A Novel Convolutional Neural Network Classification Approach of Motor-Imagery EEG Recording Based on Deep Learning

Abstract: Recently, Electroencephalography (EEG) motor imagery (MI) signals have received increasing attention because it became possible to use these signals to encode a person’s intention to perform an action. Researchers have used MI signals to help people with partial or total paralysis, control devices such as exoskeletons, wheelchairs, prostheses, and even independent driving. Therefore, classifying the motor imagery tasks of these signals is important for a Brain-Computer Interface (BCI) system. Classifying the MI tasks from EEG signals is difficult to offer a good decoder due to the dynamic nature of the signal, its low signal-to-noise ratio, complexity, and dependence on the sensor positions. In this paper, we investigate five multilayer methods for classifying MI tasks: proposed methods based on Artificial Neural Network, Convolutional Neural Network 1 (CNN1), CNN2, CNN1 with CNN2 merged, and the modified CNN1 with CNN2 merged. These proposed methods use different spatial and temporal characteristics extracted from raw EEG data. We demonstrate that our proposed CNN1-based method outperforms state-of-the-art machine/deep learning techniques for EEG classification by an accuracy value of 68.77% and use spatial and frequency characteristics on the BCI Competition IV-2a dataset, which includes nine subjects performing four MI tasks (left/right hand, feet, and tongue). The experimental results demonstrate the feasibility of this proposed method for the classification of MI-EEG signals and can be applied successfully to BCI systems where the amount of data is large due to daily recording

Particularites de l’epilepsie au cours des maladies inflammatoires du systeme nerveux central

Introduction : Les crises épileptiques (CE) font partie des manifestations neurologiques des maladies inflammatoires (MI). Elles constituent un tournant évolutif grave de la maladie. Objectifs : Nous avons évalué les particularités sémiologiques, électriques, radiologiques, thérapeutiques et évolutives de l’épilepsie au cours des MI du système nerveux central (SNC). Nous avons également discuté les mécanismes physiopathologiques de l’épilepsie ainsi que les facteurs prédictifs de survenue de CE chez ces patients. Méthodes : C’est une étude rétrospective incluant les patients suivis pour épilepsie dans le cadre d’une MI du SNC. Tous nos patients ont bénéficié d’une imagerie cérébrale. Résultat : Nous avons colligé 32 patients (11 avec sclérose en plaque, 6 avec maladie de Behcet et 15 avec lupus érythémateux disséminé). Le délai des CE au cours des MI était de 3,2 ans. Elles étaient généralisées dans 62,5 % des cas. L’IRM a montré des lésions sous corticales et des lésions du tronc cérébral respectivement dans 71,8 % et 25% des cas. Une thrombose veineuse cérébrale était diagnostiquée chez 3 malades. L’EEG a objectivé des ondes lentes dans 34% des cas, et des anomalies paroxystiques chez 3 patients. Le phénobarbital était le traitement le plus prescrit. Le contrôle des CE était obtenu dans la majorité des cas. Conclusion : La survenue des CE au cours des MI pose un problème de prise en charge. Un diagnostic précoce et un traitement de l’épilepsie permettent de contrôler ces crises afin d’éviter les états de mal épileptiques qui mettent en jeu le pronostic vital des patients. Mots clés: Epilepsie, Facteurs de risque, Maladies inflammatoires  Particularities of epilepsy associated with inflammatory diseases of the central nervous systemIntroduction: The frequency of the central nervous system involvement in autoimmune disorders is very variable. Seizures are among the most common neurological manifestations, and can be occasionally the presenting symptom.Methods: All files of 32 patients with autoimmune disorder diagnosed with epilepsy were evaluated retrospectively (11 with multiple sclerosis, 6 with Behcet disease, and 15 systemic lupus erythematosus). The demographic data, clinical findings including seizures, EEG and neuroimaging findings were reviewed. Results: The sex ratio was 0.45 (10H / 22F). Seizures started 3.2 years after the onset of the inflammatory diseases. They were during either the first or following neurological attacks in 68.7% of cases. 20 patients (62,5%) had only generalized tonic-clonic seizures. Brain magnetic resonance imaging (MRI) was performed to all patients. Sub-cortical and brainstem lesions were identified respectively in 71,8 % and 25%. MRI revealed cerebral sinus thrombosis in three patients. The EEG revealed focal epileptiform discharges in three patients. In 12 patients (34%) slow waves were seen. Antiepileptic drugs were prescribed in all cases (phenobarbital :53%, valproic acid: 31%, Carbamazepine: 15%). A sufficient control of seizures was obtained in most cases. Conclusion: Seizures often complicate systemic autoimmune disorders through a variety of mechanisms. A better understanding of the mechanisms of epileptogenesis in those patients could lead to targeted treatments and better outcomes. Key words: Epilepsy, inflammatory disease, risk factor

