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Objective: Ictal direct current shifts (icDCs) and ictal high-frequency oscillations (icHFOs) have been reported as surrogate markers for better surgical outcomes in epilepsy surgery. icDCs have been classified into two types: rapid and slow development. icDCs have been investigated with a time constant of 10 s (TC10s); however, many institutes use electroencephalography with a time constant of 2 s (TC2s). This study aimed to evaluate whether icDCs can be observed adequately with TC2s; moreover, it examined the relationship between the resected core area of icDCs or icHFOs and surgical outcomes, occurrence rate of each type of icDCs, and relationship between each type of icDCs and pathology., Methods: Twenty-five patients with intractable focal epilepsy were analyzed retrospectively. icDCs and icHFOs were defined according to common metrics. The amplitude of icDCs was defined at >200 μV and even <200 μV. The two electrodes producing the most prominent icDCs and icHFOs were defined as core electrodes. The correlation between the resected core electrode area and degree of seizure control after surgery was analyzed. icDCs were classified into two types based on a peak latency value cutoff of 8.9 s, and the occurrence rates of both patterns were investigated., Results: icDCs (142/147 seizures [96.6%]) and icHFOs (135/147 seizures [91.8%]) occurred in all patients (100%). Compared with the amplitude of icDCs with TC10s reported in previous studies, the amplitude of icDCs with TC2s was attenuated in the current study. A significant positive correlation was observed between the resected core electrode area and degree of seizure control in both icDCs and icHFOs. A rapid development pattern was observed in 202 of 264 electrodes (76.5%)., Significance: Similar to icDCs with TC10s, those with TC2s were observed adequately. Furthermore, favorable outcomes are expected using TC2s, which is currently available worldwide., (© 2023 International League Against Epilepsy.)

Objective: Postseizure functional decline is a concern in poststroke epilepsy (PSE). However, data on electroencephalogram (EEG) markers associated with functional decline are scarce. Thus, we investigated whether periodic discharges (PDs) and their specific characteristics are associated with functional decline in patients with PSE., Methods: In this observational study, patients admitted with seizures of PSE and who had scalp EEGs were included. The association between the presence or absence of PDs and postseizure short-term functional decline lasting 7 days after admission was investigated. In patients with PD, EEG markers were explored for risk stratification of short-term functional decline, according to the American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology. The association between EEG markers and imaging findings and long-term functional decline at discharge and 6 months after discharge, defined as an increase in the modified Rankin Scale score compared with the baseline, was evaluated., Results: In this study, 307 patients with PSE (median age = 75 years, range = 35-97 years, 64% males; hemorrhagic stroke, 47%) were enrolled. Compared with 247 patients without PDs, 60 patients with PDs were more likely to have short-term functional decline (12 [20%] vs. 8 [3.2%], p < .001), with an adjusted odds ratio (OR) of 4.26 (95% confidence interval [CI] = 1.44-12.6, p = .009). Patients with superimposed fast-activity PDs (PDs+F) had significantly more localized (rather than widespread) lesions (87% vs. 58%, p = .003), prolonged hyperperfusion (100% vs. 62%, p = .023), and a significantly higher risk of short-term functional decline than those with PDs without fast activity (adjusted OR = 22.0, 95% CI = 1.87-259.4, p = .014). Six months after discharge, PDs+F were significantly associated with long-term functional decline (adjusted OR = 4.21, 95% CI = 1.27-13.88, p = .018)., Significance: In PSE, PDs+F are associated with sustained neuronal excitation and hyperperfusion, which may be a predictor of postseizure short- and long-term functional decline., (© 2023 International League Against Epilepsy.)

