A Reappraisal on cortical myoclonus and brief Remarks on myoclonus of different Origins.

Myoclonus has multiple clinical manifestations and heterogeneous generators and etiologies, encompassing a spectrum of disorders and even physiological events. This paper, developed from a teaching course conducted by the Neurophysiology Commission of the Italian League against Epilepsy, aims to delineate the main types of myoclonus, identify potential underlying neurological disorders, outline diagnostic procedures, elucidate pathophysiological mechanisms, and discuss appropriate treatments. Neurophysiological techniques play a crucial role in accurately classifying myoclonic phenomena, by means of simple methods such as EEG plus polymyography (EEG + Polymyography), evoked potentials, examination of long-loop reflexes, and often more complex protocols to study intra-cortical inhibition-facilitation In clinical practice, EEG + Polymyography often represents the first step to identify myoclonus, acquire signals for off-line studies and plan the diagnostic work-up.

Correlation between autistic traits and brain functional connectivity in preschoolers with autism spectrum disorder: a resting state MEG study.

Background: Neurophysiological studies recognized that Autism Spectrum Disorder (ASD) is associated with altered patterns of over- and under-connectivity. However, little is known about network organization in children with ASD in the early phases of development and its correlation with the severity of core autistic features.

Methods: The present study aimed at investigating the association between brain connectivity derived from MEG signals and severity of ASD traits measured with different diagnostic clinical scales, in a sample of 16 children with ASD aged 2 to 6 years.

Early cortico-muscular coherence and cortical network changes in Parkinson's patients treated with MRgFUS.

Introduction: To investigate cortical network changes using Magnetoencephalography (MEG) signals in Parkinson's disease (PD) patients undergoing Magnetic Resonance-guided Focused Ultrasound (MRgFUS) thalamotomy.

Methods: We evaluated the MEG signals in 16 PD patients with drug-refractory tremor before and after 12-month from MRgFUS unilateral lesion of the ventralis intermediate nucleus (Vim) of the thalamus contralateral to the most affected body side. We recorded patients 24 h before (T0) and 24 h after MRgFUS (T1).

Anatomically compliant modes of variations: New tools for brain connectivity.

Anatomical complexity and data dimensionality present major issues when analysing brain connectivity data. The functional and anatomical aspects of the connections taking place in the brain are in fact equally relevant and strongly intertwined. However, due to theoretical challenges and computational issues, their relationship is often overlooked in neuroscience and clinical research.

Cortico-muscular coherence and brain networks in familial adult myoclonic epilepsy and progressive myoclonic epilepsy.

Objective: Familial Adult Myoclonic Epilepsy (FAME) presents with action-activated myoclonus, often associated with epilepsy, sharing various features with Progressive Myoclonic Epilepsy (PMEs), but with slower course and limited motor disability. We aimed our study to identify measures suitable to explain the different severity of FAME2 compared to EPM1, the most common PME, and to detect the signature of the distinctive brain networks.

Methods: We analyzed the EEG-EMG coherence (CMC) during segmental motor activity and indexes of connectivity in the two patient groups, and in healthy subjects (HS).

Rhythmic cortical myoclonus in patients with 6Q22.1 deletion.

DNA deletions involving 6q22.1 region result in developmental encephalopathy (DE), often associated with movement disorders and epilepsy. The phenotype is attributed to the loss of the NUS1 gene included in the deleted region.

Analyzing data in complicated 3D domains: Smoothing, semiparametric regression, and functional principal component analysis.

In this work, we introduce a family of methods for the analysis of data observed at locations scattered in three-dimensional (3D) domains, with possibly complicated shapes. The proposed family of methods includes smoothing, regression, and functional principal component analysis for functional signals defined over (possibly nonconvex) 3D domains, appropriately complying with the nontrivial shape of the domain. This constitutes an important advance with respect to the literature, because the available methods to analyze data observed in 3D domains rely on Euclidean distances, which are inappropriate when the shape of the domain influences the phenomenon under study.

MRI-guided focused-ultrasound thalamotomy in essential tremor: Immediate and delayed changes in cortico-muscular coherence and cortico-cortical out-strength.

Objective: Drug-resistant essential tremor (ET) can be treated by Magnetic-Resonance-guided Focused-Ultrasound (MRgFUS) targeted to thalamic ventralis-intermediate nucleus (ViM). We are presenting the results obtained in ET patients by evaluating the cortico-muscular coherence (CMC) and the out-strength among cortical areas.

Methods: We recorded MEG-EMG signals in 16 patients with predominant tremor on the right upper limb.

Comparison of Resampling Techniques for Imbalanced Datasets in Machine Learning: Application to Epileptogenic Zone Localization From Interictal Intracranial EEG Recordings in Patients With Focal Epilepsy.

