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Objective: To describe the association between preoperative ictal scalp electroencephalogram (EEG) results and surgical outcomes in patients with focal epilepsies. Methods: The data of consecutive patients with focal epilepsies who received surgical treatments at our center from January 2012 to December 2021 were retrospectively analyzed. Results: Our data showed that 44.2% (322/729) of patients had ictal EEG recorded on video EEG monitoring during preoperative evaluation, of which 60.6% (195/322) had a concordant ictal EEG results. No significant difference of surgery outcomes between patients with and without ictal EEG was discovered. Among MRI-negative patients, those with concordant ictal EEG had a significantly better outcome than those without ictal EEG (75.7% vs. 43.8%, p = 0.024). Further logistic regression analysis showed that concordant ictal EEG was an independent predictor for a favorable outcome (OR = 4.430, 95%CI 1.175–16.694, p = 0.028). Among MRI-positive patients, those with extra-temporal lesions and discordant ictal EEG results had a worse outcome compared to those without an ictal EEG result (44.7% vs. 68.8%, p = 0.005). Further logistic regression analysis showed that discordant ictal EEG was an independent predictor of worse outcome (OR = 0.387, 95%CI 0.186–0.807, p = 0.011) in these patients. Furthermore, our data indicated that the number of seizures was not associated with the concordance rates of the ictal EEG, nor the surgical outcomes. Conclusions: The value of ictal scalp EEG for epilepsy surgery varies widely among patients. A concordant ictal EEG predicts a good surgical outcome in MRI-negative patients, whereas a discordant ictal EEG predicts a poor postoperative outcome in lesional extratemporal lobe epilepsy. [ABSTRACT FROM AUTHOR]

Background: Temporal lobe epilepsy associated with hippocampal sclerosis (TLE-HS) is a surgically treatable epileptic syndrome. While the core of pre-surgical evaluations rely on video-EEG, recent studies question the necessity of recorded seizures denying a possible role of ictal EEG in surgical decision. This study aims to retrospectively assess the prognostic value of EEG ictal patterns in TLE-HS, in order to identify which patients need further investigations before offering surgery. Methods: We included TLE-HS patients who underwent surgery with at least one captured seizure during non-invasive pre-surgical video-EEG recordings. They were classified in "mesial" and "lateral/mixed", according to the ictal EEG patterns, defined by the frequency of the discharge (mesial ≥ 5 Hz, lateral < 5 Hz). Seizure outcome was assessed by Engel's Class. Statistical analyses were performed to evaluate associations between EEG patterns and post-surgical outcomes. Results: Sixty-nine exhibited a mesial pattern, forty- two displayed lateral/mixed patterns. Mesial pattern group had a significantly higher rate of postsurgical seizure freedom (82.7% vs. 28.6%). Gender, age of onset, age at surgery, duration of epilepsy, seizure frequency, and lateralization did not influence the outcome. Mesial pattern significantly correlated with favorable outcomes (p < 0.001), suggesting its potential predictive value. Conclusion: This retrospective study proposes ictal EEG patterns as possible predictors of postoperative prognosis in TLE-HS. A mesial pattern correlates with better outcomes, indicating a potentially more circumscribed epileptogenic zone. Patients with lateral/mixed patterns may benefit from additional investigations to delineate the epileptogenic zone. Further studies are warranted to validate and extend these findings. [ABSTRACT FROM AUTHOR]