PTPA variants and impaired PP2A activity in early-onset parkinsonism with intellectual disability

The protein phosphatase 2A complex (PP2A), the major Ser/Thr phosphatase in the brain, is involved in a number of signalling pathways and functions, including the regulation of crucial proteins for neurodegeneration, such as alpha-synuclein, tau and LRRK2. Here, we report the identification of variants in the PTPA/PPP2R4 gene, encoding a major PP2A activator, in two families with early-onset parkinsonism and intellectual disability. We carried out clinical studies and genetic analyses, including genome-wide linkage analysis, whole-exome sequencing, and Sanger sequencing of candidate variants. We next performed functional studies on the disease-associated variants in cultured cells and knock-down of ptpa in Drosophila melanogaster. We first identified a homozygous PTPA variant, c.893T&gt;G (p.Met298Arg), in patients from a South African family with early-onset parkinsonism and intellectual disability. Screening of a large series of additional families yielded a second homozygous variant, c.512C&gt;A (p.Ala171Asp), in a Libyan family with a similar phenotype. Both variants co-segregate with disease in the respective families. The affected subjects display juvenile-onset parkinsonism and intellectual disability. The motor symptoms were responsive to treatment with levodopa and deep brain stimulation of the subthalamic nucleus. In overexpression studies, both the PTPA p.Ala171Asp and p.Met298Arg variants were associated with decreased PTPA RNA stability and decreased PTPA protein levels; the p.Ala171Asp variant additionally displayed decreased PTPA protein stability. Crucially, expression of both variants was associated with decreased PP2A complex levels and impaired PP2A phosphatase activation. PTPA orthologue knock-down in Drosophila neurons induced a significant impairment of locomotion in the climbing test. This defect was age-dependent and fully reversed by L-DOPA treatment. We conclude that bi-allelic missense PTPA variants associated with impaired activation of the PP2A phosphatase cause autosomal recessive early-onset parkinsonism with intellectual disability. Our findings might also provide new insights for understanding the role of the PP2A complex in the pathogenesis of more common forms of neurodegeneration.</p

PTPA variants and impaired PP2A activity in early-onset Parkinsonism with intellectual disability