Objective: To assess whether post-stroke epilepsy (PSE) is associated with neuroimaging findings of hemosiderin in a case-control study, and whether the addition of hemosiderin markers improves the risk stratification models of PSE., Methods: We performed a post-hoc analysis of the PROgnosis of POST-Stroke Epilepsy study enrolling PSE patients at National Cerebral and Cardiovascular Center, Osaka, Japan, from November 2014 to September 2019. PSE was diagnosed when one unprovoked seizure was experienced >7 days after the index stroke, as proposed by the International League Against Epilepsy. As controls, consecutive acute stroke patients with no history or absence of any late seizure or continuing antiseizure medications at least 3 months after stroke were retrospectively enrolled during the same study period. We examined cortical microbleeds and cortical superficial siderosis (cSS) using gradient-echo T2*-weighted images. A logistic regression model with ridge penalties was tuned using 10-fold cross-validation. We added the item of cSS to the existing models (SeLECT and CAVE) for predicting PSE and evaluated performance of new models., Results: The study included 180 patients with PSE (67 women; median age 74 years) and 1,183 controls (440 women; median age 74 years). The cSS frequency was higher in PSE than control groups (48.9% vs 5.7%, p < 0.0001). Compared with the existing models, the new models with cSS (SeLECT-S and CAVE-S) demonstrated significantly better predictive performance of PSE (net reclassification improvement 0.63 [p = 0.004] for SeLECT-S and 0.88 [p = 0.001] for CAVE-S at the testing data)., Interpretation: Cortical superficial siderosis was associated with PSE, stratifying stroke survivors at high risk of PSE. ANN NEUROL 2023;93:357-370., (© 2022 The Authors. Annals of Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Objective: The significance of ictal magnetoencephalography (MEG) is not well appreciated. We evaluated the relationships between ictal MEG, MRI, intracranial electroencephalography (ICEEG), surgery and postoperative seizure outcome., Methods: A total of 45 patients (46 cases) with ictal MEG who underwent epilepsy surgery was included. We examined the localization of each modality, surgical resection area and seizure freedom after surgery., Results: Twenty-one (45.7%) out of 46 cases were seizure-free at more than 6 months follow-up. Median duration of postoperative follow-up was 16.5 months. The patients in whom ictal, interictal single equivalent current dipole (SECD) and MRI lesion localization were completely included in the resection had a higher chance of being seizure-free significantly (p < 0.05). Concordance between ictal and interictal SECD localizations was significantly associated with seizure-freedom. Concordance between MRI lesion and ictal SECD, concordance between ictal ICEEG and ictal and interictal SECD, as well as concordance between ictal ICEEG and MRI lesion were significantly associated with seizure freedom., Conclusions: Ictal MEG can contribute useful information for delineating the resection area in epilepsy surgery., Significance: Resection should include ictal, interictal SECDs and MRI lesion localization, when feasible. Concordant ictal and interictal SECDs on MEG can be a favorable predictor of seizure freedom., Competing Interests: Conflicts of interest The authors report no competing interests., (Copyright © 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Precise localization of the "epileptogenic zone(EZ)" is the goal of presurgical investigations in patients with drug-resistant focal epilepsy. Intracranial electroencephalography recordings are required when noninvasive evaluation results are not consistent. Although subdural grid electrodes(SDG)have been widely used in Japan, stereoelectroencephalography(SEEG)has been recently introduced. The principle of SEEG is based on anatomo-electro-clinical correlations to investigate surgical hypotheses that are primarily driven by the analysis of seizure semiology as well as other noninvasive investigations. The most important element of the SEEG methodology is to formulate preimplantation electrode trajectories considering the anatomo-electro-clinical correlations of epileptic seizures. If the preimplantation hypotheses are insufficient or incorrect, SEEG recordings will not identify the EZ. A detailed analysis of seizure semiology with respect to anatomo-electro-clinical correlates, particularly including various deep structures, such as the insular, operculum, and cingulate cortex, forms the basis of the implantation strategy for SEEG. The strategy of implantation is not to map the lobes/lobules but the epileptic networks, which usually involve multiple lobes, indicating that the theory of SEEG is completely different from that of SDG. Herein, we introduce the basics of SEEG, especially presurgical evaluations, with a representative case presentation.

Objective: Motivated by the challenges raised by diagnosing poststroke epilepsy (PSE), especially in nonmotor onset seizure (non-MOS), we aimed to investigate the features of non-MOS, including seizure sequences, patient characteristics, and electrophysiological and imaging findings in PSE., Methods: This observational cohort study enrolled patients with PSE whose seizure onset was witnessed. According to the International League Against Epilepsy (ILAE) 2017 seizure classification, we classified seizure-onset symptoms into the non-MOS and MOS groups. We compared the different clinical characteristics between the two groups., Results: Between 2011 and 2018, we enrolled 225 patients with PSE (median age, 75 years), consisting of 97 (43%) with non-MOS and 128 (57%) with MOS. Overall, 65 (67%) of the patients without MOS had no subsequent convulsions. Multivariable logistic regression analysis showed significant associations of non-MOS with absence of poststroke hemiparesis (adjusted odds ratio [OR], 1.88; 95% confidence interval [CI], 1.03-3.42), frontal stroke lobe lesions (OR, 2.11; 95% CI, 1.14-3.91), and putaminal stroke lesions (OR, 2.51; 95% CI, 1.22-5.18) as negative indicators. Postictal single-photon emission computed tomography (SPECT) detected prolonged hyperperfusion in the temporal lobe more frequently in the non-MOS than in the MOS group (48% vs 31%; p = .02). The detection rate was higher than spikes/sharp waves in scalp electroencephalography, both in the non-MOS group (72% vs 33%; p < .001) and the MOS group (68% vs 29%; p < .001)., Significance: This study provides the clinical features of non-MOS in patients with PSE. Compared with the patients with MOS, patients with non-MOS showed less likely subsequent convulsive seizures, highlighting the clinical challenges. Postictal perfusion imaging and negative indicators of the non-MOS type may help diagnose and stratify PSE., (© 2022 International League Against Epilepsy.)