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Objective: Long‐term automatic detection of focal seizures remains one of the major challenges in epilepsy due to the unacceptably high number of false alarms from state‐of‐the‐art methods. Our aim was to investigate to what extent a new patient‐specific approach based on similarly occurring morphological electroencephalographic (EEG) signal patterns could be used to distinguish seizures from nonseizure events, as well as to estimate its maximum performance. Methods: We evaluated our approach on >5500 h of long‐term EEG recordings using two public datasets: the PhysioNet.org Children's Hospital Boston–Massachusetts Institute of Technology (CHB‐MIT) Scalp EEG database and the EPILEPSIAE European epilepsy database. We visually identified a set of similarly occurring morphological patterns (seizure signature) seen simultaneously over two different EEG channels, and within two randomly selected seizures from each individual. The same seizure signature was then searched for in the entire recording from the same patient using dynamic time warping (DTW) as a similarity metric, with a threshold set to reflect the maximum sensitivity our algorithm could achieve without false alarm. Results: At a DTW threshold providing no false alarm during the entire recordings, the mean seizure detection sensitivity across patients was 84%, including 96% for the CHB‐MIT database and 74% for the European epilepsy database. A 100% sensitivity was reached in 50% of patients, including 79% from the CHB‐MIT database and 27% from the European epilepsy database. The median latency from seizure onset to its detection was 17 ± 10 s, with 84% of seizures being detected within 40 s. Significance: Personalized EEG signature combined with DTW appears to be a promising method to detect ictal events from a limited number of EEG channels with high sensitivity despite low rate of false alarms, high degree of interpretability, and low computational complexity, compatible with its future use in wearable devices. [ABSTRACT FROM AUTHOR]

Typical absence seizures (TAS) are seen in idiopathic generalized epilepsy. Electroencephalography (EEG) contributes to syndrome characterization and counseling in an area where genetics does not currently play a significant role. Prominent interictal EEG findings are seen in juvenile absence epilepsy (JAE) and are thus thought to be associated with less favorable outcome in any TAS case despite lack of evidence. Our study evaluates EEG findings and their association with seizure outcomes in children with TAS. Retrospective cohort study of 123 children over 10 years with extensive EEG analysis and medical record review. Phone interviews ascertained longer-term outcomes. EEG reviewers were unaware of outcomes. Total cohort included 123 children with phone review completed in 98. Median follow-up was 5 years 9 months. Seizure freedom was seen in 59% off antiseizure medicines (ASMs). Interictal findings included focal discharges in 29%, fragments of spike-wave (SW) discharges in 82.1%, and generalized interictal discharges in 63.4%. Interictal SW was more likely in those who slept (100%, 18 of 18) versus those who did not (57%, 60 of 105) (P < 0.001). Outcome analysis found no associations between focal or generalized interictal findings and seizure freedom, relapse off ASM, occurrence of other seizure types, or response to first ASM. Focal and generalized interictal EEG discharges are common in children with TAS and are not associated with poorer outcomes. These interictal findings were traditionally associated with JAE rather than childhood absence epilepsy and were thus believed to be associated with potentially poorer outcome, which is probably not the case. [ABSTRACT FROM AUTHOR]

Objectives:EEG training can be provided during neurology residency and in PhD, observership or fellowship programmes after residency in Turkey. In this study, we aim to reveal the EEG profile of a reference epilepsy center which provides EEG training in Turkey, by evaluating our patients’ clinical data and EEG findings within three months.Methods:The patients’ clinical data and EEG findings were retrospectively assessed and categorized in groups. EEG recordings that have multiple EEG findings (both focal slowing and interictal epileptic abnormality) were added into each group. EEGs with NCSE, clinical or subclinical ictal recordings, PNES and arrhythmias were noted.Results:Most of the 867 EEGs (56.2%) were performed for epilepsy. Three hundred thirty-six of the EEG recordings (39%) had normal findings while the rest had minimum one abnormal findings. One hundred ninety of the EEG’S (22%) had interictal epileptic discharges, 198 EEGs (23%) had focal or hemispheric slowing, 358 EEGs (41%) had non-specific findings. Fifteen (2%) EEGs had ictal recordings and 19 (2%) had NCSE. NCSE was found in 26% of patients presenting with altered consciousness. Habitual seizures were present with verbal induction in 3/11 patients diagnosis with PNES. Arrhythmia was found 4%.Conclusion:The most common reason to perform a routine EEG is epilepsy. The NCSE, ictal recordings, PNES and arrhythmias are not rare in an outpatient EEG laboratory. NCSE can be observed in 1/4 of patients who underwent EEG recording due to altered consciousness. This study reveals a cross-sectional profile of the reference hospital. EEG training would be provided with experienced specialists by interpreting quantitatively and qualitatively adequate EEGs.