APPENDIX 1 : French and Mediterranean clinicians’ network for Parkinson’s disease genetics (the PDG group) collaborators French PDG collaborators Yves Agid, Mathieu Anheim, Michel Borg, Alexis Brice, Emmanuel Broussolle, Jean-Christophe Corvol, Philippe Damier, Luc Defebvre, Alexandra Dürr, Franck Durif, Jean Luc Houeto, Paul Krack, Stephan Klebe, Suzanne Lesage, Ebba Lohmann, Maria Martinez, Graziella Mangone, Louise-Laure Mariani, Pierre Pollak, Olivier Rascol, François Tison, Christine Tranchant, Marc Vérin, François Viallet, and Marie Vidailhet. Collaborators from Mediterranean countries Ebba Lohmann, Murat Emre, Hasmet Hanagasi, Basar Bilgic, Bedia Marangozoğlu, Mustapha Benmahdjoub, Mohammed Arezki, Sofiane A. Bouchetara, Traki Benhassine, Meriem Tazir, Mouna Ben Djebara, Riadh Gouider, Sawssan Ben Romdhan, Chokri Mhiri, Ahmed Bouhouche.APPENDIX 2 : Collaborators of the International Parkinsonism Genetics Network. Vincenzo Bonifati, Wim Mandemakers, Anneke J. A. Kievit, Agnita J. W. Boon, Joaquim J. Ferreira, Leonor Correia Guedes, Murat Emre, Hasmet A. Hanagasi, Basar Bilgic, Zeynep Tufekcioglu, Bülent Elibol, Okan Doğu, Murat Gultekin, Hsin F. Chien, Egberto Barbosa, Laura Bannach Jardim, Carlos R. M. Rieder, Hsiu-Chen Chang, Chin-Song Lu, Yah-Huei Wu-Chou, Tu-Hsueh Yeh, Leonardo Lopiano, Cristina Tassorelli, Claudio Pacchetti, Cristoforo Comi, Francesco Raudino, Laura Bertolasi, Michele Tinazzi, Alberto Bonizzato, Carlo Ferracci, Roberto Marconi, Marco Guidi, Marco Onofrj, Astrid Thomas, Nicola Vanacore, Giuseppe Meco, Edito Fabrizio, Giovanni Fabbrini, Alfredo Berardelli, Fabrizio Stocchi, Laura Vacca, Paolo Barone, Marina Picillo, Giuseppe De Michele, Chiara Criscuolo, Michele De Mari, Claudia Dell’Aquila, Giovanni Iliceto, Vincenzo Toni, Giorgio Trianni, Valeria Saddi, Gianni Cossu, Maurizio Melis.The protein phosphatase 2A complex (PP2A), the major Ser/Thr phosphatase in the brain, is involved in a number of signalling pathways and functions, including the regulation of crucial proteins for neurodegeneration, such as alphasynuclein, tau and LRRK2. Here, we report the identification of variants in the PTPA/PPP2R4 gene, encoding a major PP2A activator, in two families with early-onset parkinsonism and intellectual disability. We carried out clinical studies and genetic analyses, including genome-wide linkage analysis, whole-exome sequencing, and Sanger sequencing of candidate variants. We next performed functional studies on the disease-associated variants in cultured cells and knock-down of ptpa in Drosophila melanogaster. We first identified a homozygous PTPA variant, c.893T>G (p.Met298Arg), in patients from a South African family with early-onset parkinsonism and intellectual disability. Screening of a large series of additional families yielded a second homozygous variant, c.512C>A (p.Ala171Asp), in a Libyan family with a similar phenotype. Both variants co-segregate with disease in the respective families. The affected subjects display juvenile-onset parkinsonism and intellectual disability. The motor symptoms were responsive to treatment with levodopa and deep brain stimulation of the subthalamic nucleus. In overexpression studies, both the PTPA p.Ala171Asp and p.Met298Arg variants were associated with decreased PTPA RNA stability and decreased PTPA protein levels; the p.Ala171Asp variant additionally displayed decreased PTPA protein stability. Crucially, expression of both variants was associated with decreased PP2A complex levels and impaired PP2A phosphatase activation. PTPA orthologue knock-down in Drosophila neurons induced a significant impairment of locomotion in the climbing test. This defect was age-dependent and fully reversed by L-DOPA treatment. We conclude that bi-allelic missense PTPA variants associated with impaired activation of the PP2A phosphatase cause autosomal recessive early-onset parkinsonism with intellectual disability. Our findings might also provide new insights for understanding the role of the PP2A complex in the pathogenesis of more common forms of neurodegeneration.The Stichting ParkinsonFonds (The Netherlands); the Fondation pour la Recherche Médicale; PTC Therapeutics, the Fondation de France, France-Parkinson Association, la Fédération pour la Recherche sur le Cerveau (FRC) and the French program ‘Investissements d’avenir’ (ANR-10-IAIHU-06) to AB; and grants from the South African Medical Research Council (Self-Initiated Research Grant) and the National Research Foundation of South Africa.https://academic.oup.com/brainNeurologySDG-03:Good heatlh and well-bein

Analysis of DNM3 and VAMP4 as genetic modifiers of LRRK2 Parkinson's disease.

The LRRK2 gene has rare (p.G2019S) and common risk variants for Parkinson's disease (PD). DNM3 has previously been reported as a genetic modifier of the age at onset in PD patients carrying the LRRK2 p.G2019S mutation. We analyzed this effect in a new cohort of LRRK2 p.G2019S heterozygotes (n = 724) and meta-analyzed our data with previously published data (n = 754). VAMP4 is in close proximity to DNM3, and was associated with PD in a recent study, so it is possible that variants in this gene may be important. We also analyzed the effect of VAMP4 rs11578699 on LRRK2 penetrance. Our analysis of DNM3 in previously unpublished data does not show an effect on age at onset in LRRK2 p.G2019S carriers; however, the inter-study heterogeneity may indicate ethnic or population-specific effects of DNM3. There was no evidence for linkage disequilibrium between DNM3 and VAMP4. Analysis of sporadic patients stratified by the risk variant LRRK2 rs10878226 indicates a possible interaction between common variation in LRRK2 and VAMP4 in disease risk

