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Objective: Degree of indication for epilepsy surgery is determined by taking multiple factors into account. This study aimed to investigate the usefulness of the Specific Consistency Score (SCS), a proposed score for focal epilepsy to rate the indication for epilepsy focal resection. Methods: This retrospective cohort study included patients considered for resective epilepsy surgery in Kyoto University Hospital from 2011 to 2022. Plausible epileptic focus was tentatively defined. Cardinal findings were scored based on specificity and consistency with the estimated laterality and lobe. The total points represented SCS. The association between SCS and the following clinical parameters was assessed by univariate and multivariate analysis: (1) probability of undergoing resective epilepsy surgery, (2) good postoperative seizure outcome (Engel I and II or Engel I only), and (3) lobar concordance between the noninvasively estimated focus and intracranial electroencephalographic (EEG) recordings. Results: A total of 131 patients were evaluated. Univariate analysis revealed higher SCS in the (1) epilepsy surgery group (8.4 [95% confidence interval (CI) = 7.8–8.9] vs. 4.9 [95% CI = 4.3–5.5] points; p <.001), (2) good postoperative seizure outcome group (Engel I and II; 8.7 [95% CI = 8.2–9.3] vs. 6.4 [95% CI = 4.5–8.3] points; p =.008), and (3) patients whose focus defined by intracranial EEG matched the noninvasively estimated focus (8.3 [95% CI = 7.3–9.2] vs. 5.4 [95% CI = 3.5–7.3] points; p =.004). Multivariate analysis revealed areas under the curve of.843,.825, and.881 for Parameters 1, 2, and 3, respectively. Significance: SCS provides a reliable index of good indication for resective epilepsy surgery and can be easily available in many institutions not necessarily specializing in epilepsy. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [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]

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. [ABSTRACT FROM AUTHOR]

Summary: Objective: For future artificial intelligence–based brain mapping, development of a rational and safe scoring system for a brain motor mapping algorithm using electrocorticography (ECoG score), which contains various spectral, purely intrinsic brain activities, is necessary for either before or in the absence of electrical cortical stimulation (ECS). Methods: We evaluated 1114 electrodes of 10 consecutive focal epilepsy patients who underwent subdural electrode implantation before epilepsy surgery at Kyoto University Hospital during 2011‐2017. Data from ECoG‐based mapping (bandpass filter of 0.016‐300/600 Hz) to define the primary motor area (M1) localization were used to create an ECoG score (range = 0‐4) by assigning 1 point each for the occurrence of ECoG components: very slow movement‐related cortical potentials (<0.5‐1.0 Hz), event‐related synchronization (76‐100 Hz or 100‐200 Hz), and event‐related desynchronization (8‐12 Hz or 12‐24 Hz). The ECoG score was assessed by calculating the sensitivity, specificity, and cutoff values of the score for localization concordance with M1 defined using only ECS as a reference. Results: With an area under the receiver operating characteristic curve (AUC) of 0.76, cutoffs of scores of 4 and 1 showed high specificity (94%) and sensitivity (98%) in concordance with ECS‐based mapping, respectively. The ECoG score for mapping M1 of the upper limb achieved greater accuracy (AUC = 0.85) compared to that of the face (AUC = 0.64). Significance: The ECoG score proposed in the present study is rational, simple, and useful to define M1, and it is spatially concordant with ECS. Although ECS is still widely employed for presurgical examination, our proposed application of the ECoG score may be suitable for future brain M1 mapping, and possibly beyond M1 mapping, independently of ECS. [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]