Fast oscillations (FOs) >40 Hz in electroencephalograms (EEGs) are associated with ictogenesis and epileptogenesis in adults and children with epilepsy. However, only a few previous studies showed FOs in neonates. Reported frequencies of such neonatal FOs were in the low-gamma (60 Hz in the high-gamma band in human neonatal seizures, which were previously observed in animal studies. Further studies are needed to elucidate the pathophysiology of ictal FOs in neonatal seizures.

• Twenty-three patients with mesial temporal lobe epilepsy with pathologically confirmed hippocampal sclerosis were reviewed. • Ictal EEG findings of the initial delta and delayed theta/alpha pattern suggest purely hippocampal epileptogenicity. • Patients with this pattern are likely to become seizure-free after selective amygdalohippocampectomy. To determine whether the ictal scalp EEG findings suggest purely hippocampal epileptogenicity in patients with mesial temporal lobe epilepsy (mTLE) associated with hippocampal sclerosis (HS). Twenty-three patients with mTLE with pathologically confirmed HS were divided into 12 with epileptogenicity only in the hippocampus (HS only group) and 11 with epileptogenicity in both the hippocampus and temporal neocortex or other locations (HS plus group), based on the combination of surgical procedures, postoperative outcome, and pathological findings. Sixteen underwent selective amygdalohippocampectomy (SelAH) and 7 received anterior temporal lobectomy. Ictal scalp EEG findings of 79 focal impaired awareness seizures were compared between the HS only and HS plus groups. We focused on the 1–4 Hz rhythmic delta activity at ictal onset followed by 5–9 Hz rhythmic theta/alpha activity 10–30 s after the onset in the temporal region. The initial delta and delayed theta/alpha (ID-DT) pattern was observed in 8 of 12 patients in the HS only group, but in none of 11 patients in the HS plus group (p < 0.01). ID-DT pattern on ictal EEG suggests purely hippocampal epileptogenicity in mTLE with HS. Patients with the ID-DT pattern are likely to become seizure-free after SelAH. [ABSTRACT FROM AUTHOR]

Objectives: EEG training can be provided during neurology residency and in PhD, observership or fellowship programmes after residency in Turkey. In this study, we aim to reveal the EEG profile of a reference epilepsy center which provides EEG training in Turkey, by evaluating our patients' clinical data and EEG findings within three months. Methods: The patients' clinical data and EEG findings were retrospectively assessed and categorized in groups. EEG recordings that have multiple EEG findings (both focal slowing and interictal epileptic abnormality) were added into each group. EEGs with NCSE, clinical or subclinical ictal recordings, PNES and arrhythmias were noted. Results: Most of the 867 EEGs (56.2%) were performed for epilepsy. Three hundred thirty-six of the EEG recordings (39%) had normal findings while the rest had minimum one abnormal findings. One hundred ninety of the EEG'S (22%) had interictal epileptic discharges, 198 EEGs (23%) had focal or hemispheric slowing, 358 EEGs (41%) had non-specific findings. Fifteen (2%) EEGs had ictal recordings and 19 (2%) had NCSE. NCSE was found in 26% of patients presenting with altered consciousness. Habitual seizures were present with verbal induction in 3/11 patients diagnosis with PNES. Arrhythmia was found 4%. Conclusion: The most common reason to perform a routine EEG is epilepsy. The NCSE, ictal recordings, PNES and arrhythmias are not rare in an outpatient EEG laboratory. NCSE can be observed in 1/4 of patients who underwent EEG recording due to altered consciousness. This study reveals a cross-sectional profile of the reference hospital. EEG training would be provided with experienced specialists by interpreting quantitatively and qualitatively adequate EEGs. [ABSTRACT FROM AUTHOR]