Background and Objectives: The functional outcome and mortality of patients with poststroke epilepsy (PSE) have not been assessed in a prospective study. Previous reports have suggested that patients with PSE may suffer from prolonged functional deterioration after a seizure. In this study, we prospectively investigated the functional outcome and mortality of patients with PSE and analyzed the effect of seizure recurrence on the outcomes., Methods: This is part of the Prognosis of Post-Stroke Epilepsy study, a multicenter, prospective observational cohort study, where 392 patients with PSE (at least 1 unprovoked seizure more than 7 days after the onset of the last symptomatic stroke) were followed for at least 1 year at 8 hospitals in Japan. This study included only PSE patients with a first-ever seizure and assessed their functional decline and mortality at 1 year. Functional decline was defined as an increase in modified Rankin Scale (mRS) score at 1 year compared with baseline, excluding death. The associations between the seizure recurrence and the outcomes were analyzed statistically., Results: A total of 211 patients (median age of 75 years; median mRS score of 3) were identified. At 1 year, 50 patients (23.7%) experienced seizure recurrence. Regarding outcomes, 25 patients (11.8%) demonstrated functional decline and 20 (9.5%) had died. Most patients died of pneumonia or cardiac disease (7 patients each), and no known causes of death were directly related to recurrent seizures. Seizure recurrence was significantly associated with functional decline (odds ratio [OR] 2.96, 95% CI 1.25-7.03, p = 0.01), even after adjusting for potential confounders (adjusted OR 3.26, 95% CI 1.27-8.36, p = 0.01), but not with mortality (OR 0.79, 95% CI 0.25-2.48, p = 0.68). Moreover, there was a significant trend where patients with more recurrent seizures were more likely to have functional decline (8.7%, 20.6%, and 28.6% in none, 1, and 2 or more recurrent seizures, respectively; p = 0.006)., Discussion: One-year functional outcome and mortality of patients with PSE were poor. Seizure recurrence was significantly associated with functional outcome, but not with mortality. Further studies are needed to ascertain whether early and adequate antiseizure treatment can prevent the functional deterioration of patients with PSE., (© 2022 American Academy of Neurology.)