SSVEP Enhancement Using Moving Average Filter Controlled by Phase Features

Brain-computer interface (BCI) systems translate the human neurophysiological activities into commands through EEG analysis. Improving the BCI performances leads to faster and easier use and less fatigue. In this study, we proposed a new prepossessing approach to increase the robustness of a steady-state visual evoked potential (SSVEP) based BCI. Inspiring from the known properties of the SSVEP frequency components, the goal was to enhance the signal quality by making it more convenient to be interpreted by the decision-making step. We first investigated the potential to detect the deteriorating periods based on the physiological properties of the SSVEP. The proposed system localizes the intervals which can obscure the SSVEP frequencies by a new algorithm founded on the processing and the analysis of the instantaneous phase. The piecewise linear regression allows a sampler comprehension of the phase signal. Then, these intervals are filtered by the moving average filter to enhance the SSVEP quality. Finally, the decision making is made by the canonical correlation analysis (CCA) algorithm. The results of experiments, using real EEG signals from five subjects, show that the proposed approach significantly increases the performances in terms of accuracy and information transfer rate by about 7.3% and 3.85 bits/min, respectively, in case of 2 s segment length. On the other hand, the spatial filtering methods of the literature weaken the system performances

L1 Adaptive Fractional Control Optimized by Genetic Algorithms with Application to Polyarticulated Robotic Systems

Recently, an adaptive control approach has been proposed. This approach, named L1 adaptive control, involves the insertion of a low-pass filter at the input of the Model Reference Adaptive Control (MRAC). This controller has been designed to overcome several limitations of classical adaptive controllers such as (i) the initialization of estimated parameters, (ii) the stability problems with high adaptation gains, and (iii) the appropriate parameter excitation. In this paper, a new design of the filter is presented, used for L1 adaptive control, for which the desired performances are guaranteed (appropriate values of the control during start-up, a high filtering of noises, a reduced time lag, and a reduced energy consumption). Parameters of the new proposed filter have been optimised by genetic algorithms. The proposed L1 adaptive fractional control is applied to a polyarticulated robotic system. Simulation results show the efficiency of the proposed control approach with respect to the classical L1 adaptive control in the nominal case and in the presence of a multiplicative noise

Cerebral rheumatoid vasculitis: a case report

Abstract Introduction Central nervous system involvement in rheumatoid arthritis is infrequent. The most frequent neurological manifestations of rheumatoid arthritis are peripheral neuropathy and cervical spinal cord compression due to subluxation of the cervical vertebrae. Cerebral rheumatoid vasculitis is an uncommon and serious complication which can be life-threatening. Case presentation A 52-year-old North African Tunisian Caucasian woman presented with a six-week history of headache. She had suffered seropositive and destructive rheumatoid arthritis for nine years without any extra-articular complications. Magnetic resonance imaging of the brain with the T2 sequence showed high-intensity signal images at the frontal and parietal cortico-subcortical junction suggesting hemispheric vasculitis. Conclusions Cerebral vasculitis is an infrequent complication in rheumatoid arthritis which is associated with high morbidity and in some cases can be life-threatening. Early assessment and a high index of suspicion to recognize such complications are essential in managing these patients.</p

Deletion analysis of SMN and NAIP genes in Tunisian patients with spinal muscular atrophy

Background: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder involving degeneration of anterior horn cells of spinal cord, resulting in progressive muscle weakness and atrophy. Aims: The purpose of our study was to determine the frequency of SMN and NAIP deletions in Tunisian SMA patients. Materials and Methods: Polymerase chain reaction (PCR) combined with restriction fragment length polymorphism (RFLP) was used to detect the deletion of exon 7 and exon 8 of SMN1 gene, as well as multiplex PCR for exon 5 and 13 of NAIP gene. Results: Fifteen (45.4%) out of 33 SMA patients were homozygously deleted for exons 7 and/or 8 of SMN1. Homozygous deletion of NAIP gene was observed in 20% (3 / 15) of patients. Conclusions: The molecular diagnosis system based on PCR-RFLP analysis can conveniently be applied in the clinical testing, genetic counseling, prenatal diagnosis, and pre-implantation genetic diagnosis of SMA