• Recursive decomposition of ictal EEG and elimination of unwanted independent components (ICs) help to find the best ictal IC. • Quantitative feature is useful to reduce the dependency on visual inspection for ictal IC selection. • Cortical source of ictal rhythm can be estimated more concordantly from the best ictal component. This study aimed to present a new ictal component selection technique, named as recursive ICA-decomposition for ictal component selection (RIDICS), for potential application in epileptogenic zone localization. The proposed technique decomposes ictal EEG recursively, eliminates a few unwanted components in every recursive cycle, and finally selects the most significant ictal component. Back-projected EEG, regenerated from that component, was used for source estimation. Fifty sets of simulated EEGs and 24 seizures in 8 patients were analyzed. Dipole sources of simulated-EEGs were compared with a known dipole location whereas epileptogenic zones of the seizures were compared with their corresponding sites of successful surgery. The RIDICS technique was compared with a conventional technique. The RIDICS technique estimated the dipole sources at an average distance of 12.86 mm from the original dipole location, shorter than the distances obtained using the conventional technique. Epileptogenic zones of the patients, determined by the RIDICS technique, were highly concordant with the sites of surgery with a concordance rate of 83.33%. Results show that the RIDICS technique can be a promising quantitative technique for ictal component selection. Properly selected ictal component gives good approximation of epileptogenic zone, which eventually leads to successful epilepsy surgery. [ABSTRACT FROM AUTHOR]

West syndrome is an epileptic syndrome, characterized by a triad of symptoms: infantile spasms, hypsarrhythmia on interictal EEG, and a regression or delay of psycho-motoric development. According to the current concept, two of these three criteria suffice for the diagnosis. The incidence of this syndrome is 1 per 2000 newborns. This article reviews recent publications on the etiology, pathogenesis, clinical course, diagnosis, and treatment options in West syndrome. The text is supplemented with illustrations of ictal EEG at infantile spasms and variants of hypsarrhythmia. Today, in addition to classical hypsarrhythmia, five versions of modified hypsarrhythmia are proposed: synchronized version, asymmetric version, version with stable focus of spikes or acute waves, version with rhythmic flattening episodes, version with high-amplitude and asynchronous slow activity. The hormonal therapy is recommended to begin the treatment; if not effective, vigabatrin is to be used as the second choice medication.

Introduction: Reflex bathing seizures are described during the course of bathing in water near body temperature. These seizures differ from other epilepsies characterized by bathing-induced seizures such as hot water epilepsy, but there are few well-described patients and only some of these have been documented by ictal video-electroencephalography.Methods: Our objective was to characterize the clinical presentation of bathing-induced seizures demonstrated by ictal video-electroencephalographic recordings with water temperature below 38°C. We described two previously unreported infants and reviewed additional cases in the literature that fulfilled those criteria.Results: Eighteen infants were indentified. They were predominantly male (72%), and the mean age of seizure onset was 15 months (one to 36 months). The most frequent seizure triggers included pouring water over the face and immersion. Seizures were of focal onset with loss of awareness and prominent autonomic symptoms. Ictal video-electroencephalography revealed delta-theta high-amplitude focal waves involving temporal and adjacent regions, with a rapid spread to the ipsilateral hemisphere or generalization. Avoiding known triggers usually controlled the seizures, but carbamazepine, valproate, and levetiracetam were also helpful. Neuroimaging was normal in all cases, and neurodevelopment was unaffected.Discussion: Bathing seizures predominate in boys with an early onset and a benign self-limited course. The use of ictal video-electroencephalographic recordings in these cases leads to diagnosis and reveals individual differences in triggers. [ABSTRACT FROM AUTHOR]

Abstract: rolandic Epilepsy is one of the most common forms of idiopathic epilepsy. Its clinical profile and intercritical EEG are well-defined and widely described in medical literature. However, ictal EEG patterns in benign focal epilepsy with centrotemporal spikes are rarely recorded due to low frequency of seizures, mostly occurring during sleep. Only a small number of publications on the subject are available globally. This article provides a description of an ictal EEG during a roladic epileptic seizure.