Objective: To determine clinically ictal direct current (DC) shifts that can be identified by a time constant (TC) of 2 s and to delineate different types of DC shifts by different attenuation patterns between TC of 10 s and 2 s., Methods: Twenty-one patients who underwent subdural electrode implantation for epilepsy surgery were investigated. For habitual seizures, we compared (1) the peak amplitude and (2) peak latency of the earliest ictal DC shifts between TC of 10 s and 2 s. Cluster and logistic regression analyses were performed based on the attenuation rate of amplitude and peak latency with TC 10 s., Results: Ictal DC shifts in 120 seizures were analyzed; 89.1% of which were appropriately depicted even by a TC of 2 s. Cluster and logistic regression analyses revealed two types of ictal DC shift. Namely, a rapid development pattern was defined as the ictal DC shifts with a shorter peak latency and they also showed smaller attenuation rate of amplitude (73/120 seizures). Slow development pattern was defined as the ictal DC shifts with crosscurrent of a rapid development pattern, i.e., a longer peak latency and larger attenuation rate of amplitude (47/120 seizures). Focal cortical dysplasia (FCD) 1A tended to show a rapid development pattern (22/29 seizures) and FCD2A tended to show a slow development pattern (13 /18 seizures), indicating there might be some correlations between two types of ictal DC shift and certain pathologies., Conclusions: Ictal DC shifts, especially rapid development pattern, can be recorded and identified by the AC amplifiers of TC of 2 s which is widely used in many institutes compared to that of TC of 10 s. Two types of ictal DC shifts were identified with possibility of corresponding pathology., Significance: Ictal DC shifts can be distinguished by their attenuation patterns., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Background and Purpose: The management of post-stroke epilepsy (PSE) should ideally include prevention of both seizure and adverse effects; however, an optimal antiseizure medications (ASM) regimen has yet been established. The purpose of this study is to assess seizure recurrence, retention, and tolerability of older-generation and newer-generation ASM for PSE., Methods: This prospective multicenter cohort study (PROgnosis of Post-Stroke Epilepsy [PROPOSE] study) was conducted from November 2014 to September 2019 at eight hospitals. A total of 372 patients admitted and treated with ASM at discharge were recruited. Due to the non-interventional nature of the study, ASM regimen was not adjusted and followed standard hospital practices. The primary outcome was seizure recurrence in patients receiving older-generation and newer-generation ASM. The secondary outcomes were the retention and tolerability of ASM regimens., Results: Of the 372 PSE patients with ASM at discharge (median [IQR] age, 73 [64-81] years; 139 women [37.4%]), 36 were treated with older-generation, 286 with newer-generation, and 50 with mixed-generation ASM. In older- and newer-generation ASM groups (n = 322), 98 patients (30.4%) had recurrent seizures and 91 patients (28.3%) switched ASM regimen during the follow-up (371 [347-420] days). Seizure recurrence was lower in newer-generation, compared with the older-generation, ASM (hazard ratio [HR], 0.42, 95%CI 0.27-0.70; p = .0013). ASM regimen withdrawal and change of dosages were lower in newer-generation ASM (HR, 0.34, 95% CI 0.21-0.56, p < .0001)., Conclusions: Newer-generation ASM possess advantages over older-generation ASM for secondary prophylaxis of post-stroke seizures in clinical practice., (© 2021 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)

Diagnosis of post-stroke epilepsy is often challenging because of a low incidence of epileptiform abnormalities on electroencephalography (EEG). Hence, this study evaluated whether postictal subtraction single-photon emission computed tomography (SPECT) could visualize epileptic activity and act as a diagnostic modality in post-stroke epilepsy. Fifty post-stroke epilepsy patients, who had undergone Tc-99m-ECD SPECT twice (postictal and interictal), were enrolled. The postictal hyperperfusion area was identified by subtraction (postictal-interictal) SPECT and classified into two distribution types: superficial or deep-seated. Laterality and distribution of postictal hyperperfusion on subtraction SPECT were compared with stroke lesions, seizure symptoms, and epileptiform EEG findings. Forty-three of the 50 patients (86%) had hyperperfusion on subtraction SPECT and 26 (52%) had epileptiform EEG findings. Subtraction SPECT showed prolonged postictal hyperperfusion despite the relatively long interval between seizure end and postictal SPECT (median: 19.1 h, range: 2.2-112.5 h). The laterality of the hyperperfusion area had a high concordance rate with the laterality of stroke lesions (97.7%), seizure symptoms (91.9%), and epileptiform EEG findings (100%). Scalp EEG identified epileptiform activity more frequently in superficial type of SPECT, but less frequently in deep-seated type (both, P  = 0.03). Postictal SPECT can be complementary to scalp EEG in endorsing the diagnosis and location of post-stroke epilepsy.

Objective: Multispectrum electrocorticographic components are critical for mapping the nonprimary motor area (NPMA). The objective of this study was to derive and validate a reliable scoring system for electrocorticography-based NPMA mapping (NPMA score) to replace electrical cortical stimulation (ECS) during brain surgery., Methods: We analyzed 14 consecutive epilepsy patients with subdural electrodes implanted in the frontal lobe at Kyoto University Hospital. The NPMA score was retrospectively derived from multivariate analysis in the derivation group (patients = 7, electrodes = 713, during 2010-2013) and validated in the validation group (patients = 7, electrodes = 772, during 2014-2017). We assessed the accuracy and reliability of the score relative to ECS in determining the NPMA and predicting postoperative functional outcomes., Results: Multivariate analysis in the derivation group led to an 8-point score for predicting ECS-based NPMA (1 point for anatomical localization of the electrode and 1 or 2 points for movement-related electrocorticographic components regardless of somatotopy in very slow cortical potential shifts [<0.5 Hz], 40-80-Hz band power increase, and 8-24-Hz band power decrease), which was validated in the validation group. The area under the receiver operating characteristic curve (AUC) was 0.89 in the derivation group. Good prediction (specificity = 94%, sensitivity = 100%) and discrimination (AUC = 0.87) were reproduced in the validation group. Overall, higher NPMA scores identified 2 patients with postoperative deficits after frontal lobe resection., Significance: The NPMA score is reliable for NPMA mapping, potentially replacing ECS. It is a potential prognostic marker for postoperative functional deficits., (Wiley Periodicals, Inc. © 2019 International League Against Epilepsy.)

