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Objective: Encephaloceles (ENCs) may cause clinical complications, including drug-resistant epilepsy that can be cured with epilepsy surgery., Methods: We describe clinical, diagnostic, and neuropathological findings of 12 patients with temporal ENC and epilepsy evaluated for surgery and compare them with a control group of 26 temporal lobe epilepsy (TLE) patients., Results: Six patients had unilateral and 6 bilateral temporal ENCs. Compared to TLEs, ENCs showed i) later epilepsy onset, ii) higher prevalence of psychiatric comorbidities, iii) no history of febrile convulsions, and iv) ictal semiology differences. Seven patients had MRI signs of gliosis, and 9 of intracranial hypertension. Interictal EEG analysis in ENCs demonstrated significant differences with controls: prominent activity in the beta/gamma frequency bands in frontal regions, interictal short sequences of low-voltage fast activity, and less frequent and more localized interictal epileptiform discharges. Ictal EEG patterns analyzed in 9 ENCs showed delayed and slower contralateral spread compared to TLEs. All ENCs that underwent surgery (7 lobectomies and 1 lesionectomy) are in Engel class I. Neuropathological examination revealed 4 patterns: herniated brain fragments, focal layer I distortion, white matter septa extending into the cortex, and altered gyral profile., Conclusions and Significance: The described peculiarities might help clinicians to suspect the presence of largely underdiagnosed ENCs., (© 2023. Fondazione Società Italiana di Neurologia.)

Objectives: To investigate the relationship between N20-P25 peak-to-peak amplitude (N20p-P25p) of somatosensory evoked potentials (SEPs) and the occurrence of abnormalities of the peripheral and/or central sensory pathways and of myoclonus/epilepsy, in 308 patients with increased SEPs amplitude from upper limb stimulation., Methods: We compared cortical response (N20p-P25p) in different groups of patients identified by demographic, clinical, and neurophysiological factors and performed a cluster analysis for classifying the natural occurrence of subgroups of patients., Results: No significant differences of N20p-P25p were found among different age-dependent groups, and in patients with or without PNS/CNS abnormalities of sensory pathways, while myoclonic/epileptic patients showed higher N20p-P25p than other groups. Cluster analysis identified four clusters of patients including myoclonus/epilepsy, central sensory abnormalities, peripheral sensory abnormalities, and absence of myoclonus and sensory abnormalities., Conclusions: Increased N20p-P25p prompts different possible pathophysiological substrates: larger N20p-P25p in patients with cortical myoclonus and/or epilepsy is likely sustained by strong cortical hyperexcitability, while milder increase of N20p-P25p could be underpinned by plastic cortical changes following abnormalities of sensory pathways, or degenerative process involving the cortex. SEPs increased in amplitude cannot be considered an exclusive hallmark of myoclonus/epilepsy. Indeed, in several neurological disorders, it may represent a sign of adaptive, plastic, and/or degenerative cortical changes., (© 2022. Fondazione Società Italiana di Neurologia.)

The present work aims at validating a Bayesian multi-dipole modeling algorithm (SESAME) in the clinical scenario consisting of localizing the generators of single interictal epileptiform discharges from resting state magnetoencephalographic recordings. We use the results of Equivalent Current Dipole fitting, performed by an expert user, as a benchmark, and compare the results of SESAME with those of two widely used source localization methods, RAP-MUSIC and wMNE. In addition, we investigate the relation between post-surgical outcome and concordance of the surgical plan with the cerebral lobes singled out by the methods. Unlike dipole fitting, the tested algorithms do not rely on any subjective channel selection and thus contribute towards making source localization more unbiased and automatic. We show that the two dipolar methods, SESAME and RAP-MUSIC, generally agree with dipole fitting in terms of identified cerebral lobes and that the results of the former are closer to the fitted equivalent current dipoles than those of the latter. In addition, for all the tested methods and particularly for SESAME, concordance with surgical plan is a good predictor of seizure freedom while discordance is not a good predictor of poor post-surgical outcome. The results suggest that the dipolar methods, especially SESAME, represent a reliable and more objective alternative to manual dipole fitting for clinical applications in the field of epilepsy surgery.