Purpose: Infantile spasms are described as flexor extensor and mixed; but more features of their semiology and ictal electroencephalography (EEG) changes are sparse in the literature. The purpose of the study was to describe the clinical and ictal video-EEG characteristics of consecutive cases with infantile spasms and to try to find an association with the etiology. Materials and Methods: The clinical phenomenology and EEG characteristics on video-EEG were analyzed in 16 babies with infantile spasms. Results: A total of 869 spasms were reviewed. Nine (56.3%) showed focal seizures at least once during the recording and 1 (6.3%) had multifocal myoclonus in addition to the spasms. The duration of the cluster and interval between spasms was totally variable in all patients. Lateralizing phenomena were present in at least some of the spasms in all patients. Unilateral manual automatism in the form of holding the pinna was noted in three patients following the spasm. The ictal EEG activity in the majority (75%) was the slow wave. Four (25%) showed fast generalized spindle-like ictal discharges. Spikes, spike and wave activity, or electrodecremental pattern alone during the ictus was seen in none. On bivariate analysis, no factor noted on the video EEG had association with the etiology. Conclusion: Infantile spasms could be associated with focal and other seizures, has unique, non-uniform and variable semiology from patient to patient. The ictal EEG manifestation in the majority (75%) of our patients was the slow wave transient with 25% showing generalized fast spindle-like activity.

Summary: Objective: To evaluate the necessity of recording ictal electroencephalography (EEG) in patients with temporal lobe epilepsy (TLE) considered for resective surgery who have unilateral temporal interictal epileptiform discharges (IEDs) and concordant ipsitemporal magnetic resonance imaging (MRI) pathology. To calculate the necessary number of recorded EEG seizure patterns (ESPs) to achieve adequate lateralization probability. Methods: In a retrospective analysis, the localization and lateralization of interictal and ictal EEG of 304 patients with lesional TLE were analyzed. The probability of further contralateral ESPs was calculated based on a total of 1967 recorded ESPs, using Bayes’ theorem. Results: Two hundred seventy‐one patients had unilateral TLE, and in 98% of them (265 of 271), IEDs were recorded during video‐EEG monitoring. Purely unilateral temporal IEDs were present in 61% (166 of 271 patients). Ipsilateral temporal MRI pathology was found in 83% (138 of 166). Ictal EEG was concordant with the clinical side of TLE in 99% (136 of 138) of these patients. Two patients had discordant ictal EEG with both ipsilateral and contralateral ESPs. Epilepsy surgery with resection in the lesioned temporal lobe was still performed, and both patients remain seizure‐free. Probability calculations demonstrate that at least 6 recorded unilateral ESPs result in a >95% probability for a concordance of >0.9 of any further ESPs. Significance: The combination of purely unilateral temporal IED with ipsitemporal MRI pathology is sufficient to identify the epileptogenic zone, and the recording of ictal ESP did not add any surgically relevant information in these 138 patients. Rarely, discordant ESPs might be recorded, but the surgical outcome remains excellent after surgery on the lesioned side. [ABSTRACT FROM AUTHOR]

Objective Ictal scalp EEG patterns have been reported to vary across onset regions. We assessed the sequential EEG changes during seizure events on scalp EEG, and tested our hypothesis that patients with focal seizures arising from the cortex facing the interhemispheric fissure (IHF cortex) would be specifically characterized by 3 phase-EEG patterns (3Ph-EEG). Methods Patient inclusion criteria were: 1) focal epilepsy and 2) ictal onset records on scalp and intracranial video-EEG. Patients were classified into one of the three groups: the IHF group, mesial temporal (MT) group, or lateral convexity (LC) group, based on the localization of the ictal onset zone (IOZ) on intracranial video-EEG. We defined 3Ph-EEG on ictal scalp EEG as follows: phase 1, brief spike/fast wave burst; phase 2, diffuse attenuation; and phase 3, focal rhythmic activity with evolution. We determined if the occurrence ratios of 3Ph-EEG and each of the three phases differed between the groups (IHF and others). Results We studied 36 patients aged 8–59 years (mean, 30 years). Ten patients were classified as IHF, 16 as MT, and 10 as LC group from 303 ictal events on intracranial EEG. 193 seizures on scalp EEG consisted of 79 seizures in IHF; 58 in MT; 56 in LC group. Sixty-nine seizures (92%) in nine patients (90%) in IHF group showed 3Ph-EEG, whereas none of the seizures in MT and LC groups showed the 3Ph-EEG. Multivariate logistic regression analysis suggested that the presence of 3Ph-EEG ( p  < 0.01) and phase 2 ( p  = 0.03) components were predictive of IHF scalp EEG onset. Significance The 3Ph-EEG may be observed preferentially in patients with focal seizures from IHF cortex. Observation of the ictal phases on scalp EEG may warrant consideration of intracranial EEG sampling for the presurgical evaluation. [ABSTRACT FROM AUTHOR]