The epilepsy syndrome of autoimmune etiology, namely, autoimmune epilepsy has attracted attention in recent years, as was reflected in the new etiology of "immunity" in the Epilepsy Classification of the International League Against Epilepsy (2017). However, no specific tests other than neuronal antibodies have been established. We proposed a diagnostic algorithm for autoimmune epilepsy and preliminarily investigated its clinical utility. We applied this algorithm to 70 patients who were suspected as having autoimmune epilepsy from clinical symptoms and laboratory findings in our institute. At least one of the three neuronal antibodies (antibodies to N-methyl-D-aspartic acid receptor (NMDAR), glutamic acid decarboxylase (GAD), and voltage-gated potassium channels (VGKC) complex) was evaluated. In this two-step algorithm, the patients were initially screened by clinical features and then evaluated by laboratory findings (neuronal antibodies, cerebrospinal fluid (CSF), MRI, FDG-PET). The results of preliminary application of the algorithm are described. One of the three neuronal antibodies was positive in 13 patients. In this preliminary investigation, it was suggested that two or more abnormal findings in the diagnostic tests (CSF, MRI, FDG-PET) favors the diagnosis of autoimmune epilepsy. On the other hand, two patients with a positive neuronal antibody test failed the first step (clinical features), partly because epilepsy was not the major manifestation of autoimmune encephalitis (VGKC complex antibody) or due to a relatively low titer of the antibody (GAD antibody). Recruitment of the patient cohort with comprehensive neuronal antibody testing and multivariate analysis of laboratory findings is warranted for validation and modification of the proposed algorithm.

In recent years, stereotactic electroencephalography(SEEG)has been focused on as a new invasive method for epileptic focus detection. Although the covering area of the brain surface is smaller than the invasive estimation with subdural electrodes, SEEG can evaluate foci that are deeply seated, noncontiguous leaves, and/or bilateral hemispheres. In addition, SEEG can capture consecutive changes in seizure activity in three dimensions. Due to the development of neuroimaging, computer-assisted, and robotic surgery technology, SEEG insertion began to be commonly used worldwide. Although the approximate complication rates of SEEG are estimated as 1% to 3%, which is lower than that of subdural electrode implantation, the risks of major complications, such as permanent neurological deficit and death, are equivalent. Therefore, meticulous procedure must be needed. To introduce SEEG for intractable partial epilepsy, we acquired approval from the institutional review board and concurrently imported surgical devices and electrodes from the manufacturer in the United States for two surgical candidates. We safely performed SEEG insertion, focal identification, and brain functional mapping by cortical electrical stimulation in two cases. Insertion was difficult for some electrodes, which could be due to the lack of adequate surgical device and large skull angle. Hopefully, the official installation of SEEG will be planned in the near future. We hereby reported tips and pitfalls of SEEG implantation through our own experience in a single institute.