Objective: We evaluated four imaging techniques, i.e. Electroencephalography (EEG)-functional Magnetic Resonance Imaging (MRI) (EEG-fMRI), High-resolution EEG (HR-EEG), Magnetoencephalography (MEG) and 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (PET), for the identification of the epileptogenic zone (EZ) in 41 patients with negative MRI, candidate to neurosurgery., Methods: For each technique, results were compared to the Stereo-EEG. Diagnostic measures were calculated with respect to the post-surgical outcome, either for all the patients (39/41, two patients excluded) and for the subgroup of patients with the EZ involving more than one lobe (20/41)., Results: When considered individually, each functional technique showed accuracy values ranging 54,6%-63,2%, having PET, MEG and HR-EEG higher sensitivity, and EEG-fMRI higher specificity. In patients with multilobar epileptogenic zone, functional techniques achieved the best accuracies (up to 80%) when three techniques, including EEG-fMRI, were considered together., Conclusions: The study highlights the accuracy of a combination of functional imaging techniques in the identification of EZ in MRI negative focal epilepsy. The best diagnostic yield was obtained if the combination of PET, MEG (or HR-EEG as alternative), EEG-fMRI were considered together., Significance: The functional imaging techniques may improve the presurgical workup of MRI negative focal epilepsy, if epileptogenic zone involves more than one lobe., Competing Interests: Declaration of Competing Interest None of the authors has any conflict of interest to disclose. We confirm that we have read the journal’s position on the issues involved in ethical publication, and affirm that this report is consistent with those guidelines., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: We aimed this study at identifying cortical areas involved in the generation of interictal spikes in Rasmussen's Encephalitis (RE) patients using magnetoencephalography (MEG), at comparing spike localization with the degree of cortical atrophy detected by MRI, and at identifying short-term changes during the follow-up., Methods: Five patients with RE underwent two MEG and magnetic resonance imaging (MRI) (six months interval). The sources of visually detected spikes were estimated using equivalent current dipoles technique; these were then superimposed on individual MRI and clustered; the locations of the clusters were related to the MRI stage of cortical atrophy., Results: All patients showed spikes and clusters located in different cortical areas in both recordings; the locations had a limited correspondence with cortical atrophy. The second recordings showed changes in the localisation of spikes and clusters, and confirmed the dissimilarities with neuroradiological abnormalities., Conclusions: The presence of clusters of spikes of variable localisation suggests that RE progresses in a multifocal and fluctuating manner. The cortical areas most involved in epileptogenesis did not completely coincide with the most atrophic areas., Significance: MEG can contribute to evaluating multifocal hemispheric spikes in RE and to better understand the time course of epileptogenic process., (Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: To classify the grade of antiepileptic drug (AED) resistance in a cohort of patients with focal epilepsies, to recognize the risk factors for AED resistance, and to estimate the helpfulness of "new-generation" AEDs., Methods: We included 1,155 adults with focal epilepsies who were observed consecutively after 1990 and followed regularly at two epilepsy centers. We systematically collected the clinical, diagnostic, and therapeutic data using a custom-written database. We classified the patients as seizure-free or AED resistant according to the International League Against Epilepsy (ILAE) criteria, and we evaluated the risk factors associated with AED resistance using logistic regression analysis. We further grouped AED-resistant patients in different grades (I, II, and III) according to the number of AEDs already tried as proposed by Perucca., Key Findings: AED resistance occurred in 57.8% of the 729 patients with symptomatic focal epilepsies and was positively associated with electroencephalography (EEG) abnormalities, seizure type, and the presence of mesial temporal sclerosis. Among 426 patients without detectable causes, the percentage of AED resistance was significantly lower (39.2%) and correlated with EEG abnormalities and psychiatric symptoms. Among AED-resistant patients, the majority (64.6%) had tried three or more AEDs, which fit the more severe grade III proposed by Perucca. Among seizure-free patients, more than one-half (57%) needed to try two or more AEDs before reaching seizure control (14.9% needed three or more AEDs). Furthermore, among seizure-free patients who could be previously classified as resistant to two or more AEDs, 52.2% reached seizure freedom while receiving treatment with "new generation" AEDs., Significance: The ILAE classification of AED resistance, as well the graded classification proposed by Perucca, was easily exploitable in our patients, although these classifications systems appear to have a limited value in predicting seizure outcome. Actually, a small but not negligible percentage of patients reached seizure freedom after trying several AEDs (including "new" AEDs), suggesting repeated trials may be necessary for seizure control., (Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.)