Objective We explored fast (40–150 Hz) oscillations (FOs) from the ictal scalp electroencephalogram (EEG) data of myoclonic seizures in pediatric patients to obtain insight into the pathophysiological mechanisms involved in the generation of myoclonic seizures. Subjects and methods The participants were 21 children (11 boys, 10 girls; age ranging from 5 months to 17 years 2 months) with myoclonic seizures associated with generalized (poly)spike-wave bursts in the ictal EEG data. The patients had heterogeneous etiologies and epilepsy diagnoses. In the ictal data, we detected FOs that clearly showed oscillatory morphology in filtered EEG traces and an outstanding spectral blob in time-frequency analysis. Results We identified FOs in 61 (88.4%) of all 69 myoclonic seizures. Every patient had at least one myoclonic seizure-associated FO. The observed FOs were embedded in the spike component of (poly)spike-wave discharges, and they had a focal distribution with frontal predominance. They ranged in frequency from 41.0 to 123.0 Hz and involved both the gamma and ripple bands, and their spectral peak frequencies were higher in the group of patients with a genetic background free of apparent fundamental brain pathology than in the group of other patients ( p  = 0.019). Conclusion FOs were found to represent at least part of the cortical pathophysiological process in the generation of myoclonic seizures that should involve the thalamocortical network system. [ABSTRACT FROM AUTHOR]

Objective To elucidate the generative mechanisms of epileptic spasms (ESs) in West syndrome, we investigated the temporal relationship between scalp fast (40–150 Hz) oscillations (FOs) and slow waves in the ictal electroencephalograms (EEGs) of ESs. Methods In 11 infants with WS, ictal FOs were detected in a bipolar montage based on spectral and waveform criteria. Their temporal distribution was analyzed in terms of the positive peaks (trough point, T T ) of identical EEG data in a referential montage. Among six EEG data sections defined according to T T , the number of FOs, peak power values, and peak frequencies were compared. Results We identified a total of 1014 FOs (946 gamma and 68 ripple oscillations), which clustered closely at T T . The number of gamma oscillations in the 1 s epoch including T T was significantly higher than those in the prior and subsequent phases. Peak power values and frequencies tended to be higher in these positive phase sections. Conclusions The temporal association of FO clustering and positive slow waves in the ictal EEGs of ES indicated that active neuronal firing related to FOs underlies the generation of ESs and their ictal slow waves. [ABSTRACT FROM AUTHOR]

Background Electroencephalography source imaging (ESI) is a promising tool for localizing the cortical sources of both ictal and interictal epileptic activities. Many studies have shown the clinical usefulness of interictal ESI, but very few have investigated the utility of ictal ESI. The aim of this article is to examine the clinical usefulness of ictal ESI for epileptic focus localization in patients with refractory focal epilepsy, especially extratemporal lobe epilepsy. Methods Both ictal and interictal ESI were performed by the use of patient-specific realistic forward models and 3 different linear distributed inverse models. Lateralization as well as concordance between ESI-estimated focuses and single-photon emission computed tomography (SPECT) focuses were assessed. Results All the ESI focuses (both ictal and interictal) were found lateralized to the same hemisphere as ictal SPECT focuses. Lateralization results also were in agreement with the lesion sides as visualized on magnetic resonance imaging. Ictal ESI results, obtained from the best-performing inverse model, were fully concordant with the same cortical lobe as SPECT focuses, whereas the corresponding concordance rate is 87.50% in case of interictal ESI. Conclusions Our findings show that ictal ESI gives fully lateralized and highly concordant results with ictal SPECT and may provide a cost-effective substitute for ictal SPECT. [ABSTRACT FROM AUTHOR]