Objective: To assess the feasibility of multi-component electrocorticography (ECoG)-based mapping using "wide-spectrum, intrinsic-brain activities" for identifying the primary sensori-motor area (S1-M1)., Methods: We evaluated 14 epilepsy patients with 1514 subdural electrodes implantation covering the perirolandic cortices at Kyoto University Hospital between 2011 and 2016. We performed multi-component, ECoG-based mapping (band-pass filter, 0.016-300/600 Hz) involving combined analyses of the single components: movement-related cortical potential (<0.5-1 Hz), event-related synchronization (76-200 Hz), and event-related de-synchronization (8-24 Hz) to identify the S1-M1. The feasibility of multi-component mapping was assessed through comparisons with single-component mapping and electrical cortical stimulation (ECS)., Results: Among 54 functional areas evaluation, ECoG-based maps showed significantly higher rate of localization concordances with ECS maps when the three single-component maps were consistent than when those were inconsistent with each other (p < 0.001 in motor, and p = 0.02 in sensory mappings). Multi-component mapping revealed high sensitivity (89-90%) and specificity (94-97%) as compared with ECS., Conclusions: Wide-spectrum, multi-component ECoG-based mapping is feasible, having high sensitivity/specificity relative to ECS., Significance: This safe (non-stimulus) mapping strategy, alternative to ECS, would allow clinicians to rule in/out the possibility of brain function prior to resection surgery., (Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Physiological high frequency activities (HFA) are related to various brain functions. Factors, however, regulating its frequency have not been well elucidated in humans. To validate the hypothesis that different propagation modes (thalamo-cortical vs. cortico-coritcal projections), or different terminal layers (layer IV vs. layer II/III) affect its frequency, we, in the primary somatosensory cortex (SI), compared HFAs induced by median nerve stimulation with those induced by electrical stimulation of the cortex connecting to SI. We employed 6 patients who underwent chronic subdural electrode implantation for presurgical evaluation. We evaluated the HFA power values in reference to the baseline overriding N20 (earliest cortical response) and N80 (late response) of somatosensory evoked potentials (HFA(SEP(N20)) and HFA(SEP(N80))) and compared those overriding N1 and N2 (first and second responses) of cortico-cortical evoked potentials (HFA(CCEP(N1)) and HFA(CCEP(N2))). HFA(SEP(N20)) showed the power peak in the frequency above 200 Hz, while HFA(CCEP(N1)) had its power peak in the frequency below 200 Hz. Different propagation modes and/or different terminal layers seemed to determine HFA frequency. Since HFA(CCEP(N1)) and HFA induced during various brain functions share a similar broadband profile of the power spectrum, cortico-coritcal horizontal propagation seems to represent common mode of neural transmission for processing these functions.

Background: The clinical diagnostic criteria for benign adult familial myoclonus epilepsy (BAFME) originally included (1) cortical tremor and infrequent generalized seizures, (2) autosomal dominant inheritance, (3) lack of cognitive decline and other neurological symptoms, (4) electrophysiological findings of cortical reflex myoclonus, and (5) lack of clear clinical progression (BAFME criteria‐1). It was revised such that (1) included partial seizures, and (3) and (5) may develop among middle‐aged patients (Revised criteria‐2). The Japanese Ministry of Health, Labor and Welfare proposed their criteria, which included the EEG and MRI findings (MHLW criteria‐3). Recently, high‐frequency oscillations, superimposed on the giant somatosensory evoked potential P25 component (P25‐HFOs), have been found useful as a biomarker for BAFME diagnosis. Aim: We examined the genetic diagnosis of BAFME type 1 and its consistency with the three diagnostic criteria and P25‐HFOs. Methods: Twenty‐four Japanese patients, who underwent BAFME genetic testing, were rated using three independent diagnostic criteria and P25‐HFOs. Results: Twenty‐one patients were genetically diagnosed with BAFME type 1. Nineteen patients fulfilled BAFME‐1 (sensitivity 90%), and 21 fulfilled Revised‐2 and MHLW criteria‐3 (sensitivity 100%). We could evaluate P25‐HFOs in 19 of the 21 gene‐positive patients, and 17 of the 19 patients showed P25‐HFOs. Three patients with negative genetic testing did not meet any of the criteria and had no P25‐HFOs. Conclusions: The three available clinical diagnostic criteria for BAFME were highly concordant with the positive result for genetic testing. [ABSTRACT FROM AUTHOR]

Objective: To determine whether brain connectivity differs between focal cortical dysplasia (FCD) types I and II. Methods: We compared cortico‐cortical evoked potentials (CCEPs) as measures of effective brain connectivity in 25 FCD patients with drug‐resistant focal epilepsy who underwent intracranial evaluation with stereo‐electroencephalography (SEEG). We analyzed the amplitude and latency of CCEP responses following ictal‐onset single‐pulse electrical stimulation (iSPES). Results: In comparison to FCD type II, patients with type I demonstrated significantly larger responses in the electrodes near the ictal‐onset zone (<50 mm). These findings persisted when controlling for the location of the epileptogenic zone, as noted in patients with temporal lobe epilepsies, as well as controlling for seizure type, as noted in patients with focal to bilateral tonic‐clonic seizures (FBTCS). In type II, the root mean square (RMS) of CCEP responses dropped substantially from the early segment (10–60 ms) to the middle and late segments (60–600 ms). The middle and late CCEP latency segments showed the largest differences between FCD types I and II. Significance: Focal cortical dysplasia type I may have a greater degree of cortical hyperexcitability as compared with FCD type II. In addition, FCD type II displays a more restrictive area of hyperexcitability in both temporal and spatial domains. In patients with FBTCS and type I FCD, the increased amplitudes of RMS in the middle and late CCEP periods appear consistent with the cortico‐thalamo‐cortical network involvement of FBTCS. The notable differences in degree and extent of hyperexcitability may contribute to the different postsurgical seizure outcomes noted between these two pathological substrates. [ABSTRACT FROM AUTHOR]