In neuroscience research, data are quite often characterized by an imbalanced distribution between the majority and minority classes, an issue that can limit or even worsen the prediction performance of machine learning methods. Different resampling procedures have been developed to face this problem and a lot of work has been done in comparing their effectiveness in different scenarios. Notably, the robustness of such techniques has been tested among a wide variety of different datasets, without considering the performance of each specific dataset.

Different circuitry dysfunction in drug-naive patients with juvenile myoclonic epilepsy and juvenile absence epilepsy.

Rationale: Juvenile myoclonic epilepsy (JME) and juvenile absence epilepsy (JAE) are generalized epileptic syndromes presenting in the same age range. To explore whether uneven network dysfunctions may underlie the two different phenotypes, we examined drug-naive patients with JME and JAE at the time of their earliest presentation.

Methods: Patients were recruited based on typical JME (n = 23) or JAE (n = 18) presentation and compared with 16 age-matched healthy subjects (HS).

Impaired awareness in mesial temporal lobe epilepsy: Network analysis of foramen ovale and scalp EEG.

Objective: We use co-registration of foramen-ovale and scalp-EEG to investigate network alterations in temporal-lobe epilepsy during focal seizures without (aura) or with impairment of awareness (SIA).

Methods: One aura and one SIA were selected from six patients. Temporal dynamic among 4 epochs, as well as the differences between aura and SIA, were analyzed through partial directed coherence and graph theory-based indices of centrality.

Analyzing the Loss and the Recovery of Consciousness: Functional Connectivity Patterns and Changes in Heart Rate Variability During Propofol-Induced Anesthesia.

The analysis of the central and the autonomic nervous systems (CNS, ANS) activities during general anesthesia (GA) provides fundamental information for the study of neural processes that support alterations of the consciousness level. In the present pilot study, we analyzed EEG signals and the heart rate (HR) variability (HRV) in a sample of 11 patients undergoing spinal surgery to investigate their CNS and ANS activities during GA obtained with propofol administration. Data were analyzed during different stages of GA: baseline, the first period of anesthetic induction, the period before the loss of consciousness, the first period after propofol discontinuation, and the period before the recovery of consciousness (ROC).

Cortico-muscular and cortico-cortical coherence changes resulting from Perampanel treatment in patients with cortical myoclonus.

Objective: To investigate the mechanisms by which Perampanel (PER) reduces the severity of action myoclonus, we studied on MEG signals the changes occurring in cortico-muscular coherence (CMC) and cortico-cortical connectivity in patients with progressive myoclonus epilepsies.

Methods: The subjects performed an isometric extension of the hand; CMC and cortico-cortical connectivity were assessed using autoregressive models and generalized partial-directed coherence. The contralateral (Co) sensors showing average CMC values >0.

Towards the Automatic Localization of the Irritative Zone Through Magnetic Source Imaging.

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.

Identifying the epileptogenic zone by four non-invasive imaging techniques versus stereo-EEG in MRI-negative pre-surgery epilepsy patients.

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.

Cortical network dysfunction revealed by magnetoencephalography in carriers of spinocerebellar ataxia 1 or 2 mutation.

Objective: In patients with spinocerebellar ataxia type 1 or 2 (SCA1 or SCA2) and in their asymptomatic gene-positive relatives (AsyRs) we investigated the event-related desynchronization and synchronisation (ERD/ERS) on magnetoencephalographic signals to assess the changes occurring before manifest ataxia, by comparing the results obtained in AsyRs and in their gene-negative healthy relatives (HRs).

Methods: Twenty-four patients (12 SCA1, 12 SCA2), 24 AsyRs (13 SCA1, 11 SCA2) and 17 HRs performed a visually cued Go/No-go task. We evaluated the ERD/ERS in regions of interest corresponding to the frontal, central and parietal cortices.

Distortion of the cortical motor map in patients with Unverricht-Lundborg disease: A combined TMS-MRI study.

Objective: To assess functional organization of the motor cortex in patients with Unverricht-Lundborg disease (EPM1A) using a combined neurophysiologic and imaging approach.

Methods: EPM1A patients underwent transcranial magnetic stimulation (TMS)-based cortical mapping of the motor hand area. Moreover, they performed neuroimaging studies to assess functional magnetic resonance imaging (fMRI) activation maps related to motor hand task and cortical thickness (CTH) on T1-weighted 3D images.

Connectivity measures suggest a sub-cortical generator of myoclonus in Angelman syndrome.

Objective: The clinical and neurophysiological characteristics of myoclonus in Angelman syndrome (AS) have been evaluated in single case or small cohorts, with contrasting results. We evaluated the features of myoclonus in a wide cohort of AS patients.

Methods: We performed polygraphic EEG-EMG recording in 24 patients with genetically confirmed AS and myoclonus.