Objectives Access to epilepsy surgery remains a considerable challenge in contemporary healthcare systems. Given the limitations in resources and demand for Epilepsy Monitoring Unit (EMU) assessments, information that can be used to expedite the process is of great value. The purpose of this study was to identify variables prior to EMU admission that may be associated with candidacy for prospective epilepsy surgery. Methods This was a prospective study conducted at the Department of Neurology, All India Institute of Medical Sciences, New Delhi, India. We identified two subgroups of patients from 501 drug refractory epilepsy (DRE) patients admitted in EMU of Neurology Department, AIIMS from 2006 onwards following validation of proposed tool in 40 patients. They on subsequent investigations were either cleared or not cleared for epilepsy surgery. A tool consisting of variables likely to predict surgical candidacy in persons with DRE in Indian settings was developed for identification of patients who might benefit from an early epilepsy surgery evaluation. Results Statistical analysis revealed significant differences between the two groups for several variables. Non-surgical candidates had non-disabling seizures, seizures improved with a combination of drugs, had little/no AEDs side effects and had near normal or normal scalp EEG and MRI brain. Significance Using the best available evidence, we developed a decision making tool which can provide a comprehensive quick guide for determining candidacy for epilepsy surgery evaluations in resource limited settings. Given the demand for EMU assessments, information that can be used to expedite the process is of value. [ABSTRACT FROM AUTHOR]

Purpose: Infantile spasms are described as flexor extensor and mixed; but more features of their semiology and ictal electroencephalography (EEG) changes are sparse in the literature. The purpose of the study was to describe the clinical and ictal video-EEG characteristics of consecutive cases with infantile spasms and to try to find an association with the etiology. Materials and Methods: The clinical phenomenology and EEG characteristics on video-EEG were analyzed in 16 babies with infantile spasms. Results: A total of 869 spasms were reviewed. Nine (56.3%) showed focal seizures at least once during the recording and 1 (6.3%) had multifocal myoclonus in addition to the spasms. The duration of the cluster and interval between spasms was totally variable in all patients. Lateralizing phenomena were present in at least some of the spasms in all patients. Unilateral manual automatism in the form of holding the pinna was noted in three patients following the spasm. The ictal EEG activity in the majority (75%) was the slow wave. Four (25%) showed fast generalized spindle-like ictal discharges. Spikes, spike and wave activity, or electrodecremental pattern alone during the ictus was seen in none. On bivariate analysis, no factor noted on the video EEG had association with the etiology. Conclusion: Infantile spasms could be associated with focal and other seizures, has unique, non-uniform and variable semiology from patient to patient. The ictal EEG manifestation in the majority (75%) of our patients was the slow wave transient with 25% showing generalized fast spindle-like activity. [ABSTRACT FROM AUTHOR]

