3 times fewer (20%: 53.8% and 20%:61.5%; p = 0.0001). Only one of 10 combinations of carbamazepine (CBM) and PER was successful. Aggression, fear, and psychosis, which occurred in 5 (17.8%) patients taking PER 2–6 mg/day, were the most common adverse reactions associated with its discontinuation. PER is an effective agent to overcome of drug resistance in epilepsy. The benefit of the drug is that it may be used in undifferentiated antiepileptic therapy regimens. When predicting the effects of PER, preliminary switch from CBZ to oxcarbazepine or eslicarbazepine is reasonable.

Ripples on spikes show increased phase-amplitude coupling in mesial temporal lobe epilepsy seizure-onset zones.

Ripples (80-150 Hz) recorded from clinical macroelectrodes have been shown to be an accurate biomarker of epileptogenic brain tissue. We investigated coupling between epileptiform spike phase and ripple amplitude to better understand the mechanisms that generate this type of pathologic ripple (pRipple) event. We quantified phase amplitude coupling (PAC) between epileptiform electroencephalography (EEG) spike phase and ripple amplitude recorded from intracranial depth macroelectrodes during episodes of sleep in 12 patients with mesial temporal lobe epilepsy. PAC was determined by (1) a phasor transform that corresponds to the strength and rate of ripples coupled with spikes, and a (2) ripple-triggered average to measure the strength, morphology, and spectral frequency of the modulating and modulated signals. Coupling strength was evaluated in relation to recording sites within and outside the seizure-onset zone (SOZ). Both the phasor transform and ripple-triggered averaging methods showed that ripple amplitude was often robustly coupled with epileptiform EEG spike phase. Coupling was found more regularly inside than outside the SOZ, and coupling strength correlated with the likelihood a macroelectrode's location was within the SOZ (p < 0.01). The ratio of the rate of ripples coupled with EEG spikes inside the SOZ to rates of coupled ripples in non-SOZ was greater than the ratio of rates of ripples on spikes detected irrespective of coupling (p < 0.05). Coupling strength correlated with an increase in mean normalized ripple amplitude (p < 0.01), and a decrease in mean ripple spectral frequency (p < 0.05). Generation of low-frequency (80-150 Hz) pRipples in the SOZ involves coupling between epileptiform spike phase and ripple amplitude. The changes in excitability reflected as epileptiform spikes may also cause clusters of pathologically interconnected bursting neurons to grow and synchronize into aberrantly large neuronal assemblies.