Abstract: We studied changes in event-related desynchronization/synchronization (ERD/ERS) patterns in patients with Unverricht–Lundborg disease (ULD), presenting with prominent action myoclonus. We analyzed the movement-related ERD/ERS in α and β frequency bands in 15 patients using self-paced finger extension as a motor paradigm and we compared the results with those obtained in 12 healthy volunteers. In all ULD patients, α- and β-ERD regularly occurred with onset and location similar to that found in healthy controls, but the desynchronization of α activity was significantly greater than in controls (C3: −64.4±9.8% vs. −49.7±14.8%; p =0.004). Moreover, in the patients, both α- and β-ERD spread toward frontal electrodes. In controls, the post-movement β-ERS regularly occurred; it was absent in eight patients with severe action myoclonus, while, in seven patients with mild or moderate myoclonus, the β-peak was significantly smaller with respect to that measured in controls (55.6±15.1% vs. 153.9±99.8%, p =0.006). The failure of β-ERS well-correlated with motor impairment resulting from action myoclonus, whereas SSEPs and long-loop reflexes performed to detect signs of cortical hyperexcitability showed inconsistent changes. In ULD patients, ERD/ERS changes indicate an increased activation of motor cortex during movement planning and a great reduction of post-excitatory inhibition of motor cortex. The changes involving β-ERS had a significant relationship with the functional disability in individual patients and might play a pathogenic role in the motor dysfunction. [Copyright &y& Elsevier]

Magnetoencephalography (MEG) recordings of interictal and/or ictal discharges can provide valuable information about the location of the epileptogenic area in the brain. Rasmussen Encephalitis (RE) is characterized by intractable epilepsy, progressive hemiparesis, and unilateral hemispheric atrophy. The progression of the symptoms to significant neurological impairment usually occurs within months to a few years. Five patients (mean age at first observation 7.6 ± 3 years) fitting Bien’s criteria for the diagnosis of RE were enrolled for the study and follow-up for at least 1.5 years (4–7 MEG measures per patient), in order to evaluate correlations between the evolution of clinical picture, neuroradiological and MEG findings. MEG data were visually inspected and interictal spikes were selected for the source localization by means of equivalent current dipoles (ECDs). Cortical thickness was evaluated from Magnetic Resonance Imaging (MRI). All patients showed ictal/interictal multifocality, reduction of background cortical magnetic activity, and progressive focal cortical atrophy on MRI of the affected hemisphere. Moreover, our preliminary data showed that dipole clusters were found mainly in the most atrophic cortical regions, suggesting a close relationship between MRI and MEG alterations. [ABSTRACT FROM AUTHOR]

Objective: To study electroencephalography–electromyography (EEG–EMG) relationships in patients with different forms of progressive myoclonic epilepsies (PME).Methods: EEG–EMG auto-spectra, coherence and phase functions were estimated by means of bivariate and time varying autoregressive (AR) models in 15 patients: 8 with Unverricht–Lundborg, 4 with Lafora body disease, and 3 with sialidosis.Results: The coherence spectra of the EMG epochs including action myoclonus and contralateral frontocentral EEG derivations showed a main beta peak (average coherence: 0.60–0.79) in all patients, regardless of the type of PME. The time lag from cortex to muscle was 13.0–21.3 ms. Significantly, coherent gamma activity was consistently found only in the 3 patients with sialidosis; the most heterogeneous results were obtained in the patients with Lafora disease, who showed a more complex coherence profile. Periods of normal muscle contractions, which could be recorded in patients with Unverricht–Lundborg PME, were characterised by the presence of an EEG–EMG beta coherence peak on the same frequency as in the case of action myoclonus, but with a lower coherence value.Conclusions: AR models were capable of describing EEG–EMG relationships in patients with PME, and indicated that coherent cortical and EMG beta oscillations are crucially involved in the generation of myoclonus. Moreover, they could detect the uneven spectral profiles characterising the different forms of PME. [Copyright &y& Elsevier]