Zusammenfassung In diesem Übersichtsartikel werden die typischen EEG-Muster im epileptischen Anfall bei generalisierten und fokalen Epilepsien erläutert. Bei generalisierten Epilepsien treten viele der typischen interiktalen epilepsietypischen Potentiale auch im Anfall auf. Die Entladungsdauer ist nur länger. Selten sehen die EEG-Anfallsmuster anders aus. Im Gegensatz hierzu entsprechen bei fokalen Epilepsien die EEG-Anfallsmuster meist nicht den interiktalen Potentialen. Bei fokalen Anfällen sieht man oft niedrigamplitudige hochfrequente Betawellen, die sich in der Frequenz und Amplitude mit zunehmender Anfallsdauer verändern („Evoluation in Raum und Zeit“). Bei Schläfenlappen-Epilepsien zeigen sich im Anfall typischerweise rhythmische Thetawellen, die sich über die Anfallsdauer in Frequenz und Amplitude verändern. Das Erkennen von EEG-Anfallsmustern ist wichtig für die EEG-MTA, um die Bewusstseinslage und Kontakfähigkeit der Patienten während der EEG-Ableitung überprüfen zu können. Summary This review addresses the typical ictal EEG seizure patterns encountered in patients with generalized and focal epilepsies. Whereas in generalized epilepsies the ictal EEG seizure patterns are similar to the interictal epileptiform discharges, this is not the case in focal epilepsies. The duration of epileptiform discharges is longer during seizures in generalized epilepsies than the duration of the interictal discharges. In focal epilepsies, cortically generated seizures are typically associated with low amplitude, high frequency discharges which change in amplitude and frequency over time (evolution of the EEG seizure pattern). Ictal EEG seizure patterns in temporal lobe epilepsies are typically characterized by rhythmical theta waves which evolve in amplitude and frequency over time. EEG technicians need to identify EEG seizrue patterns during EEG recordings in order to test the patients’ ictal response and consciousness. [ABSTRACT FROM AUTHOR]

Aim Recently, epilepsy with late-onset epileptic spasms (ES) has been reported to be distinct from West syndrome and Lennox-Gastaut syndrome. We identified the characteristics of this clinical entity by analyzing clinical data, including ictal electroencephalography (EEG) and electromyography (EMG) in symptomatic patients. Methods We evaluated retrospectively eight symptomatic patients with epilepsy with late-onset ES. All patients underwent video-EEG analysis for more than 24 hours and have been followed up for at least 1 year. Interictal EEG, ictal EEG, ictal EMG, coexistence seizures, response to treatment, and intellectual or daily activity level were assessed. Ictal EMG was evaluated by spectral analysis. Results All patients exhibited neurological deterioration and had multiple seizure types; seven of them had intractable seizures. Interictal EEG showed no typical hypsarrhythmia in any case. Ictal EMG analysis revealed that the predominant seizure types presenting with the tonic component were distributed among ES, spasms followed by tonic seizures (SFT), and tonic seizures. Conclusions The clinical characteristics of our patients were identical to infantile epileptic encephalopathy with late-onset spasms. Our patients had ES, SFT, and tonic seizures as the core seizure types, developed ES beyond the age of 1 year, and showed neurological deterioration. These may be essential symptoms of this clinical entity. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: High resolution MRI findings suggestive of mesial temporal sclerosis (MRI-MTS) correlate with good outcome after surgery. However, a large group of patients present with normal brain MRI (N-MRI) and temporal lobe epilepsy (TLE). We aim to compare pre-operative ictal EEG patterns in predicting surgical outcomes in the population with MRI-MTS vs. N-MRI after selective anterior-mesial temporal lobe (AMTL) resection. Methods: 241 patients with unilateral anterior ictal EEG findings underwent selective AMTL resection. 143 MRI-MTS and 98 N-MRI patients were identified. Outcome was based on the modified Engel classification, ictal EEG pattern at seizure onset, demographics and MRI findings. Results: Seizure-free outcome was seen in the MRI-MTS in 79% of patients, compared to 59.1% (p <.005) of the N-MRI group. No significant difference was identified in ictal EEG patterns at presentation between groups. Class I outcome was achieved in 78.9% of patients that had theta rhythm and MRI-MTS compared to 57.9% of patients that had theta rhythm and N-MRI (p <0.05). Discussion and conclusion: Surgical treatment for mesial TLE is effective. Positive MRI suggestive of mesial temporal sclerosis (MTS) predicts better seizure control after surgery. Theta rhythm is the most common ictal pattern and seems to carry the best prognosis for TLE. However, a well-selected group of patients with N-MRI will benefit from surgical intervention, and similar outcome to MRI-MTS patients can be achieved if delta ictal EEG pattern is presented at initial onset. Early referral to an epilepsy center cannot be emphasized enough, even in situations when high-resolution brain MRI is normal. [Copyright &y& Elsevier]