Summary The clinical anticipation in Japanese benign adult familial myoclonus epilepsy (BAFME), defined as earlier onset age of either cortical tremor or generalized seizures or new appearance of those symptoms in the next generation, remains unknown. The onset age and the degree of both cortical tremor and generalized seizures were investigated in nine patients of four BAFME families (mean age: 46.6 ± 18.7 years). Clinical anticipation in the onset age of cortical tremor or generalized seizures was observed in three families, and generalized seizures newly appeared in the next generation in those two families and in another family. Clinical anticipation was observed in four families, which suggests the clinical progression over generation in Japanese BAFME families. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To delineate long-term change of cortical excitability by measuring somatosensory evoked potentials (SEPs) in patients with Unverricht–Lundborg disease (ULD). Methods: SEPs to median nerve stimulation were repeatedly examined in two genetically proven ULD patients manifesting stable condition over 16years, namely disabling but non-progressive myoclonus and cessation of generalised tonic–clonic seizures. Results: In both patients, five sets of early cortical components were identified 16years ago: two tangential components of N20–P20 and P30–N30 and three radial components of P25, N35 and N40. Cortical SEPs were regarded as abnormally enhanced ‘giant’ based on the N35 amplitude (>mean+3 SD of normal controls). The bimodal negative peaks of N35 and N40 showed different spatial distribution: N35 maximum in the central area and N40 in the centro-parietal area. At present, N35 remained giant while N40 disappeared in both patients. Conclusions: It is possible that currently preserved giant SEPs at least at N35 reflect disabling cortical myoclonus and that disappearance of N40 might reflect a lesser degree of increased cortico-cortical connectivity and/or decreased cortical hyperexcitability in the association cortices. It might possibly have resulted in the disappearance of GTCSs. Significance: We delineated long-term change of giant SEP in ULD. [Copyright &y& Elsevier]

Benign adult familial myoclonus epilepsy (BAFME) manifests an autosomal dominant trait, cortical tremor resembling essential tremor and infrequent generalized tonic-clonic seizures. BAFME also shows electrophysiological features of cortical reflex myoclonus. To clarify the positive rate of giant somatosensory evoked potential (giant SEP) and C reflex in BAFME, we retrospectively analyzed 19 patients in a total of 14 families (5 men and 14 women, age: 51 ± 16 years) about positive rate of giant SEP and C reflex. The positive rates of giant SEP and C reflex were 17/19 (89%) and 16/18 (88%), respectively. Relatively young 3 patients (27, 30, and 34 years old) showed no giant SEP or no C reflex. 1 patient (34 years old) showed neither giant SEP nor C reflex, who was examined within 1 year from the clinical onset. Whereas even 1 patient without cortical tremor showed giant SEP. The positive rate of giant SEP and C reflex is quite high in BAFME. Even presymptomatic patient showed giant SEP. However, some younger patients did not show giant SEP and/or C reflex. Therefore, family history of both clinical and electrophysiological findings is crucial for the diagnosis of BAFME. [ABSTRACT FROM AUTHOR]

By using cortico-cortical evoked potentials [CCEP: early negative (N1) and late negative (N2) components], we aimed to clarify high frequency oscillation (HFO) correlates of CCEPs and its relation to human epileptogenesis. We recruited 12 patients with intractable partial epilepsy who underwent invasive presurgical evaluation with chronic implantation of subdural electrodes. Repetitive single-pulse electrical stimulation (1Hz) was applied to (1) the seizure onset zone (SOZ) and (2) the control cortex (nSOZ), and CCEPs were recorded from the surrounding cortices within SOZ and nSOZ, respectively. We applied short-time Fourier transform to obtain induced responses at the timing of N1 (HFO N1) and N2 (HFO N2) and analyzed the logarithmic power change of HFO N1 and HFO N2 in reference to the baseline activity for ripple (120–200Hz) and fast ripple (>200Hz) bands. Seventeen clear CCEP responses were recorded for both SOZ and nSOZ across patients. In both SOZ and nSOZ stimulation, HFO N1 generally showed power increase and HFO N2 power decrease across the 2 frequency bands. HFO N1 power at SOZ increased more significantly than that at nSOZ in FR band. The present study suggests HFO correlates of CCEPs could be a surrogate marker of abnormally enhanced cortical excitability in human epileptic focus. [Copyright &y& Elsevier]

Electric cortical stimulation (ECS) is known to have suppressive effects on epileptic focus. However, the inhibitory mechanism remains to be elucidated. We investigated the effect of ECS on human epileptic focus by evaluating wideband cortical activities accompanied with interictal epileptiform discharges (IEDs). We recruited 9 patients with intractable partial epilepsy who underwent invasive pre-surgical evaluation with subdural electrodes. 50-Hz stimulation (0.3 ms pulse, 1–15 mA, 1–5 s) was applied at seizure onset zone (SOZ) as a part of functional cortical mapping. By performing Hilbert transform, we calculated the power of 4 frequency bands: fast ripple (200–300 Hz), ripple (80–200 Hz), low gamma (30–50 Hz) and beta (15–30 Hz). We compared them between pre- and post ECS at the timing of spike peak of IEDs. 2 patients were excluded due to artifacts or no examinations. In 3 patients, the power decreased after ECS in all frequency bands. The power did not change in 1, and the power change varied depending on the frequency band or the time after ECS in 3. We demonstrated that 50-Hz ECS on epileptic focus can suppress wide-band activities accompanied with IEDs, suggesting its potential ability to modulate cortical excitability toward less excitation and more inhibition. [ABSTRACT FROM AUTHOR]

Introduction. Although low-dose perampanel (PER) is reportedly effective on cortical myoclonus in a limited number of patients, its underlying mechanisms remain unclear. We aimed to extract and elaborate the clinical effects of PER on refractory cortical myoclonus for dose, etiology and also somatosensory-evoked potential (SEP) findings. Method. We examined 18 epilepsy patients with seizure and cortical myoclonus (10 males; mean age, 48.4 ± 16.2 years; Unverricht-Lundborg disease = 7, benign adult familial myoclonus epilepsy = 6, dentatorubral-pallidoluysian atrophy = 2, Gaucher disease = 1, and Lance-Adams syndrome = 2). Based on data accumulated before and after PER treatment, activities of daily life [ADL]), short latency, cortical components of SEP, and PER blood concentration were analyzed. Results. PER (mean dose: 3.2 ± 2.1 mg/day) significantly improved seizure frequency, myoclonus and ADL scores. It also significantly decreased the amplitude of and prolonged correlate with clinical scores among all patients. In contrast, the degree of P25 prolongation ms) significantly correlated with improved ADL score (p = 0.019) and blood PER concentration (p = 0.011). The degree of N33 prolongation (32.1 ± 4.0 to 33.7 ± 3.4 ms) was positively correlated with ADL score and blood PER concentration (p = 0.025 and p = 0.025, respectively). Conclusion. Low-dose PER markedly improved myoclonus and ADL in patients with refractory cortical myoclonus. SEP, especially P25 latency, is a potentially good biomarker to assess the objective effects of PER on intractable cortical myoclonus. (https://doi.org/10.1016/j.clinph.2019.07.006). [ABSTRACT FROM AUTHOR]

A 69-year-old woman undergoing treatment for hypertension and epilepsy was scheduled to undergo cataract surgery. All preoperative examination results were within normal limits. Despite being tense, she walked to the operating room. Approximately 2 minutes after an intravenous line was established by an anesthesia resident, severe hypoxia and bradycardia developed, and she lost consciousness. Cardiopulmonary resuscitation was initiated immediately, and after 1 minute, she regained consciousness, and her breathing and circulation recovered. After admission to the intensive care unit, emergency coronary angiography was performed. The blood flow in all the coronary arteries was normal. However, a decrease in the apical left ventricular wall motion and an increase in the basal wall motion were observed. Based on these findings, Takotsubo cardiomyopathy was diagnosed. The wall motion gradually improved and the patient was discharged from the hospital on postoperative day 15. The respiratory depression and bradycardia were thought to be due to an inadvertent bolus of remifentanil. We surmised that the patient had received a slight amount of retained medication when the anesthesia resident established the intravenous line, which caused severe respiratory depression. It is important to note that adverse effects such as severe respiratory depression and bradycardia can be caused by even small doses of remifentanil. [ABSTRACT FROM AUTHOR]